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Sample records for macroporous resin xad-2

  1. Adsorption of di-2-pyridyl ketone salicyloylhydrazone on Amberlite XAD-2 and XAD-7 resins: characteristics and isotherms.

    Science.gov (United States)

    Freitas, P A M; Iha, K; Felinto, M C F C; Suárez-Iha, M E V

    2008-07-01

    The adsorption of DPKSH onto Amberlite XAD-2 (styrene resin) and XAD-7 (acrylic ester resin) has been investigated, at (25+/-1) degrees C and pH 4.7. The experimental equilibrium data were fitted to the Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) models. These three models provide a very good fit for both resins and the respective constants KL, KF, and KDR were calculated. For the same DPKSH concentration interval, the minimum time of contact for adsorption maximum at XAD-7 was smaller than at XAD-2 and the maximum amount of DPKSH adsorbed per gram of XAD-2 is smaller than at XAD-7. The investigation indicates that the mean sorption energy (E) characterizes a physical adsorption and the surfaces of both resins are energetically heterogeneous. The constants obtained in these studied systems were correlated and compared with those obtained for the silica gel/DPKSH system.

  2. Sorption of a diverse set of organic chemical vapors onto XAD-2 resin: Measurement, prediction and implications for air sampling

    Science.gov (United States)

    Hayward, Stephen J.; Lei, Ying D.; Wania, Frank

    2011-01-01

    The wide-spread use of styrene-divinylbenzene-copolymeric resin (XAD-2) in air sampling necessitates a quantitative understanding of its sorption characteristics for organic chemicals. Inverse Gas Chromatography (IGC) was used to measure the sorption of a diverse set of 52 organic chemicals to XAD-2 at temperatures between 40 °C and 100 °C and at relative humidities between 0 and 87%. Even though relative humidity has been shown to influence sorption to other sorbents, it did not significantly influence most chemicals' sorption to XAD-2, indicating that water does not form a strong physical barrier to sorption on XAD-2 at high relative humidity. The resin-air partition coefficients ( KXAD) determined by IGC and the enthalpies of sorption derived from them were regressed against solute descriptors to derive poly-parameter Linear Free Energy Relationships (ppLFERs) which allow the estimation of KXAD for chemicals which are not sufficiently volatile to be amenable to IGC and for temperatures outside the experimental range. KXAD values at 20 °C estimated for a set of 296 chemicals for which solute descriptors are available, including polychlorinated biphenyls, polycyclic aromatic hydrocarbons, and pesticides, indicate that for many of the substances commonly found in the atmosphere sorption is higher to XAD-2 than to poly-urethane foam, another popular air sampling sorbent.

  3. Efficiency of Polyphenol Extraction from Artificial Honey Using C18 Cartridges and Amberlite® XAD-2 Resin: A Comparative Study

    Directory of Open Access Journals (Sweden)

    Chua Yung An

    2016-01-01

    Full Text Available A comparative study of the extraction efficiency of nine known polyphenols [phenolic acids (benzoic acid, dihydroxybenzoic acid, gallic acid, trans-cinnamic acid, and vanillic acid and flavonoids (naringenin, naringin, quercetin, and rutin] was conducted by deliberately adding the polyphenols to an artificial honey solution and performing solid phase extraction (SPE. Two SPE methods were compared: one using Amberlite XAD-2 resin and another one using a C18 cartridge. A gradient high performance liquid chromatography system with an RP18 column and photodiode array detector was utilized to analyze the extracted polyphenols. The mean percent of recovery from the C18 cartridges was 74.2%, while that from the Amberlite XAD-2 resin was 43.7%. The recoveries of vanillic acid, naringin, and rutin were excellent (>90%; however, gallic acid was not obtained when C18 cartridges were used. Additionally, the reusability of Amberlite XAD-2 resin was investigated, revealing that the mean recovery of polyphenols decreased from 43.7% (1st extraction to 29.3% (3rd extraction. It was concluded that although Amberlite XAD-2 resin yielded a higher number of compounds, C18 cartridges gave a better extraction recovery. The lower recovery seen for the Amberlite XAD-2 resin also cannot be compensated by repeated extractions due to the gradual decrease of extraction recovery when reused.

  4. Monitoring of polycyclic aromatic hydrocarbons (PAHs) in the atmosphere of southern Luxembourg using XAD-2 resin-based passive samplers.

    Science.gov (United States)

    Schummer, Claude; Appenzeller, Brice M; Millet, Maurice

    2014-02-01

    XAD-2 resin-based passive samplers (PAS) with dimensions adapted to 100 mL accelerated solvent extraction cells were used to study the temporal and spatial variations of 17 PAHs on five sites in the atmosphere of southern Luxembourg. This new design allowed extracting the PAS without emptying the resin from the shelter. PAH analyses were done with gas chromatography-tandem mass spectrometry. PAS were deployed for 1 year with varying sampling periodicities, and 16 PAHs were detected with concentrations ranging from 1 ng/PAS for chrysene to 9,727 ng/PAS for naphthalene. The PAS were found adapted to the monitoring of temporal and spatial variations for lightweight PAHs (up to four aromatic rings) though not for heavy PAHs with five aromatic rings or more, as these compounds are preferably in the particle phase of the atmosphere and the amount of these PAHs trapped on the PAS will be too low.

  5. Effects of haemoperfusion through charcoal or XAD-2 resin on an animal model of fulminant liver failure

    Science.gov (United States)

    Weston, M. J.; Gazzard, B. G.; Buxton, B. H.; Winch, J.; Machado, A. L.; Flax, H.; Williams, Roger

    1974-01-01

    In a group of dogs in whom fulminant liver failure had been induced, perfusion of blood through activated charcoal resulted in a significantly longer survival than that of a similar group of dogs whose blood was not so treated. An otherwise progressive rise in blood ammonia concentration was halted in the treatment group. In another group of dogs with fulminant liver failure perfusion of blood through the resin Amberlite XAD-2 was associated with a fall in the serum bilirubin concentration and complete clearance from the blood of 14C-labelled sodium glycocholate. Survival in this group of animals was not significantly prolonged. This was due at least in part to the occurrence of haemorrhage due to thrombocytopenia. Platelets adhere to the resin but do not adhere to the same degree to charcoal coated with a thin layer of polymer. PMID:4851751

  6. Radiocarbon, 13C and 15N analysis of fossil bone: Removal of humates with XAD-2 resin

    Science.gov (United States)

    Stafford, Thomas W., Jr.; Brendel, Klaus; Duhamel, Raymond C.

    1988-09-01

    Humic acids are the predominant source of error in the 14C and stable isotope analysis of fossil bone organic matter. XAD-2 resin will quantitatively remove humates and give the highest yields of protein from bones with variable types of preservation. Decalcified bone, gelatin and base-leached residues can vary up to 5%. for δ 13C and by 1%. on δ 15N relative to XAD-treated fractions. Simultaneous analysis of 14C age, δ 13C and δ 15N is recommended because each isotope value can be independently affected by the bone's diagenetic history. Radiocarbon analysis is the most sensitive and δ 15N is least sensitive for detecting exogenous organic matter. The uncertainty of analyses on the best pretreated protein is ±0.5%. for both δ 13C and δ 15N and is larger than previous estimates. The accuracy for all isotope analyses will be better assessed by using individual amino acids instead of total collagenous residues. Inaccurate 14C dates on severely degraded bone are an indication that this class of fossils may be unsuitable for any isotopic analysis.

  7. Efficiency of Polyphenol Extraction from Artificial Honey Using C18 Cartridges and Amberlite® XAD-2 Resin: A Comparative Study

    OpenAIRE

    Chua Yung An; Md. Murad Hossain; Fahmida Alam; Md. Asiful Islam; Md. Ibrahim Khalil; Nadia Alam; Siew Hua Gan,

    2016-01-01

    A comparative study of the extraction efficiency of nine known polyphenols [phenolic acids (benzoic acid, dihydroxybenzoic acid, gallic acid, trans-cinnamic acid, and vanillic acid) and flavonoids (naringenin, naringin, quercetin, and rutin)] was conducted by deliberately adding the polyphenols to an artificial honey solution and performing solid phase extraction (SPE). Two SPE methods were compared: one using Amberlite XAD-2 resin and another one using a C18 cartridge. A gradient high perfor...

  8. Concentration of mutagens from urine by absorption with the nonpolar resin XAD-2: cigarette smokers have mutagenic urine.

    Science.gov (United States)

    Yamasaki, E; Ames, B N

    1977-01-01

    A method is described for concentrating mutagens/carcinogens from human urine about 200-fold for subsequent assay in the Salmonella/mammalian microsome mutagenicity test. The method is also applicable for other aqueous liquids and for other in vitro tests for mutagens/carcinogens. The urine (up to 500 ml) is put through a column with a 1.5-cm3 bed volume of XAD-2 (styrene-divinylbenzene polymer) and the adsorbed material is then eluted with a few milliliters of acetone. The acetone is taken to dryness and the residue is dissolved in dimethyl sulfoxide. This is the urine concentrate that is assayed for mutagenicity. Various mutagens/carcinogens have been added to human urine and the recoveries have been measured after adsorption on XAD-2, XAD-4, and Tenax GC (diphenyl-p-phenylene oxide polymer). We propose that this method be used in monitoring the urine of human populations and of experimental animals in toxicological studies. It is shown with this procedure that cigarette smokers have mutagenic urine while nonsmokers do not. PMID:333441

  9. Preparative Purification of Liriodendrin from Sargentodoxa cuneata by Macroporous Resin

    OpenAIRE

    Di-Hua Li; Yan Wang; Yuan-Shan Lv; Jun-Hong Liu; Lei Yang; Shu-Kun Zhang; Yu-Zhen Zhuo

    2015-01-01

    The preparative purification of liriodendrin from Sargentodoxa cuneata using macroporous resin combined with crystallization process was evaluated. The properties of adsorption/desorption of liriodendrin on eight macroporous resins were investigated systematically. X-5 resin was selected as the most suitable medium for liriodendrin purification. The adsorption of liriodendrin on X-5 resin fitted well with the pseudo-second-order kinetic model and Langmuir isotherm model. Dynamic adsorption/de...

  10. XAD-2树脂富集-高效液相色谱法检测水体中微囊藻毒素%Determination of Microcystins in Freshwater by XAD-2 Resin Concentration-HPLC

    Institute of Scientific and Technical Information of China (English)

    邹雯雯; 弓爱君; 曹艳秋; 刘明娜; 苑海涛

    2008-01-01

    建立了XAD-2树脂富集一高效液相色谱(HPLC)检测淡水水体中痕量微囊藻毒素(MCs)的方法.通过对样品前处理中MCs的富集、洗脱等关键环节的单因素考察,确立的树脂富集方法能够高效稳定地将淡水水体中的MCs浓缩富集6000倍,MC-LR和MC-RR的回收率均达到90%以上,效果良好.

  11. Mutagenic potentials of Amberlite XAD-2-resin extracts obtained from river and drinking waters in the Northwest district of Chiba, Japan.

    Science.gov (United States)

    Kanno, Ayako; Nishi, Iwaki; Kishi, Tomohiro; Kawakami, Tsuyoshi; Takahashi, Yasuo; Onodera, Sukeo

    2010-12-01

    Amberlite XAD-2 resin extracts of river and drinking water sampled from the Northwest district of Chiba Prefecture in each month during the period from January to December 2008 were investigated to characterize and determine their mutagenic potentials and polycyclic aromatic hydrocarbon (PAH) levels. The extracts from the river water were shown to be mutagenic in Salmonella typhimurium TA98 (a flameshift mutagen) without S9 mix, with higher mutagenic responses in summer and early fall seasons. While the drinking water extracts exhibited weak mutagenicity in both the TA98 and TA100 strains (a base-pair substitution mutagen) without S9 mix, with high mutagenic responses in fall and early winter seasons. GC/MS determinations of the water concentrates showed some seasonal scatter in PAH levels in river water. In contrast, comparatively high concentrations of PAHs were observed for drinking water samples collected during warmer seasons. Statistical studies revealed that there is a lower correlation between the levels of flameshift mutagenicity and the concentrations of PAH in the river water concentrations, but a higher correlation between them in the drinking water samples.

  12. Azocalix[4]pyrrole Amberlite XAD-2: new polymeric chelating resins for the extraction, preconcentration and sequential separation of Cu(II), Zn(II) and Cd(II) in natural water samples.

    Science.gov (United States)

    Jain, Vinod K; Mandalia, Hiren C; Gupte, Hrishikesh S; Vyas, Disha J

    2009-10-15

    Two novel azocalix[4]pyrrole Amberlite XAD-2 polymeric chelating resins were synthesized by covalently linking diazotized Amberlite XAD-2 with calix[4]pyrrole macrocycles. The chelating resins were used for extraction, preconcentration and sequential separation of metal ions such as Cu(II), Zn(II) and Cd(II) by column chromatography prior to their determination by UV/vis spectrophotometry or flame atomic absorption spectrophotometry (FAAS) or inductively coupled plasma atomic emission spectroscopy (ICP-AES). Various parameters such as effect of pH on absorption, concentration of eluting agents, flow rate, total sorption capacity, exchange kinetics, preconcentration factor, distribution coefficient, breakthrough capacity and resin stability, were optimized for effective separation and preconcentration. The resin showed good ability for the separation of metal ions from binary and ternary mixture on the basis of pH of absorption and concentration of eluting agents. The newly synthesized resins showed good potential for trace enrichment of Cu(II), Zn(II) and Cd(II) metal ions, especially for Cu(II), as compared to the earlier reported resins. The synthesized resins were recycled at least 8-10 times without much affecting column sorption capacity. The presented method was successfully applied for determination of Cu(II), Zn(II) and Cd(II) in natural and ground water samples.

  13. Study on Adsorption Properties of M-nitrophenol by XAD-2 Resin in Aqueous Solution%XAD-2树脂对溶液中间硝基苯酚的吸附特性研究

    Institute of Scientific and Technical Information of China (English)

    高月桃; 邓丹凤; 周克丹; 张启伟

    2011-01-01

    研究了XAD-2大孔树脂对水相中间硝基苯酚的吸附特性.研究内容包括接触时间、pH、吸附剂质量、吸附温度对吸附的影响.树脂能有效的除去水相中的间硝基苯酚,在pH=3.6~6.2的范围内树脂对问硝基苯酚均有较大的吸附,其最佳酸度为pH=5.9,最大吸附率可达98.9%;研究表明Langmuir等温吸附模型能较好的描述吸附过程.用1.5~2.0 mol/L NaOH对吸附后的树脂进行再生试验,脱附率可达93%.

  14. Preparative Purification of Liriodendrin from Sargentodoxa cuneata by Macroporous Resin.

    Science.gov (United States)

    Li, Di-Hua; Wang, Yan; Lv, Yuan-Shan; Liu, Jun-Hong; Yang, Lei; Zhang, Shu-Kun; Zhuo, Yu-Zhen

    2015-01-01

    The preparative purification of liriodendrin from Sargentodoxa cuneata using macroporous resin combined with crystallization process was evaluated. The properties of adsorption/desorption of liriodendrin on eight macroporous resins were investigated systematically. X-5 resin was selected as the most suitable medium for liriodendrin purification. The adsorption of liriodendrin on X-5 resin fitted well with the pseudo-second-order kinetic model and Langmuir isotherm model. Dynamic adsorption/desorption tests were performed using a glass column packed with X-5 resin to optimize the separation process of liriodendrin. After one treatment with X-5 resin, the content of liriodendrin in the product was increased 48.73-fold, from 0.85% to 41.42%, with a recovery yield of 88.9%. 97.48% liriodendrin was obtained by further crystallization and determined by HPLC. The purified product possessed strong antioxidant activity. In conclusion, purification of liriodendrin might expend its further pharmacological researches and further applications in pharmacy.

  15. Purification of total flavonoids from loquat leaves by macroporous resin and corresponding antioxidant capacity

    OpenAIRE

    Huang Suhua; Lin Biaosheng; Li Binbin; Tan Bi; Hong Yanping

    2017-01-01

    Flavonoids is one of the major active compounds in loquat leaves. In this study, the purification process of total flavonoids in loquat leaves by macroporous resin was researched and the antioxidant activity of total flavonoids was determined. The active compounds were extracted by 95% ethanol, and the total flavonoids was purified by macroporous resin. Comparing the static and dynamic adsorption and desorption characters of 6 macroporous resin, the best type of macroporous resin was determin...

  16. Kinetic and thermodynamic studies of sulforaphane adsorption on macroporous resin.

    Science.gov (United States)

    Yuanfeng, Wu; Lei, Zhang; Jianwei, Mao; Shiwang, Liu; Jun, Huang; Yuru, You; Lehe, Mei

    2016-08-15

    The adsorption equilibrium, kinetic and thermodynamic of sulforaphane (SF) adsorption onto macroporous resin in aqueous phase were studied. The SP850 resin was screened as the appropriate resin for SF purification. From the equilibrium studies, the Redlich-Peterson model was found to be the best for description of the adsorption behavior of SF onto SP850 resin, followed by the Freundlich model and the Langmuir model. Batch equilibrium experiments demonstrated that, in the examined temperature range, the equilibrium adsorption capacity of SP850 resin decreased with increasing adsorption temperature. Thermodynamics studies indicated that the adsorption of SF was a physical, exothermic, and spontaneous process. The adsorption kinetics revealed that the pseudo-second-order kinetic model was suitable to characterize the kinetics of adsorption of SF onto SP850. Finally, the intra-particle diffusion model demonstrated that SF diffused quickly into macropores, and that diffusion slowed down in the meso- and micropores.

  17. Application of XAD-2 resin-based passive samplers and SPME-GC-MS/MS analysis for the monitoring of spatial and temporal variations of atmospheric pesticides in Luxembourg.

    Science.gov (United States)

    Schummer, Claude; Tuduri, Ludovic; Briand, Olivier; Appenzeller, Brice M; Millet, Maurice

    2012-11-01

    Passive air sampling has been shown to be a very interesting alternative to high-volume sampling by overcoming its disadvantages (size, weight, expensiveness). However, to date, only limited data is available about passive air sampling of current-use pesticides. In order to test if passive samplers allow monitoring of spatial and temporal variations of atmospheric pesticide concentrations, five XAD-2-resin based passive air samplers were deployed at five locations in Luxembourg. Samplers were analyzed using accelerated solvent extraction coupled to solid-phase microextraction and gas chromatography with tandem mass spectrometry. Collected data was used to study the spatial and temporal variations of the concentrations of the compounds. Twenty two pesticides were detected between March and October, while no pesticides were detected from November to February. Highest concentrations were measured on the rural sites, suggesting that the used XAD-2 resin-based passive samplers allow the simultaneous monitoring of multiple current-use pesticides and identifying spatial and temporal variations.

  18. CTEPP STANDARD OPERATING PROCEDURE FOR PRE-CLEANING FILTERS AND XAD-2 (SOP-5.10)

    Science.gov (United States)

    This SOP summarizes the method for pre-cleaning XAD-2 resin and quartz fiber filters. The procedure provides a cleaning method to help reduce potential background contamination in the resin and filters.

  19. Preparative Purification of Liriodendrin from Sargentodoxa cuneata by Macroporous Resin

    Directory of Open Access Journals (Sweden)

    Di-Hua Li

    2015-01-01

    Full Text Available The preparative purification of liriodendrin from Sargentodoxa cuneata using macroporous resin combined with crystallization process was evaluated. The properties of adsorption/desorption of liriodendrin on eight macroporous resins were investigated systematically. X-5 resin was selected as the most suitable medium for liriodendrin purification. The adsorption of liriodendrin on X-5 resin fitted well with the pseudo-second-order kinetic model and Langmuir isotherm model. Dynamic adsorption/desorption tests were performed using a glass column packed with X-5 resin to optimize the separation process of liriodendrin. After one treatment with X-5 resin, the content of liriodendrin in the product was increased 48.73-fold, from 0.85% to 41.42%, with a recovery yield of 88.9%. 97.48% liriodendrin was obtained by further crystallization and determined by HPLC. The purified product possessed strong antioxidant activity. In conclusion, purification of liriodendrin might expend its further pharmacological researches and further applications in pharmacy.

  20. Quantification and Purification of Mulberry Anthocyanins with Macroporous Resins

    Directory of Open Access Journals (Sweden)

    Xueming Liu

    2004-01-01

    Full Text Available Total anthocyanins in different cultivars of mulberry were measured and a process for the industrial preparation of mulberry anthocyanins as a natural food colorant was studied. In 31 cultivars of mulberry, the total anthocyanins, calculated as cyanidin 3-glucoside, ranged from 147.68 to 2725.46 mg/L juice. Extracting and purifying with macroporous resins was found to be an efficient potential method for the industrial production of mulberry anthocyanins as a food colorant. Of six resins tested, X-5 demonstrated the best adsorbent capability for mulberry anthocyanins (91 mg/mL resin. The adsorption capacity of resins increased with the surface area and the pore radius. Residual mulberry fruit juice after extraction of pigment retained most of its nutrients, except for anthocyanins, and may provide a substrate for further processing.

  1. Separation of capsaicin from capsaicinoids by macroporous resin adsorption chromatography.

    Science.gov (United States)

    Liu, Changxia; Liu, Ruican; Zhang, Peng; Chen, Yiming; Xu, Tao; Wang, Fang; Tan, Tianwei; Liu, Chunqiao

    2015-12-01

    The aim of present study is to develop an efficient and low-cost method for capsaicin production isolated from capsaicinoids by macroporous resin adsorption chromatography. HZ816 resin has shown the best adsorption and desorption capacities for capsaicin among other resins. To optimize the operating parameters for separation, initial concentration, diameter-to-height ratio, mobile phase ratio, and crystallization method were investigated. When capsaicinoids solution (5 g/L) was loaded onto the column (diameter-to-height ratio = 1:12) with ethanol/1% w/w NaOH (4:6, v/v) as the mobile phase, capsaicin was purified most effectively. By using acid neutralization as the crystallization method, the purity of capsaicin improved from 90.3 to 99.5% with 82.3% yield. In conclusion, this study provides a simple and low-cost method for the industrial-scale production of high-purity capsaicin.

  2. ADSORPTION OF MACROPOROUS PHOSPHONIC ACID RESIN FOR INDIUM

    Institute of Scientific and Technical Information of China (English)

    WANG Huijun; XIONG Chunhua; YAO Caiping

    2004-01-01

    The adsorption kinetics and mechanism of a novel chelate resin, macroporous phosphonic acid resin (PAR) for In(III) were investigated. The statically saturated adsorption capacity is 216mg·g-1resin at 298K in HAc-NaAc medium. The apparent adsorption rate constant is k298=4.84×10-5 s-1. The adsorption behavior of PAR for In(III) obeys the Freundlich isotherm. The thermodynamic adsorption parameters, enthalpy change △H, free energy change △G and entropy change △S of PAR for In(III) are 11.5kJ/mol, -12.6kJ/mol and 80.8J/mol·K, respectively. The apparent activation energy is Ea=3.5kJ/mol. The molar coordination ratio of the functional group of PAR to In(III) is about 3∶1.

  3. Comparison of PoraPak Rxn RP and XAD-2 adsorbents for monitoring dissolved hydrophobic organic contaminants.

    Science.gov (United States)

    Omara, Mark; Holsen, Thomas M; Xia, Xiaoyan; Pagano, James J; Crimmins, Bernard S; Hopke, Philip K

    2014-11-01

    Accurate determination of the levels of dissolved hydrophobic organic contaminants (HOCs) is an important step in estimating the dynamics of their inputs and losses in aqueous systems. This study explores an alternative method for efficiently sampling dissolved HOCs while mitigating a number of sampling artifacts associated with traditional methods. The adsorption characteristics of a new polymeric resin, PoraPak Rxn RP (PPR), were assessed using sorption isotherm experiments and fixed bed adsorption studies. The adsorption capacities and breakthrough times for four model contaminants (phenol, p-nitrophenol, naphthalene, and 2,4,6-tribromophenol) were proportional to the contaminant's hydrophobicity. The ability of PPR to isolate dissolved polychlorinated biphenyls (PCBs) in real samples was compared with that of XAD-2, a well-known macroporous polymer that suffers from high background contamination. The results indicated that the PPR resin can be effectively used for monitoring HOCs, with low ∑PCB levels in blanks, decreasing solvent use, and reducing extraction times.

  4. Adsorption of Macroporous Phosphonic Acid Resin for Nickel

    Institute of Scientific and Technical Information of China (English)

    XIONG Chunhua; YAO Caiping; LI Jianrong

    2005-01-01

    The adsorption behavior and mechanism of a novel chelate resin, macroporous phosphonic acid resin ( PAR ) for Ni ( Ⅱ ) were investigated. The statically saturated adsorption capacity is 64.3 mg · g - 1 resin at 298 K in HAc-NaAc medium. The Ni( Ⅱ ) adsorbed on PAR can be elated by 0.5mol· L-1 HCl and the elution percentage reaches 96.6% . The resin can be regenerated and reused without obvious decrease in adsorption capacity. The apparent adsorption rate coastant is k298 = 2.6 × 10-5 s -1 . The adsorption behavior of PAR for Ni ( Ⅱ ) obeys the Freundlich isotherm. The thermodynamic adsorption parameters, enthalpy change △ H, free en ergy change △ G and entropy change △ S of PAR for Ni ( Ⅱ ) are 3. 36 kJ· mol-1 , - 5.47 kJ· mol - 1 and 29.6J·mol-1 · K- 1, respectively. The apparent activation energy is Ea =12 . 2 kJ · mol-1 The molar coordination ratio of the functional group of PAR to Ni( Ⅱ ) is about 4: 1. The adsorption mechanism of PAR for Ni( Ⅱ ) was examined by a chemical method and IR spectrometry.

  5. Preparative Separation and Purification of the Total Flavonoids in Scorzonera austriaca with Macroporous Resins

    OpenAIRE

    Yang Xie; Qiu-Shi Guo; Guang-Shu Wang

    2016-01-01

    The use of macroporous resins for the separation and purification of total flavonoids to obtain high-purity total flavonoids from Scorzonera austriaca was studied. The optimal conditions for separation and purification of total flavonoids in S. austriaca with macroporous resins were as follows: D4020 resin columns were loaded with crude flavonoid extract solution, and after reaching adsorptive saturation, the columns were eluted successively with 5 bed volumes (BV) of water, 5 BV of 5% (v/v) ...

  6. Adsorption Characteristics of Macroporous Resin for Oil Removal from Desulphurization Wastewater on Board

    Science.gov (United States)

    Li, Tie; Chen, Chen; Jin, Qi; Zhao, Jiao; Tang, Xiaojia; Zhu, Yimin

    2017-01-01

    According to our previous results on the magnesium-based exhaust gas cleaning system (Mg-EGCS), PAHs and total oil content were the main factors affecting the COD in the wastewater. In this work, three kinds of adsorption materials were investigated and macroporous resin was selected for oil removal. The effects of the dosage of macroporous resin, adsorption time and the flow rate were studied, and thermodynamics equation was used to characterize the adsorption process. The results showed that macroporous resin is a good candidate for oil removal from desulphurization wastewater on board, and the COD after treatment can meet the discharge criteria set by the International Maritime Organization (IMO).

  7. Macroporous resin purification of peptides with umami taste from soy sauce.

    Science.gov (United States)

    Zhuang, Mingzhu; Zhao, Mouming; Lin, Lianzhu; Dong, Yi; Chen, Huiping; Feng, Mengying; Sun-Waterhouse, Dongxiao; Su, Guowan

    2016-01-01

    In this study, the performance and separation characteristics of four macroporous resins for purifying umami peptides from soy sauce were examined. Results showed that the resins could separate the peptides of soy sauce, and the particle diffusion kinetics model was suitable for describing the whole exothermic (ΔH resins, while the pseudo-second-order kinetics model accurately described the XAD-16 and HP-2 MGL resins. Furthermore, the adsorption processes of the peptides followed the Freundlich model. The XAD-16 resin was the most effective resin for the enrichment of peptides due to its high adsorption and total desorption capacities. Interestingly, the umami peptides were enriched in the deionized water fraction. This study provides new insights into exploring performance and separation characteristics of macroporous resins on soy sauce, and indicated that peptide may be the contributor to the umami taste in Chinese soy sauce.

  8. Study for highly functional resin (macroporous resin) superior in removing micro particles in PWR primary circuit: on-site test

    Energy Technology Data Exchange (ETDEWEB)

    Itou, A.; Kondo, K.; Kouzuma, Y., E-mail: ayumu_itou@kyuden.co.jp [Kyusyu Electric Power Co., Inc., Minami-ku, Fukuoka (Japan); Umehara, R.; Shimizu, Y., E-mail: Ruyji_Umehara@mhi.co.jp [Mitsubishi Heavy Industries, Ltd., Hyogo-ku, Kobe (Japan); Kogawa, N.; Nagamine, K., E-mail: nkogawa@ndc.hq.mhi.co.jp [Nuclear Development Corp., Tokaimura, Ibaraki (Japan)

    2010-07-01

    In Japanese PWR plants, efforts to remove particulate constituents containing radioactive cobalt which provides a source of radiation exposure, are needed. Performance evaluation study was conducted for macroporous resin which was said to possess excellent performance in removing particulate constituents and whose practical accomplishment at plants in USA was reported to be good. As one of the means for radiation exposure reduction in PWR, a study for application of crud removing resin to actual plant was executed by laboratory experiments using simulated crud (Fe{sub 3}O{sub 4} particle). In this study, following two mechanisms were demonstrated as the particle capturing mechanism of macroporous resin; physical trapping by fine pores on resin surface; electrical adsorption onto resin surface. In addition, in parallel to the study for application of macroporous resin to actual PWR plant, on-site study was planned to investigate the primary system water chemistry during various stages of actual plant operation and to research performance of particle capturing in detail. As the on-site study, column experiments, there water was let pass through the column, were planned for various operation stage (startup period, power operation period and shutdown period). A kind of conventional gel-type resin and three kinds of macroporous resin were examined for onsite tests. As to particulate capturing, basic knowledge regarding capturing efficiency and influence of water chemistry on capturing performance were ordered. Capturing performance of each resin tested became clear and was ordered by comparison. Effectiveness of macroporous resin with regard to crud removal in primary coolant was confirmed. (author)

  9. STUDIES ON THE SORPTION OF MACROPOROUS PHOSPHONIC ACID RESIN FOR LANTHANUM

    Institute of Scientific and Technical Information of China (English)

    XiongChunhua; ChenYiyong; 等

    1998-01-01

    The influences of Medium pH,sorption temperature,sorption time,etc.on the sorption capacity of macroporous phosphonic acid resin for La3+ were determined.The sorption rate constant was k298=7.64×10-5 s-1. The complex ratio of phosphonic groups of the resin to La3+ was 3:1.The basic sorption parameters were determined. The sorption mechanism of macroporous phosphonic acid resin for La3+ was examined by chemical analysis and IR-spectrometry.

  10. Separation of matrine and oxymatrine from Sophora flavescens extract through cation exchange resin coupled with macroporous absorption resin

    Directory of Open Access Journals (Sweden)

    Chen Haohao

    2016-06-01

    Full Text Available A simple method for separation of matrine and oxymatrine from Sophora flavescens was developed with cation exchange resin coupled with macroporous resin. Based on the adsorption characteristics of matrine and oxymatrine, 001×732 cation exchange resin was used to absorb target alkaloids for removing most of the foreign matter, while BS-65 macroporous resin was chosen to purify these alkaloids. The result showed that the equilibrium adsorption data of matrine and oxymatrine on 001×732 resin and BS-65 resin at 30°C was fitted to Langmuir isotherm and Freundlich isotherm, respectively. The contents of matrine and oxymatrine were increased from 0.73% and 2.2% in the crude extract of the root of Sophora flavescens to 67.2% and 66.8% in the final eluent products with the recoveries of 90.3% and 86.9%, respectively.

  11. [Purification technology of procymidone residues in ginseng extracts by macroporous resins].

    Science.gov (United States)

    Cui, Li-Li; Zheng, Pei-He; Wang, Ying-Ping

    2014-07-01

    The macroporous resin separation technology has been mainly applied in the enrichment of saponins, flavonoids, alkaloids and other ingredients, and used in the removal of heavy metal impurities and pesticide residues in recent years. This paper focuses on the synthesis of the new-type macroporous adsorption resin LKS-11 according to the molecular structure characteristics of procymidone. Specifically, the selective absorptive property and other advantages of macroporous resin were utilized to analyze the procymidone removal efficiency in ginseng extracts from different sources. The type of macroporous resins, absorptive property and desorption conditions were observed respectively by static and dynamic adsorption methods to determined the optimum process conditions. According to the results, LKS-11 showed a good absorptive property to procymidone in ginseng extracts and provided a theoretical basis for studies on the removal of procymidone residues from ginseng extracts by using macroporous adsorption resin. Because of no secondary pollution on samples, low production and operation costs, high procymidone removal efficiency and high product recovery rate, this method is suitable to be applied in production.

  12. Separation and Purification of Total Phloroglucinols inDryopteris crassirhizoma with DM-130 Macroporous Adsorption Resin

    Institute of Scientific and Technical Information of China (English)

    Jin Zhe; Huang Jian-ping; Wang He-meng; Ju han-xun; Ren Si-rui; Chang Ying

    2015-01-01

    To improve the purity of the total phloroglucinols fromDryopteris crassirhizoma extracts, the separation and purification conditions of the total phloroglucinols fromDryopteris crassirhizoma were studied with DM-130 macroporous adsorption resin in this study. Adsorption rate, elution rate and purity of the total phloroglucinols were used as indexes to investigate the adsorption and desorption capacity of the total phloroglucinols with DM-130 macroporous adsorption resin. Through the study, the optimum sample concentration of the total phloroglucinols and maximum sample volume were 1.5 mg• mL-1 and 7 BV (210 mL), respectively. The optimum desorption conditions were achieved by using 80% ethanol as desorption solvent at elution flow rate of 1.0 mL• min-1. The result showed DM-130 macroporous adsorption resin performed effective adsorption and desorption. After purification, the purity of the total phloroglucinols increased by 11.5-fold.

  13. Determination of Aluminium in Water Samples by Alizarin Red Spectrophotometry after Solid Phase Extraction on XAD-2-Catechol Resin%邻苯二酚螯合树脂的合成及水样中铝的测定

    Institute of Scientific and Technical Information of China (English)

    于涛; 耿伟; 杨枝; 曹维鹏

    2006-01-01

    合成并表征了新螯合树脂--邻苯二酚螯合树脂(XAD-2-Catechol),研究了XAD-2-Catechol吸附铝的特性和茜素红-铝的显色反应,在pH4. 5的HAc-NaAc缓冲介质中,茜素红和铝(Ⅲ)反应生成红色络合物,λmax=500 nm,铝的含量在0-50 μg/25 mL内符合比耳定律.建立了邻苯二酚螯合树脂分离/富集-茜素红分光光度法测定天然水样中铝的新方法,对水样中铝形态进行测定,结果满意.

  14. Enrichment and separation of chlorogenic acid from the extract of Eupatorium adenophorum Spreng by macroporous resin.

    Science.gov (United States)

    Liu, Boyan; Dong, Beitao; Yuan, Xiaofan; Kuang, Qirong; Zhao, Qingsheng; Yang, Mei; Liu, Jie; Zhao, Bing

    2016-01-01

    A simple and efficient chromatographic method for separation of chlorogenic acid from Eupatorium adenophorum Spreng extract was developed. The adsorption properties of nine macroporous resins were evaluated. NKA-II resin showed much better adsorption/desorption properties. The adsorption of chlorogenic acid on NKA-II resin at 25°C was well fitted to Langmuir isotherm model and pseudo-second-order kinetic model. The dynamic adsorption and desorption experiments were carried out on columns packed with NKA-II resin to optimize the separation process. The content of chlorogenic acid in the product increased to 22.17%, with a recovery yield of 82.41%.

  15. Monosized macroporous resins with epoxy groups and their structure and gel chromatography properties

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The monosized macroporous-polymer beads based on cross-linked poly(glycidyl methacrylate) have been synthesized by a new improving method--combining dispersion polymerization with swelling polymerization and polymeric solution porogens. The structure and gel chromatographic properties of the resins have been studied. The resins as matrix materials of various types of high performance liquid chromatography (HPLC) packings possess excellent separation properties

  16. Isolation of brefeldin A from Eupenicillium brefeldianum broth using macroporous resin adsorption chromatography.

    Science.gov (United States)

    Wang, Ya-Jun; Wu, Ye-Fei; Xue, Feng; Wu, Zhi-Xian; Xue, Ya-Ping; Zheng, Yu-Guo; Shen, Yin-Chu

    2012-05-01

    Brefeldin A (BFA) is a macrolide lactone antibiotic, possessing antitumor, antiviral, antifungal activities. In this work, a separation strategy involving one-step macroporous resin adsorption chromatography combined with crystallization was established for BFA purification from Eupenicillium brefeldianum CCTCC M 208113 fermentation broth. Among six macroporous resin adsorbents tested, the non-polar resin HZ830 had the best adsorption and desorption performance. The static equilibrium adsorption data fitted well with the Freundlich equation, and the adsorption kinetic followed the pseudo-second order model. Through experimental optimization of column adsorption and desorption, BFA in purity of 90.4% (w/w), 92.1% (w/w) yield was obtained by a one-step macroporous resin adsorption chromatography, using a stepwise elution protocol. Furthermore, high purity (>99%, w/w) of BFA crystals were prepared from E. brefeldianum CCTCC M 208113 fermentation broth in an overall recovery of 67.0% (w/w), using a combination of adsorption chromatography packed with non-polar macroporous adsorbent HZ830 and crystallization in acetone. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Separation and Purification of Two Flavone Glucuronides from Erigeron multiradiatus (Lindl. Benth with Macroporous Resins

    Directory of Open Access Journals (Sweden)

    Zhi-feng Zhang

    2009-01-01

    Full Text Available Scutellarein-7-O-β-D-glucuronide (SG and apigenin-7-O-β-D-glucuronide (AG are two major bioactive constituents with known pharmacological effects in Erigeron multiradiatus. In this study, a simple method for preparative separation of the two flavone glucuronides was established with macroporous resins. The performance and adsorption characteristics of eight macroporous resins including AB-8, HPD100, HPD450, HPD600, D100, D101, D141, and D160 have been evaluated. The results confirmed that D141 resin offered the best adsorption and desorption capacities and the highest desorption ratio for the two glucuronides among the tested resins. Sorption isotherms were constructed for D141 resin under optimal ethanol conditions and fitted well to the Freundlich and Langmuir models (R2>0.95. Dynamic adsorption and desorption tests was performed on column packed with D141 resin. After one-run treatment with D141 resin, the two-constituent content in the final product was increased from 2.14% and 1.34 % in the crude extract of Erigeron multiradiatus to 24.63% and 18.42% in the final products with the recoveries of 82.5% and 85.4%, respectively. The preparative separation of SG and AG can be easily and effectively achieved via adsorption and desorption on D141 resin, and the method developed can be referenced for large-scale separation and purification of flavone glucuronides from herbal raw materials.

  18. Separation of salvianic acid A from the fermentation broth of engineered Escherichia coli using macroporous resins.

    Science.gov (United States)

    Bai, Chen-Long; Zhao, Guang-Rong

    2015-08-01

    Salvianic acid A (also known as danshensu) is a plant-derived polyphenolic acid, and has a variety of physiological and pharmacological activities. Our laboratory previously constructed an unprecedented artificial biosynthetic pathway in Escherichia coli and established the fermentation process to produce salvianic acid A. Here, we developed an efficient method for separating salvianic acid A from the fermentation broth of engineered Escherichia coli by macroporous resins. Among ten tested macroporous resins, the static and dynamic adsorption/desorption experiments demonstrated that X5 resin was the best to separate salvianic acid A from fermentation broth. Other parameters during static and dynamic procedures were also investigated. Under the optimum separation conditions, the average adsorption capacity of SAA were 10.66±0.54 mg/g dry resin and the desorption ratio was 85.6±4.1%. The purity and recovery yield of salvianic acid A in the final dry product were 90.2±1.5 and 81.5±2.3%, respectively. The results show that adsorption separation with macroporous resin X5 was an efficient method to prepare salvianic acid A from fermentation broth. This work will benefit the development and application of plant-derived salvianic acid A and its derivatives. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Effect of macroporous adsorption resin-membrane bioreactor hybrid system against fouling for municipal wastewater treatment.

    Science.gov (United States)

    Chen, Weiwei; Luo, Jing; Cao, Ruyi; Li, Yuting; Liu, Jinrong

    2017-01-01

    Membrane bioreactor (MBR) displays significant advantages in effluent quality, sludge production, footprint, and operation. However, membrane fouling limits the application of MBR. This study investigated membrane fouling in a macroporous adsorption resin-membrane bioreactor hybrid system established by adding macroporous adsorption resin (MAR) into MBR. MAR addition increased the critical flux by 27.97%, indicating that membrane fouling was successfully mitigated. Consequently, comparative experiments were designed to analyze the pathway. MAR addition mitigated external fouling development and improved mixed liquor characteristics, thereby mitigating gel layer formation and sludge floc deposition on the membrane surface. MAR effectively reduced the supernatant viscosity and dissolved COD by adsorbing soluble microbial products. Sludge production decreased because the sludge activity in MAR-MBR was inhibited. The fouled MAR could be regenerated effectively by deionized water and chemical cleaning. This work demonstrated the feasibility of using MAR-MBR to mitigate fouling in municipal wastewater treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Adsorption of Monobutyl Phthalate from Aqueous Phase onto Two Macroporous Anion-Exchange Resins

    OpenAIRE

    Zhengwen Xu; Yunlong Zhao; Jing Shi; Jiangang Lu; Ling Cheng; Mindong Chen

    2014-01-01

    As new emerging pollutants, phthalic acid monoesters (PAMs) pose potential ecological and human health risks. In the present study, adsorption performance of monobutyl phthalate (MBP) onto two macroporous base anion-exchange resins (D-201 and D-301) was discussed. It was found that the adsorption isotherms were best fitted by the Langmuir equation while the adsorption kinetics were well described by pseudo-first-order model. Analyses of sorption isotherms and thermodynamics proved that the ad...

  1. Preparation and adsorption properties of macroporous tannin resins

    Institute of Scientific and Technical Information of China (English)

    Zhang Li-ping; Du Jie; Liu Jian

    2006-01-01

    In this paper, a new kind of adsorption resin with multi-phenolic hydroxyl was created by immobilizing black wattle bark tannins to chloromethyl polystyrene resin. Its adsorption capacity to cation dye was tested. With an orthogonal test the optimal conditions of synthesis were determined: the concentration of sodium hydroxide solution 1.0 mol·L-1; the reaction time is one hour and the mass concentration of tannins 5%. With single factorial experiment the optimal conditions of adsorption were confirmed: a solidified pH of 5.0; an adsorption temperature of 25℃ and a cation dye concentration of 100 mg·L-1. The adsorption for cation dye can be similar to Langmuir isotherms.

  2. Preparative separation of echinocandin B from Aspergillus nidulans broth using macroporous resin adsorption chromatography.

    Science.gov (United States)

    Zou, Shu-Ping; Liu, Miao; Wang, Qiu-Liang; Xiong, Yan; Niu, Kun; Zheng, Yu-Guo; Shen, Yin-Chu

    2015-01-26

    Echinocandin B (ECB), an echinocandin type of lipopeptide antibiotic produced by Aspergillus nidulans, is a precursor for the synthesis of novel anti-fungal drug - anidulafungin. In this work, a separation strategy involving one-step macroporous resin adsorption chromatography was established for ECB purification from Aspergillus nidulans CCTCC M 2010275 fermentation broth. Among nine macroporous resin adsorbents tested, the non-polar resin HP-20 had the best adsorption and desorption performance. The static equilibrium adsorption data fitted well with the Langmuir equation, and the adsorption kinetic followed the pseudo-second order model. The separation parameters of ECB from broth were optimised by dynamic adsorption/desorption experiments with the column packed with HP-20 resin. Under optimal conditions, the purity increased by 3.8-fold from 23.2% in broth to 88.5% in eluent with 87.1% recovery yield by a one-step treatment. Our study provided a one-step and effective method for large-scale production of ECB, and offered references for separating other echinocandins from broth. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Separation and purification of rebaudioside A from extract of Stevia Rebaudiana leaves by macroporous adsorption resins

    Directory of Open Access Journals (Sweden)

    Anvari Masoumeh

    2016-03-01

    Full Text Available The separation and purification of rebaudioside A from Stevia rebaudiana crude extracts (Steviosides by macroporous resin were optimized by Taguchi orthogonal array (OA experimental design methodology. This approach was applied to evaluate the influence of five factors (adsorption temperature, desorption time, elution solution ratio, adsorption volume and type of resin on the rebaudioside A yield. The percentage contribution of each factor was also determined. The results showed that elution solution ratio and adsorption volume made the greatest (59.6% and the lowest (1.3% contribution, respectively. The results showed that the Taguchi method is able to model the purification of rebaudioside A process well (R2 > 0.998 and can therefore be applied in future studies conducted in various fields. Adsorption temperature 35°C, desorption time 60min, elution solution ratio 3, adsorption volume 200ml and HPD-400 as resin were the best conditions determined by the Taguchi method.

  4. ADSORPTION AND DESORPTION OF DSD ACID MANUFACTURING WASTEWATER ON MACROPOROUS RESIN

    Institute of Scientific and Technical Information of China (English)

    LONGChao; ZHANGQuanxing; 等

    2001-01-01

    4,4'-diaminostilbene-2,2'-disulfonic acid (DSD acid) manufacturing wastewater was treated by a macroporous resin in a fixed-bed column.The results showed that this method was suitable for removal of chemical oxygen demands(COD) and color,About 91% COD and 99.5% color removal were obtained under the optimum adsorption conditions.i.e.temperature 20℃,flow rate lbed volume/hour(BV/hr)and pH1-2.The resin was efficiently regenerated with aqueous sodium hydroxide and water.Furthermore,65.5% of 4,4'-dinitrostilbene-2,2'-disulfonic acid(DNS) could be recovered from wastewater for possible recycling to the manufactureing process.The adsorption capacity of resin remained constant during the repetition process of adsorption and desorption.

  5. Extraction of anthocyanins from black bean canning wastewater with macroporous resins.

    Science.gov (United States)

    Wang, Xiaoxi; Hansen, Conly; Allen, Karin

    2014-02-01

    This study investigated purification of anthocyanins from black bean canning wastewater by column chromatography with 5 types of macroporous resins (Diaion Hp20, Sepabeads Sp70, Sepabeads Sp207, Sepabeads Sp700, and Sepabeads Sp710). By-product of canned black beans was partially purified by filtration, in anticipation of higher performance during column chromatography. Equilibrium adsorption isotherms were measured and analyzed using Langmuir and Freundlich isotherm models. Both Langmuir (all R² ≥ 0.98) and Freundlich (all R² ≥ 0.97) models can describe the adsorption process of anthocyanins from black bean canning wastewater using the tested resins. The adsorption and desorption behaviors of anthocyanins were studied using a dynamic method on the 5 types of resins, and Sp700 presented the highest adsorption capacity (39 ± 4 mg/g; P canning wastewater.

  6. ADSORPTION AND DESORPTION OF DSD ACID MANUFACTURING WASTEWATER ON MACROPOROUS RESIN

    Institute of Scientific and Technical Information of China (English)

    LONG Chao; ZHANG Quanxing; XU Zhaoyi; CHEN Jinlong; LI Aimin; CHENG Zhiqiang

    2001-01-01

    4,4'-diaminostilbene-2, 2'-disulfonic acid (DSD acid) manufacturing wastewater was treated by a macroporous resin in a fixed-bed column. The results showed that this method was suitable for removal of chemical oxygen demands (COD) and color About 91% COD and 99.5% color removal were obtained under the optimum adsorption conditions, i.e. temperature 20 ℃, flow rate 1 bed volume/hour (BV/hr) and pH1-2. The resin was efficiently regenerated with aqueous sodium hydroxide and water. Furthermore, 65.5% of 4, 4 '-dinitrostilbene-2, 2 '-disulfonic acid (DNS) could be recovered from wastewater for possible recycling to the manufacturing process. The adsorption capacity of resin remained constant during the repetition process of adsorption and desorption.

  7. 应用XAD一2树脂浓集测定地下水中痕量有机氯农药%Determination of Trace Organic Chloric Pesticide in Underground Water by Concentration through XAD-2Resins

    Institute of Scientific and Technical Information of China (English)

    卞有生; 丁廷华

    1984-01-01

    @@利用多孔高聚物浓缩提取水中痕量有机化合物,是国外近年来提出的一项新技术,可适用于水中多种痕量有机物[1,2]。目前已广泛用于实验室研究和实际水样分析。最近几年国内对该项技术也有所注意[3]。但大多处于实验室研究阶段,即对有机化合物的纯溶液进行吸附实验研究,实际应用的报道尚不多见。本工作对XAD-2树脂吸附水中ppb量级有机氯农药的条件进行了研究,并用实际水样分析将树脂吸附提取法与经典的溶剂萃取法进行了比较,结果基本一致。

  8. Preparative Separation and Purification of the Total Flavonoids in Scorzonera austriaca with Macroporous Resins.

    Science.gov (United States)

    Xie, Yang; Guo, Qiu-Shi; Wang, Guang-Shu

    2016-06-13

    The use of macroporous resins for the separation and purification of total flavonoids to obtain high-purity total flavonoids from Scorzonera austriaca was studied. The optimal conditions for separation and purification of total flavonoids in S. austriaca with macroporous resins were as follows: D4020 resin columns were loaded with crude flavonoid extract solution, and after reaching adsorptive saturation, the columns were eluted successively with 5 bed volumes (BV) of water, 5 BV of 5% (v/v) aqueous ethanol and 5 BV of 30% (v/v) aqueous ethanol at an elute flow rate of 2 BV·h(-1). Total flavonoids were obtained from the 30% aqueous ethanol eluate by vacuum distillation recovery. The content of flavonoid compounds in the total flavonoids was 93.5%, which represents an improvement by about 150%. In addition, five flavonoid compounds in the product were identified as 2″-O-β-d-xylopyranosyl isoorientin, 6-C-α-l-arabipyranosyl orientin, orientin, isoorientin and vitexin by LC-ESI-MS analysis and internal standard methods. The results in this study could represent a method for the large-scale production of total flavonoids from S. austriaca.

  9. Preparative Separation and Purification of the Total Flavonoids in Scorzonera austriaca with Macroporous Resins

    Directory of Open Access Journals (Sweden)

    Yang Xie

    2016-06-01

    Full Text Available The use of macroporous resins for the separation and purification of total flavonoids to obtain high-purity total flavonoids from Scorzonera austriaca was studied. The optimal conditions for separation and purification of total flavonoids in S. austriaca with macroporous resins were as follows: D4020 resin columns were loaded with crude flavonoid extract solution, and after reaching adsorptive saturation, the columns were eluted successively with 5 bed volumes (BV of water, 5 BV of 5% (v/v aqueous ethanol and 5 BV of 30% (v/v aqueous ethanol at an elute flow rate of 2 BV·h−1. Total flavonoids were obtained from the 30% aqueous ethanol eluate by vacuum distillation recovery. The content of flavonoid compounds in the total flavonoids was 93.5%, which represents an improvement by about 150%. In addition, five flavonoid compounds in the product were identified as 2″-O-β-d-xylopyranosyl isoorientin, 6-C-α-l-arabipyranosyl orientin, orientin, isoorientin and vitexin by LC-ESI-MS analysis and internal standard methods. The results in this study could represent a method for the large-scale production of total flavonoids from S. austriaca.

  10. Adsorption Behaviors and Mechanism of Macroporous Phosphonic Acid Resin for Gadolinium

    Institute of Scientific and Technical Information of China (English)

    吴香梅; 熊春华; 姚彩萍

    2004-01-01

    The adsorption behaviors and mechanism of a novel chelate resin, macroporous phosphonic acid resin(PAR)for Gd(Ⅲ)were investigated. The statically and dynamically saturated adsorption capacity is respectively 308 mg·g-1resin and 296 mg·g-1resin at 298 K in Hac-NaAc medium at pH 5.6. Gd(Ⅲ)adsorbed on PAR can be reductively eluted by 0.5~5.0 mol·L-1 HCl used as eluant and the elution percentage is up to 94.7% in 1.0 mol·L-1 HCl. The resin can be regenerated and reused without apparent decrease in adsorption capacity. The apparent adsorption rate constant is k298=3.96×10-5 s-1. The adsorption behavior of PAR for Gd(Ⅲ) conforms to the Freundlich isotherm. The thermodynamic adsorption parameter, enthalpy change △H of PAR for Gd(Ⅲ)is 22.6kJ·mol-1. The apparent adsorption activation energy(Ea)of PAR for Gd(Ⅲ)is 5.0 kJ·mol-1. The molar coordination ratio of the functional group of PAR to Gd(Ⅲ)is about 3∶1. The adsorption mechanism of PAR for Gd(Ⅲ)was examined by using chemical method and IR spectrometry.

  11. Adsorption of Monobutyl Phthalate from Aqueous Phase onto Two Macroporous Anion-Exchange Resins

    Directory of Open Access Journals (Sweden)

    Zhengwen Xu

    2014-01-01

    Full Text Available As new emerging pollutants, phthalic acid monoesters (PAMs pose potential ecological and human health risks. In the present study, adsorption performance of monobutyl phthalate (MBP onto two macroporous base anion-exchange resins (D-201 and D-301 was discussed. It was found that the adsorption isotherms were best fitted by the Langmuir equation while the adsorption kinetics were well described by pseudo-first-order model. Analyses of sorption isotherms and thermodynamics proved that the adsorption mechanisms for DBP onto D-201 were ion exchange. However, the obtained enthalpy values indicate that the sorption process of MBP onto D-301 is physical adsorption. The equilibrium adsorption capacities and adsorption rates of DBP on two different resins increased with the increasing temperature of the solution. D-301 exhibited a higher adsorption capacity of MBP than D-201. These results proved that D-301, as an effective sorbent, can be used to remove phthalic acid monoesters from aqueous solution.

  12. SYNTESIS OF THE COMPLEXES OF MACROPOROUS SULFONATED RESINS WITH FERRIC CHLORIDE AND THEIR CATALYTIC BEHAVIOR FOR SETERIFICATION OF ACETIC ACID WITH BUTANOL

    Institute of Scientific and Technical Information of China (English)

    HuangWenqiang; HouXin; 等

    1997-01-01

    The complex resins prepared from macroporous sulfonated resin D72(H+ form) with ferric chloride or ferric chloride hexahydrate have both sites of Bronsted acid and Lewis acid.In the catalysis of exterification of acetic acid with butanol the complex resins show to have much higher catalytic activity than that of its matrix.a conventional sulfonated cation exchange resin D72.

  13. The effects of ionizing radiation on Reillex trademark HPQ, a new macroporous polyvinylpyridine resin, and on four conventional polystyrene anion exchange resins

    Energy Technology Data Exchange (ETDEWEB)

    Marsh, S.F.

    1990-11-01

    This study compares the effects of ionizing radiation on Reillex{trademark} HPQ, a recently available macroporous copolymer of 1-methyl-4-vinylpyridine/divinylbenzene, and on four conventional strong-base polystyrene anion exchange resins. The polystyrene resins investigated included one gel type, Dowex{trademark} 1 {times} 4, and three macroporous resins: Dow{trademark} MSA-1, Amberlite{trademark} IRA-900, and Lewatit{trademark} MP-500-FK. Each resin, in 7 M nitric acid, was subjected to seven different levels of {sup 60}Co gamma radiation ranging from 100 to 1000 megarads. Irradiated resins were measured for changes in dry weight, wet volume, chloride and Pu(IV) exchange capacities, and thermal stability. In separate experiments, each resin was subjected to approximately 340 megarads of in situ alpha particles from sorbed plutonium. Resin damage from alpha particles was less than half that caused by gamma rays, which may be a consequence of different production rates of radiolytic nitrite and nitro radicals in the two systems. Reillex{trademark} HPQ resin provided the greatest radiation stability, whereas Lewatit{trademark} MP-500-FK was the least stable of the resins tested. Thermogravimetric analyses of dry, nitrate-form resin revealed that dry Reillex{trademark} HPQ resin offered the best thermal stability for absorbed gamma doses to 370 megarads, but the worst thermal stability after exposures of 550 megarads or more. 25 refs., 11 figs., 13 tabs.

  14. Absorption and desorption behaviour of the flavonoids from Glycyrrhiza glabra L. leaf on macroporous adsorption resins.

    Science.gov (United States)

    Dong, Yi; Zhao, Mouming; Sun-Waterhouse, Dongxiao; Zhuang, Mingzhu; Chen, Huiping; Feng, Mengying; Lin, Lianzhu

    2015-02-01

    The kinetics of adsorption and desorption behaviours of five macroporous resins for enriching flavonoids from Glycyrrhizaglabra L. leaf were investigated. All five resins showed similar and effective adsorption and desorption properties. A pseudo-second-order kinetics model was suitable for evaluating the whole adsorption process. Additionally, two representative resins (XAD-16 and SP825) were chosen for adsorption thermodynamics study. The adsorption of the representative resins was an exothermic and physical adsorption process. Further column chromatography of XAD-16 and SP825 showed that the total flavonoids (from 16.8% to 55.6% by XAD-16 and to 53.9% by SP825) and pinocembrin (from 5.49% to 15.2% by XAD-16 and to 19.8% by SP825) were enriched in 90% ethanol fractions. Meanwhile, the antioxidant capacities and nitrite-scavenging capacities were 2-3times higher than those of the crude extract. The fractions with high flavonoid and pinocembrin contents could be used as biologically active ingredients in functional food.

  15. Separation and purification of amygdalin from thinned bayberry kernels by macroporous adsorption resins.

    Science.gov (United States)

    Wang, Tao; Lu, Shengmin; Xia, Qile; Fang, Zhongxiang; Johnson, Stuart

    2015-01-15

    To utilize the low-value thinned bayberry (Myrica rubra Sieb. et Zucc) kernels (TBKs) waste, an efficient method using macroporous adsorption resins (MARs) for separation and purification of amygdalin from TBKs crude extracts was developed. An aqueous crude sample was prepared from a methanol TBK extract, followed by resin separation. A series of MARs were initially screened for adsorption/desorption of amygdalin in the extract, and D101 was selected for characterization and method development. The static adsorption data of amygdalin on D101 was best fitted to the pseudo-second-order kinetics model. The solute affinity toward D101 at 30 °C was described and the equilibrium experimental data were well-fitted to Langmuir and Freundlich isotherms. Through one cycle of dynamic adsorption/desorption, the purity of amygdalin in the extract, determined by HPLC, increased about 17-fold from 4.8% to 82.0%, with 77.9% recovery. The results suggested that D101 resin effectively separate amygdalin from TBKs. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. STUDY ON SYNTHESIS OF PVC SERIES OF MACROPOROUS SULFORIC RESINS AND THEIR APPLICATIONS IN CATALYTIC ESTERIFICATION AND WATER TREATMENT

    Institute of Scientific and Technical Information of China (English)

    LIYanfeng; FULiandi; 等

    1999-01-01

    The PVC serves of macroporous sulfonic cation-exchange resins were prepared by the sulfonation of a macroporous PVC bead with concentrated sulfonic acid or chlorosulfonic acid.the resulting sulfonic resin was employed in the investigation of catalytic esterification and solftening of water,The results show that the yields of esters reach 60.0-84.4% according as different fatty acids and alcohols,the refractive indexes of esters obtained resemble those reported in the references basically,meanwhile,345L softened water which holds ≤0.06mmol/L hardness would be prepared by 1 L wet sulfonic resin reusing for 4 times.The resulting sulfonic resins would have 1.6-2.0or 2.5-3.0mmol/g exchange capacity by using concentrated sulfonic acid or chlorosulfonic acid as sulfonating agent,respectively,The sulfonic resin has a macroporous structure taking the morphology with agglomerates of minutely spherical gel particles as characteristic.

  17. AMS radiocarbon age for fossil bone by XAD-2 chromatography method

    Science.gov (United States)

    Minami, Masayo; Nakamura, Toshio

    2000-10-01

    The XAD-2 chromatography method was examined for its ability to efficiently eliminate exogenous organic matter from fossil bones and to improve the accuracy of radiocarbon ( 14C) dating and stable isotope determinations on bone proteins. The fossil bones used in the experiment were animal fossil bones collected from the Awazu submarine archaeological site, Shiga, Japan. For comparison, the gelatin-extraction method was also applied to the same samples. It was found that the gelatin-extraction method is sufficient for 14C dating on well-preserved bones, but insufficient on poorly preserved bones, containing less than 1% extractable gelatin. The XAD-2 resin is useful for the clean up of proteins especially from poorly preserved bones. The carbon stable isotope fractionation of around 1‰ by XAD-2 treatment on modern collagen standards was larger than reported previously. The isotopic variation by sequential extraction of bones probably originates from changes in the amino acid composition and seems to be less sensitive to the indication of the removal of organic contamination.

  18. Purification of Houttuynia cordata Thunb. Essential Oil Using Macroporous Resin Followed by Microemulsion Encapsulation to Improve Its Safety and Antiviral Activity

    National Research Council Canada - National Science Library

    Pang, Jianmei; Dong, Wujun; Li, Yuhuan; Xia, Xuejun; Liu, Zhihua; Hao, Huazhen; Jiang, Lingmin; Liu, Yuling

    2017-01-01

    .... Herein, we proposed a strategy to prepare H. cordata essential oil (HEO) safely and effectively by combining the solvent extraction and the macroporous resin purification flexibly, and then encapsulating it using microemulsion...

  19. Isolation of α-arbutin from Xanthomonas CGMCC 1243 fermentation broth by macroporous resin adsorption chromatography.

    Science.gov (United States)

    Liu, Chunqiao; Zhang, Peng; Liu, Luo; Xu, Tao; Tan, Tianwei; Wang, Fang; Deng, Li

    2013-04-15

    α-Arbutin is a glycosylated hydroquinone which has inhibitory function against tyrosinase. In this work, a one-step isolation of α-arbutin from Xanthomonas CGMCC 1243 fermentation broth by macroporous resin adsorption chromatography was investigated. The research results indicated that S-8 resin offered the best adsorption and desorption capacities for α-arbutin than others and its equilibrium adsorption data were well-fitted to the Freundlich isotherm. In order to optimize the operating parameters for separating α-arbutin, dynamic adsorption and desorption tests on S-8 column chromatography were carried out. Under optimized conditions (adsorption volume of 7 bed volume (BV), mobile phase of 25% (v/v) ethanol solution and elution volume of 3 BV), the purity and recovery of α-arbutin were 97.3% (w/w) and 90.9% (w/w), respectively. The product was identified as α-arbutin by (13)C NMR and (1)H NMR analysis. Moreover, we scaled up S-8 column from laboratory test (10 cm × 2 cm ID) to large scale (500 cm × 100 cm ID) without diminishing α-arbutin yield. In conclusion, the results in this work provide a one-step and cost-effective method for large-scale production of α-arbutin. Copyright © 2013. Published by Elsevier B.V.

  20. Separation and purification of epigallocatechin-3-gallate (EGCG) from green tea using combined macroporous resin and polyamide column chromatography.

    Science.gov (United States)

    Jin, Xin; Liu, Mingyan; Chen, Zaixing; Mao, Ruikun; Xiao, Qinghuan; Gao, Hua; Wei, Minjie

    2015-10-01

    Epigallocatechin-3-gallate (EGCG) is a major bioactive ingredient of green tea that produces beneficial neuroprotective effects. In this paper, to optimize the EGCG enrichment, thirteen macroporous resins with different chemical and physical properties were systemically evaluated. Among the thirteen tested resins, the H-bond resin HPD826 exhibited best adsorption/desorption capabilities and desorption ratio, as well as weakest affinity for caffeine. The absorption of EGCG on the HPD826 resin followed the pseudo-second-order kinetics and Langmuir isotherm model. The separation parameters of EGCG were optimized by dynamic adsorption/desorption experiments with the HPD826 resin column. Under the optimal condition, the content of EGCG in the 30% ethanol eluent increased by 5.8-fold from 7.7% to 44.6%, with the recovery yield of 72.1%. After further purification on a polyamide column, EGCG with 74.8% purity was obtained in the 40-50% ethanol fraction with a recovery rate of 88.4%. In addition, EGCG with 95.1% purity could be easily obtained after one-step crystallization in distilled water. Our study suggests that the combined macroporous resin and polyamide column chromatography is a simple method for large-scale separation and purification of EGCG from natural plants for food and pharmaceutical applications.

  1. SYNTHESIS OF MACROPOROUS HUMIC ACID RESINS AND THEIR CHELATING PROPERTIES FOR HEAVY METAL IONS

    Institute of Scientific and Technical Information of China (English)

    CHEN Yiyong; MAO Xueqin; ZHU Dongwei; ZHENG Ping

    1984-01-01

    Macroporous HA resins (HAR) can be prepared in pearl form by grafting HA onto crosslinkec PS through azo or through ester and / or ether linkages. At pH 13 and the HA / PSNH2 weight ratio 0.7-1.0, PSN2+Cl-couples with HA and results in the formation of azo-type HA resin (HAR-A), which shows good adsorbility towards heavy metal ions. The Cu2+ sorption capacity of ester / ether type humic acid resin (HAR-E) is increased by lengthening the reaction time of HA and PSCH2Cl. The structure of HAR is discussed on the basis of the IR spectra. The sorption capacity of HAR-A is 1.01 mmol / g for Cd2+and 0.6-0.53 mmol/g for Ni2+,Mn2+,Cu2+,Co3+ and Zn2+, respectively. The calculated distribution coefficients of heavy metal ions on HAR-A can be arranged in the following order: CuV+(8.7 × 103)>Cd2+(3.8 × 102)>Zn2+(2.4 × 102)>Ni2+(1. 8 × 102)>Mn2+(4.9 × 10). At pH 6.5, Cu2+, Cd2+, Ni2+, Mn2+ can be quantitatively adsorbed by HAR-A and completely eluted with 1N HNO3. HAR-A can be regenerated and reused Trace quantities of the above-mentioned heavy metal ions in four samples of the natural occurring water and one sample of the tap water were analyzed by using HAR-A.

  2. Adsorption Behavior and Mechanism of Macroporous Phosphonic Acid Resin for Lu3+

    Institute of Scientific and Technical Information of China (English)

    WANG Hui-jun; XIONG Chun-hua

    2006-01-01

    The article is based on a research on the adsorption behavior and adsorption mechanism of macroporous phosphonic acid resin (PAR) for Lu3+ and the influence of the medium's pH, adsorption temperature, adsorption time, etc on adsorbing Lu3 + . The best value of medium's pH to the adsorption of PAR for Lu3 + was found to be 4.92. The static adsorption maximum capacity of PAR for Lu3 + is 220 mg· g-1. The thermodynamic adsorption parameters are respectively △H= 11.3 kJ·mol-1, △S =46.3 J·mol-1 ·K-1, △G = - 2.50 kJ·mol-1 and the apparent activity energy is Ea= 31.4 kJ· mol- 1. The adsorption behavior of PAR for Lu3 + obeys the Freundlich isotherm. The apparent adsorption rate constant is k298 = 4.68 × 10-5 s-1. The coordinate ratio of the functional radical to Lu3 + is approximately 4: 1. The best eluant is 1.0 mol· L- 1 HCl. The adsorption mechanism of PAR for Lu3 + was separately confirmed by chemical analysis and IR spectra.

  3. Enrichment and purification of six Aconitum alkaloids from Aconiti kusnezoffii radix by macroporous resins and quantification by HPLC-MS.

    Science.gov (United States)

    Liu, Jingjing; Li, Qing; Liu, Ran; Yin, Yidi; Chen, Xiaohui; Bi, Kaishun

    2014-06-01

    Aconitine, mesaconitine, hypaconitine, benzoylaconine, benzoylmesaconine and benzoylhypaconine are six main Aconitum alkaloids from traditional Chinese medicine, Aconiti kusnezoffii radix, which possess highly bioactive as well as highly toxic character for medicinal use. In the present study, for the purpose of better utilizing the toxic herbal material, the performance characteristics of NKA-II, D101, X-5, AB-8, S-8, HPD722 and HPD750 macroporous resins for the enrichment and purification of these six Aconitum alkaloids were critically evaluated. Results showed that NKA-II offered the best adsorption and desorption capacities for six Aconitum alkaloids among the seven macroporous resins tested, which were affected significantly by the pH value. Subsequently, dynamic adsorption and desorption experiments had been carried out with the column packed by NKA-II resin to optimize the separation process of six Aconitum alkaloids. After one run treatment with NKA-II resin, the content of total six Aconitum alkaloids were increased from 5.87% to 60.3%, the recovery was 75.8%. Meanwhile, a validated HPLC-MS method had been developed to qualitative and quantitative these six Aconitum alkaloids. This method would provide scientific references to the large-scale production of six Aconitum alkaloids from Aconiti kusnezoffii radix or other plants and might also expand the secure application of these highly toxic components for pharmacy.

  4. Enrichment and Purification of Deoxyschizandrin and γ-Schizandrin from the Extract of Schisandra chinensis Fruit by Macroporous Resins

    Directory of Open Access Journals (Sweden)

    Ying Zhang

    2012-03-01

    Full Text Available In present study, the performance and separation characteristics of 21 macroporous resins for the enrichment and purification of deoxyschizandrin and γ-schizandrin, the two major lignans from Schisandra chinensis extracts, were evaluated. According to our results, HPD5000, which adsorbs by the molecular tiers model, was the best macroporous resin, offering higher adsorption and desorption capacities and higher adsorption speed for deoxyschizandrin and γ-schizandrin than other resins. Columns packed with HPD5000 resin were used to perform dynamic adsorption and desorption tests to optimize the technical parameters of the separation process. The results showed that the best adsorption time is 4 h, the rate of adsorption is 0.85 mL/min (4 BV/h and the rate of desorption is 0.43 mL/min (2 BV/h. After elution with 90% ethanol, the purity of deoxy-schizandrin increased 12.62-fold from 0.37% to 4.67%, the purity of γ-schizandrin increased 15.8-fold from 0.65% to 10.27%, and the recovery rate was more than 80%.

  5. Separation and purification of both tea seed polysaccharide and saponin from camellia cake extract using macroporous resin.

    Science.gov (United States)

    Yang, Pengjie; Zhou, Mingda; Zhou, Chengyun; Wang, Qian; Zhang, Fangfang; Chen, Jian

    2015-02-01

    A novel method to separate and purify tea seed polysaccharide and tea seed saponin from camellia cake extract by macroporous resin was developed. Among four kinds of resins (AB-8, NKA-9, XDA-6, and D4020) tested, AB-8 macroporous resin possessed optimal separating capacity for the two substances and thus was selected for the separation, in which deionized water was used to elute tea seed polysaccharide, 0.25% NaOH solution to remove the undesired pigments, and 90% ethanol to elute tea seed saponin. Further dynamic adsorption/desorption experiments on AB-8 resin-based column chromatography were conducted to obtain the optimal parameters. Under optimal dynamic adsorption and desorption conditions, 18.7 and 11.8% yield of tea seed polysaccharide and tea seed saponin were obtained with purities of 89.2 and 96.0%, respectively. The developed method provides a potential approach for the large-scale production of tea seed polysaccharide and tea seed saponin from camellia cake. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Removal of chloramphenicol by macroporous adsorption resins in honey: a novel approach on reutilization of antibiotics contaminated honey.

    Science.gov (United States)

    Cheng, Ni; Gao, Hui; Deng, Jianjun; Wang, Bini; Xu, Ruihan; Cao, Wei

    2012-09-01

    The effects of different steps in honey production on chloramphenicol (CAP) levels and CAP removal from honey using macroporous adsorption resins (MARs) were investigated in this study. CAP residues in honey were quantified by enzyme-linked immunosorbent assay after each processing step including preheating, filtration, vacuum concentration and pasteurization. Vacuum concentration contributes the most reduction of CAP level (9.9%). Meanwhile, 5 types of MARs (including LSI-1, LSI-2, LSI-3, LS-803, and LS-903) were used in CAP adsorption. The results showed that LS-803 resin had higher adsorption rate of 86% than other resins in removing CAP from honey, and its optimal adsorption time and temperature were 40 min and 55 °C, respectively. The treated honey could be used as feed additive or biomass energy. Therefore, it would be a novel approach to reutilization of antibiotics contaminated honey.

  7. A Simplified Method for Sampling and Analysis of High Volume Surface Water for Organic Contaminants Using XAD-2

    Science.gov (United States)

    Datta, S.; Do, L.V.; Young, T.M.

    2004-01-01

    A simple compressed-gas driven system for field processing and extracting water for subsequent analyses of hydrophobic organic compounds is presented. The pumping device is a pneumatically driven pump and filtration system that can easily clarify at 4L/min. The extraction device uses compressed gas to drive filtered water through two parallel XAD-2 resin columns, at about 200 mL/min. No batteries or inverters are required for water collection or processing. Solvent extractions were performed directly in the XAD-2 glass columns. Final extracts are cleaned-up on Florisil cartridges without fractionation and contaminants analyzed by GC-MS. Method detection limits (MDLs) and recoveries for dissolved organic contaminants, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and pesticides are reported along with results of surface water analysis for the San Francisco Bay, CA.

  8. Separation of Caffeine and Tea Poly-phenols from Instant (Soluble Tea Waste Liquor by Macro-porous Resins

    Directory of Open Access Journals (Sweden)

    Xueling Gao

    2014-06-01

    Full Text Available Instant tea is presently manufactured by spraying and freeze drying the concentrated brew of processed tea leaves and dust. The purpose of this study was to develop a technique using macro-porous resins for separating Caffeine (Caf and Tea Poly-phenols (TP from the waste liquor generated by manufacturing instant tea. Optimum adsorption conditions were obtained using an initial concentration of Caf solution of 80 mg/L and a flow rate of 1.5 mL/min at 60°C; The optimal desorption conditions were determined using a flow rate of 1.0 mL/min, 80% aqueous ethanol of, eluent volume of 4 times of Bed Volume (BV. After column separation, the purity of Caf was enhanced from 6 to 23%, TP from 38 to 61% and with the final yield of 16.9% following the separation by D101 resin. This study demonstrated macro-porous resin can effectively separated Caf and TP from instant tea waste liquor.

  9. Synthesis and application of amberlite XAD-2 functionalized with dithizone for field preconcentration and separation of trace cadmium in seawater.

    Science.gov (United States)

    Wu, Dongmei; Wang, Aixia; Guo, Liping

    2006-09-01

    A chelating resin coupling Amberlite XAD-2 functionalized with dithizone is synthesized and characterized. Dissolved cadmium is field-preconcentrated using a minicolumn packed with the synthesized resin and determined by flame atomic absorption spectrometry. Five experimental variables are evaluated. The enrichment factor of 416 is obtained for 50 mL of sampling volume, and the detection limit (3 sigma) of the procedure is 6.7 ng L(-1). The precision (RSD) for 11 independent determinations is 1.97%. This method has been successfully applied to the determination of cadmium in natural seawater samples.

  10. Enrichment of antioxidants in black garlic juice using macroporous resins and their protective effects on oxidation-damaged human erythrocytes.

    Science.gov (United States)

    Zou, Ying; Zhao, Mouming; Yang, Kun; Lin, Lianzhu; Wang, Yong

    2017-08-15

    The black garlic juice is popular for its nutritive value. Enrichment of antioxidants is needed to make black garlic extract an effective functional ingredient. Five macroporous resins were evaluated for their capacity in adsorbing antioxidants in black garlic juice. XAD-16 resin was chosen for further study due to its high adsorption and desorption ratios. Pseudo-second-order kinetics (qe=625μmol Trolox equiv/g dry resin, k2=0.0001463) and Freundlich isotherm models (ΔH=-10.1547kJ/mol) were suitable for describing the whole exothermic and physical adsorption processes of the antioxidants from black garlic juice on XAD-16 resin. The antioxidants and phenolics were mostly enriched in 40% ethanol fraction by XAD-16 resin column chromatography. The black garlic extract and its fractions could protect erythrocytes against AAPH-induced hemolysis in dose-dependent manners. The pretreatment of AAPH-damaged erythrocytes with 40% ethanol fractions (2.5mg/mL) significantly decreased the hemolysis ratios from 53.58% to 3.79%. The 40% ethanol fraction possessing strong intracellular antioxidant activity could be used as a functional food ingredient. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Purification of two triterpenoids from Schisandra chinensis by macroporous resin combined with high-speed counter-current chromatography.

    Science.gov (United States)

    Zhu, Lijie; Li, Bin; Liu, Xiuying; Meng, Xianjun

    2014-10-01

    A method for preparative purification of corosolic acid and nigranoic acid from Schisandra chinensis (SC) was established using a combination of macroporous absorption resin column separation and high-speed counter-current chromatography (HSCCC). The crude extracts obtained from SC using 70% ethanol were separated on a macroporous resin column and then eluted with a graded ethanol series. The 70% ethanol fraction was used as the sample for separation of the two triterpenoids by HSCCC. The two-phase solvent system used for HSCCC separation was chloroform-n-butanol-methanol-water (10:0.5:7:4, v/v/v/v). The upper phase was used as the stationary phase of HSCCC. Corosolic acid (16.4 mg) of 96.3% purity and nigranoic acid (9.5 mg) of 98.9% purity were obtained in a one-step HSCCC separation from 100 mg of the sample. The structures of corosolic acid and nigranoic acid were identified by (1)H-nuclear magnetic resonance (NMR) and (13)C-NMR.

  12. Preparative purification of morroniside and loganin from Fructus corni by combination of macroporous absorption resin and HSCCC.

    Science.gov (United States)

    Liu, Liangpo; Sun, Ailing; Wu, Sujuan; Liu, Renmin

    2009-01-01

    A method for preparative purification of loganin and morroniside from Fructus corni was established by combination of macroporous absorption resin column separation and high-speed counter-current chromatography (HSCCC). The crude extracts obtained from Fructus corni by ultrasonic extraction with 50% methanol were subjected to separation on a macroporous resin column and then eluted with 15% and 40% ethanol, respectively. A fraction of 40% ethanol was used as the sample for separation of morroniside and loganin by HSCCC. The two-phase solvent system used for HSCCC separation was n-butanol-methanol-1% acetic acid water (4:1:6, v/v). The upper phase was used as the stationary phase of HSCCC. Morroniside (28.7 mg) of 97.8% purity and loganin (11.5 mg) of 98.6% purity were obtained in a one-step HSCCC separation from 50 mg of sample. The structures of morroniside and loganin were identified by 1H-NMR and 13C-NMR.

  13. Comparison of XAD macroporous resins for the concentration of fulvic acid from aqueous solution

    Science.gov (United States)

    Aiken, G.R.

    1979-01-01

    Five macroreticular, nonlonlc AmberlHe XAD resins were evaluated for concentration and Isolation of fulvlc acid from aqueous solution. The capacity of each resin for fulvlc acid was measured by both batch and column techniques. Elution efficiencies were determined by desorptlon with 0.1 N NaOH. Highest recoveries were obtained with the acrylic ester resins which proved to be most efficient for both adsorption and elution of fulvlc acid. Compared to the acrylic ester resins, usefulness of the styrene dvlnybenzene resins to remove fulvlc acid is limited because of slow diffusion-controlled adsorption and formation of charge-transfer complexes, which hinders elution. ?? 1979 American Chemical Society.

  14. Comparison of adsorption equilibrium of fructose, glucose and sucrose on potassium gel-type and macroporous sodium ion-exchange resins.

    Science.gov (United States)

    Nobre, C; Santos, M J; Dominguez, A; Torres, D; Rocha, O; Peres, A M; Rocha, I; Ferreira, E C; Teixeira, J A; Rodrigues, L R

    2009-11-03

    Adsorption equilibrium of fructose, glucose and sucrose was evaluated on sulfonated poly(styrene-co-divinylbenzene) cation-exchange resins. Two types of resins were used: potassium (K+) gel-type and sodium (Na+) macroporous resins. Influence of the cation and effect of the resin structure on adsorption were studied. The adsorption isotherms were determined by the static method in batch mode for mono-component and multi-component sugar mixtures, at 25 and 40 degrees C, in a range of concentrations between 5 and 250 g L(-1). All adsorption isotherms were fitted by a linear model in this range of concentrations. Sugars were adsorbed in both resins by the following order: fructose > glucose > sucrose. Sucrose was more adsorbed in the Na+ macroporous resin, glucose was identically adsorbed, and fructose was more adsorbed in the K+ gel-type resin. Data obtained from the adsorption of multi-component mixtures as compared to the mono-component ones showed a competitive effect on the adsorption at 25 degrees C, and a synergetic effect at 40 degrees C. The temperature increase conducted to a decrease on the adsorption capacity for mono-component sugar mixtures, and to an increase for the multi-component mixtures. Based on the selectivity results, K+ gel-type resin seems to be the best choice for the separation of fructose, glucose and sucrose, at 25 degrees C.

  15. Preparative separation and purification of Rebaudioside A from Stevia rebaudiana Bertoni crude extracts by mixed bed of macroporous adsorption resins.

    Science.gov (United States)

    Li, Jie; Chen, Zhenbin; Di, Duolong

    2012-05-01

    The separation and purification of Rebaudioside A (RA) from Stevia rebaudiana Bertoni crude extracts (Steviosides) by macroporous adsorption resin (MAR) mixed bed were systematically investigated. MAR mixed bed of HPD750-LSA40-LSA30-DS401 was selected due to its better separation degree. Based on the kinetics/thermodynamics experiment of the mixed bed, it was found that the experimental data fitted better to the pseudo-second-order model, and intra-particle diffusion was rate-limiting step. The adsorption isotherm was consistent with IV equilibrium adsorption isotherm classified by Brunauer. Furthermore, the influencing factors for the separation of RA based on HPLC were also investigated. Under the optimal conditions, the separation degree for RA (DAS) increased from 0.771 to 1.54. Moreover, the experimental results showed that the purity of the obtained product increased from 60% to 97%.

  16. Enrichment and purification of total flavonoids from Flos Populi extracts with macroporous resins and evaluation of antioxidant activities in vitro.

    Science.gov (United States)

    Wan, Pengfei; Sheng, Zunlai; Han, Qiang; Zhao, Yulin; Cheng, Guangdong; Li, Yanhua

    2014-01-15

    Enrichment and purification of total flavonoids from Flos Populi extracts were studied using five macroporous resins. The static tests indicated that NKA-9 resin was appropriate and its adsorption data were well fitted to the Langmuir and Freundlich isotherms. To optimize the separation process, dynamic adsorption and desorption tests were carried out. The optimal adsorption parameters were initial concentrations in sample solution of 7.64mg/mL, pH of 5.0, sample loading amount of 2.3BV, flow rate of 2BV/h, temperature of 25°C. The optimal desorption parameters were deionized water and 20% ethanol each 5BV, then 60% ethanol of 10 BV, flow rate of 2BV/h. After one run treatment with NKA-9 resin, the content of total flavonoids in the product increased from 11.38% to 53.41%, and the recovery yield was 82.24%. The results showed that NKA-9 resin revealed a good ability to enrichment total flavonoids from Flos Populi, and the method can be referenced for the enrichment of total flavonoids from other materials. The antioxidant activities of the purified flavonoids were further evaluated in vitro. It showed that the DPPH radical scavenging increased from 59.46% to 82.63% at different concentrations (0.06-0.14mg/mL). At different concentrations (0.6-1.4mg/mL), the hydroxyl radical scavenging increased from 35.39% to 74.12%. Moreover, the reducing ability and total oxidant capacity appeared to be dose-dependent of flavonoids. It indicated that the purified flavonoids can be used as a source of potential antioxidant.

  17. An Efficient Protocol for Preparation of Gallic Acid from Terminalia bellirica (Gaertn.) Roxb by Combination of Macroporous Resin and Preparative High-Performance Liquid Chromatography.

    Science.gov (United States)

    Zou, Denglang; Chen, Tao; Chen, Chen; Li, Hongmei; Liu, Yongling; Li, Yulin

    2016-08-01

    In this article, macroporous resin column chromatography and preparative high-performance liquid chromatography were applied for preparation of gallic acid from Terminalia bellirica (Gaertn.) Roxb. In the first step, six kinds of resins were investigated by adsorption and desorption tests and AB-8 macroporous resin was selected for the enrichment of gallic acid. As a result, 20 g of gallic acid at a purity of 71% could be separated from 100 g of crude extract in which the content of gallic acid was 16.7% and the recovery of gallic acid reached 85.0%. In the second step, preparative high-performance liquid chromatography was selected to purify gallic acid. As a result, 640 mg of gallic acid at a purity of 99.1% was obtained from 1 g of sample in 35 min. The results demonstrated that macroporous resin coupled with preparative high-performance liquid chromatography was suitable for preparation of gallic acid from T. bellirica (Gaertn.) Roxb.

  18. PREPARATION AND PROPERTIES OF MACRO-POROUS CHELATE RESINS OF CROSSLINKED POLYSTYRENE BEARING DITHIOCARBAMATE GROUPS

    Institute of Scientific and Technical Information of China (English)

    CHEN Yiyong; GU Zhenmei

    1983-01-01

    The title resins (DTC resins) with high adsorption capacity were prepared. The influences of various reaction conditions of amination and dithiocarboxylation were examined. The adsorption capacities of the produced DTC resin for Hg2+, Cu2+, Zn2+ and Cd2+ are 4.40, 2.44, 1.77 and 1.36mmol/g, respectively. It is highly effective in collecting traces of heavy metal ions in water over a wide pH range. The conversion of the functional groups were confirmed by the IR-spectra and elementary analysis.

  19. Comparison of humic substances isolated from peatbog water by sorption on DEAE-cellulose and amberlite XAD-2

    Science.gov (United States)

    Hejzlar, J.; Szpakowska, B.; Wershaw, R. L.

    1994-01-01

    Aquatic humic substances (AHS) were isolated from peatbog water by adsorption (1) on diethylaminoethyl cellulose (DEAE-C) and (2) on Amberlite XAD-2 (XAD) to compare yields of the methods and the composition of the isolated AHS. To provide a detailed comparison, the isolates were fractionated using size-exclusion and hydrophobic-interaction chromatography on Sephadex G-50. The fractions were characterized by ultraviolet-visible, infrared and 13C-nuclear magnetic spectroscopies and analyzed for elemental, functional-group, carbohydrate and amino acid compositions. More AHS adsorbed onto DEAE-C than onto XAD-2 (94 and 74%, respectively). However, only 76% of the AHS adsorbed onto DEAE-C was recovered using 0.1 M NaOH, whereas 98% of the AHS adsorbed onto XAD was released by consecutive elution with 1 M NH4OH (91%) and methanol (7%). Four main fractions of different composition were obtained from each of the alkali-desorbed AHS samples by Sephadex-gel chromatography. General agreement was found in relative amounts, spectroscopic characteristics and composition of corresponding fractions of both isolates except nitrogen content, which was significantly higher in AHS isolated with XAD, apparently due to the reaction of AHS with NH4OH used for the desorption from the resin.Aquatic humic substances (AHS) were isolated from peatbog water by adsorption (1) on diethylaminoethyl cellulose (DEAE-C) and (2) on Amberlite XAD-2 (XAD) to compare yields of the methods and the composition of the isolated AHS. To provide a detailed comparison, the isolates were fractionated using size-exclusion and hydrophobic-interaction chromatography on Sephadex G-50. The fractions were characterized by ultraviolet-visible, infrared and 13C-nuclear magnetic spectroscopies and analyzed for elemental, functional-group, carbohydrate and amino acid compositions. More AHS adsorbed onto DEAE-C than onto XAD-2 (94 and 74%, respectively). However, only 76% of the AHS adsorbed onto DEAE-C was recovered

  20. Separation and purification of neohesperidin from the albedo of Citrus reticulata cv. Suavissima by combination of macroporous resin and high-speed counter-current chromatography.

    Science.gov (United States)

    Zhang, Jiukai; Zhu, Xiaoyan; Luo, Fenglei; Sun, Chongde; Huang, Jianzhen; Li, Xian; Chen, Kunsong

    2012-01-01

    In this article, a simple and efficient protocol for rapid preparation and separation of neohesperidin from the albedo of Citrus reticulata cv. Suavissima was established by the combination of macroporous resin column chromatography and high-speed counter-current chromatography (HSCCC). Six types of resin were investigated by adsorption and desorption tests, and D101 macroporous resin was selected for the first cleaning-up procedure, in which 55% aqueous ethanol was used to elute neohesperidin. After treatment with D101 resin, the neohesperidin purity increased 11.83-fold from 4.92% in the crude extract to 58.22% in the resin-refined sample, with a recovery of 68.97%. The resin-refined sample was directly subjected to HSCCC purification with a two-phase solvent system composed of ethyl acetate-n-butanol-water (4:1:5, v/v), and 23.6 mg neohesperidin with 97.47% purity was obtained from 60 mg sample in only one run. The recovery of neohesperidin in HSCCC separation procedure was 65.85%. The chemical structure of the purified neohesperidin was identified by both HPLC and LC-MS. The established purification process will be helpful for further characterization and utilization of Citrus neohesperidin.

  1. Analysis of Flavonoids in Lotus (Nelumbo nucifera) Leaves and Their Antioxidant Activity Using Macroporous Resin Chromatography Coupled with LC-MS/MS and Antioxidant Biochemical Assays.

    Science.gov (United States)

    Zhu, Ming-Zhi; Wu, Wei; Jiao, Li-Li; Yang, Ping-Fang; Guo, Ming-Quan

    2015-06-08

    Lotus (Nelumbo nucifera) leaves, a traditional Chinese medicinal herb, are rich in flavonoids. In an effort to thoroughly analyze their flavonoid components, macroporous resin chromatography coupled with HPLC-MS/MS was employed to simultaneously enrich and identify flavonoids from lotus leaves. Flavonoids extracted from lotus leaves were selectively enriched in the macroporous resin column, eluted subsequently as fraction II, and successively subjected to analysis with the HPLC-MS/MS and bioactivity assays. Altogether, fourteen flavonoids were identified, four of which were identified from lotus leaves for the first time, including quercetin 3-O-rhamnopyranosyl-(1→2)-glucopyranoside, quercetin 3-O-arabinoside, diosmetin 7-O-hexose, and isorhamnetin 3-O-arabino- pyranosyl-(1→2)-glucopyranoside. Further bioactivity assays revealed that these flavonoids from lotus leaves possess strong antioxidant activity, and demonstrate very good potential to be explored as food supplements or even pharmaceutical products to improve human health.

  2. Analysis of Flavonoids in Lotus (Nelumbo nucifera Leaves and Their Antioxidant Activity Using Macroporous Resin Chromatography Coupled with LC-MS/MS and Antioxidant Biochemical Assays

    Directory of Open Access Journals (Sweden)

    Ming-Zhi Zhu

    2015-06-01

    Full Text Available Lotus (Nelumbo nucifera leaves, a traditional Chinese medicinal herb, are rich in flavonoids. In an effort to thoroughly analyze their flavonoid components, macroporous resin chromatography coupled with HPLC-MS/MS was employed to simultaneously enrich and identify flavonoids from lotus leaves. Flavonoids extracted from lotus leaves were selectively enriched in the macroporous resin column, eluted subsequently as fraction II, and successively subjected to analysis with the HPLC-MS/MS and bioactivity assays. Altogether, fourteen flavonoids were identified, four of which were identified from lotus leaves for the first time, including quercetin 3-O-rhamnopyranosyl-(1→2-glucopyranoside, quercetin 3-O-arabinoside, diosmetin 7-O-hexose, and isorhamnetin 3-O-arabino- pyranosyl-(1→2-glucopyranoside. Further bioactivity assays revealed that these flavonoids from lotus leaves possess strong antioxidant activity, and demonstrate very good potential to be explored as food supplements or even pharmaceutical products to improve human health.

  3. Two solid-phase recycling method for basic ionic liquid [C4mim]Ac by macroporous resin and ion exchange resin from Schisandra chinensis fruits extract.

    Science.gov (United States)

    Ma, Chun-hui; Zu, Yuan-gang; Yang, Lei; Li, Jian

    2015-01-22

    In this study, two solid-phase recycling method for basic ionic liquid (IL) 1-butyl-3-methylimidazolium acetate ([C4mim]Ac) were studied through a digestion extraction system of extracting biphenyl cyclooctene lignans from Schisandra chinensis. The RP-HPLC detection method for [C4mim]Ac was established in order to investigate the recovery efficiency of IL. The recycling method of [C4mim]Ac is divided into two steps, the first step was the separation of lignans from the IL solution containing HPD 5000 macroporous resin, the recovery efficiency and purity of [C4mim]Ac achieved were 97.8% and 67.7%, respectively. This method cannot only separate the lignans from [C4mim]Ac solution, also improve the purity of lignans, the absorption rate of lignans in [C4mim]Ac solution was found to be higher (69.2%) than that in ethanol solution (57.7%). The second step was the purification of [C4mim]Ac by the SK1B strong acid ion exchange resin, an [C4mim]Ac recovery efficiency of 55.9% and the purity higher than 90% were achieved. Additionally, [C4mim]Ac as solvent extraction of lignans from S. chinensis was optimized, the hydrolysis temperature was 90°C and the hydrolysis time was 2h.

  4. Enhanced Production of Botrallin and TMC-264 with in Situ Macroporous Resin Adsorption in Mycelial Liquid Culture of the Endophytic Fungus Hyalodendriella sp. Ponipodef12

    Directory of Open Access Journals (Sweden)

    Haiyu Luo

    2014-09-01

    Full Text Available Hyalodendriella sp. Ponipodef12, an endophytic fungus from the hybrid “Neva” of Populus deltoides × P. nigra, is a high producer of the bioactive dibenzo-α-pyrones botrallin and TMC-264. However, both the botrallin and TMC-264 produced by Hyalodendriella sp. Ponipodef12 were retained as both intracellular and extracellular products. The aim of this study was to evaluate an in situ macroporous resin adsorption for enhancement of botrallin and TMC-264 production in mycelial liquid culture of Hyalodendriella sp. Ponipodef12. Production of botrallin and TMC-264 was most effectively enhanced by macroporous resin DM-301 among the thirteen nonionic macroporous resins tested. The highest botrallin yield (51.47 mg/L, which was 2.29-fold higher than the control at 22.49 mg/L was obtained by adding resin DM-301 at 4.38% (g/mL to the culture broth on day 24 and allowing a period of 4 days for adsorption. The highest TMC-264 yield reached 47.74 mg/L, which was 11.76-fold higher than that of the control (4.06 mg/L, and was achieved by adding DM-301 resin at 4.38% (w/v in the culture broth on day 24 and allowing a period of 6 days for adsorption. The results show that in situ resin adsorption is an effective strategy for enhancing production of botrallin and TMC-264, and also for facilitating their recovery from mycelial liquid culture of Hyalodendriella sp. Ponipodef12.

  5. ADSORPTION OF TANNIN ACID ONTO AN AMINATED MACROPOROUS RESIN FROM AQUEOUS SOLUTIONS

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A macroporous polymeric adsorbent NG-8 was synthesized with divinylbenzene using conventional suspension polymerization technique. Its aminated product NG-9 was prepared by introducing tertiary amino groups into NG-8 for removal of tannin acid from aqueous solutions. NG-9 could be used directly without a wetting process and had higher adsorption capacity than NG-8, which might be attributed to the enhanced adsorbent-adsorbate interaction due to the tertiary amino groups on the polymeric matrix. The Langmuir equation was successfully employed to describe the adsorption process. The adsorption enthalpy change further validated the uptake of tannin acid on NG-9 to be an enhanced physical adsorption because of the Lewis acid-base interaction. In addition, adsorption kinetic studies testified that the tertiary amino groups on the polymer matrix could decrease the adsorption rate maybe for the hindrance of the tertiary amino groups and water clusters built up.

  6. Preparation of Aminated Macroporous Polyvinyl Alcohol Resins and Evaluation for Bilirubin Adsorption

    Institute of Scientific and Technical Information of China (English)

    WANG Wei-chao; ZHANG Sheng-nan; HU Yue-han; XIE Hui; OU Lai-liang; YU Yao-ting; KONG De-ling; GU Han-qing

    2008-01-01

    In the present study we prepared macroporous polyvinyl alcohol beads. A series of bilirubin adsorbents were generated by immobilization of eight amine agents to the beads as ligands. The adsorption of bilirubin was evaluated by in vitro static and dynamic adsorption tests. The results show that these adsorbents have excellent adsorption efficiency and capacity. Among the eight ligands, trimethylamine (TMA), triethylamine (TEA) and 1,6- hexanediamine(HAD) showed the highest adsorption capacity. The adsorption equilibrium can be achieved in half an hour, and the adsorption percentage of bilirubin was up to 80%. Static electricity and hydrophobic interaction played the main role in bilirubin adsorption, and the adsorption was found to match the monolayer model. The excellent adsorption of these adsorbents indicates their potential in clinical treatment.

  7. Selective removal of nitrate by using a novel macroporous acrylic anion exchange resin

    Institute of Scientific and Technical Information of China (English)

    Hai Ou Song; Yang Zhou; Ai Min Li; Sandra Mueller

    2012-01-01

    An anion exchange resin NDP-5 has been prepared successfully and applied on the selective removal of nit-ate from SO42-/NO3- binary co-existence system.The composition and morphology of NDP-5 were confirmed by FT-IR and SEM.The NDP-5 resin exhibits the completely different behavior on the adsorption capacity,adsorption kinetic and the effect of the completing anion in the absence or presence of sulfate,compared to D213.And,the resultants of kinetic are well fitted by the pseudo-first-order and pseudo-second-order models.These results are very important to develop novel resins with great features.

  8. Kinetics of lipase recovery from the aqueous phase of biodiesel production by macroporous resin adsorption and reuse of the adsorbed lipase for biodiesel preparation.

    Science.gov (United States)

    Zhao, Xuebing; Fan, Ming; Zeng, Jing; Du, Wei; Liu, Canming; Liu, Dehua

    2013-04-10

    A commercial macroporous resin (D3520) was screened for lipase recovery by adsorption from the aqueous phase of biodiesel production. The influences of several factors on the adsorption kinetics were investigated. It was found that the kinetic behavior of lipase adsorption by macroporous resin could be well described by pseudo-first-order model. Temperature had no significant effects on lipase adsorption, while resin-to-protein ratio (R) significantly affected both rate constant (k1) and equilibrium adsorption capacity (Qe). No lipase was adsorbed when mixing (shaking) was not performed; however, protein recovery reached 98% after the adsorption was conducted at 200rpm for 5h in a shaker. The presence of methanol and glycerol showed significant negative influence on lipase adsorption kinetics. Particularly, increasing glycerol concentration could dramatically decrease k1 but not impact Qe. Biodiesel was found to dramatically decrease Qe even present at a concentration as low as 0.02%, while k1 was found to increase with biodiesel concentration. The adsorbed lipase showed a relatively stable catalytic activity in tert-butanol system, but poor stability in solvent-free system when used for biodiesel preparation. Oil and biodiesel were also found to adsorb onto resin during transesterification in solvent-free system. Therefore, the resin had to be washed by anhydrous methanol before re-used for lipase recovery.

  9. Adsorption characteristics of rebaudioside A and stevioside on cross-linked poly(styrene-co-divinylbenzene) macroporous resins functionalized with chloromethyl, amino and phenylboronic acid groups.

    Science.gov (United States)

    Ye, Fayin; Yang, Ruijin; Hua, Xiao; Zhao, Guohua

    2014-09-15

    The adsorptive separation of each steviol glycoside from aqueous solutions by polymeric adsorbents has attracted a lot of interest in recent years. The adsorption properties of chloromethylated cross-linked poly(styrene-co-divinylbenzene) macroporous resins, functionalised with chloromethyl, amino and phenylboronic acid groups, towards rebaudioside A and stevioside were studied. The results revealed that the resins with amino and phenylboronic acid groups preferred to adsorb stevioside rather than rebaudioside A, and their adsorption kinetics fitted a pseudo-second-order model. Isothermal equilibrium curves of rebaudioside A and stevioside showed a good fitness with the Langmuir and Freundlich models. The adsorption of rebaudioside A and stevioside onto resins was a spontaneous and exothermic process as indicated by the negative values in free energy and enthalpy. Results from the resin-packed column demonstrated that an effluent rich in rebaudioside A (purity 98%) was obtained prior to the breakthrough point of stevioside.

  10. [Effects and mechanism on removing organics and reduction of membrane fouling using granular macro-porous anion exchange resin in drinking water treatment].

    Science.gov (United States)

    He, Huan; Dong, Bing-Zhi; Xu, Guang-Hong; Yan, Zhao-Hui

    2014-05-01

    A granular macro-porous anion exchange resin combined with coagulation was used as pretreatment of microfiltration membrane, and their effects and mechanism on removing organics and reduction of membrane fouling were evaluated. The results showed that resin could be effective in removing organics with medium and small molecular weight ( Mr) but ineffective in removing organics with large Mr, while couagulation could significantly remove organics with large Mr, with a limited removal for organics with medium and small Mr. Using resin alone as pretreatment could be effective in removal of organics but limited in reduction of membrane fouling. With combination of coagulation and resin as pretreatment of microfiltration, not only organics could be removed effectively, but also membrane fouling could be reduced.

  11. Adsorption thermodynamics of macroporous resin adsorbing paeoniflorin%大孔树脂吸附芍药苷的吸附热力学研究

    Institute of Scientific and Technical Information of China (English)

    王玥; 杜守颖; 徐冰

    2011-01-01

    目的 选择7种不同极性的大孔树脂,以芍药苷为指标优选最佳的树脂富集、纯化牡丹皮药材中的有效成分,并研究芍药苷在此树脂上吸附的热力学特性.方法 采用静态吸附法考察了不同型号大孔树脂对芍药苷的吸附和解吸性能,以优选的树脂对芍药苷的吸附热力学参数为依据,利用热力学函数关系计算出了吸附焓、吸附自由能和吸附熵等,从物理化学的角度探讨了树脂的吸附机理.结果 HPD200A型大孔树脂对牡丹皮中的芍药苷有良好的吸附和解吸性能,优于其他树脂.该树脂对芍药苷的吸附平衡数据符合Freundlich吸附等温方程,平衡吸附系数随温度的升高而增大且吸附焓大于零,确定该吸附属于吸热过程;特征常数大于1且吸附自由能小于零表明该吸附属于自发过程;吸附焓小于40,显示发生了一种物理吸附并伴有氢键吸附的过程.结论 热力学参数显示,温度升高有利于该树脂吸附的进行,在实际生产中,可将提取液趁热上大孔树脂纯化,既节省冷却的步骤,又增大了吸附量.%Objective To select 7 types of macroporous resins with different polarities, optimize the best one taken paeoniflorin as index for enriching and purifying the active principles of Mudanpi ( Cortex Moulan Radicis) , and study the characteristics of adsorption thermodynamics. Methods The adsorption and desorption capabilityies of different types of macroporous resins to paeoniflorin were investigated by using static adsorption method. Taking adsorption thermodynamic parameters of optimized resin to paeoniflorin as a base, the adsorption enthalpy, adsorption free energy and adsorption entropy were calculated by using functional relation of thermodynamics. The adsorption mechanism of macroporous resin was studied from the aspect of chemicophysics. Results The type of HPD200A macroporous resin had good capabilities of adsorption and desorption for paeoniflorin

  12. Preparative separation and purification of rebaudioside a from steviol glycosides using mixed-mode macroporous adsorption resins.

    Science.gov (United States)

    Liu, Yongfeng; Di, Duolong; Bai, Qingqing; Li, Jintian; Chen, Zhenbin; Lou, Song; Ye, Helin

    2011-09-14

    Preparative separation and purification of rebaudioside A from steviol glycosides using mixed-mode macroporous adsorption resins (MARs) were systematically investigated. Mixed-mode MARs were prepared by a physical blending method. By evaluation of the adsorption/desorption ratio and adsorption/desorption capacity of mixed-mode MARs with different proportions toward RA and ST, the mixed-mode MAR 18 was chosen as the optimum strategy. On the basis of the static tests, it was found that the experimental data fitted best to the pseudosecond-order kinetics and Temkin-Pyzhev isotherm. Furthermore, the dynamic adsorption/desorption experiments were performed on the mini column packed with mixed-mode MAR 18. After one run treatment, the purity of rebaudioside A in purified product increased from 40.77 to 60.53%, with a yield rate of 38.73% (W/W), and that in residual product decreased from 40.77 to 36.17%, with a recovery yield of 57.61% (W/W). The total recovery yield reached 96.34% (W/W). The results showed that this method could be utilized in large-scale production of rebaudioside A from steviol glycosides in industry.

  13. Optimization of polyphenol removal from kiwifruit juice using a macroporous resin.

    Science.gov (United States)

    Gao, Zhenpeng; Yu, Zhifang; Yue, Tianli; Quek, Siew Young

    2017-06-01

    The separation of polyphenols from kiwifruit juice is essential for enhancing sensory properties and prevent the browning reaction in juice during processing and storage. The present study investigated the dynamic adsorption and desorption of polyphenols in kiwifruit juice using AB-8 resin. The model obtained could be successfully applied to predict the experimental results of dynamic adsorption capacity (DAC) and dynamic desorption quantity (DDQ). The results showed that dynamic adsorption of polyphenols could be optimised in a juice concentration of 19 °Brix, with a feed flow-rate of 1.3 mL min(-1) and a feed volume of 7 bed volume (BV). The optimum conditions for dynamic desorption of polyphenols from the AB-8 resin were an ethanol concentration of 43% (v/v), an elute flow-rate of 2.2 mL min(-1) and an elute volume of 3 BV. The optimized DAC value was 3.16 g of polyphenols kg(-1) resin, whereas that for DDQ was 917.5 g kg(-1) , with both values being consistent with the predicted values generated by the regression models. The major polyphenols in the dynamic desorption solution consisted of seven compositions. The present study could be scaled-up using a continuous column system for industrial application, thus contributing to the improved flavor and color of kiwifruit juice. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  14. Highly specific separation for antitumor Spiropreussione A from endophytic fungal [Preussia sp.] fermentation broth by one-step macroporous resins AB-8 treatment.

    Science.gov (United States)

    Li, Bing; Wang, Chunlan; Chen, Xiaomei; Lyu, Jing; Guo, Shunxing

    2013-11-01

    It is attractive to pharmaceutical works to seek useful material from endophytic fungi. Spiropreussione A (SA) which is isolated from endophytic fungus Preussia sp. is a novel anti-tumor product. Since previous preparation method cannot provide enough SA, and considering the large volume of broth and low concentration of the target product, macroporous resins were introduced to separate SA in our study. Four kinds of macroporous resins ADS-8, H103, X-5 and AB-8 were applied for separating SA, and AB-8 was selected as the optimal resin according to its performances through static and dynamic measurements. HPLC was used to analyze SA in all samples. Under optimal conditions, the specific SA adsorption capacity of AB-8 resin was 15.23mg/g, and the purity increased by 2.5-fold from 35.0% in broth to 90.0% in eluent with 70.0% recovery yield by a one-step treatment. Conclusively, our study achieved the goal of separating and purifying SA in high efficiency, and offered references for further fermentation works. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Enrichment and Purification of Syringin, Eleutheroside E and Isofraxidin from Acanthopanax senticosus by Macroporous Resin

    Directory of Open Access Journals (Sweden)

    Yuangang Zu

    2012-07-01

    Full Text Available In order to screen a suitable resin for the preparative simultaneous separation and purification of syringin, eleutheroside E and isofraxidin from Acanthopanax senticosus, the adsorption and desorption properties of 17 widely used commercial macroporous resins were evaluated. According to our results, HPD100C, which adsorbs by the molecular tiers model, was the best macroporous resin, offering higher adsorption and desorption capacities and higher adsorption speed for syringin, eleutheroside E and isofraxidin than other resins. Dynamic adsorption and desorption tests were carried out to optimize the process parameters. The optimal conditions were as follows: for adsorption, processing volume: 24 BV, flow rate: 2 BV/h; for desorption, ethanol–water solution: 60:40 (v/v, eluent volume: 4 BV, flow rate: 3 BV/h. Under the above conditions, the contents of syringin, eleutheroside E and isofraxidin increased 174-fold, 20-fold and 5-fold and their recoveries were 80.93%, 93.97% and 93.79%, respectively.

  16. Esterification of Palmitic Acid with Methanol in the Presence of Macroporous Ion Exchange Resin as Catalyst

    Directory of Open Access Journals (Sweden)

    Amelia Qarina Yaakob and Subhash Bhatia

    2012-10-01

    Full Text Available The esterification of palmitic acid with methanol was studied in a batch reactor using macro porous ion exchange resin Amberlyst 15 as a catalyst. Methyl palmitate was produced from the reaction between palmitic acid and methanol in the presence of catalyst. The effects of processing parameters, molar ratio of alcohol to acid M, (4-10, catalyst loading (0-10 g cat/liter, water inhibition (0-2 mol/liter, agitator speed (200-800 rpm and reaction temperature (343-373K were studied. The experimental kinetic data were correlated using homogenous as well as heterogeneous models (based on single as well as dual site mechanisms. The activation energy of the reaction was 11.552 kJ/mol for forward reaction whilst 5.464 kJ/mol for backward reaction. The experimental data fitted well with the simulated data obtained from the kinetic models. Keywords: Palmitic Acid, Methanol, Esterification, Ion Exchange Resin, Kinetics.

  17. 大孔吸附树脂对辣椒素类似物的富集%Enrichment of capsaicin analogues by macroporous adsorption resin

    Institute of Scientific and Technical Information of China (English)

    金红星; 田方; 成文玉

    2009-01-01

    为纯化发酵产物,用大孔吸附树脂对辣椒素类似物进行富集.通过静态吸附解吸附试验,筛选一种性能较好的树脂.进一步研究该树脂对辣椒素类似物的动态吸附与解吸性能,并确定其最优条件.富集后溶液中辣椒素类似物的含量提高约1.8倍.%To purify the fermentation product the capsaicin analogues were enriched with macroporous adsorption resin.A macroporous adsorption resin was selected as the medium for the purification of capsaicin analogues after comparing static adsorption and elution performances.Furthermore the optimal concentrations were determined after the investigation of dynamic adsorption and elution behavior of this resin.The content of capsaicin analogues in solution was enriched about 1.8 times than before.

  18. Purification of Houttuynia cordata Thunb. Essential Oil Using Macroporous Resin Followed by Microemulsion Encapsulation to Improve Its Safety and Antiviral Activity.

    Science.gov (United States)

    Pang, Jianmei; Dong, Wujun; Li, Yuhuan; Xia, Xuejun; Liu, Zhihua; Hao, Huazhen; Jiang, Lingmin; Liu, Yuling

    2017-02-15

    Essential oil extracted from Houttuynia cordata Thunb. (H. cordata) is widely used in traditional Chinese medicine due to its excellent biological activities. However, impurities and deficient preparations of the essential oil limit its safety and effectiveness. Herein, we proposed a strategy to prepare H. cordata essential oil (HEO) safely and effectively by combining the solvent extraction and the macroporous resin purification flexibly, and then encapsulating it using microemulsion. The extraction and purification process were optimized by orthogonal experimental design and adsorption-desorption tests, respectively. The average houttuynin content in pure HEO was then validated at 44.3% ± 2.01%, which presented a great potential for industrial application. Subsequently, pure HEO-loaded microemulsion was prepared by high-pressure homogenization and was then fully characterized. Results showed that the pure HEO-loaded microemulsion was successfully prepared with an average particle size of 179.1 nm and a high encapsulation rate of 94.7%. Furthermore, safety evaluation tests and in vitro antiviral testing indicated that the safety and activity of HEO were significantly improved after purification using D101 resin and were further improved by microemulsion encapsulation. These results demonstrated that the purification of HEO by macroporous resin followed by microemulsion encapsulation would be a promising approach for industrial application of HEO for the antiviral therapies.

  19. Separation of vitexin-4″-O-glucoside and vitexin-2″-O-rhamnoside from hawthorn leaves extracts using macroporous resins.

    Science.gov (United States)

    Li, Hongjuan; Liu, Ying; Jin, Haizhu; Liu, Sujing; Fang, Shengtao; Wang, Chunhua; Xia, Chuanhai

    2015-12-15

    Vitexin-4″-O-glucoside and vitexin-2″-O-rhamnoside are the major flavonoids of hawthorn leaves. In this work, the adsorption and desorption characteristics of vitexin-4″-O-glucoside and vitexin-2″-O-rhamnoside on seven macroporous resins were evaluated. Among the tested resins, the HPD-400 resin showed the best adsorption and desorption capacities. Adsorption isotherms were constructed for the HPD-400 resin and well fitted to Langmuir and Freundlich models. Dynamic adsorption and desorption tests were performed on column packed with the HPD-400 resin to optimize the chromatographic parameters. After one run treatment with the HPD-400 resin, the contents of vitexin-4″-O-glucoside and vitexin-2″-O-rhamnoside in the product were increased 8.44-fold and 8.43-fold from 0.720% and 2.63% to 6.08% and 22.2% with recovery yields of 79.1% and 81.2%, respectively. These results show that the developed method is a promising basis for the large-scale purification of vitexin-4″-O-glucoside and vitexin-2″-O-rhamnoside from hawthorn leaves and other plant materials.

  20. Synthesis and Efficiency of a Spherical Macroporous Epoxy-dicyandiamide Chelate Resin for Preconcentrating and Separating Trace Au, Hg, Pd and Ru from Samples

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A novel spherical macroporous epoxy-dicyandiamide chelate resin was synthesized simply and rapidly from epoxy resin and used for the preconcentration and separation of trace amounts of Au( Ⅲ ), Hg (Ⅱ ), Pd ( Ⅳ ) and Ru ( Ⅲ ) ions from solution samples. The analyzed ions can be quantitatively concentrated by the resin at a flow rate of 2.0 mL/min at pH 4, and can also be desorbed with 15 mL of 4 mol/L HCl+0.3 g thiourea from the resin column with recoveries of 96.5%-99.0%. After the chelate resin was reused for 7 times, the recoveries of these ions were still over 92%, and 400-1 000 times of excess of Fe( Ⅲ ), Al( Ⅲ ), Ni( Ⅱ ), Mn( Ⅱ ), Cr ( Ⅲ ), Cu ( Ⅱ ), Cd ( Ⅱ ) and Pb( Ⅱ ) caused little interference with the determination of these ions by an inductively coupled plasma optical emission spectrometer (ICP-OES). The capacities of the resin for the analytes are in the range of 0.35~0.92 mmol/g. The RSDs of the proposed method are in the range of 1.1%~4.0% for each kind of the analyzed ions. The recoveries of a standard added in real solution samples are between 96.5 % and 98. 5 %, and the results for the analyzed ions in a powder sample are in good agreement with their reported values.

  1. Macropores and macropore transport

    DEFF Research Database (Denmark)

    Iversen, Bo Vangsø; Lamandé, Mathieu; Torp, Søren Bent

    2012-01-01

    a stronger relationship was found at saturation. Results of a test of the number of soil columns needed for a representative distribution of macropores for the measurement of saturated hydraulic conductivity indicated that approximately six soil columns were enough. Our work suggests that integrating......Preferential transport of water through soil macropores is a governing process in the facilitated transport of strongly sorbing compounds. The aim of this study was to investigate the relationships between macropore density and the hydraulic conductivity of the soil and to test the sampling...... representativeness of soil columns for the measurement of saturated hydraulic conductivity. Macropore density was determined in three horizons in four typical, Danish soil types (third year of pasture) and saturated hydraulic conductivity and near-saturated hydraulic conductivity were measured in the laboratory...

  2. Purification of Raspberry Flavonoids Using Macro-porous Resin%大孔树脂纯化覆盆子黄酮的研究

    Institute of Scientific and Technical Information of China (English)

    张家瑞

    2013-01-01

    本实验采用大孔树脂对覆盆子黄酮进行分离纯化,确定其分离纯化条件,树脂的筛选实验结果和静态吸附动态学研究表明:所选的7种大孔树脂,AB-8树脂属于快速吸附树脂,吸附率和解吸率都很高,是理想用于覆盆子黄酮分离纯化的树脂,AB-8树脂动态吸附、解吸实验表明:当上样流速0.2 mL/min,上样浓度1.2 mg/mL,pH=4.5,用2.0 mL/min 70%的乙醇做解吸剂进行解吸时,覆盆子黄酮纯度可达到 40.32%,纯度提高7.16倍.%Raspberry flavonoids were isolated and purified by macro-porous resin in this article. The results showed that AB-8 resin can rapidly adsorbe lavonoids with higher adsorption and desorption rates than other macro-porous resin. Therefore, AB-8 resin was chosen as the best resion to isolate and purify raspberry flavonoids. Dynamic adsorption and desorption experiments showed that, when the sample flow rate, sample concentration, pH, desorption regent, desoption regent concentration and elution rate were 0.2 mL/min, 1.2 mg/mL, 4.5, ethanol, 70% and 2.0 mL/min, respectively, the raspberry flavonoids purity can reach 40.32%.

  3. On-line coupling of macroporous resin column chromatography with direct analysis in real time mass spectrometry utilizing a surface flowing mode sample holder.

    Science.gov (United States)

    Zeng, Shanshan; Wang, Lu; Chen, Teng; Qu, Haibin

    2014-02-06

    A surface flowing mode sample holder was designed as an alternative sampling strategy for direct analysis in real time mass spectrometry (DART-MS). With the sample holder, the on-line coupling of macroporous resin column chromatography with DART-MS was explored and the new system was employed to monitor the column chromatography elution process of Panax notoginseng. The effluent from macroporous resin column was first diluted and mixed with a derivatization reagent on-line, and the mixture was then directly transferred into the ionization region of DART-MS by the sample holder. Notoginsenosides were methylated and ionized in a metastable helium gas stream, and was introduced into MS for detection. The on-line system showed reasonable repeatability with a relative standard deviation of 12.3% for the peak area. Three notoginsenosides, i.e. notoginsenoside R1, ginsenoside Rb1 and ginsenoside Rg1, were simultaneously determined during the eluting process. The alteration of the chemical composition in the effluent was accurately identified in 9 min, agreeing well with the off-line analysis. The presented technique is more convenient compared to the traditional UPLC method. These results suggest that the surface flowing mode DART-MS has a good potential for the on-line process monitoring in the pharmaceutical industry.

  4. A Continuous Procedure Based on Column Chromatography to Purify Anthocyanins from Schisandra chinensis by a Macroporous Resin plus Gel Filtration Chromatography.

    Science.gov (United States)

    Yue, Daran; Yang, Lei; Liu, Shouxin; Li, Jian; Li, Wei; Ma, Chunhui

    2016-02-06

    In our previous study, as natural food colorants and antioxidants, the color and content stabilities of Schisandra chinensis (S. chinensis) anthocyanins were investigated. In this work, the purification process parameters of S. chinensis anthocyanins using a macroporous resin and gel filtration chromatography were evaluated. The optimized parameters of static adsorption and desorption were as follows. The selected resin is HPD-300 (nonpolar copolymer styrene type resin), and the anthocyanins adsorption saturation capacity of HPD-300 resin was 0.475 mg/g dry resin. Adsorption time was 4 h, and 0.517 mg/mL of S. chinensis anthocyanins was adsorbed on the resin column with a flow rate of 39 mL/h (3 BV/h). After adsorption, the anthocyanins were completely desorpted with 2.5 BV of 90% (v/v) ethanol solution, and the desorption flow rate was 13 mL/h (1 BV/h). After purification by dynamic adsorption and desorption, the anthocyanins content in the effluent increased from 47.6 mg/g to 128.4 mg/g, the purity of anthocyanins increased six-fold from 5.08% to 30.43%, and the anthocyanins recovery was 96.5%. The major constituent of S. chinensis anthocyanins was isolated with Bio-Gel P2 gel filtration chromatography, and it was detected by liquid chromatography electrospray ionisation tandem mass spectrometry (LC-ESI-MS) as cyanidin-3-O-xylosylrutinoside. Moreover, the antioxidant activities of S. chinensis anthocyanins were investigated. After purification using the HPD-300 resin, the antioxidant activities of anthocyanins were increased 1.2-fold (FRAP) and 1.7-fold (ABTS).

  5. A Continuous Procedure Based on Column Chromatography to Purify Anthocyanins from Schisandra chinensis by a Macroporous Resin plus Gel Filtration Chromatography

    Directory of Open Access Journals (Sweden)

    Daran Yue

    2016-02-01

    Full Text Available In our previous study, as natural food colorants and antioxidants, the color and content stabilities of Schisandra chinensis (S. chinensis anthocyanins were investigated. In this work, the purification process parameters of S. chinensis anthocyanins using a macroporous resin and gel filtration chromatography were evaluated. The optimized parameters of static adsorption and desorption were as follows. The selected resin is HPD-300 (nonpolar copolymer styrene type resin, and the anthocyanins adsorption saturation capacity of HPD-300 resin was 0.475 mg/g dry resin. Adsorption time was 4 h, and 0.517 mg/mL of S. chinensis anthocyanins was adsorbed on the resin column with a flow rate of 39 mL/h (3 BV/h. After adsorption, the anthocyanins were completely desorpted with 2.5 BV of 90% (v/v ethanol solution, and the desorption flow rate was 13 mL/h (1 BV/h. After purification by dynamic adsorption and desorption, the anthocyanins content in the effluent increased from 47.6 mg/g to 128.4 mg/g, the purity of anthocyanins increased six-fold from 5.08% to 30.43%, and the anthocyanins recovery was 96.5%. The major constituent of S. chinensis anthocyanins was isolated with Bio-Gel P2 gel filtration chromatography, and it was detected by liquid chromatography electrospray ionisation tandem mass spectrometry (LC-ESI-MS as cyanidin-3-O-xylosylrutinoside. Moreover, the antioxidant activities of S. chinensis anthocyanins were investigated. After purification using the HPD-300 resin, the antioxidant activities of anthocyanins were increased 1.2-fold (FRAP and 1.7-fold (ABTS.

  6. Adsorption Mechanism of Macroporous Adsorption Resins%大孔吸附树脂的吸附机理

    Institute of Scientific and Technical Information of China (English)

    娄嵩; 刘永峰; 白清清; 邸多隆

    2012-01-01

    大孔吸附树脂(macroprous adsorption resin,MAR)是近几十年发展起来的一种具有多孔立体结构、人工合成的有机高分子聚合物。由于其特殊的理化性质和吸附性能,已被广泛应用于化学、医药、环保和食品等领域。本文介绍了近年来国内外对大孔吸附树脂在吸附机理研究方面的进展,重点介绍了不同温度条件下大孔吸附树脂对靶标分子的吸附热力学行为模式,靶标分子在大孔吸附树脂表面及孔内的吸附扩散行为模式。此外,大孔吸附树脂性能参数和靶标分子结构参数之间构效关系也对其吸附选择性规律具有重要的影响。因此,大孔吸附树脂与底物间构效关系的匹配程度及其对选择性的影响是大孔吸附树脂分离理论研究的核心。本文最后介绍了可以准确客观描述吸附过程并具有一定使用范围的大孔吸附树脂吸附模型的建立和评价。%Macroporous adsorption resins (MARs) , which are synthetic porous crosslinked polymer beads, have been developed into a kind of novel functional materials since 1950' They have widely been used in the fields such as pharmaceutical, chemical, food industries, and wastewater treatment. Besides the traditional research on applications of the commercial MARs in the enrichment process of target compound, some theoretical researches on the adsorption features of MARs are also introduced in this article, including adsorption isotherms, kinetics, driving forces, and interaction models. First, the adsorption isotherm patterns of target compound on MARs are discussed. Second, the diffusion patterns of targets on the surface and internal MARs are illustrated. The relationship between properties of MARs and structures of target compound effects the law of adsorption selection,and the investigation of this relationship is the key problem of theoretical research on separation and adsorption. Moreover, the ultimate purpose of

  7. Separation of isorhamnetin 3-sulphate and astragalin from Flaveria bidentis (L.) Kuntze using macroporous resin and followed by high-speed countercurrent chromatography.

    Science.gov (United States)

    Shaheen, Nusrat; Yin, Li; Gu, Yanxiang; Rwigimba, Eric; Xie, Qianqian; Wei, Yun

    2015-06-01

    D4020 resin offered the best dynamic adsorption and desorption capacity for total flavonoids based on the research results from ten kinds of macroporous resin. A column packed with D4020 resin was used to optimize the separation of total flavonoids from Flaveria bidentis (L.) Kuntze extracts. The content of flavonoids in the product was increased from 4.3 to 30.1% with a recovery yield of 90%. After the treatment with gradient elution on D4020 resin, the contents of isorhamnetin 3-sulfate and astragalin were increased from 0.49 to 8.70% with a recovery yield of 74.1% and 1.16 to 30.8%, with a recovery yield of 92.2%, respectively. Further purification was carried out by one-run high-speed countercurrent chromatography yielding 4.5 mg of isorhamnetin 3-sulfate at a high purity of 96.48% and yielding 24.4 mg of astragalin at a high purity of over 98.46%.

  8. 大孔吸附树脂纯化鬼针草总黄酮的工艺优选%Optimization of Purification Technology for Total Flavonoids in Bidens bipinnata by Macroporous Adsorption Resin

    Institute of Scientific and Technical Information of China (English)

    瞿慧; 曹园; 方祝元; 刘志辉

    2013-01-01

    Objective To optimize purification technology of total flavonoids in Bidens bipinnata by macroporous resin. Method With adsorption rate and desorption rate of total flavonoids as indexes, adsorption property of six different kinds of macroporous resins for total flavonoids in B. bipinnata was compared by static adsorption and desorption experiments, in order to select optimum macroporous resin. Single factor test was used to investigate adsorption and elution conditions of macroporous resin. Result HPD400 macroporous resin presented the best effect of purification. Its optimum purification parameters were as followings:the sample concentration 0.5 g/L,pH 4,sample flow rate 2 BV/h,eluted with 9 BV 60%ethanol at 3 BV/h. After purification by macroporous resin, purity of total flavonoids in ethanol extract of B. bipinnata would be increased from 24.47%to 62.33%. Conclusion HPD400 macroporous resin was among the most suitable one for purification of total flavonoids in B. bipinnata. Optimized purification technology was stable and feasible.%目的:优选大孔树脂纯化鬼针草总黄酮的工艺条件。方法以鬼针草总黄酮的吸附率和洗脱率为指标,通过静态吸附试验比较不同种大孔树脂对鬼针草总黄酮的吸附能力,筛选出合适的大孔树脂型号;通过单因素试验优选鬼针草总黄酮的纯化工艺参数。结果 HPD400型大孔树脂纯化效果最好,其最佳工艺参数为药液中质量浓度0.5 mg/mL,pH=4.0,吸附速率2 BV/h,用9 BV 60%乙醇洗脱,洗脱速率3 BV/h,经大孔树脂纯化后鬼针草提取液中总黄酮纯度由原来的24.47%提高至58.41%。结论 HPD400型大孔树脂适用于鬼针草总黄酮的纯化,优选的纯化工艺稳定可行。

  9. Amberlite XAD-2 functionalized with 2-aminothiophenol as a new sorbent for on-line preconcentration of cadmium and copper.

    Science.gov (United States)

    Lemos, Valfredo Azevedo; Baliza, Patrícia Xavier

    2005-09-15

    A new functionalized resin has been applied in an on-line preconcentration system for copper and cadmium determination. Amberlite XAD-2 was functionalized by coupling it to 2-aminothiophenol (AT-XAD) by means of an NN spacer. This resin was packed in a minicolumn and used as sorbent in the on-line system. Metal ions were sorbed in the minicolumn, from which it could be eluted directly to the nebulizer-burner system of the flame atomic absorption spectrometer (FAAS). Elution of Cd(II) and Cu(II) from minicolumn can be made with 0.50moll(-1) HCl or HNO(3). The enrichment factors obtained were 28 (Cd) and 14 (Cu), for 60s preconcentration time, and 74 (Cd) and 35 (Cu), if used 180 s preconcentration time. The proposed procedure allowed the determination of cadmium and copper with detection limits of 0.14 and 0.54mugl(-1), respectively, when used preconcentration periods of 180s. The effects of foreign ions on the adsorption of these metal ions are reported. The validation of the procedure was carried out by analysis of certified reference material. This procedure was applied to cadmium and copper determination in natural, drink and tap water samples.

  10. Macroporous poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) resins-Versatile immobilization supports for biocatalysts

    NARCIS (Netherlands)

    Miletic, Nemanja; Vukovic, Zorica; Nastasovic, Aleksandra; Loos, Katja; Miletić, Nemanja; Vuković, Zorica; Nastasović, Aleksandra

    2009-01-01

    Crosslinked macroporous hydrophilic poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate)s [abbreviated poly(GMA-co-EGDMA)] with identical chemical structure (60% of glycidyl methacrylate) but with varied average pore sizes (from 30 to 560 nm), specific surface areas (from 13.2 to 106.0 m(2)

  11. Macroporous poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) resins-Versatile immobilization supports for biocatalysts

    NARCIS (Netherlands)

    Miletic, Nemanja; Vukovic, Zorica; Nastasovic, Aleksandra; Loos, Katja; Miletić, Nemanja; Vuković, Zorica; Nastasović, Aleksandra

    Crosslinked macroporous hydrophilic poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate)s [abbreviated poly(GMA-co-EGDMA)] with identical chemical structure (60% of glycidyl methacrylate) but with varied average pore sizes (from 30 to 560 nm), specific surface areas (from 13.2 to 106.0

  12. 大孔树脂分离纯化苦苣菜黄酮的工艺研究%Study on separation and purification of Sonchus oleraceus L total flavonoids by AB-8 macroporous resin with response surface analysis

    Institute of Scientific and Technical Information of China (English)

    安卓; 贾昌喜

    2012-01-01

    To study the purification conditions with macroporous resin in Sonchus culture. Using the static adsorption method for screening optimum macroporous resin to be purification of Sonchus oleraceus flavones, using dynamic adsorption method to study optimum macro-porous resin conditions of purification of Sonchus oleraceus flavonoid. Results the macroporous resin adsorption of AB-8 on Sonchus flavone was the best, the best purification conditions were; 3- 73% sample concentration, sample liquid rate of 3. 6 tnL / min, sample liquid pH was 5.18; by 78. 20% ethanol solution, with 120 mL(column volume) 2. 88 mL / min rate elution. Using macroporous adsorption resin AB8. under the optimum conditions, the adsorption rate is up to 84. 32% s desorption rate 91. 73%.%研究大孔树脂纯化苦苣菜黄酮的条件.利用静态吸附方法筛选纯化苦苣菜黄酮的最适大孔树脂,利用动态吸附方法研究最适大孔树脂纯化苦苣菜黄酮的条件.结果表明,大孔树脂AB-8对吸附苦苣菜黄酮的效果最好,最佳纯化条件:上样液浓度为3.73%,上样液速率为3.6 mL/min,上样液pH 5.18;用78.20%的乙醇溶液、以120 mL 2.88 mL/min的速率洗脱.利用大孔吸附树脂AB-8在上述最佳条件下,吸附率可达84.32%;解吸率91.73%.

  13. Preparative separation of polyphenols from water-soluble fraction of Chinese propolis using macroporous absorptive resin coupled with preparative high performance liquid chromatography.

    Science.gov (United States)

    Li, Aifeng; Xuan, Hongzhuan; Sun, Ailing; Liu, Renmin; Cui, Jichun

    2016-02-15

    In this study, a preparative separation method was developed for isolation of eleven polyphenols from water-soluble fraction of Chinese propolis using macroporous absorptive resin (MAR) coupled with preparative high performance liquid chromatography (PHPLC). Water-soluble fraction of Chinese propolis was first "prefractioned" using MAR, which yielded four subfractions. The four subfractions were then isolated by PHPLC with an isocratic elution of methanol-water. Finally, eleven polyphenols were purified from Chinese propolis including caffeic acid, ferulic acid, isoferulic acid, 3,4-dimethoxy cinnamic acid, pinobanksin, caffeic acid benzyl ester, caffeic acid phenethyl ester, apigenin, pinocembrin, chrysin and galangin. The purities of the compounds were determined by HPLC and the chemical structures were confirmed by UV and NMR analysis. The method developed was simple, effective, rapid, scalable and economical, and it was a promising basis for large-scale preparation of multiple components from natural products.

  14. Separation and purification of three stilbenes from the radix of Polygonum cillinerve (Nakai Ohwl by macroporous resin column chromatography combined with high-speed counter-current chromatography

    Directory of Open Access Journals (Sweden)

    Xiaofeng Chi

    2014-01-01

    Full Text Available An effective method for the rapid separation and purification of three stilbenes from the radix of Polygonum cillinerve (Nakai Ohwl by macroporous resin column chromatography combined with high-speed counter-current chromatography (HSCCC was successfully established. In the present study, a two-phase solvent system composed of chloroform-n-butanol-methanol-water (4:1:4:2, v/v/v/v was used for HSCCC separation. A one-step separation in 4 h from 150 mg of crude extract produced 26.3 mg of trans-resveratrol-3-O-glucoside, 42.0 mg of pieceid-2"-O-gallate, and 17.9 mg of trans-resveratrol with purities of 99.1%, 97.8%, and 99.4%, respectively, as determined by high-performance liquid chromatography (HPLC. The chemical structures of these compounds were identified by nuclear magnetic resonance (NMR spectroscopy.

  15. XDA-1 Macroporous Resin for Separation and Purification of Polyphenols Elaeagnus%XDA-1型大孔树脂对沙枣多酚分离纯化工艺研究

    Institute of Scientific and Technical Information of China (English)

    查培; 廉宜君; 杨金凤; 刘红

    2012-01-01

    通过动态吸附及解析试验,研究了XDA-1型大孔树脂对沙枣多酚的吸附及解析性能。试验结果表明,XDA-1型大孔树脂对沙枣的动态吸附率为73.42%,动态解析率为93.20%,是一种较好的分离沙枣多酚的树脂材料。%The dynamic adsorption and analysis of experiments, the XDA-1 macroporous resin adsorption of polyphenols angustifolia and parsing performance were studied. Experimental results showed that, XDA-1 macroporous resin adsorption rate of the dynamic angustifolia 73.42%, 93.20% rate of dynamic analysis was a better separation of polyphenols angustifolia resin material.

  16. 大孔吸附树脂纯化甘草提取物中甘草酸的研究%Macroporous Adsorption Resin Purification of Glycyrrhizic Acid in Glycyrrhiza Extract Research

    Institute of Scientific and Technical Information of China (English)

    丁利营; 李红艳

    2014-01-01

    Objective To study the best macroporous resin purification process for Glycyrrhizic acid from glycyrrhiza glabra. Methods Glycyrrhizic acid content in macroporous resin purification as the investigation index, select the best macroporous resin from 24 kinds of macroporous resins for Glycyrrhizic acid from liquorice extract, and determine the optimum process conditions for this purification. Results AB-8 macroporous adsorption resin has the best purification ef ect for glycyrrhizic acid, and the optimum process conditions:liquorice extract concentration is 0.11mg/ml, diameter/height is 1:8, liquorice extract volume is 2 times of the resin, the rates of using liquorice extract and elution both are 2bv/h, remove impurities with 30%&50%ETOH, and accumulate glycyrrhizic acid by using 80%ETOH. After purification, the purity of the product is 60.74%, the yield rate is 3.29%, the transfer rate is 76.72%. Conclusion Using AB-8 macroporous adsorption resin can purify glycyrrhizic acid very wel .%目的研究光果甘草中甘草酸的最佳大孔树脂纯化工艺。方法以大孔吸附树脂纯化物中甘草酸的含量为考察指标,从24种大孔吸附树脂中筛选出纯化甘草粗提物中甘草酸的最佳大孔吸附树脂,并确定纯化甘草酸的最佳工艺条件。结果 AB-8大孔吸附树脂纯化甘草酸效果最佳,最佳工艺条件院上柱液浓度为0.11mg/mL,径高比为1:8,上样体积为所用树脂2BV,上样速度与洗脱速度均为2BV/h,用30%、50%的乙醇除杂,用80%乙醇富集甘草酸。纯化后产品纯度为60.74%,收率为3.29%,转移率为76.33%。结论采用AB-8大孔吸附树脂可较好地纯化甘草酸。

  17. Solid phase extraction of Cd, Cu, and Ni from leafy vegetables and plant leaves using amberlite XAD-2 functionalized with 2-hydroxy-acetophenone-thiosemicarbazone (HAPTSC) and determination by inductively coupled plasma atomic emission spectroscopy.

    Science.gov (United States)

    Rao, G Purna Chandra; Seshaiah, Kalluru; Rao, Yerra Koteswara; Wang, M C

    2006-04-19

    A method for solid phase extraction of trace metals, namely, Cd, Cu, and Ni, using Amberlite XAD-2 functionalized with a new chelating ligand, 2-hydroxy-acetophenone-3-thiosemicarbazone (Amberlite XAD-2-HAPTSC), has been developed. The optimum experimental conditions for the quantitative sorption of three metals, pH, effect of flow rate, concentration of eluent, sorption capacity, kinetics of sorption, and the effect of diverse ions on the sorption of analytes have been investigated. The chelating resin could be reused for more than 20 cycles of sorption-desorption without any significant change (<1.5%). The accuracy of the proposed procedure was evaluated by standard reference materials. The proposed method was applied for the determination of trace metal ions in leafy vegetable samples collected from different sources and medicinal plant leaves.

  18. Simultaneously preparative purification of Huperzine A and Huperzine B from Huperzia serrata by macroporous resin and preparative high performance liquid chromatography.

    Science.gov (United States)

    Zhang, Hongchao; Liang, Hao; Kuang, Pengqun; Yuan, Qipeng; Wang, Yan

    2012-09-01

    Huperzine A (HupA) and Huperzine B (HupB) are natural alkaloids existed in Lycopodium plants. They both have potential clinical application for treating Alzheimer's Disease (AD). For the purpose of better utilizing the limited plant resources, a quick and low cost method to separate and purify HupA and HupB from Huperzia serrata (Thunb. ex Murray) was established in this paper. Low polarity macroporous resin SP850 was selected from eight kinds of resins during initial purification. Trifluoroacetic acid (TFA) was proved to be the best acid modifier reagent among all acids used in our experiment for improving separation. HupA and HupB were baseline separated on a C18 column by preparative high performance liquid chromatography (Preparative HPLC), the optimal gradient mobile phase system contained methanol increasing from 15% (v/v) to 35% (v/v) and 0.1% (v/v) TFA within the water. The purity of HupA and HupB obtained was 99.1% and 98.6%, respectively, and the total recovery for them was 83.0% and 81.8%, respectively.

  19. Preliminary extraction of tannins by 1-butyl-3-methylimidazole bromide and its subsequent removal from Galla chinensis extract using macroporous resins.

    Science.gov (United States)

    Lu, Chunxia; Luo, Xiaoling; Lu, Liliang; Li, Hongmin; Chen, Xia; Ji, Yong

    2013-03-01

    In recent years, ionic liquids have become increasingly attractive as 'green solvents' used in the extraction of bioactive compounds from natural plant. However, the separation of ionic liquid from the target compounds was difficult, due to their low vapour pressure and high stabilities. In our study, ionic liquid-based ultrasonic and microwave-assisted extraction was used to obtain the crude tannins, then the macroporous resin adsorption technology was further employed to purify the tannins and remove the ionic liquid from crude extract. The results showed that XDA-6 had higher separation efficiency than other tested resins, and the equilibrium experimental data were well fitted to Langmuir isotherms. Dynamic adsorption and desorption were performed on XDA-6 packed in glass columns to optimise the separation process. The optimum conditions as follows: the ratio of column height to diameter bed was 1:8, flow rate 1 BV/h (bed volume per hour), 85% ethanol was used as eluant while the elution volume was 2 BV. Under the optimised conditions, the adsorption and desoption rate of tannins in XDA-6 were 94.81 and 91.63%, respectively. The content of tannins was increased from 70.24% in Galla chinensis extract to 85.12% with a recovery of 99.06%. The result of ultra-performance liquid chromatography (UPLC)-MS/MS analysis showed that [bmim]Br could be removed from extract.

  20. Efficient extraction and preparative separation of four main isoflavonoids from Dalbergia odorifera T. Chen leaves by deep eutectic solvents-based negative pressure cavitation extraction followed by macroporous resin column chromatography.

    Science.gov (United States)

    Li, Lu; Liu, Ju-Zhao; Luo, Meng; Wang, Wei; Huang, Yu-Yan; Efferth, Thomas; Wang, Hui-Mei; Fu, Yu-Jie

    2016-10-15

    In this study, green and efficient deep eutectic solvent-based negative pressure cavitation-assisted extraction (DES-NPCE) followed by macroporous resin column chromatography was developed to extract and separate four main isoflavonoids, i.e. prunetin, tectorigenin, genistein and biochanin A from Dalbergia odorifera T. Chen leaves. The extraction procedure was optimized systematically by single-factor experiments and a Box-Behnken experimental design combined with response surface methodology. The maximum extraction yields of prunetin, tectorigenin, genistein and biochanin A reached 1.204, 1.057, 0.911 and 2.448mg/g dry weight, respectively. Moreover, the direct enrichment and separation of four isoflavonoids in DES extraction solution was successfully achieved by macroporous resin AB-8 with recovery yields of more than 80%. The present study provides a convenient and efficient method for the green extraction and preparative separation of active compounds from plants.

  1. Comparison of extracts and toxicities of organic compounds in drinking water concentrated by single and composite XAD resins.

    Science.gov (United States)

    Zhou, Xue; Xiang, Lunhui; Wu, Fenghong; Peng, Xiaoling; Xie, Hong; Wang, Jiachun; Yang, Kedi; Lu, Wenqing; Wu, Zhigang

    2013-12-01

    We compared extracts and toxicities of organic compounds (OCs) in drinking water concentrated by composite XAD-2/8 resin (mixed with an equal volume of XAD-2 and XAD-8 resins) with those extracted by single XAD-2 (non-polar) and XAD-8 (polar) resins. Drinking water was processed from raw water of the Han River and the Yangtze River in Wuhan section, China. The extraction efficiency of all resins was controlled at 30%. The types of extracted OCs were detected by gas chromatography-mass spectrometry, and the cytotoxicity and genotoxicity were assessed by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and comet assays, respectively, in human hepatoma HepG2 cells. Our results showed that XAD-2/8 extracted a larger variety of OCs, compared with XAD-8 and XAD-2. The cytotoxicity and genotoxicity of extracted OCs were in the order of XAD-8> XAD-2/8> XAD-2 at almost all tested concentrations after 24 h treatment (P < 0.05). Our findings suggest that single XAD resin selectively extracts either polar or non-polar OCs, which would lead to over- or under-estimation of the toxicity of drinking water. Nevertheless, composite resin extracts both polar and non-polar OCs, and could be utilized as a useful extraction technique to evaluate the level and toxicity of OCs in drinking water.

  2. Macroporous Resin Adsorption for Purification of Flavonoids in Houttuynia cordata Thunb%大孔吸附树脂精制鱼腥草黄酮类化合物

    Institute of Scientific and Technical Information of China (English)

    张颖; 李淑芬; 吴希文; 赵星

    2007-01-01

    Flavonoids are one main kind of effective components in Houttuynia cordata Thunb.,which display a wide range of pharmacological activity. In this study supercritical fluid extraction (SFE) with carbon dioxide was first used as preparation step to remove the volatile components,which are also active components,from Houttuynia cordata Thunb. Then ultrasound-assisted extraction was used to obtain the crude flavonoids and the macroporous resin adsorption technology was further employed to purify the flavonoids. Nine kinds of macroporous resins with different properties were tested through static adsorption,and one macroporous resin labeled as D101 was selected. The effect of several factors,such as the ratio of column height to diameter,initial concentration and pH,on both flavonoids yield and content were explored by dynamic adsorption to obtain reasonable conditions of adsorption and desorption. The experimental results show that the content of flavonoids can be above 60% with flavonoids recovery of 93.3 % under the optimum conditions of purification. HPLC analysis of the final flavonoids product shows it contains quercitrin,hyperin,rutin and quercetin.

  3. Phenolic Profiling of Duchesnea indica Combining Macroporous Resin Chromatography (MRC with HPLC-ESI-MS/MS and ESI-IT-MS

    Directory of Open Access Journals (Sweden)

    Mingzhi Zhu

    2015-12-01

    Full Text Available Duchesnea indica (D. indica is an important traditional Chinese medicine, and has long been clinically used to treat cancer in Asian countries. It has been described previously as a rich source of phenolic compounds with a broad array of diversified structures, which are the major active ingredients. However, an accurate and complete phenolic profiling has not been determined yet. In the present work, the total phenolic compounds in crude extracts from D. indica were enriched and fractionated over a macroporous resin column, then identified by HPLC-ESI-MS/MS and ESI-IT-MS (ion trap MS. A total of 27 phenolic compounds were identified in D. indica, of which 21 compounds were identified for the first time. These 27 phenolic compounds encompassing four phenolic groups, including ellagitannins, ellagic acid and ellagic acid glycosides, hydroxybenzoic acid and hydroxycinnamic acid derivatives, and flavonols, were then successfully quantified using peak areas against those of the corresponding standards with good linearity (R2 > 0.998 in the range of the tested concentrations. As a result, the contents of individual phenolic compounds varied from 6.69 mg per 100 g dry weight (DW for ellagic acid to 71.36 mg per 100 g DW for brevifolin carboxylate. Not only did this study provide the first phenolic profiling of D. indica, but both the qualitative identification and the subsequent quantitative analysis of 27 phenolic compounds from D. indica should provide a good basis for future exploration of this valuable medicinal plant.

  4. Isolation and purification of six iridoid glycosides from gardenia jasminoides fruit by medium-pressure liquid chromatography combined with macroporous resin chromatography.

    Science.gov (United States)

    Wang, Yun; Liu, Hui; Shen, Lifeng; Yao, Lan; Ma, Yinlian; Yu, Dingrong; Chen, Jianhong; Li, Puling; Chen, Ying; Zhang, Cun

    2015-12-01

    Gardeniae fructus is one of the most frequently used herbs in traditional Chinese medicine. In the present study, a process for the enrichment of six iridoid glycosides from Gardeniae fructus was developed using medium-pressure liquid chromatography combined with macroporous resin and reversed-phase chromatography. The purities of different fractions from Gardeniae fructus were assessed using quantitative high-performance liquid chromatography. After fractionation using HPD-100 column chromatography, a 30% ethanol fraction was selected based on high-performance liquid chromatography and liquid chromatography with mass spectrometry qualitative analysis to separate and purify. Based on the orientation analysis results, six compounds-deacetyl asperulosidic acid methyl ester, gardenoside, ixoroside, scandoside methyl ester, genipin-1-O-β-d-gentiobioside, and geniposide-were successfully isolated and purified in three to four combined steps from Gardeniae fructus. The purities of these compounds were found by high-performance liquid chromatography analysis to be 97.9, 98.1, 95.5, 96.3, 97.1, and 98.7%, respectively. Moreover, their structures were elucidated by NMR spectroscopy and liquid chromatography with tandem mass spectrometry. The separation process was highly efficient, rapid, and accurate, making it a potential approach for the large-scale production of iridoids in the laboratory and providing several marker compounds for quality control. This procedure may be meaningful for the purification of other natural products used in traditional Chinese medicine.

  5. Development of a fluidized bed system for adsorption of phenol from aqueous solutions with commercial macroporous resins

    Directory of Open Access Journals (Sweden)

    R. A. Corrêa

    2007-03-01

    Full Text Available This work is related to removal of phenol from wastewaters by adsorption onto polymeric resins, a current alternative to activated carbon. A closed circuit, bench-scale liquid fluidized bed system was developed for this purpose. Phenol aqueous solutions with initial concentrations in the range of 0.084 to 0.451 kg/m³ were used to fluidize small permeable capsules of stainless steel screen containing a commercial resin at 308 K. Experiments were carried out using a fluidizing velocity 20% above that of the minimum fluidization of the capsules. Typically, 30 passages of the liquid volume circulating through the bed were required to reach a quasi-equilibrium concentration of phenol in the treated effluent. A simple batch adsorption model using the Freundlich isotherm successfully predicted final phenol concentrations. Suspended solids, often present in residual waters and a common cause of fixed bed clogging, were simulated with wood sawdust.

  6. 大孔树脂分离富集匙羹藤总皂苷研究%Enrichment of saponins of Gymnema sylvestre by macroporous resins

    Institute of Scientific and Technical Information of China (English)

    韦泽昭; 孙建华; 寥丹葵; 陈晓光; 韦藤幼; 邹昀; 童张法

    2011-01-01

    采用大孔树脂对匙羹藤总皂苷进行分离富集.考察了5种树脂对匙羹藤总皂苷的静态吸附效果并筛选出D101树脂用于分离富集匙羹藤总皂苷,通过动态吸附性能考察,确定了D101树脂固定床分离富集匙羹藤总皂苷的工艺条件,在ρ(总皂苷)=5 mg/mL,pH=6,料液以1.0 mL/min的流速通过D101树脂固定床进行吸附,分别用去离子水和ψ(乙醇)=10%溶液洗脱杂质后,再用ψ(乙醇)=75%溶液洗脱匙羹藤总皂苷.经过分离富集后,ω(总皂苷)由粗浸膏的25.33%提高到51.07%,总皂苷的回收率为83.26%.%Total saponins of Gymnema sylvestre were separated and enriched with macroporous resins. The adsorption capacity and adsorption ratio of five kinds of adsorption resins for total saponins in ex-traction of Gymnema sylvestre were investigated. The results of saturated static adsorption of different types of resins showed that D101 was suitable for the separation of total saponins. Further,the concen-tration and Ph of total saponins of Gymnema sylvestre in solution, flow rate, the concentration of the elution reagent were optimized. The results showed that the purity of total saponins of Gymnema syl-vestre was raised to 51. 07% from 25. 33% and the recovery was 83. 26%. Total saponins of Gymnema sylvestre was enriched effectively.

  7. ADSORPTION OF PHENYLACETIC ACID ON MACROPOROUS POLYMERIC ADSORBENTS

    Institute of Scientific and Technical Information of China (English)

    PANBingcai; CHENJinlong; 等

    2002-01-01

    Several macroporous polymeric adsorbents(NDA-999,XAD-8,X-5 and XAD-2)were emplyed in the study to adsorb phenylacetic acid from aqueous solution.Effect of salt and ambient temperature on adsorption was studied using NDA-999 adsorbent and the adsorption process conforms to Freundlich′s model reasonably.Adsorption dynamics were conducted in batch experiments in order to make clear the mechanism of adsorption process.It is proved that the squared driving force mass transfer model can be adopted to elucidate the process.The treatment process of industrial wastewater containing high strength of phenylacetic acid was proposed for cleaner production of phenylacetic acid.

  8. ADSORPTION OF PHENYLACETIC ACID ON MACROPOROUS POLYMERIC ADSORBENTS

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Several macroporous polymeric adsorbents (NDA-999, XAD-8, X-5 and XAD-2) wereemployed in the study to adsorb phenylacetic acid from aqueous solution. Effect of salt and ambienttemperature on adsorption was studied using NDA-999 adsorbent and the adsorption processconforms to Freundlich's model reasonably. Adsorption dynamics were conducted in batchexperiments in order to make clear the mechanism of adsorption process. It is proved that thesquared driving force mass transfer model can be adopted to elucidate the process. The treatmentprocess of industrial wastewater containing high strength of phenylacetic acid was proposed forcleaner production of phenylacetic acid.

  9. Preparative separation of gallocatechin gallate from Camellia ptilophylla using macroporous resins followed by sephadex LH-20 column chromatography.

    Science.gov (United States)

    Li, Kaikai; Zhou, Xuelin; Liu, Cheuk-Lun; Yang, Xiaorong; Han, Xiaoqiang; Shi, Xianggang; Song, Xiaohong; Ye, Chuangxing; Ko, Chun-hay

    2016-02-01

    Gallocatechin gallate (GCG) possesses multiple potential biological activities. However, the content of GCG in traditional green tea is too low which limits its in-depth pharmacological research and application. In the present study, a simple, efficient and environment-friendly chromatographic separation method was developed for preparative enrichment and separation of GCG from cocoa tea (Camellia ptilophylla) which contains high content of GCG. In the first step, the adsorption properties of selected resins were evaluated, and XAD-7HP resin was chosen by its adsorption and desorption properties for GCG. In order to maximize column efficiency for GCG collection, the operating parameters (e.g., flow rate, ethanol concentration, and bed height) were optimized. We found that the best combination was the feed concentration at 20mg/mL, flow rate at 0.75 BV/h and the ratio of diameter to bed heights as 1:12. Under these conditions, the purity of GCG was 45% with a recovery of 89%. In order to obtain pure target, a second step was established using column chromatography with sephadex LH-20 gel and 55% ethanol-water solution as eluent. After this step, the purity of the GCG was 91% with a recovery of 68% finally.

  10. Ionic Liquid-Based Vacuum Microwave-Assisted Extraction Followed by Macroporous Resin Enrichment for the Separation of the Three Glycosides Salicin, Hyperin and Rutin from Populus Bark

    Directory of Open Access Journals (Sweden)

    Fengli Chen

    2014-07-01

    Full Text Available An effective ionic liquid vacuum microwave-assisted method was developed for extraction of the thermo- and oxygen-sensitive glycosides salicin, hyperin and rutin from Populus bark due to the strong solvating effects of ionic liquids on plant cell walls. In this study, [C4mim]BF4 solution was selected as the extracting solution for extraction of the target analytes. After optimization by single factor experiments and response surface methodology, the optimum condition parameters were achieved, which included 1.0 M [C4mim]BF4, 2 h soaking time, −0.08 MPa vacuum, 20 min microwave irradiation time, 400 W microwave irradiation power and 25 mL/g liquid/solid ratio. Under the optimum conditions, higher extraction yields of salicin (35.53 mg/g, hyperin (1.32 mg/g and rutin (2.40 mg/g were obtained. Compared with other extraction methods, the developed method provided higher yields of the three target components after a relatively shorter extraction time (20 min. No obvious degradation of the target analytes was observed under the optimum conditions in performed stability studies and the proposed method had a high reproducibility. Meanwhile, after adsorption and desorption on macroporous D101 resin, the target analytes can be effectively separated from the [C4mim]BF4 ionic liquid extraction solution and the yields of salicin, hyperin and rutin were 89%, 82% and 84%, respectively. The recovered [C4mim]BF4 ionic liquid presented a good extraction effect on the three analytes after recycling five times.

  11. Ionic liquid-based vacuum microwave-assisted extraction followed by macroporous resin enrichment for the separation of the three glycosides salicin, hyperin and rutin from Populus bark.

    Science.gov (United States)

    Chen, Fengli; Mo, Kailin; Liu, Zhaizhi; Yang, Fengjian; Hou, Kexin; Li, Shuangyang; Zu, Yuangang; Yang, Lei

    2014-07-07

    An effective ionic liquid vacuum microwave-assisted method was developed for extraction of the thermo- and oxygen-sensitive glycosides salicin, hyperin and rutin from Populus bark due to the strong solvating effects of ionic liquids on plant cell walls. In this study, [C4mim]BF4 solution was selected as the extracting solution for extraction of the target analytes. After optimization by single factor experiments and response surface methodology, the optimum condition parameters were achieved, which included 1.0 M [C4mim]BF4, 2 h soaking time, -0.08 MPa vacuum, 20 min microwave irradiation time, 400 W microwave irradiation power and 25 mL/g liquid/solid ratio. Under the optimum conditions, higher extraction yields of salicin (35.53 mg/g), hyperin (1.32 mg/g) and rutin (2.40 mg/g) were obtained. Compared with other extraction methods, the developed method provided higher yields of the three target components after a relatively shorter extraction time (20 min). No obvious degradation of the target analytes was observed under the optimum conditions in performed stability studies and the proposed method had a high reproducibility. Meanwhile, after adsorption and desorption on macroporous D101 resin, the target analytes can be effectively separated from the [C4mim]BF4 ionic liquid extraction solution and the yields of salicin, hyperin and rutin were 89%, 82% and 84%, respectively. The recovered [C4mim]BF4 ionic liquid presented a good extraction effect on the three analytes after recycling five times.

  12. On-line coupling of counter-current chromatography and macroporous resin chromatography for continuous isolation of arctiin from the fruit of Arctium lappa L.

    Science.gov (United States)

    Guo, Mengzhe; Liang, Junling; Wu, Shihua

    2010-08-13

    In this work, we have developed a novel hybrid two-dimensional counter-current chromatography and liquid chromatography (2D CCC x LC) system for the continuous purification of arctiin from crude extract of Arctium lappa. The first dimensional CCC column has been designed to fractionalize crude complex extract into pure arctiin effluent using a one-component organic/salt-containing system, and the second dimensional LC column has been packed with macroporous resin for on-line adsorption, desalination and desorption of arctiin which was effluent purified from the first CCC dimension. Thus, the crude arctiin mixture has been purified efficiently and conveniently by on-line CCC x LC in spite of the use of a salt-containing solvent system in CCC separation. As a result, high purity (more than 97%) of arctiin has been isolated by repeated injections both using the ethyl acetate-8% sodium chloride aqueous solution and butanol-1% sodium chloride aqueous solution. By contrast with the traditional CCC processes using multi-component organic/aqueous solvent systems, the present on-line CCC x LC process only used a one-component organic solvent and thus the solvent is easier to recover and regenerate. All of used solvents such as ethyl acetate, n-butanol and NaCl aqueous solution are low toxicity and environment-friendly. Moreover, the lower phase of salt-containing aqueous solution used as mobile phase, only contained minor organic solvent, which will save much organic solvent in continuous separation. In summary, our results indicated that the on-line hybrid 2D CCC x LC system using one-component organic/salt-containing aqueous solution is very promising and powerful tool for high-throughput purification of arctiin from fruits of A. lappa.

  13. Study on purification of flavonoids from coriander with AB-8 macroporous resin%AB -8大孔树脂对芫荽黄酮的纯化工艺研究

    Institute of Scientific and Technical Information of China (English)

    王珊珊; 吴春

    2014-01-01

    利用AB-8大孔树脂纯化芫荽黄酮,通过静态和动态结合的方法,确定最佳工艺参数.结果表明,静态,吸附平衡时间为3 h,解析平衡时间为1.5 h;动态,上样液质量浓度为1.0 mg/mL,上样液pH值为6.0,上样流速为2 mL/min,洗脱剂质量浓度为70%乙醇溶液,洗脱流速为2 mL/min.在此条件下,AB-8大孔树脂可以较好的分离纯化芫荽中总黄酮.%AB-8 macroporous resin was used to separate and purify coriander flavonoids , static and dynamic adsorption and desorption behaviors of AB -8 macroporous resin were e-valuated for achieving the best purification of total flavonoids .The static:adsorption equilib-rium time was 4 h, desorption time was 1.5 h.The dynamic:the best adsorption was sample concentration of 1.0 mg/mL, pH of 6.0 and the flow rate of 2.0 mL/min.The desorption flow rate of 2.0 mL/min and 70% ethanol elution were the best .With definite technical process , the AB-8 macroporous resin could be used to purify the flavonoids of coriander .

  14. 鱼腥草总生物碱的大孔吸附树脂纯化工艺%Purification Process of Total Alkaloids from Houttuynia cordata by Macroporous Resin

    Institute of Scientific and Technical Information of China (English)

    孟江; 梁慧超; 陈磊; 卢国勇; 巫丹凤

    2012-01-01

    Objective: To optimize separation and purification technology of total alkaloids from Houttuynia cordata by macroporous resin. Method: With the content of berberine hydrochloride, pepper lactam and aristololactam B as indexes, separation and purification capacity of total alkaloids from H. Cordata was compared with different types of macroporous resin and different technology conditions. Result; HPD-100 macroporous resin had the best separation and purification capacity for total alkaloids in following technology conditions; sample concentration was 20 g ? L-1 with Ph 3, flow rate was 0. 5 Ml ? Min -1, eluting reagent was ethanol solution of ammonia ( ammonia concentration 0. 5 mol ? L-1, the volume fraction of ethanol 80% ) with the amount of 4 BV, eluting velocity was 3.0 Ml ? Min-1. Conclution: HPD-100 macroporous resin could be applied to purify alkaloids from H. Cordata.%目的:优选鱼腥草总生物碱大孔吸附树脂的分离纯化工艺.方法:以盐酸小檗碱、胡椒内酰胺及马兜铃内酰胺B含量为指标,比较不同型号树脂和不同工艺条件对鱼腥草总生物碱的分离纯化能力.结果:HPD-100型大孔树脂对鱼腥草总生物碱有良好的吸附分离性能,最佳工艺条件为药液质量浓度20 g?L-1,pH 3,吸附流速0.5 mL? min -1,洗脱溶剂为氨水乙醇溶液(氨水浓度0.5 mol?L-1,乙醇体积分数80%),洗脱剂用量4 BV,洗脱速度3.0mL?min -1.结论:HPD-100型大孔树脂可用于鱼腥草总生物碱的提取纯化.

  15. 不同大孔树脂富集山茱萸中环烯醚萜苷的效果比较%Comparison of Enrichment Effect of Iridoid Glycosides from Cornus officinalis by Different Macroporous Resins

    Institute of Scientific and Technical Information of China (English)

    蔡黎明; 周盈; 蔡宝昌; 刘芳; 皮文霞

    2013-01-01

    目的:考察不同类型大孔树脂对山茱萸中环烯醚萜苷类成分的分离效果.方法:采用HPLC测定山茱萸中马钱苷及莫诺苷的含量,考察不同大孔吸附树脂分离山茱萸中环烯醚萜苷类成分的有效性.结果:马钱苷、莫诺苷的回归方程依次为y=17.245X+ 13.362(r=0.999 9),Y=15.468X-41.275(r=1.000 0);线性范围分别为21.75~435,35.8 ~716 μg;加样回收率分别为98.27%,96.29%.HPD-400型大孔树脂的分离效果最好.结论:选取马钱苷和莫诺苷含量为指标筛选富集环烯醚萜苷的大孔树脂类型是可行的,研究结果为分离山茱萸中有效部位的后续研究提供实验依据.%Objective:To investigate separation effect of iridoid glycosides from Cornus officinalis by different types of macroporous resin.Method:The content of loganin and morroniside from C.officinalis was determined by HPLC,effectiveness of different macroporous adsorption resin on separating iridoid glycosides from C.officinalis was investigated.Result:HPD-400 type of macroporous resin had the best separation effect.Regression equation of loganin and morroniside were Y =17.245X + 13.362 (r =0.999 9),Y =15.468X-41.275 (r =1.000 0) ; The linear range of them were 21.75-435,35.8-716 μg; Recoveries were 98.27%,96.29%,respectively.Conclusion:It was feasible that selected the content of loganin and morroniside as index to screen macroporous resin for enrichment iridoid glycosides from C.officinalis,this study could provide experimental basis for the follow-up study of separation of effective parts from C.officinalis.

  16. Preparative isolation of cordycepin, N(6)-(2-hydroxyethyl)-adenosine and adenosine from Cordyceps militaris by macroporous resin and purification by recycling high-speed counter-current chromatography.

    Science.gov (United States)

    Zhang, Zhong; Tudi, Tuernisan; Liu, Yanfang; Zhou, Shuai; Feng, Na; Yang, Yan; Tang, Chuanhong; Tang, Qingjiu; Zhang, Jingsong

    2016-10-15

    In this study, cordycepin, N(6)-(2-hydroxyethyl)-adenosine (HEA) and adenosine from the fruiting bodies of Cordyceps militaris were separated by using macroporous resin NKA-II adsorption. The parameters of static adsorption were tested and the optimized conditions were as follow: the total adsorption time was 12h, 50% ethanol was used for desorption and the desorption time was 9h. The crude sample that was prepared by macroporous resin NKA-II contained 3.4% cordycepin, 3.7% HEA and 4.9% adenosine. Then the crude sample was further purified by recycling high-speed counter-current chromatography (HSCCC) with ethyl acetate, n-butanol, 1.5% aqueous ammonium hydroxide (1:4:5, v/v/v) as the optimized two-phase solvent system. Three nucleosides including 15.6mg of cordycepin, 16.9mg of HEA and 23.2mg of adenosine were obtained from 500mg of crude sample in one-step separation. The purities of three compounds were 98.5, 98.3 and 98.0%, respectively, as determined by high performance liquid chromatography. Copyright © 2016. Published by Elsevier B.V.

  17. Study of XAD-2 adsorbent for the enrichment of trace levels of phthalate esters in hydroalcoholic food beverages and analysis by gas chromatography coupled with flame ionization and ion-trap mass spectrometry detectors.

    Science.gov (United States)

    Cinelli, Giuseppe; Avino, Pasquale; Notardonato, Ivan; Centola, Angela; Russo, Mario Vincenzo

    2014-03-01

    An analytical method based on solid-phase extraction (SPE) with Amberlite XAD-2 adsorbent used as stationary phase for determining phthalate esters (PAEs) in hydroalcoholic food beverages by GC-FID (and peak confirmation by GC-IT/MS) has been set up. The XAD-2 resin shows excellent properties for determining PAEs in solutions at very large alcoholic range (10-40% v/v): 500mL of hydroalcoholic solution spiked with a PAE mixture solution (20pgμL(-1) of each PAE) and containing 25gL(-1) of NaCl are passed onto a cartridge containing 500mg XAD-2 adsorbent and re-extracted for GC analysis. The effects of NaCl concentration (0, 12, 25 and 50gL(-1)) and different solvents (CS2, toluene, acetone, n-hexane, ethyl acetate) are extensively studied as well the PAE recoveries both in hydroalcoholic aqueous solutions (ranging between 94% and 103% with a Relative Standard Deviation, RSD, below 8.3) and spiked (5, 10 and 25pgμL(-1) of each PAE) real samples (between 90% and 106% with a RSD below 9.9). The correlation coefficients (R(2)) of each PAE vary between 0.9830 and 0.9950 and they are calculated in the linear range 5-100pgμL(-1). The limits of detection (LOD) in GC-FID vary between 1.21 and 2.51pgμL(-1) (RSD⩽11.1) whereas the Limits of Quantification (LOQ) range between 2.42 and 5.03pgμL(-1) (RSD⩽8.9) whereas the infra-day and inter-day repeatabilities calculated as RSD for hydroalcoholic solutions, are between 6.5% and 13.7%.

  18. Application of alkyl polyglycoside surfactant in ultrasonic-assisted extraction followed by macroporous resin enrichment for the separation of vitexin-2″-O-rhamnoside and vitexin from Crataegus pinnatifida leaves.

    Science.gov (United States)

    Han, Feng; Guo, Yupin; Gu, Huiyan; Li, Fenglan; Hu, Baozhong; Yang, Lei

    2016-02-15

    An alkyl polyglycoside (APG) surfactant was used in ultrasonic-assisted extraction to effectively extract vitexin-2″-O-rhamnoside (VOR) and vitexin (VIT) from Crataegus pinnatifida leaves. APG0810 was selected as the surfactant. The extraction process was optimized for ultrasonic power, the APG concentration, ultrasonic time, soaking time, and liquid-solid ratio. The proposed approach showed good recovery (99.80-102.50% for VOR and 98.83-103.19% for VIT) and reproducibility (relative standard deviation, n=5; 3.7% for VOR and 4.2% for VIT) for both components. The proposed sample preparation method is both simple and effective. The use of APG for extraction of key herbal ingredients shows great potential. Ten widely used commercial macroporous resins were evaluated in a screening study to identify a suitable resin for the separation and purification of VOR and VIT. After comparing static and dynamic adsorption and desorption processes, HPD100B was selected as the most suitable resin. After column adsorption and desorption on this resin, the target compounds VOR and VIT can be effectively separated from the APG0810 extraction solution. Recoveries of VOR and VIT were 89.27%±0.42% and 85.29%±0.36%, respectively. The purity of VOR increased from 35.0% to 58.3% and the purity of VIT increased from 12.5% to 19.9%. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. 树脂法提取野酸梅皮色素工艺研究%Macroporous Resin Adsorption for Purification of Pigments from Wild Plum Skins and Their Stability

    Institute of Scientific and Technical Information of China (English)

    李紫薇; 欧阳艳; 腊萍; 张学荣; 马晓荣

    2012-01-01

    研究大孔树脂分离纯化野酸梅皮色素的条件与方法,并对树脂法所得色素的性质进行检测。结果表明:D101树脂对野酸梅皮色素的吸附效果最佳,以体积分数80%乙醇溶液作洗脱剂洗脱效果较好;野酸梅果皮色素在酸性条件T(pH≤4)较为稳定,耐光、热性较差;金属离子Al^3+、Fe^3+、Mg^2+、Cu^2+、Na^+对野酸梅果皮色素有不同程度的降色作用。%The purification of pigments from wild plum skins was studied by macroporous resin adsorption. Macroporous resin type DI01 showed the best adsorption effect on pigments from wild plum skins among the resins tested, and the best elution results were achieved using 80% ethanol solution. Pigments from wild plum skins were stable under acidic conditions (pH ~〈 4), but unstable when exposed to light and heat.Al^3+、Fe^3+、Mg^2+、Cu^2+and Na^+had obvious hypochromic effect on the pigments.

  20. 大孔吸附树脂对牛蒡子中牛蒡苷的纯化工艺研究%Study on Purification of Arctiin from Arctium lappa by Macroporous Resin

    Institute of Scientific and Technical Information of China (English)

    孙瑜; 何凡; 窦德强; 康廷国

    2011-01-01

    Objective:To establish an appropriate and technical process for the purification of Arctium lappa by macroporous resins. Method: The HPLC was used to analyze the content of arctiin in A. lappa, and the adsorption behavior of macroporous resins to arctiin in A. lappa was examined for the adsorption rate and desorption rate. Result: The D101 resin was the suitable for enriching arctiin. The sample concentration of arctiin was 28.69 g·L-1 with the elution flow rate of 3 BV·h-1. 5 BV water and 10 BV 30% ethanol were used as eluant of arcttin,respectively. Portions of 30% ethanol were collected, concentrated, and dried. Conclusion: This method is simple and feasible with good effect of enrichment in arctiin.%目的:优选出牛蒡子药材醇提液经树脂纯化的最佳工艺条件.方法:用高效液相色谱法测定牛蒡苷的含量,用树脂吸附率、解析率为指标考查大孔吸附树脂对牛蒡苷的吸附行为.结果:D101树脂对牛蒡苷提取液纯化最优,上样液牛蒡苷浓度为28.69g·L-1,洗脱流速3 BV·h-1,用蒸馏水5 BV洗脱,然后用30%乙醇10 BV洗脱,收集洗脱液,浓缩、干燥,即得到牛蒡苷总苷.结论:该方法简单、可行,能够用来富集纯化牛蒡子中牛蒡苷.

  1. Kinetics and Thermodynamics of Adsorption Glycyrrhizic Acid Triammonium Salt on NKA Macroporous Resin%NKA大孔吸附树脂对甘酸三铵盐吸附的动力学和热力学研究

    Institute of Scientific and Technical Information of China (English)

    何秀娟; 洪成林; 齐誉; 乔秀文; 但建明

    2013-01-01

    By static adsorption experiments,this paper studied the kinetics and adsorption thermodynamic characteristics of NKA macroporous resin in the process of adsorbing glycyrrhizic acid triammonium salt(GATS),and provided theoretical support for GATS macroporous adsorption resin separation and purification.Ultraviolet and visible spectrophotometry was used to detect the adsorptive kinetics curve and the adsorption equilibrium curve at different tenperatures.The adsorption kinetics behavior was well described by the pseudo-second-order kinetice equation.The thermodynamics behavior was correlated with Langmuir equation.In GATS adsorption process of NKA macroporous resin,enthalpy change ΔH and entropy change ΔS were positive,free energy change ΔG were negative,and adsorption activation energy was 36.01 kJ/mol when temperatures were in the range of 293~313 K.It is indicated that the adsorption was a spontaneous and endothermic process,the process of adsorption was mainly physical adsorption.%本文通过静态吸附实验,研究了NKA大孔吸附树脂吸附甘草酸三铵盐过程的吸附动力学和吸附热力学特征,以期为甘草酸大孔吸附树脂分离提纯提供理论支持.实验采用紫外可见分光光度法测定了吸附动力学曲线和不同温度时的吸附等温线,用拟二级动力学方程很好地描述了吸附动力学过程,使用Langmuir方程较好地拟合了等温吸附热力学过程.实验结果显示:NKA大孔吸附树脂对甘草酸三铵盐吸附焓变ΔH吸附和熵变ΔS吸附为正值,自由能变△G为负值,吸附活化能为Ea =36.01 kJ/mol;该吸附过程是自发的吸热过程,属于物理吸附范畴.

  2. Enrichment and Purification of Alkaloids from Aconitum carmichaelii with D101 Macroporous Resin%D101型大孔树脂纯化附子生物碱

    Institute of Scientific and Technical Information of China (English)

    彭拓华; 张少俊; 钟世顺; 杨毅达; 杨彤

    2012-01-01

    Objective; To resarch chemical composition change after enrichment and purification of alkaloids from Aconitum carmichaelii with D101 macroporous resin. Method: Taking transfer rate of total alkaloids, diester diterpenoid alkaloids, aconitine, hypaconitine and mesaconitine as indexes, before and after purification, the content of alkaloids from extracts of A. carmichaelii was determined by UV and HPLC, ingredients of alkaloids differentiated by TLC. Result; Alkaloids from A. carmichaelii was enriched by D101 macroporous resin, transfer rate and purity of total alkaloids were 83. 70% , 67. 34% , respectively; Transfer rate of aconitine, hypaconitine and mesaconitine were 77.78% , 94. 12% , 52.63% ; It showed 6 similar biological spots by TLC comparison, this indicated that there was no significant difference before and after enrichment of alkaloids composition. Conclusion; D101 type macroporous resin could effectively enhance purity of total alkaloids from A. carmichaelii with high transfer rate of alkaloids, it could be used for production promotion.%目的:研究附子生物碱经D101型大孔树脂富集后化学成分的变化.方法:以附子中总生物碱、酯型生物碱、乌头碱、次乌头碱及新乌头碱的转移率为指标,采用UV,HPLC,TLC分别对富集前后附子提取物中的生物碱进行含量测定及其成分鉴别.结果:采用D101型大孔树脂富集附子生物碱,总生物碱转移率83.70%,纯度67.34%;乌头碱转移率77.78%,次乌头碱转移率94.12%,新乌头碱转移率52.63%;TLC比较发现显示6个相似的生物斑点,说明富集前后生物碱化学成分无明显差异.结论:D101型大孔树脂能有效提高附子中总生物碱的纯度,且各生物碱转移率较高,可用于大生产推广.

  3. 大孔吸附树脂富集枸杞子中总黄酮的工艺研究%Extraction Research of Total Flavonoids from Lycii Fructus by Macroporous Adsorption Resin

    Institute of Scientific and Technical Information of China (English)

    胡晓莲; 张华

    2013-01-01

    Objective To study the optimum extraction technology of flavonoids from Lycii fructus by macroporous adsorption resin and improve the purity of product. Methods Optimizing suitable macroporous adsorption resin and process parameters, and using colorimetric method for the determination of Lycii fructus. Results The appropriate adsorption resin was DA-201, sample loading was 10bed volume (BV), sample concentration was 15 mg/mL, the flow rate was lBV /h, pH 3; desorption experimental elution agent was 40 % ethanol, and amount of ethanol was 8 BV. The yield was 75.85 %, and the purity of flavonoids was 35.70 %. Conclusion Under the certain process condition, flavonoids can be effective extracted and purified by DA201 type resin, and the resin can be reused with a good application prospect.%  目的筛选富集纯化枸杞子中总黄酮的大孔吸附树脂并确立其工艺参数,以提高产品纯度。方法优选大孔吸附树脂,并考察其工艺参数,采用比色法测定枸杞含量。结果筛选合适的吸附树脂DA-201,得到最佳的工艺参数为:上样量10柱床体积(BV),上样液浓度15 mg/mL,上样液流速1 BV/h,上样液pH3;解吸洗脱剂乙醇浓度为40%,乙醇用量8 BV。富集纯化总黄酮得率75.85%,总黄酮纯度35.70%。结论 DA-201型树脂在所确定的工艺条件下富集纯化总黄酮效果良好,树脂可重复利用,成本低,具有很好的应用前景。

  4. 2种大孔树脂用于麒麟菜生产卡拉胶的脱色%Decolorization of carrageenane from eucheuma by two kinds of macroporous resin

    Institute of Scientific and Technical Information of China (English)

    闫静芳; 焦琳舒; 张生生; 陈阳阳; 王昱沣

    2015-01-01

    卡拉胶作为一种具有商业价值的亲水凝胶,在食品、药品等领域具有广泛的应用,但在提取过程中色素的溶出会影响产品的品质.文中采用大孔树脂D301和D315对麒麟菜卡拉胶进行脱色研究,以脱色率和多糖保留率为指标,在单因素的基础上,采用正交实验对2种大孔树脂的脱色工艺进行优化.结果表明:大孔树脂D301的脱色效果优于D315,最佳脱色条件为温度50℃、pH 9.0、树脂用量为0.12 g/mL、脱色时间80 min,在此条件下的脱色率达48.44%,多糖保留率则为84.30%.所采用方法操作简单,成本低,为工业生产中卡拉胶脱色提供了理论基础.%As a kind of hydrophilic gel which had commercial value,carrageenan was applied widely in the industry of medicine and food.But the existence of color material would affect the quality of it.In this research,macroporous resin D301 and D315 were used to decolor carrageenan extracted from Eucheuma.Taking decoloration rate and retention rate of polysaccharide as evaluation standards,and comparing with the decolor result of active carbon,orthofonal method was applied to optimize the decolor procession of the two decolorants on the basis of single factor experiments for the first time.The results showed that the decoloration rate of active carbon was relatively low with numerous residue of active carbon in the carrageenan solvent.The performance of macroporous resin D315 was not efficient for having a low rentation rate of polysaccharide.The macroporous resin D301 had the most efficient performance in the decoloration procession.The optimal conditions were that the temperature was 50 ℃,the pH was 7.0,the amount of macroporous resin was 0.12 g/mL,and the used time was 80 min.On the optimal conditions,the decoloration rate was 48.44%,and the polysaccharide rentation rate was 84.30%.The method we applied is simple and cheap,as well as provides base for the industrial decolor procession of carrageenan.

  5. Comparison of polyurethane foam and XAD-2 sampling matrices to measure airborne organophosphorus pesticides and their oxygen analogs in an agricultural community.

    Science.gov (United States)

    Armstrong, Jenna L; Fenske, Richard A; Yost, Michael G; Tchong-French, Maria; Yu, Jianbo

    2013-07-01

    Side-by-side active air sampling for the organophosphorus (OP) pesticide, chlorpyrifos (CPF) and its oxygen analog, chlorpyrifos-oxon (CPF-O) was conducted with two recommended air sampling matrices: OSHA Versatile Sampling (OVS) tubes with XAD-2 resin, polyurethane foam (PUF) tubes, and passive PUF deposition disks. The study compared the proportion of artificially transformed CPF-O in the laboratory and in the field during a tree fruit application in Washington State. Lab results demonstrated that the NIOSH-recommended OVS tubes artificially transformed up to 32% of CPF to CPF-O during the sampling process, whereas PUF tubes had little to no artificial transformation (⩽0.1%). In the field, the proportion of CPF-O in the sample was significantly higher on OVS tubes than on PUF tubes (p<0.001), confirming that OVS tubes were converting a significant portion of CPF to CPF-O. In addition, PUF tubes reported measurable levels CPF-O in the field even when no artificial transformation was expected. We conclude that the PUF matrix is the superior sampling medium for OP oxygen analogs when compared to XAD-two resin. Community-located PUF tube samples 24h post-application had considerably higher levels CPF-O (16-21ngm(-3)) than near field samples during application (2-14ngm(-3)), suggesting that the oxygen analog is volatile and formed during atmospheric transport. It is recommended that worker and community risk assessments begin to take into consideration the presence of the more toxic oxygen analogs when measuring for OP pesticide mixtures.

  6. Dynamic adsorption and desorption characteristics of D208 macroporous resin to heparin sodium%D208大孔径树脂对肝素钠动态吸附与解吸特性研究

    Institute of Scientific and Technical Information of China (English)

    葛庆丰; 周雷; 于海; 王捷; 汪志君

    2011-01-01

    Based on preliminary tests, D208 macroporous resin was optimized to extract heparin sodium. Dynamic adsorption and desorption characteristics of D208 macroporous resin for heparin sodium was studied to determine the best process condition for getting most heparin sodium. The results indicated that the best adsorption effect could be obtained at 2 mL · min-1 of adsorption flow rate, 6 mg · mL-1 of sample content and pH 8. 5 condition, and the optimum desorption condition was 5 bed volume 3 mol · L-1 sodium chloride solution as elution solveni, and 1 mL · min-1 of desorption flow rate, and the best desorption effect was achieved.%在前期试验基础上,以优选出的D208大孔径树脂提取、分离肝素钠,通过对D208大孔径树脂不同条件下动态吸附与解吸特性的研究,确定D208大孔径树脂提取、分离肝素钠的最佳工艺条件.结果表明:吸附流速为2 mL· min-1,上样浓度为6 mg·mL-1,上样溶液pH值为8.5,树脂对肝素钠的吸附效果最佳.用5倍柱床体积3 mol·L-1氯化钠溶液为洗脱液,洗脱速度为1 mL· min-1,洗脱效果最佳.

  7. Optimization of Purification Technology for Tea Polyphenol from Tea Stalk by Macroporous Resin%大孔树脂纯化茶梗中茶多酚的工艺优选

    Institute of Scientific and Technical Information of China (English)

    陈沛鑫; 高英; 李卫民; 李竞

    2012-01-01

    Objective: To optimize purification technology of tea-polyphenol from tea stalk by macroporous resin, and provide a reference for secondary development of tea stalk. Method: Static absorption-desorption and dynamic adsorption-desorption was used to select the best one from 9 different type macroporous resin; With the content of tea-polyphenol as index, purification technology parameters of tea polyphenol were optimized by single factor test. Result: LX-18 type resin showed the best purifying profile, its optimum technology conditions were as follows: crude drugs-dry resin weight 1:1, adsorption rate of 2 mL · min-1 , eluted by 10 BV distilled water and 10 BV 50% ethanol; Purity of tea polyphenol was 53.79%. Conclusion: This optimized technology was simple and feasible with good purification effect, so it could provide a reference for development of related products of tea polyphenol.%目的:优选大孔吸附树脂纯化茶梗中茶多酚的工艺条件,为茶梗二次开发提供参考.方法:采用静态吸附-解吸和动态吸附-解吸试验对9种不同型号树脂进行筛选;以茶多酚含量为指标,采用单因素试验优选大孔树脂纯化茶多酚的工艺参数.结果:LX-18型大孔吸附树脂纯化效果最好;最佳工艺条件为上样液中生药与树脂的质量比1∶1,吸附速度2 mL·min-1,分别用10倍量水、50%乙醇洗脱;茶多酚纯度53.79%.结论:该优选的方法简便可行、纯化效果好,可为茶多酚相关产品的开发提供参考.

  8. 大孔树脂吸附纯化桑黄粗多糖的研究%A STUDY OF THE MACROPOROUS RESIN'S ABSORPTION AND PURIFICATION OF THE PHELLINUS LINTEUS POLYSACCHARIDE

    Institute of Scientific and Technical Information of China (English)

    张慧洋; 秦俊哲

    2011-01-01

    The characteristic of absorption and adsorption of five kinds of macroporous resins to crude polysaccharide of Phellinus linteus was studied. Suitable resin for purification of polysaccharide was screened from five resins, and its characteristic of absorption and adsorption was investigated. The results indicated that D-101-I resin had better absorption and adsorption property for purification of crude polysaccharide from Phellinus linteus, the polysaccharide solution which concentration was 500 mg · L-1 had achieved balance for 240 min at room temperature, the amount of balance adsorption was 80 mg · g-1, stock solution was sample, and the best sample volume was 6 BV, the polysaccharide can enrich when the eluant was 60% ethanol and its' volume was 2 BV.%比较了5种大孔树脂对桑黄粗多糖的吸附和解吸效果,从中筛选出适合桑黄多糖分离纯化的树脂,并对其吸附和解吸条件进行了探讨.结果表明:D-101-I树脂纯化桑黄粗多糖较好,浓度为500 mg·L-1的多糖溶液在室温下吸附24 min时达到平衡,平衡吸附量为80 mg·g-1,原液上样,最佳上样量为6 BV;60%乙醇作洗脱剂,用量为2 BV时,富集洗脱多糖效果较好.

  9. Simultaneous preconcentration of vanadium(V/IV) species with palmitoyl quinolin-8-ol bonded to amberlite XAD 2 and their separate spectrophotometric determination with 4-(2-pyridylazo)-resorcinol using CDTA as masking agent

    Energy Technology Data Exchange (ETDEWEB)

    Filik, Hayati; Berker, Kadriye Isil; Balkis, Nuray; Apak, Resat

    2004-08-02

    This paper reports the simultaneous preconcentration and separation of trace amounts of V species in synthetic solutions and seawater with palmitoyl quinolin-8-ol bonded amberlite XAD 2 copolymer resin column prior to simultaneous speciation analysis. Both V(IV) and V(V) species could be sorbed and preconcentrated by the resin. Both vanadium species were quantitatively eluted together from the resin column using HCl as stripping agent and used for speciation studies. For the speciation analysis of eluted V species, the selected route involved spectrophotometric determination of total vanadium with 4-(2-pyridylazo)-resorcinol (PAR) and vanadate estimation by masking vanadyl with 1,2 cyclohexanediaminetetraacetic acid (CDTA). The preconcentrated V species were assayed spectrophotometrically with PAR at 542 nm, and the results were compared with those of FAAS. The detection limits of V(V) with spectrophotometry and FAAS were 1.6 and 0.9 {mu}g l{sup -1}, respectively. The optimal experimental parameters such as pH, sample flow rate, desorption flow rate, redox behaviour of V(IV) and V(V) in resin and volume of eluent and sample were investigated. The values obtained for the preconcentration factor by the two methods were nearly consistent, and were in the range 150-fold. Analysis of certified reference material (IAEA-405) by the proposed method showed good agreement with the certified value. The established procedure was employed for preconcentrating the vanadium species from artificial and real seawater.

  10. Technology of Adsorption and Separation of ACE Inhibition Peptide from Rice Bran by Macroporous Resin%大孔树脂吸附分离米糠中ACE抑制肽工艺

    Institute of Scientific and Technical Information of China (English)

    张焱; 翟爱华

    2013-01-01

    To screen the isolation and purification of rice bran protein,macroporous adsorption resin was used to separate rice bran ACE inhibition peptide,and compared the effect of adsorption and desorption of rice bran protein peptide in the 6 kinds of macroporous adsorption resin. The results showed that the HPD-400 type resin was the most suitable in the rice bran protein peptide. Process parameters were confirmed by systematacially studying the influence of various factors on the resin adsorption and desorption.The time for static adsorption equilibrium of HPD-400 resin to rice bran polypeptide was 4 h,appropriate adsorption temperature was about 45℃,after adsorption time was over 2 h,adsorption capacity of HPD-400 resin to rice bran protein peptide had already reached saturation,when pH was 4,adsorption effect was better,and the adsorption rate was 85.4%. Desorption solution was 70% ethanol solution and pH was 8. The elution time was determined as 30 min. The experiments of dynamic adsorption and separation showed that the resin could achieve the purpose of purification of ACE inhibitory peptides from rice bran.%采用大孔吸附树脂对米糠ACE抑制肽进行分离,比较6种大孔吸附树脂对米糠蛋白中肽的静态吸附和解吸效果,从中筛选出适合该米糠蛋白中肽分离纯化的树脂。结果表明,筛选出HPD-400型树脂最适合米糠蛋白中肽的混合物的纯化。通过对影响树脂吸附解吸的各种因素进行系统地研究,确定工艺参数。HPD-400树脂对米糠多肽的静态吸附4 h左右基本达到吸附平衡,选择吸附温度45℃较为适宜;吸附时间达到2 h后HPD-400型树脂对米糠蛋白肽的吸附量已达到饱和;在pH 4.0时吸附效果好,吸附率达85.4%。解吸液为pH 8.0的70%乙醇溶液,洗脱时间确定为30 min。通过动态吸附分离实验得出,该树脂可以达到分离纯化米糠ACE抑制肽的目的。

  11. 优化大孔树脂提取分离苋菜红色素的工艺%Optimization of Extraction and Separation of Red Pigment from Amaranthus Paniculatus with Macroporous Adsorption Resin

    Institute of Scientific and Technical Information of China (English)

    林海珠; 张云玲; 胥秀英; 郑一敏; 乔源; 傅善权

    2013-01-01

    AB-8 resin was selected out to purify the red pigment of Amaranthus paniculatus by orthogonal design. The best conditions for isolation of the red pigment of Amaranthus paniculatus were determined as follows: pH 3, adsorption velocity 1.2 mL/min, solution adsorbent 15% ethanol and elution velocity 0.9 mL/min. After AB-8 macroporous resin purification, greatly enhance the pigment quality.%采用正交设计实验筛选AB-8大孔树脂纯化苋菜红色素的最佳工艺条件.其最佳工艺为:上样pH值为3、吸附流速1.2mL/min、洗脱剂浓度为15%乙醇溶液、洗脱流速0.9 mL/min.经过AB-8大孔树脂提纯后,提高了苋菜红色素的品质.

  12. A strategy for identification and structural characterization of compounds from Gardenia jasminoides by integrating macroporous resin column chromatography and liquid chromatography-tandem mass spectrometry combined with ion-mobility spectrometry.

    Science.gov (United States)

    Wang, Lu; Liu, Shu; Zhang, Xueju; Xing, Junpeng; Liu, Zhiqiang; Song, Fengrui

    2016-06-24

    In this paper, an analysis strategy integrating macroporous resin (AB-8) column chromatography and high performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS) combined with ion mobility spectrometry (IMS) was proposed and applied for identification and structural characterization of compounds from the fruits of Gardenia jasminoides. The extracts of G. jasminoides were separated by AB-8 resin column chromatography combined with reversed phase liquid chromatography (C18 column) and detected by electrospray ionization tandem mass spectrometry. Additionally, ion mobility spectrometry (IMS) was employed as a supplementary separation technique to discover previously undetected isomers from the fruits of G. jasminoides. A total of 71 compounds, including iridoids, flavonoids, triterpenes, monoterpenoids, carotenoids and phenolic acids were identified by the characteristic high resolution mass spectrometry and the ESI-MS/MS fragmentations. In conclusion, the IMS-MS technique achieved the separation of isomers in crocin-3 and crocin-4 according to their acquired mobility drift times differing from classical analysis by mass spectrometry. The proposed strategy can be used as a highly sensitive and efficient procedure for identification and separation isomeric components in extracts of herbal medicines.

  13. Enrichment of water-soluble constituents in Danshen (Radix Salviae Miltiorrhizae) with macroporous resin*%大孔树脂富集丹参水溶性有效成分的工艺研究

    Institute of Scientific and Technical Information of China (English)

    周琳; 吴清; 刘晓帆

    2011-01-01

    Objective To study the enriching technique for 3 active principles in the water extract of Danshen (Radix Salviae Miltiorrhizae), salvanic acid A sodium, protocatechualdehyde and salvianolic acid B, by macroporous resin. Methods The content changes of 3 active principles were detected by HPLC before and after the separation taken the summed content of salvianic acid A sodium,protocatechualdehyde and salvianolic acid B as index. The types, concentration of sample solution, pH values, volume of sample, and concentration, quantity and flow velocity of eluant were observed by using the single factor investigation method. Results The parameters of the best purification technique were as follows: the concentration of sample solution was 1 g/mL according to the volume of sample ( 1.1 g/mL, crude medicinal volume to resin volume) and pH value was 3. The sample solution was rested on the macroporous adsorption resin column of D101, and eluted with deionized water of 5 BV at a flow velocity of 0. 5 mL/min and then eluted again with 40% alcohol of 6 BV at a flow velocity of 0. 5 mL/min. The content of total salvianolic acid was 85% in the obtained fine product and the transfer rate was as high as 70%. Conclusion Macroporous resin of D101 can improve the purification technique, remove impurities and increase the quantity of active principles in crude extract.%目的 考察利用大孔树脂富集丹参水提取液中有效成分丹参素钠、原儿茶醛和丹酚酸B的工艺方法.方法 以丹参素钠、原儿茶醛和丹酚酸B含量之和为指标,HPLC检测分离前后有效成分的含量变化.采用单因素考察法对树脂种类、上样溶液浓度、pH值、上样量、洗脱剂浓度、用量和流速等进行考察.结果 最佳纯化工艺参数为:按1.1g/mL(生药量/树脂量)的上样量配制浓度为1g/mL的上样溶液,调其pH值为3,上D101型大孔吸附树脂柱,采用去离子水以0.5 mL/min的流速,洗脱5倍体积(BV),然后再用6 BV

  14. 大孔吸附树脂富集沙枣花中总黄酮的工艺研究%Study on the Enrichment Technology of Total Flavonoids in Elaeagnus Angustifolia Flower by Macroporous Adsorption Resin

    Institute of Scientific and Technical Information of China (English)

    徐泉; 王培先; 程芬; 王妍

    2012-01-01

    OBJECTIVE To screen the best macroporous adsorptive resin for separation and purification of flower Elaeagnus angustifolia flavonoids and to establish the purification process parameters. METHODS Using macroporous adsorption resin adsorption rate and desorption rate as the indexes, the best resin was screened out for enriching flower Elaeagnus angustifolia flavonoids. The optimal process conditions were investigated through single factor test. RESULTS DA201 resin showed good adsorption and separation property for Elaeagnus anguslifolia flavonoids. The detailed process conditions were as follows: the ratio of diameter to height of resin column was 1:8, sample loading rate was 0. 5 mL·min -1 , sample concentration was 20 mg·mL-1, pH was adjusted to 4, with elution rate of 0. 5 mL·min-1, the largest sample load was 4. 5 BV, eluent concentration was 80% and the dosage was 12 BV. CONCLUSION DA201 type resin, showed good purification effect for flavonoids Elaeagnus angustifolia in the defined process conditions with a yield of 85. 23%. The purity of total flavonoids achieved 14. 95% , which was 3 times of that by coarse extraction (4. 901% ).%目的 筛选适合分离和纯化沙枣花总黄酮的大孔吸附树脂并确立纯化工艺参数.方法 以大孔吸附树脂吸附率及解吸率为指标,筛选出富集沙枣花总黄酮的最佳树脂,并通过单因素考察该树脂分离、纯化沙枣花总黄酮的最佳工艺条件.结果 DA201树脂对沙枣花总黄酮有良好的吸附分离性能.其具体工艺条件为:树脂柱径高比为1∶8、控制上样流速为0.5mL·min- 1、上样液浓度20 mg·mL-1、调pH为4、洗脱流速为0.5 mL·min-1、最大上样为4.5 BV、洗脱剂浓度80%、洗脱剂用量12 BV.结论 DA201型树脂在所确定的工艺条件下,纯化沙枣花总黄酮效果良好,总黄酮得率达到85.23%,总黄酮纯度达到了14.95%,比粗提样品纯度(4.901%)提高了3倍.

  15. Research on removal of metal impurities from wet-process phosphoric acid with macroporous strong acid cation exchange resin%大孔阳离子树脂脱除湿法磷酸中阳离子的研究

    Institute of Scientific and Technical Information of China (English)

    熊祥祖; 徐彪; 王威; 杜文; 胡利锋

    2011-01-01

    采用D001大孔强酸性阳离子交换树脂三级处理湿法磷酸中的金属杂质,考察了搅拌速度、温度、树脂用量及反应时间对金属阳离子去除率的影响.结果表明,在搅拌速度为200 r/min、树脂质量磷酸质量为12、反应温度为400 ℃、反应时间为10 min时,效果最好,铁的去除率可达到86.75%、铝的去除率可达到76.13%、镁的去除率可到达40.38%、钙的去除率可到达47.49%.%The removal rate of metal impurities in Wet-Process Phosphoric Acid with D001 macroporous strong acid cation exchange resin was researched.Some important factors which affect the removal rate of metal impurities such as stirring speed, temperature, the mass ratio of resin to phosphoric acid and reaction time were studied respectively.The results show that the removal efficiency of iron,aluminum,magnesium,calcium can be up to 86.75%, 76.13%, 40.38%, 47.49%, respectively, when the stirring speed was 200 r/min, the mass ratio of resin to phosphoric acid was 1:2, the temperature was 40 ℃,the reaction time was 10min.

  16. Selective separation of biobutanol from acetone-butanol-ethanol fermentation broth by means of sorption methodology based on a novel macroporous resin.

    Science.gov (United States)

    Lin, Xiaoqing; Wu, Jinglan; Jin, Xiaohong; Fan, Jiansheng; Li, Renjie; Wen, Qingshi; Qian, Wenbin; Liu, Dong; Chen, Xiaochun; Chen, Yong; Xie, Jingjing; Bai, Jianxin; Ying, Hanjie

    2012-07-01

    The traditional distillation method for recovery of butanol from fermentation broth is an energy-intensive process. Separation of butanol based on adsorption methodology has advantages in terms of biocompatibility and stability, as well as economy, and therefore gains much attention. However, the application of the commercial adsorbents in the integrated acetone-butanol-ethanol (ABE) fermentation process is restricted due to the low recovery (less than 85%) and the weak capability of enrichment in the eluent (3-4 times). In this study, we investigated the sorption properties of butanol onto three kinds of adsorbents with different polarities developed in our laboratory, that is, XD-41, H-511, and KA-I resin. The sorption behaviors of single component and ABE ternary mixtures presented in the fermentation broths on KA-I resin were investigated. KA-I resin had higher affinity for butanol than for acetone, ethanol, glucose, acetic acid, and butyric acid. Multicomponent ABE sorption on KA-I resin was modeled using a single site extended Langmuir isotherm model. In a desorption study, all the adsorbed components were desorbed in one bed volume of methanol, and the recovery of butanol from KA-I resin was 99.7%. The concentration of butanol in the eluent was increased by a factor of 6.13. In addition, KA-I resin was successfully regenerated by two bed volumes of water. Because of its quick sorption, high sorption capacity, low cost, and ease of desorption and regeneration, KA-I resin exhibits good potential for compatibility with future ABE fermentation coupled with in situ recovery product removal techniques. Copyright © 2012 American Institute of Chemical Engineers (AIChE).

  17. Effects of Macroporous Resin Size on Candida antarctica Lipase B Adsorption, Fraction of Active Molecules, and Catalytic Activity for Polyester Synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Chen,B.; Miller, E.; Miller, L.; Maikner, J.; Gross, R.

    2007-01-01

    Methyl methacrylate resins with identical average pore diameter (250 {angstrom}) and surface area (500 m{sup 2}/g) but with varied particle size (35 to 560-710 {mu}m) were employed to study how immobilization resin particle size influences Candida antarctica Lipase B (CALB) loading, fraction of active sites, and catalytic properties for polyester synthesis. CALB adsorbed more rapidly on smaller beads. Saturation occurred in less than 30 s and 48 h for beads with diameters 35 and 560-710 {mu}m, respectively. Linearization of adsorption isotherm data by the Scatchard analysis showed for the 35 {mu}m resin that: (1) CALB loading at saturation was well below that required to form a monolayer and fully cover the support surface and (2) CALB has a high affinity for this resin surface. Infrared microspectroscopy showed that CALB forms protein loading fronts for resins with particle sizes 560-710 and 120 {mu}m. In contrast, CALB appears evenly distributed throughout 35 {mu}m resins. By titration with p-nitrophenyl n-hexyl phosphate (MNPHP), the fraction of active CALB molecules adsorbed onto resins was <50% which was not influenced by particle size. The fraction of active CALB molecules on the 35 {mu}m support increased from 30 to 43% as enzyme loading was increased from 0.9 to 5.7% (w/w) leading to increased activity for {epsilon}-caprolactone ({epsilon}-CL) ring-opening polymerization. At about 5% w/w CALB loading, by decreasing the immobilization support diameter from 560-710 to 120, 75, and 35 {mu}m, conversion of {epsilon}-CL % to polyester increased (20 to 36, 42, and 61%, respectively, at 80 min). Similar trends were observed for condensation polymerizations between 1,8-octanediol and adipic acid.

  18. Separation and Purification of Oridonin by Macro-porous Resin and Silica Column Chromatography%大孔吸附树脂联用硅胶柱层析法分离纯化冬凌草甲素

    Institute of Scientific and Technical Information of China (English)

    何建峰; 邬泉周; 黄少梅

    2012-01-01

    目的:建立大孔吸附树脂联用硅胶柱层析法分离纯化冬凌草甲素的工艺流程.方法:将冬凌草粉碎,用95%乙醇提取,浓缩成浸膏;以冬凌草甲素含量为指标,采用大孔吸附树脂联用硅胶柱层析法分离纯化冬凌草甲素,并用红外光谱、熔点测定和高效液相色谱(HPLC)法对重结晶产品的纯度和结构进行分析和表征.结果:优化的工艺为采用苯乙烯型大孔吸附树脂(HZ-841)先对浸膏进行粗分离,再选取乙酸乙酯-石油醚(6∶4,V/V)为洗脱溶剂,石油醚-丙酮(2∶3,VV)为重结晶溶剂进行硅胶柱分离纯化,在此条件下,得到的冬凌草甲素含量为96.11%,提取率达到0.86%.结论:所选工艺简单、可行,使用溶剂安全、无毒,提取效率高,可用于分离纯化冬凌草甲素.%OBJECTIVE: To establish macro-porous resin and silica column chromatography for the separation and purification of oridonin. METHODS: Rabdosia rubescens was shattered and extracted with 95% ethanol, then concentrated to extract. Taking the content of oridonin as index, the oridonin was separated and purified by macro-porous resin and silica column chromatography. The structure and purity of the recrystallized products were analyzed and characterized with IR spectra, smelting point and HPLC. RESULTS: The optimal technology was as follows: polystyrene-type macroporous absorbing resins (HZ-841) was used to separate extract roughly and silica column was used for purification with acetic ether-petroleum benzin(6:4, V/V) as elution solvent and petroleum benzin-acetone(2 : 3, V/V). Under this condition, the content of oridonin was 96.11% and the extraction ratio reached to 0.86‰. CONCLUSIONS: The technology is simple and feasible, and solvents used are safe and non-toxic with high extraction efficient. It can be used for the separation and purification of oridonin.

  19. Application of Refractometry in Purification Technology of Active Ingredients from Citrus aurantium by Macroporous Resin%折光法在树脂精制枳实中有效成分的应用

    Institute of Scientific and Technical Information of China (English)

    曾文雪; 姚珍珍; 涂瑶生; 陈银芳; 宋小玲; 王跃生

    2013-01-01

    目的:探讨折光法在大孔树脂纯化工艺中应用的可行性.方法:选取枳实提取物为研究对象,经AB-8型大孔吸附树脂精制有效部位,用水与50%乙醇洗脱,间隔取样,在线监测洗脱液的折光率并分析其变化规律,同时以HPLC和UV检测作为参比,判断洗脱过程中始点和终点.结果:枳实有效部位精制过程中水洗终点为第4 BV(折光率0),亦即50%乙醇洗脱始点,50%乙醇洗脱终点为第9 BV(折光率16).结论:折光法准确可靠、便捷快速,具有较强的实践指导意义.%Objective: To explore application feasibility of refractometry in purification technology of macroporous resin. Method: Taking extract of Citrus aurantium as research object, active ingredients in it was refined by AB-8 macroporous resin, washed with water and 50% ethanol, interval sampled, refractive ratio of eluent was monitored on line and analyzed its regularity. At the same time, HPLC and UV spectrophotometric method was used to determine hesperidin as references, and to judge initiation point and terminal point during elution. Result: In purification process of active ingredients from C. aurantium, water elution terminal point 4 BV ( refractive index 0) of which was the initiation point by 50% ethanol, 9 BV (refractive index 16) of 50% ethanol elution was the terminal point. Conclusion: Refractometry was accurate, reliable, convenient, quickly in purification technology of active ingredients of TCM, it had a strong practical significance.

  20. Study on Desalination of DA201-C Macroporous Adsorption Resin on Fermented Bean Curd Polypeptide%DA201-C大孔吸附树脂对腐乳多肽脱盐作用的研究

    Institute of Scientific and Technical Information of China (English)

    范文; 阮长青; 王鹤霖

    2011-01-01

    In order to remove the salt of fermented bean curd, benefit the separation and purification of active peptide and realize the target of the recovery rate of fermented bean curd polypeptides,the desalting technology of fermented bean curd polypeptides which were water - soluble after ultrafiltration by DA201 - C macroporous adsorption resin was investigated. The results indicated that the optimum condition for desalting was obtained as follows: loading sample concentration of 45 mg/mL,flow speed of 120 mL/h and 70% alcohol as eluent. Under these conditions,the ratio of fermented bean curd polypeptides desalination reached to 98. 19% , and the recovery of peptides was more than 90%. Moreover,its antioxidant activity was enhanced. In conclusion,the desalination method by using DA201 -C macroporous adsorption resin applied to fermented bean curd polypeptides was a simple and available method.%为去除腐乳中的盐分,利于其中活性肽的分离纯化,以腐乳多肽的回收率为指标,采用DA201-C大孔吸附树脂对超滤的水溶性低聚肽的脱盐工艺进行了研究.结果表明:DA201-C大孔吸附树脂对腐乳多肽较佳的脱盐工艺条件为上样浓度45 mg/mL、洗脱流速120 mL/h、解吸剂为70%乙醇.腐乳多肽经DA201-C大孔吸附树脂处理后脱盐率达到98.19%,肽回收率大于90%,抗氧化活性得到提高.利用DA201-C大孔吸附树脂是进行腐乳多肽脱盐处理的一种简便有效方法.

  1. 树脂XAD-16对埃博霉素B的解吸附条件优化%Optimization of desorption conditions for epothilone B desorbed f rom macroporous resin XAD-16

    Institute of Scientific and Technical Information of China (English)

    龚国利; 赵婷峰

    2015-01-01

    埃博霉素B是一种由粘细菌纤维堆囊菌产生的新型抗肿瘤药物,目前埃博霉素B的发酵生产主要采用原位分离发酵工艺,即在发酵过程中将产生的埃博霉素B从发酵液中不断地吸附到大孔树脂上.本文以吸附有有效成分埃博霉素B的大孔树脂X A D‐16为研究对象,确定出其最适解吸附条件.通过实验得出:重复3次解吸已基本将埃博霉素B完全解吸到溶剂中,80%甲醇溶液的解吸附能力最适,解吸附时间为120 m in ,解吸附p H为6.0,最适解吸附的转速为200 r/m in .该条件的确定无论对实验室还是对于工业化条件下的埃博霉素的提取都具有一定的指导意义.%Epothilone B is a novel anti‐tumor drugs produced by myxobacteria sorangium cel‐lulosum .Now ,epothilone B is produced through in situ separation of fermentation that epot‐hilone B is adsorbed on macroporous resin continuously from fermentation liquor in the fer‐mentation process .In this paper ,macroporous resin XAD‐16 with effective components of epothilone B were the main study object ,and the best desorption conditions were deter‐mined .The results were as follows :the epothilone B had been basically complete desorbed to the solvent when desorption times was 3 ,80% aqueous methanol solution had the best ad‐sorption ability ,the best adsorption time was 120 min ,the best adsorption pH was 6 .0 ,the adsorption speed was 200 r/min .The conclusion had certain guiding significance both for la‐boratory and for industrialized extraction of epothilone .

  2. 大孔树脂对桑黄多糖提取液中色素的吸附与解吸特性研究%Adsorption and desorption characteristics of macroporous resins to pigments of Phellinus linteus polysaccharide extraction

    Institute of Scientific and Technical Information of China (English)

    秦俊哲; 程伟; 杜军国

    2013-01-01

    In order to select a kind of resin which is better on purification of polysaccharide extracted from the fruiting bodies of Phellinus Igniarius. Compared the effects of DA201 and other 5 kinds of macroporous resins in the proessing of decolorization and removal effects of liquid protein. On static adsorption and desorption experiments, select the DA201 resin for static adsorption kinetics and desorption characteristics, investigated the resin saturated adsorption, decolorization rate, protein removing rate and total sugar retention rate. The results show: DA201 resin showed a good effects of deproteinization and decolorization, and total sugar retention rate was high. For the specific polysaccharide extraction, flow rate at 1. 0 mL/min, DA201 resin column to make protein and pigment adsorption reached saturation, need continuous sampling 10 multiple column volume (BV) at least, distilled water and 50% ethanol elution desorption effects was suitable. DA201 resin was suitable for the decolorization of polysaccharide,In order to make full use of DA201 resin adsorption properties, the string column method can be considered in industrial production.%为了选择对桑黄多糖提取液纯化效果较好的树脂,比较了DA201等5种大孔吸附树脂对桑黄多糖提取液的脱色和除蛋白质效果.对5种树脂进行静态吸附与解吸试验,选择DA201树脂研究静态吸附动力学曲线及其解吸特性,考察树脂的饱和吸附量、脱色率、蛋白质脱除率及总糖的保留率.DA201树脂对桑黄多糖提取液中的蛋白质和色素的吸附较多,表明其脱蛋白和脱色效果较好,且多糖的回收率较高.对于特定的多糖提取液,流速1.0 mL/min,过DA201树脂柱要使蛋白质和色素达到吸附饱和,需要连续进样10多个柱床体积(BV),蒸馏水和50%乙醇洗脱解吸效果均较好.DA201树脂较适于桑黄多糖提取液的初步纯化,为了充分发挥DA201树脂的吸附性能,工业生产上可考虑采用串柱法.

  3. ADSORPTION DYNAMICS OF MACROPOROUS POL YMERIC ADSORBENT Ⅱ.The Studies on the FIlm DIffusion Mass—Transfer Process

    Institute of Scientific and Technical Information of China (English)

    WANGChunhong; XUMingcheng; 等

    2000-01-01

    The film diffusion mass-transfer process of adsorption of phenol on macroporous polystyrene resin was investigated in detail.In order to revise the Boyd film diffusion kinetics equation,the out-surface structure of the macroporous resin and that of gel-type ion-exchange resin was compared and the new film diffusion equation was also suggested.These results showed that the film diffusion was influenced by porosity of the macroporous resin greatly,which differed from the film diffustion behavior of ion-exchange resin obviously.

  4. XDA-8大孔树脂对高浓度咖啡因的吸附热力学研究%Thermodynamics Study on Adsorption of High-Concentration Caffeine by Macroporous Resin XDA-8

    Institute of Scientific and Technical Information of China (English)

    孙培宾; 陈江; 尹进华; 陈学玺

    2011-01-01

    Adsorption isotherms of high-concentration caffeine on polar macroporous adsorptive resin XDA8 were determined at different temperature, which was fit by Langmuir isothermal adsorption equation, and then the thermodynamics study on the adsorption behavior was conducted. The results showed that, Langmuir adsorption isothermal equation fitted the adsorption process well and caffeine was adsorbed on single layer of the resin;the process was exothermic, and higher temperature was disadvantage to the adsorption; the adsorption process was spontaneous; the motion of cafein was restricted after adsorption, and the restriction got stronger when the adsorption capacity increased.%测定了不同温度下极性大孔吸附树脂XDA-8对高浓度咖啡因的吸附等温线,并采用Langmuir吸附等温方程进行了拟合,在此基础上对吸附行为进行了热力学研究.结果表明,Langmuir吸附等温方程对吸附过程拟合程度很高,XDA-8大孔树脂对咖啡因的吸附为单分子层吸附;XDA-8大孔树脂吸附咖啡因是一个放热过程,升高温度使其吸附能力下降;吸附是自发进行的;吸附质分子被吸附后其运动受到限制,且吸附量越大,限制越大.为树脂在工业咖啡因废水处理中的应用提供了理论依据.

  5. PREPARATION OF SESAME LIGNANS FROM SESAME OIL MIXTURE BY MACROPOROUS ADSORPTION RESIN%用大孔吸附树脂法从芝麻混合油中制备木脂素

    Institute of Scientific and Technical Information of China (English)

    魏安池; 杨玲玲

    2011-01-01

    The paper determined the HI020 macroporous adsorption resin as the optimal resin for preparing sesame lignans, and optimized the process conditions. The optimized preparation conditions of the sesame lignans were as follows: room temperature, mass concentration of lignans in the sesame oil mixture 1.54 mg/mL, adsorption flow rate 2.0 BV/h, 90% ethanol as desorption agent, desorption pH 4.2, and desorption flow rate 1.0 BV/h. Under the optimal conditions, the yield of sesame lignans was larger than 65%, and the total content of lignans in the product (calculated by sesamin) was up to 85%. The results of HPLC-MS analysis showed that the lignans mainly contained sesamin, sesamolin and pinoresinolin.%确定了制备芝麻木脂素的最佳树脂为H1020型大孔吸附树脂,优化工艺条件为:室温,芝麻混合油中木脂素质量浓度1.54 mg/mL,吸附流速2.0 BV/h,解吸剂为体积分数为90%乙醇,解吸pH值4.2,解吸流速为1 BV/h.在此条件下,芝麻木脂素回收率大于65%,产品中木脂素总含量(以芝麻素计)达到85%.经液相色谱-质谱联用仪分析,制得木脂素的主要成分为芝麻素、芝麻林素和松醇素.

  6. Macroporous resin adsorption for seperation of polyphenols from Rabdosia serra (Maxim.) Hara%大孔树脂对溪黄草多酚吸附分离的工艺优化

    Institute of Scientific and Technical Information of China (English)

    李臻; 吴晖; 赖富饶

    2012-01-01

    The adsorption and desorption rates of polyphenols from Rabdosia serra (Maxim.) Hara were used as indexes to compare ten kinds of macroporous resins, and the AL-1 was proved to be the best resin and used to optimize adsorption and desorption conditions of polyphenols from Rabdosia serra (Maxim.) Hara. Results showed that the best adsorption conditions were: loading sample concentration of polyphenols 520 lag/mL, sample pH 4, loading flow rate 0.8 mL/min. The best desorption conditions were: concentration of ethanol 80%, desorption velocity 0.5 mL/min.%以溪黄草多酚为原料,通过静态吸附和解吸实验对10种大孔树脂进行筛选,确定AL-1为最优吸附树脂。通过静态与动态相结合的方法,确立AL-1树脂对溪黄草多酚的最佳吸附/解吸工艺条件。结果表明,溪黄草多酚提取液的最佳吸附条件为:上样总酚质量浓度为520μg/mL,上样液pH为4,吸附流速为0.8mL/min;最佳洗脱条件为:乙醇体积分数80%,流速0.5mL/min。

  7. Profiling and Preparation of Metabolites from Pyragrel in Human Urine by Online Solid-Phase Extraction Coupled with High Performance Liquid Chromatography Tandem Mass Spectrometry Followed by a Macroporous Resin-Based Purification Approach.

    Science.gov (United States)

    Zhao, Xin; Jiang, Jingjing; Yang, Guang; Huang, Jie; Yang, Guoping; He, Guangwei; Chu, Zhaoxing; Hang, Taijun; Fan, Guorong

    2017-03-21

    Pyragrel, a new anticoagulant drug, is derived from the molecular combination of ligustrazine and ferulic acid. Pyragrel showed significant inhibitory activity against platelet aggregation induced by adenosine diphosphate (ADP), and had been approved for a phase I clinical trial by CFDA. To characterize the metabolites of Pyragrel in human urine after intravenous administration, a reliable online solid-phase extraction couple with high performance liquid chromatography tandem mass spectrometry (online SPE-HPLC-MS(n)) method was conceived and applied. Five metabolites were detected and tentatively identified, which suggested that the major metabolic pathways of Pyragrel in human were double-bond reduction, double-bond oxidation, and then followed by glucuronide conjugation. Two main metabolites were then prepared using β-glucuronide hydrolysis and macroporous resin purification approach followed by preparative high-performance liquid chromatography (PHPLC) method, with their structures confirmed on the basis of nuclear magnetic resonance (NMR) data. This study provided information for the further study of the metabolism and excretion of Pyragrel.

  8. 大孔树脂分离纯化玫瑰果多酚及其抗氧化性%Separation and purification of rosehip polyphenols by macroporous resin and its antioxidant activity

    Institute of Scientific and Technical Information of China (English)

    甘芝霖; 倪元颖; 郭悦; 陈小松

    2015-01-01

    Rosehip contains many kinds of beneficial active substances that human body needs, for example, polyphenols. The present study focuses on the separation and purification technology of crude polyphenol extracted from rosehip by using a macroporous adsorption resin method. Four different types of macroporous resins (ADS-17, AB-8, NKA-9 and D101) were adopted. Through the comparison of the separation effect, AB-8 was selected as the experimental adsorbent due to the strong adsorption ability and high desorption rate. Based on the adsorption isotherm, the adsorptive amount of AB-8 increased gradually with the increasing of polyphenols equilibrium concentration at first and then tended to change gently. The nonlinear curve fitting was conducted with the Langmuir and Freundlich models. Both of the models performed effectively with theR2 of over 0.99, and the Langmuir (R2=0.9999) was more suitable than the Freundlich (R2=0.9948). Static and dynamic adsorption, and desorption experiment results indicated that sample concentration, temperature, pH value, flow velocity of sample, ethanol concentration, and flow velocity of desorption were the major parameters in the process of separating and purifying the rosehip polyphenols by macroporous adsorption resin technology. The optimum conditions were as follows: at room temperature, using AB-8 macroporous resin, the concentration of crude polyphenol extract was 0.80 mg/mL at pH=6.5, with the 1 mL/min flow and the adsorption injection of 200 mL, and the eluting solvent was 70% ethanol with the flow rate of 1.5 mL/min and the volume of 70 mL. Then the effect of purification was determined by total phenol content and total antioxidant capacity. Total phenol content was measured by the Folin-phenol reagent method. The result showed that purified polyphenol solution gained a concentration of 399.42 mg/g, which was 3.25 times higher than the crude polyphenol extract that was 122.90 mg/g. Also the total antioxidant capacity was

  9. Separation and purification of soluble dietary fiber from peanut null with macroporous resin%大孔树脂分离纯化花生壳水溶性膳食纤维工艺条件研究

    Institute of Scientific and Technical Information of China (English)

    牛会敏; 王若兰

    2013-01-01

      选取8种大孔吸附树脂进行静态吸附性能研究,筛选出最有效D101树脂分离纯化花生壳水溶性膳食纤维.通过动态吸附性能研究,确定应用D101树脂分离纯化花生壳水溶性膳食纤维优化工艺条件;在上样流速2 ml/min、上样液质量浓度为1 mg/mL~2 mg/mL、上样液pH为10左右条件下吸附较强;在洗脱剂乙醇体积分数为70%、洗脱液流速为1 ml/min洗脱时洗脱效果最好.经紫外光谱扫描及SDF纯化物纯度测定结果显示,经纯化后花生壳水溶性膳食纤维纯度较高,可达96.4%;且蛋白含量较少,仅为0.23%.%Eight kinds of macroporous resins adsorption property had been investigated in isolating and purifying soluble dietary fiber from peanut null. D101 type resin as the optimal absorbent material for soluble dietary fiber from peanut null was decided and its dynamic absorbing behavior was studied. The results showed that:D101 type resin possesses higher absorption and desorption capacity;the optimal technological conditions of adsorption velocity was 2 ml/min,solution concentration was 1 mg/mL to 2 mg/mL,solution pH was about 10,and the eluting solvent was 70%ethanol at 1 ml/min flow rate. UV spectral analysis and purity determination indicated the purified soluble dietary fiber from peanut null had high purity(96.4%)and contained little impurity(0.23%).

  10. Adsorptive stripping voltammetric determination of imipramine, trimipramine and desipramine employing titanium dioxide nanoparticles and an Amberlite XAD-2 modified glassy carbon paste electrode.

    Science.gov (United States)

    Sanghavi, Bankim J; Srivastava, Ashwini K

    2013-03-07

    An Amberlite XAD-2 (XAD2) and titanium dioxide nanoparticles (TNPs) modified glassy carbon paste electrode (XAD2-TNP-GCPE) was developed for the determination of imipramine (IMI), trimipramine (TRI) and desipramine (DES). The electrochemical behavior of these molecules was investigated employing cyclic voltammetry (CV), chronocoulometry (CC), electrochemical impedance spectroscopy (EIS) and adsorptive stripping differential pulse voltammetry (AdSDPV). After optimization of analytical conditions using a XAD2-TNP-GCPE electrode at pH 6.0 phosphate buffer (0.1 M), the peak currents were found to vary linearly with its concentration in the range of 1.30 × 10(-9) to 6.23 × 10(-6) M for IMI, 1.16 × 10(-9) to 6.87 × 10(-6) M for TRI and 1.43 × 10(-9) to 5.68 × 10(-6) M for DES. The detection limits (S/N = 3) of 3.93 × 10(-10), 3.51 × 10(-10) and 4.35 × 10(-10) M were obtained for IMI, TRI and DES respectively using AdSDPV. The prepared modified electrode showed several advantages such as a simple preparation method, high sensitivity, very low detection limits and excellent reproducibility. The proposed method was employed for the determination of IMI, TRI and DES in pharmaceutical formulations, blood serum and urine samples.

  11. ADSORPTION AND DESORPTION PROPERTIES OF MACROPOROUS RESIN TO PINORESINOL DIGLUCOSIDE IN LIQUID CULTURE%大孔树脂对发酵液中松脂醇二葡萄糖苷的吸脱附性能

    Institute of Scientific and Technical Information of China (English)

    刘超; 师俊玲; 刘拉平

    2011-01-01

    考察了S-8、AB-8、NKA-II、NKA-9 4种大孔吸附树脂对杜仲内生真菌拟茎点霉属XP-8发酵液中松脂醇二葡萄糖苷(Pinoresinol Diglucoside,PDG)的吸附和脱附性能,筛选出S-8树脂的吸附和脱附性能最好;探讨了S-8树脂在静态吸附条件下对发酵液中PDG的吸附平衡和吸附动力学,考察了温度和pH值对吸附效果的影响;进行了动态吸附实验,确定了最佳吸附和洗脱条件.结果表明,在静态吸附条件下,Langmuir方程可很好地描述PDG在S-8树脂上的吸附平衡,液膜扩散和颗粒内扩散分剐是控制吸附初期和后期吸附速率的主要步骤;动态吸附的最佳条件是,上样浓度为0.195mg/mL、上样温度为20℃、pH 9、进样流速1BV/h,溶液处理量20BV;最佳动态洗脱条件是,洗脱液为30%的乙醇水溶液,洗脱液流速1BV/h,用量为6BV.整个动态吸附洗脱过程结束后的PDG得率为89.8%.%Four macroporous resins, including of S-8, AB-8, NKA- II and NKA-9, were studied on separation and purification of Pinoresinol Diglucoside (PDG) in the liquid culture of Phomopsis sp., a strain isolated from Eucommia ulmoides Oliv. The experimental results showed that S-8 resin could achieve better adsorption and desorption performance than others. With S-8 resin, equilibrium and kinetics of static adsorption of PDG were studies in detail and the effects of temperature and pH on the adsorption performance were also discussed. The dynamic adsorption and desorption conditions of S-8 resin for PDG were optimized. The results indicated that isothermal sorption process of PDG on S-8 resin could be well described by Langmuir equation, and the adsorption rate of the initial stage and the later stage were controlled by liquid film diffusion and inner-particle diffusion, respectively. The optimum dynamic adsorption conditions for PDG were as follows: PDG concentration, 0.195mg/mL; pH 9; adsorption temperature, 20°C; flow rate, lBV/h; and saturated adsorption

  12. Decoloration of Raffinose Extract Solutions via Macroporous Resin Adsorption%棉籽糖提取液树脂吸附脱色

    Institute of Scientific and Technical Information of China (English)

    段舒然; 鲍宗必; 闻光东; 陈丽芬; 杨亦文

    2016-01-01

    Raffinose extract solutions contain considerable amounts of colored impurities, and those hydrophobic pigments can be removed by organic solvent extraction. However, there are still water-soluble pigments that can affect the product purity and crystallization processes. In this study, decoloration performance using several resins (HZ-801, HZ-803, HZ-806, HZ-818, D303 and D313) was compared with activated carbon, and the adsorption conditions were optimized according to raffinose decoloration ratio and loss ratio. The results show that HZ-818 is the best candidate with the highest decoloration ratio of 77.1% and loss ratio of 2.4%. The process shows the best cost-effectiveness when the dosage is 2.0 g resin per 10 mL solution under contact time of 9 h. The spent resin can be regenerated with 60% aqueous ethanol and the recycled resins are further used with decoloration ratio up to 94.0%.%棉籽糖的提取液中含有大量的有色杂质,经有机溶剂脱酚处理除去大部分疏水性色素,仍有少量水溶性色素残留,它们的存在会影响棉籽糖产品的纯度、色泽及结晶过程。研究以脱色率和棉籽糖损失率为指标,对比了HZ-801、HZ-803、HZ-806和HZ-818等四种大孔吸附树脂及D313、D303弱碱性阴离子交换树脂与活性炭的脱色性能,考察了影响静态吸附脱色的操作条件及脱色动力学,结果表明:HZ-818树脂为棉籽糖提取液的最佳脱色树脂,单次脱色率最高,达77.1%,棉籽糖损失率2.4%;树脂用量为2.0 g树脂/10 mL溶液、脱色时间为9 h时脱色过程较为经济。吸附色素的树脂可通过60%的乙醇水溶液进行再生,再生后树脂对原料液进行脱色实验,脱色率达94.0%。

  13. Report on use of XAD resins in racing chemistry.

    Science.gov (United States)

    Johnston, G. H.

    1976-01-01

    This report comprises a summary of the work done with XAD resin extraction by racing chemists and reported in the Association of Official Racing Chemists publications. It is apparent that the use of XAD resins is becoming more popular in racing laboratories as a technique for routine screening and also for the extraction of certain conjugated drugs. Most laboratories employ variations on the original Brinkmann Drug-Skreen Technique. Comparisons of the efficiency of extraction of drugs from horse urine by XAD-2 resin and by chloroform column extraction indicate that some drugs can be extracted with equal or greater efficiency by the resin technique. PMID:1000159

  14. 顶空气相色谱法测定大孔树脂提取物中的残留溶剂研究%Determination of residual solvents in macroporous resin extracts by Head-space capillary gas chromatography

    Institute of Scientific and Technical Information of China (English)

    刘冬; 杨敬芝; 杜守颖; 张东明; 赵立敏; 陈雯

    2009-01-01

    目的:建立了测定大孔树脂淫羊藿提取物、栀子提取物以及HP中乙醇、正己烷、苯、甲苯、甲基环己烷、二甲苯、苯乙烯、二乙烯苯残留有机溶剂含量的顶空气相色谱法.方法:采用顶空气相色谱法,FID检测器,以20%~50%二甲基亚砜为溶媒,顶空预热温度为90℃,预热时间为10 min,进样口温度为180℃,检测器温度为250℃,以氮气为载气,使用DB-1交联毛细管柱(60m×0.32mm,1 μm),程序升温,实现了各组分的基线分离.结果:乙醇、正己烷、苯、甲苯、甲基环己烷、二甲苯、苯乙烯、二乙烯苯在各自对应的浓度范围内,线性关系良好;乙醇、正己烷、苯、甲苯、甲基环己烷、二甲苯、苯乙烯、二乙烯苯的最小检测限分别为2.72,0.22,0.03,0.03,0.28,0.33,0.03,0.31 μg·mL~(-1);加样回收率均在75%以上,精密度较好.结论:经方法学验证,该方法灵敏、准确、可靠,可适用于大孔树脂淫羊藿提取物、栀子提取物及HP中乙醇、正己烷、苯、甲苯、甲基环己烷、二甲苯、苯乙烯、二乙烯苯等残留有机溶剂的测定.%Objective:This paper reports a Head-space GC method for determination of enthanol,hexane,benzene,toluene,methyl cyclohexane,xylene,styrene,divinyl benzene in macroporous resin extractions.Method:The analytical coluren was DB-1(60m×0.32mm,1μm).The injector temperature was 180℃ and the detector tempemture was 250℃.The column temperature was programmed raised.The carrier gas was nitrogen and the solvent was 20%-50% dimethyl sulfoxide.Results:The stand curve were linear for each solvents in the range of each consistencv.The average recoveries were all more than 75%.Conclusion:This method is simple,rapid and precise,it is suitable for measurement of residual solvents in macroporous resin extracts.

  15. 大孔吸附树脂分离纯化普那霉素的研究%Study on Isolation and Purification of Pristinamycin by Macroporous Adsorptive Resin

    Institute of Scientific and Technical Information of China (English)

    张雪霞; 李宁; 李晓露; 王健; 王海燕; 林毅; 王秀捧; 蒋沁

    2011-01-01

    用大孔吸附树脂法代替溶媒萃取法分离纯化普那霉素。将普那霉素发酵液预处理后,以大孔吸附树脂XAD1600作吸附剂,在吸附流速为2 BV·h-1的条件下进行吸附;再用40%乙醇—60%酸水(含0.1%的乙酸,下同)进行洗脱,去除色素和杂质;最后用90%乙醇—10%酸水以0.5 BV·h-1流速进行洗脱。得到的普那霉素含量达98.5%以上、收率达到64%左右,产品质量符合法国药典规定。该方法操作简便、成本低、收率高,适于工业化生产。%The pristinamycin was isolated and purified by macroporous adsorptive resin instead of by solvent extraction method. The experiment showed that pristinamycin content and yield reached above 98. 5%, about 64%, respectively, through adsorption by XAD1600 as absorbent at a flow speed of 2 BV · h-1 , and desorption by 40% ethanol-60% H2O containing 0. 1% CH3COOH to remove the coloured impurities and minor components firstly, desorption by 90% ethanol-10% H2O containing 0. 1% CH3COOH at a flow speed of 0. 5 BV · h finally. The quality of the product conformed to the requirements of the French pharmacopoeia. This method fits for industrial production with simple operation, low cost and high yield.

  16. AB-8大孔树脂对柴胡总黄酮的吸附行为研究%Adsorption behavior of AB-8 macroporous resin for total flavonoids in Bupleurum

    Institute of Scientific and Technical Information of China (English)

    徐祖伟; 于朝生; 窦烁

    2013-01-01

    采用静态吸附法研究了AB-8树脂对柴胡总黄酮的吸附动力学及热力学特性.动力学研究表明,准二级动力学模型能较好地描述整个吸附过程;颗粒内扩散模型拟合的曲线呈现多重线性,说明不同阶段的吸附速率受到树脂孔径分布的影响.热力学研究表明,在实验温度下,AB-8树脂对柴胡总黄酮的吸附过程符合Langmuir等温模型,吸附的吉布斯自由能变△G(⊕) <0,焓变△H(⊕)和熵变△S(⊕)分别为10.51 kJ/mol和44.15 J/(mol·K),说明该吸附能是自发进行的吸热过程.%The kinetics and thermodynamics of the adsorption of total flavonoids in Bupleurum by AB-8 macroporous resin were studied using the static adsorption method. The kinetics results show that the pseudo-second order kinetics model can better describe the whole adsorption process. The multicollinearity of curves fitted by the intra-particle diffusion model demonstrates that the adsorption rates at different stages are influenced by the pore size distribution. The thermodynamics results show that the adsorption process fits the Langmuir isothermal model in the studied temperature range. The thermodynamic properties,i. e. △GΘ <0,△HΘ = 10. 51 kJ/mol and ASΘ = 44. 15 J/(mol · K) , indicate that the adsorption process is spontaneous and endothermic.

  17. 大孔吸附树脂纯化“黑美人”土豆色素研究%Study on the preliminary purification of pigment from "Black Beauty" potato by macroporous resin

    Institute of Scientific and Technical Information of China (English)

    张勇; 李彩霞; 麻贝贝; 壬兴德; 王秀梅

    2012-01-01

    比较了5种大孔吸附树脂时“黑美人”土豆色素的吸附和解吸效果,研究了AB-8树脂对“黑美人”土豆色素的静态吸附和解吸性能。结果表明,“黑美人”土豆色素在AB-8树脂上吸附平衡时间为8h,解吸平衡时间为2h,在吸附液pH3.0、温度为40℃时吸附能力最强;以pH3.0的90%的乙醇为洗脱液解吸效果较好。经AB-8大孔吸附树脂纯化后的色素色价比粗品提高了8.4倍。实验结果表明,AB-8树脂可用于“黑美人”土豆色素的分离与纯化。%The absorption and desorption effects of 5 kinds of macroporous absorption resins on pigment from "Black Beauty" potato were compared,and the properties of static adsorption and desorption for AB-8 on "Black Beauty" potato pigment were further investigated.The results showed that the time of absorption and desorption equilibrium were 8h and 2h. Under the conditions of pH 3.0 and 40℃, the highest adsorpion ability for " Black Beauty" potato pigment was achieved,and elution the effect was better by using 90% ethanol solution at pH 3.0, which resulted in a 8.4-fold increase of color value.The results indicated that AB-8 resin could be used for separating and purifying for pigment from" Black Beauty" potato.

  18. Adsorption separation of olive polyphenols from olive oil processing effluent by AB-8 macroporous resin%AB-8大孔树脂吸附分离橄榄油加工废液中的橄榄多酚

    Institute of Scientific and Technical Information of China (English)

    白万明; 黄根胜; 孔维宝; 白小勇; 张继

    2015-01-01

    The olive polyphenols ( OPP) were separated from olive oil processing effluent using AB -8 macroporous resin. The process conditions of static adsorption, static desorption and dynamic elution were investigated respectively. The results showed that the optimal static adsorption conditions were obtained as follows:dosage of pretreated resin 1. 5 g, adsorption time 3 h and adsorption temperature 30℃, under these conditions,the adsorption capacity of 20 mL crude extract diluent ( OPP mass concentration 1. 52 mg/mL) reached 14. 43 mg/g;the optimal dynamic elution conditions were obtained as follows: elution rate 1. 0 mL/min, subsection elution with water, 70% and 90% of ethanol solutions. Under the com-bined condition of static adsorption and dynamic subsection elution, the purity of OPP after purification was 56. 44%,which was 7. 93 times as high as that of crude extract diluent.%采用AB-8大孔树脂吸附分离橄榄油加工废液中的橄榄多酚。分别考察了静态吸附、静态解吸和动态洗脱工艺条件。结果表明:适宜的静态吸附条件为在30℃下用1.5 g预处理的树脂吸附20 mL橄榄多酚质量浓度为1.52 mg/mL的粗提稀释液,吸附3 h时吸附量可达14.43 mg/g;动态洗脱橄榄多酚的适宜条件为洗脱流速1.0 mL/min,依次用蒸馏水、70%乙醇溶液、90%乙醇溶液进行分段洗脱。在静态吸附和动态分段洗脱的组合条件下,纯化所得橄榄多酚的纯度为56.44%,为粗提稀释液的7.93倍。

  19. Optimization of Purification Technology for Effective Parts from Compound Tongmai Granules by AB-8 Macroporous Absorption Resin%AB-8型大孔吸附树脂纯化复方通脉颗粒有效部位的工艺优选

    Institute of Scientific and Technical Information of China (English)

    陈超; 陈国芹; 陈阿丽; 崔红花; 郭嘉雯; 王淑美

    2013-01-01

    Objective:To optimize purification technology of compound Tongmai granules by macroporous resin. Method:Taking adsorption-desorption rate of total phenolic acid and puerarin as indexes, effect of the concentration of sample solution, diameter-height ratio, elution agent on purification technology of compound Tongmai granules was investigated by single factor test. Result:AB-8 macroporous absorption resin was the best resin, optimum purification technology was as following; the concentration of sample solution 110 g · L-1, diameter-height ratio of resin column 1:10, ratio of resin-material drug 2. 8:1 ( adsorbed 3 h), eluted with 2 BV water, then eluted with 6 BV 50% ethanol, collected eluent. Conclusion:This optimized purification technology was reasonable and stable, it could be extended to large-scale production applications.%目的:优选复方通脉颗粒的大孔树脂纯化工艺.方法:以总酚酸,葛根素的吸附-洗脱率为指标,采用单因素试验考察上样液质量浓度、径高比、洗脱剂等对复方通脉颗粒大孔树脂纯化工艺的影响.结果:优选的纯化工艺为上样液质量浓度110 g·L-1,树脂柱径高比1∶10,树脂体积与上样量比2.8∶1(吸附3h),加2BV水洗除杂,用6 BV 50%乙醇洗脱,收集洗脱液.结论:该纯化工艺合理、稳定,可推广于大生产应用.

  20. Separation and preconcentration of Cd(II), Cu(II), Ni(II), and Pb(II) in water and food samples using Amberlite XAD-2 functionalized with 3-(2-nitrophenyl)-1H-1,2,4-triazole-5(4H)-thione and determination by inductively coupled plasma-atomic emission spectrometry.

    Science.gov (United States)

    Kumar, Bommana Naresh; Ramana, D K Venkata; Harinath, Yapati; Seshaiah, Kalluru; Wang, M C

    2011-10-26

    A separation and preconcentration procedure was developed for the determination of trace amounts of Cd(II), Cu(II), Ni(II), and Pb(II) in water and food samples using Amberlite XAD-2 fuctionalized with a new chelating ligand, 3-(2-nitrophenyl)-1H-1,2,4-triazole-5(4H)-thione (Amberlite XAD-2-NPTT). The chelating resin was characterized by Fourier transform infrared spectroscopy (FT-IR) and used as a solid sorbent for enrichment of analytes from samples. The sorbed elements were subsequently eluted with 10 mL of 1.0 M HNO(3), and the eluates were analyzed by inductively coupled plasma-atomic emission spectrometry. The influences of the analytical parameters including pH, amount of adsorbent, eluent type and volume, flow rate of the sample solution, volume of the sample solution, and effect of matrix on the preconcentration of metal ions have been studied. The optimum pH for the sorption of four metal ions was about 6.0. The limits of detection were found to be 0.22, 0.18, 0.20, and 0.16 μg L(-1) for Cd(II), Cu(II), Ni(II), and Pb(II), respectively, with a preconcentration factor 60. The proposed method was applied successfully for the determination of metal ions in water and food samples.

  1. 大孔树脂吸附去除水中的2,4,6-三硝基甲苯%Removing 2,4,6-trinitrotoluene from water by macroporous resins

    Institute of Scientific and Technical Information of China (English)

    张青梅; 刘湛; 马超; 向仁军

    2012-01-01

    研究了2种大孔树脂XAD-4和NDA-804对水中的TNT的吸附行为。2种树脂对TNT的吸附等温线表明,温度的升高有利于吸附,在35℃条件下XAD-4树脂与NDA-804树脂对TNT的最高平衡吸附量分别达82.86 mg/g和94.26mg/g。采用Langmuir方程和Freundlich方程用于吸附等温线的解释,结果表明,吸附等温线更加符合Langmuir模型,相关系数均大于0.99。TNT在2种树脂上的吸附符合准二级动力学方程,TNT初始浓度越低,达到吸附平衡所需时间越短,在1 h内可达到吸附平衡。采用NDA-804处理对TNT废水,废水中TNT浓度由103.58 mg/L降至0.4 mg/L,去除率达99.6%,吸附后的树脂采用pH=2的乙醇和盐酸的混合液脱附可再生,高浓度再生溶液经蒸馏可回收TNT,实现了废水治理与资源化。%Adsorption of 2,4,6-trinitrotoluene onto two kinds of macroporous resin including XAD-4 and NDA-804 was studied.The adsorption isotherms of TNT onto resins were measured.Raising the temperature was advantageous to adsorption.The maximum equilibrium adsorption capacities of XAD-4 and of NDA-804 at 35 degrees were 82.86 mg/g and 94.26 mg/g,respectively.The TNT adsorption behaviors could be better described using the Langmuir adsorption model than the Freundlich adsorption model,and the correlation coefficient was greater than 0.99.The kinetics of TNT adsorption onto resins obeyed pseudo-second order kinetic model.The lower the initial TNT solution concentration,the shorter time of the adsorption equilibrium was.The time until equilibrium was 1 hour.The NDA-804 was applied to treat TNT manufacturing wastewater.The TNT concentration in the wastewater decreased from 103.58 mg/L to 0.4 mg/L after adsorption by NDA-804,indicating a high removal efficiency of 99.6%.The NDA-804 could be regenerated by a mixed solution of HCl and methanol with pH of 2.The TNT would be subsequently recovered from the high concentrated regenerant solution by distillation.

  2. 大孔吸附树脂分离纯化芝麻素的研究%STUDY ON SEPARATION AND PURIFICATION OF SESAMIN BY USING MACROPOROUS ADSORPTION RESIN

    Institute of Scientific and Technical Information of China (English)

    张涛; 魏安池; 刘若瑜

    2012-01-01

    采用DA -201大孔吸附树脂从芝麻混合油中分离纯化芝麻素,优化得到最佳工艺条件为:上样液中芝麻素浓度3.0 mg/mL左右,吸附流速3.0 BV/h;解吸液为体积分数95%的乙醇,解吸流速3.0 BV/h,解吸液用量8.0 BV;在此条件下,芝麻素回收率为85.21%,分离得到的芝麻素浓缩物中芝麻素含量为13.00%,与芝麻原油相比,纯度提高了近12倍.芝麻素浓缩物经过结晶纯化,得到最终产品中芝麻素的总回收率为62.06%,产品纯度为89.49%.%In this paper,we determined the optimized processing conditions for separating and purifying sesa-min from mixed sesame oil by using macroporous adsorption resin DA-201. The optimized conditions were as follows:the concentration of sesamin in loading solution was about 3.0 mg/mL,and the adsorption flow rate was 3. 0 BV/h;95% ethanol was used as desorption solvent;and the desorption rate and the amount of the de-sorption solvent were 3. 0 BV/h and 8. 0 BV respectively. Under the optimized conditions, the recovery rate of sesamin reached 85.21% ,and the yield of seamin was 13% , so that the purity of sesamin was improved by nearly 12 times in comparison with crude sesame oil. The total recovery rate and the purity of sesamin in the final product obtained by crystallizing the sesamin concentrate were 62. 02% and 89. 49% ,respectively.

  3. 真菌诱导子与吸附树脂对新疆紫草毛状根中萘醌积累的影响%Influence of fungal elicitor and macroporous resin on shikonin accumulation in hairy roots of Arnebia euchroma (Royle) Johnst

    Institute of Scientific and Technical Information of China (English)

    张璞; 王芳; 朱查山

    2013-01-01

    In order to investigate the effects of fungal elicitor and macroporous adsorption resin on shikonin accumulation in hairy roots of arnebia euchroma (Royle) Johnst, we used spectrophotometry to determine the total naphthoquinone content of the hairy roots, by adding different volume ratio of Aspergillus niger elicitor, Aspergillus oryzae elicitor, and the macroporous resin into the M-9 liquid medium at different culture time. The results show that the total naphthoquinone content was 2.28 times higher than the control when we added mixed elicitors of Aspergillus niger and Aspergillus oryzae at the ratio of 2.5:50 in the 10th day of hairy roots cultivating. The total naphthoquinone content was 3.71 times higher than that of the control, when we added macroporous adsorption resin NKA-9. Aspergillus niger elicitor exhibited synergistic effect with Aspergillus oryzae elicitor to enhance the naphthoquinone. Also, the total naphthoquinone level was 4.17 times higher than that of the control by adding mixed fungal elicitor and macroporous adsorption resin NKA-9 in the bioreactor. Aspergillus oryzae and mixed elicitor could promote the hairy roots proliferation, and macroporous adsorption resin NKA-9 and mixed elicitor increased the total naphthoquinone content. In summary, the measure developed for Arnebia euchroma (Royle) Johnst hairy roots cultivating in bioreactors may potential for large-scale production of naphthoquinone.%通过考察真菌诱导子与吸附树脂对新疆紫草毛状根中萘醌积累的影响,获得真菌诱导子与吸附树脂对萘醌类物质积累的最佳处理,为规模化生产提供依据.以新疆紫草毛状根为试验材料,将黑曲霉、米曲霉诱导子及其混合诱导子、大孔吸附树脂添加到M-9培养基中,采用分光光度法测定毛状根总萘醌含量.试验结果表明:在毛状根培养10d时以2.5∶50的比例添加混合诱导子,总萘醌含量是对照的2.28倍;在此结果基础上,在培养第0

  4. Purification of polyphenols from pinus sylvestris L.var. mongolica barks by macroporous resin%大孔树脂对樟子松树皮多酚的纯化工艺的研究

    Institute of Scientific and Technical Information of China (English)

    刘荣; 何娇; 王振宇

    2013-01-01

    Objective:Optimized the purification process of polyphenols from Pinus sylvestris L.bark and made the best use of its polyphenols resource.Method:The adsorption rate and desorption rate were detection indicators.Optimum resin for purification of polyphenols was determined.As the index to recovery and purity of polyphenols,influential factors were successively investigated,and the response surface design was used to optimize this process.Result:The optimum conditions of purification were sample solution concentration 3.0mg/mL,30mL sample solutionin in pH 3.5,feeding speed 5BV/h,eluting speed 4.25BV/h and the concentration of ethanol 53 %.Purity of Pinus sylvestris L.bark polyphenols was 67.91% and the recovery was 68.12 %.Conclusion:Purity of pinus sylvestris L bark polyphenols was from 37.25% to 67.91% according to this purification condition,which indicated that D101 macroporous resin had distinct effect on purification of polyphenols from pinus sylvestris Lvar.mongolica barks.%目的:优化樟子松树皮多酚纯化工艺,提高松多酚资源利用率.方法:以吸附率和解析率为衡量指标,确定纯化樟子松树皮多酚的最佳树脂;以多酚纯度和回收率为衡量指标,研究纯化过程中影响较大的因素,并且利用响应面优化樟子松树皮多酚的纯化工艺.结果:樟子松树皮多酚纯化的最佳工艺条件为:上样浓度3.0mg/mL,上样体积30mL,样液pH3.5,上样流速5BV/h,洗脱流速4.25BV/h,洗脱乙醇浓度53%.在此条件下,樟子松树皮多酚纯度可达67.91%,回收率为68.12%.结论:经D101大孔树脂纯化,樟子松树皮多酚纯度由37.25%升高至67.91%,说明D101大孔树脂对樟子松树皮多酚的纯化具有显著作用.

  5. 两种大孔吸附树脂对麻黄碱和伪麻黄碱的吸附动力学和热力学研究%ADSORPTION KINETICS OF EPHEDRINE AND PSEUDO EPHEDRINE ON TWO TYPES OF MACROPOROUS RESINS

    Institute of Scientific and Technical Information of China (English)

    索绪斌; 王文青; 徐兴; 张涵

    2014-01-01

    Isothermic adsorptions of ephedrine and pseudo ephedrine on two types of macroporous resins,AB-8 and D101,were preliminarily examined,and the experimental data were fitted by Langmuir model.Thermodynamic parameters (ΔHm,ΔGm and ΔSm) were calculated according to Van't Hoff equation.The adsorptions of ephedrine and Pseudo ephedrine on macroporous resins of AB-8 and D101 were also studied.The experimental results of adsorption kinetics showed that the data complied with the Freundlich adsorption isotherm equation and Langrnuir equilibrium adsorption rate equation.Adsorption enthalpy change (ΔHm) and entropy change (ΔSm) were greater than zero,while Gibbs energy change (ΔGm) was less than zero,which indicated that ephedrine and Pseudo ephedrine adsorbed on the resins were spontaneously physical adsorption process.%通过等温静态吸附实验研究大孔树脂AB-8和D101对麻黄碱及伪麻黄碱的等温吸附过程,根据Langmuir平衡吸附速率方程考察两种树脂对两种成分吸附的平衡速率常数,用Van'tHoff公式计算各热力学参数(ΔHm,ΔGm及ΔSm).结果表明麻黄碱、伪麻黄碱的吸附平衡数据符合Freundlich吸附等温方程和Langmuir平衡吸附速率方程,相关性良好.吸附的焓变(△Hm)和熵变(ΔSm)均大于零,吉布斯自由能变(ΔGm)均小于零,表明麻黄碱及伪麻黄碱在树脂上的吸附属于自发的物理吸附过程.

  6. Separation of Crocin and Picrocrocin from Saffron Cell Culture Broth by Macroporous Resin Adsorption%利用大孔吸附树脂吸附分离藏红花细胞培养液中藏红花素和藏红花苦素

    Institute of Scientific and Technical Information of China (English)

    吴频梅; 袁丽红; 黄晶; 孙镇

    2011-01-01

    Objective: The separation of crocin and picrocrocin from saffron cell culture broth was investigated by macroporous resin adsorption.Methods: The effectiveness of 4 types of macroporous resin was compared in separating crocin and picrocrocin.The application of HPD-100A resin for separating crocin and picrocrocin from saffron cell culture broth was optimized.Results: HPD-100A resin was the best resin to separate crocin and picrocrocin from saffron cell culture broth among the investigated ones.The best separation of crocin and picrocrocin was achieved as an adsorption rate of 94.4% and 75.5% and a desorption rate of 99.9% and 87.5%,respectively when the cell culture broth was concentrated until a concentration of 1.0 mg/mL and 24.6 mg/mL for crocin and picrocrocin,respectively,temperature 25 ℃,pH 6,and 1.5 BV of each concentrate was loaded onto the column at a flow rate of 1.5 mL/min after being adjusted to pH 6 and then eluted with 1.7 BV of 40% aqueous ethanol at a flow rate of 1.0 mL/min.Conclusion: Macroporous resin adsorption is feasible and holds promise for separating crocin and picrocrocin from saffron cell culture broth.%目的:研究大孔树脂提取藏红花细胞培养液中藏红花素和藏红花苦素的工艺。方法:对4种大孔树脂提取藏红花素和藏红花苦素的效果进行比较,考察HPD-100A大孔树脂提取藏红花素和藏红花苦素的最佳工艺条件。结果:HPD-100A树脂提取藏红花素和藏红花苦素效果最佳,其最适工艺条件为25℃、色素液pH6、藏红花素和藏红花苦素上样质量浓度分别为1.0mg/mL和24.6mg/mL、溶液处理量1.5BV、吸附流速1.5mL/min、洗脱剂为体积分数40%乙醇溶液、洗脱剂体积1.7BV、洗脱流速1.0mL/min。藏红花素和藏红花苦素的吸附率分别达到94.4%和75.5%,解吸率分别为99.9%和87.5%。结论:采用大孔吸附树脂吸附分离藏红花培养液中藏红花素和藏红花苦素方法可行,前景广阔。

  7. 不同大孔树脂对粉被虫草中 N6-(2-羟乙基)腺苷的分离特性研究%Desorption Characteristic of N6 -(2-hydroxyethyl)-Adenosine from Cordyceps pruinosa Petch by Different Macroporous Resin

    Institute of Scientific and Technical Information of China (English)

    唐远江; 雷帮星; 康冀川; 刘玉秋

    2015-01-01

    为选择合适的大孔树脂分离粉被虫草中的 N6-(2-羟乙基)腺苷(HEA),通过静态吸附与解吸附试验对4种大孔树脂吸附和解吸附 HEA 的效果进行比较,并对洗脱条件进行优化。结果表明 DM-130树脂对 HEA 的吸附量最大、解吸率较高;该树脂的最佳动态吸附条件是上样量为2倍树脂床体积(BV),吸附时间为6 h;最佳动态洗脱条件是依次用3 BV 蒸馏水,1 BV 5%乙醇和3.5 BV 10%乙醇冲洗柱床。在该条件下,经 HPLC 分析测定,洗脱液中 HEA 的峰面积百分比达到89.15%。%In order to select the appropriate macroporous resin to isolate N6 -(2-hydroxyethyl)-Adenosine from Cordyceps pruinosa Petch,tests using four kinds of macroporous resin to absorb and desorb HEA were a-dopted,and the elution conditions were also optimized.The results showed that DM-1 30 resin had the high-est resolution and greater adsorption for HEA.The best elution conditions for dynamic adsorption were as fol-lows:the loading amount was 2 times bed volume (BV)and the adsorption time was 6 h;the best elution conditions were that DM-1 30 resin should be eluted sequentially with 3 BV water,1 BV 5% ethanol and 3.5 BV 1 0% ethanol.HPLC analysis showed that under the optimum conditions peak area percentage of HEA was 89.1 5% in eluent.

  8. THE SYNTHESIS OF MACROPOROUS CROSSLINKED POLYSTYRENE AMIDOPHOSPHONIC ACID

    Institute of Scientific and Technical Information of China (English)

    HE Binlin; WANG Linfu; CHEN Weizhu

    1984-01-01

    A series of macromolecular copolymers of styrene and divinyl-benzene were prepared in the presence of iso-octanol or 2-ethyl butyl alcohol. The factors which affected the physical structures of the copolymer were discussed. The macroporous amido-phosphonic acid resin was obtained after the acetylation, phosphonylation and amination of the crosslinked polystyrene. The factors which affected each reaction were studied and the change of physical structures of the copolymer were discussed.

  9. Adsorption and Isolation of Macroporous Resin for Three Isoflavonoids from Puerariae Lobatae Radix%大孔吸附树脂对葛根中3种异黄酮类化合物的吸附分离研究

    Institute of Scientific and Technical Information of China (English)

    崔蕴慧; 王治平; 樊化; 杨珂

    2013-01-01

    Objective:To study the adsorption function of macroporous resins for the separation and purification of three isoflavonoids (3 '-hydroxypuerarin,puerarin,daidzin) in Puerariae Lobatae Radix.Methods:The contents of 3'-hydroxypuerarin,puerarin,daidzin were determined by HPLC.D101,AB-8,XDA-5,HP-20 and other five resins were systematically investigated for their adsorption capability,adsorption isothermal curve,adsorption and elution properties with static and dynamic experiments.Results:Experimental results showed that macroporous resin XDA-5 owned optimum adsorption and elution parameters.Optimal conditions for adsorption and elution the three components were:per 1 mL solution contained Puerariae Lobatae Radix 0.5~0.8g,flow rate 2BV/h,adsorbed 3'-hydroxypuerarin,puerarin and daidzin could be desorbed by alcohol at flow rate 1BV/h.Conclusion:The purity of 3'-hydroxypuerarin,puerarin and daidzin of the product obtained from Puerariae Lobatae Radix with optimum technology is 23.39%,52.09% and 19.21%,respectively.%目的:选择适合分离纯化葛根中3种成分的大孔吸附树脂.方法:以3'-羟基葛根素、葛根素及大豆苷的吸附率及解析率为评价指标,考察葛根3种异黄酮成分的吸附与解吸能力、吸附等温线、漏出曲线及洗脱曲线.结果:XDA-5树脂分离纯化3’-羟基葛根素、葛根素及大豆苷的较优工艺条件为:上样液浓度为每1mL含葛根0.5~0.8g,流速2BV/h,乙醇梯度洗脱,洗脱速度1BV/h.结论:该工艺条件所得纯化物中,3’-羟基葛根素、葛根素、大豆苷的含量分别为23.39%、52.09%和19.21%.

  10. Indium determination in different environmental materials by electrothermal atomic absorption spectrometry with Amberlite XAD-2 coated with 1-(2-pyridylazo)-2-naphthol.

    Science.gov (United States)

    Martínez A, N C; Barrera, Adela Bermejo; Bermejo B, P

    2005-04-30

    Methods were developed for indium (In) determination in complex ores by electrothermal atomization atomic absorption spectrometry using matrix modification after its separation with Amberlite XAD-2 coated with 1-(2-pyridylazo)-2-naphthol (PAN). Palladium-magnesium, nickel, and zinc nitrates were used as matrix modifiers and were compared in terms of maximum pyrolysis temperature, sensitivity and background signal. They have enhanced the absorption signals for indium, respectively eliminating the matrix interferences. The standard additions method was applied. The relative standard deviations for six replicate determinations were in the range 0.3-4.0% for indium in different ores samples for indium concentrations 7.6-209mugg(-1). The recommended method was applied to the indium determination in real samples. The data obtained by this method were in good agreement with those obtained by ICP-AES.

  11. Synthesis and Application of a New Acrylic Ester Resin for Recycling SIPA from its Water Solution

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A new acrylic ester polymer YWB-7 resin was prepared and characterized. The properties of YWB-7 resin were compared with those of the commercial Amberlite XAD-7, Diaion HP2MG and hypercrosslinked macroporous polymer NDA-150 resins. Both surface area and micropore area of YWB-7 resin were bigger than those of XAD-7 resin and HP2MG resin. The YWB-7 resin was successfully employed to recycle 5-sodiosulfoisophthalic acids (SIPA) from its solutions with and without methanol.

  12. Monitoring of PAHs in air by collection on XAD-2 adsorbent then microwave-assisted thermal desorption coupled with headspace solid-phase microextraction and gas chromatography with mass spectrometric detection.

    Science.gov (United States)

    Wei, Ming-Chi; Chang, Wan-Ting; Jen, Jen-Fon

    2007-02-01

    Microwave-assisted thermal desorption (MAD) coupled to headspace solid-phase microextraction (HS-SPME) has been studied for in-situ, one-step, sample preparation for PAHs collected on XAD-2 adsorbent, before gas chromatography with mass spectrometric detection. The PAHs on XAD-2 were desorbed into the extraction solution, evaporated into the headspace by use of microwave irradiation, and absorbed directly on a solid-phase microextraction fiber in the headspace. After desorption from the SPME fiber in the hot GC injection port, PAHs were analyzed by GC-MS. Conditions affecting extraction efficiency, for example extraction solution, addition of salt, stirring speed, SPME fiber coating, sampling temperature, microwave power and irradiation time, and desorption conditions were investigated. Experimental results indicated that extraction of 275 mg XAD-2, containing 10-200 ng PAHs, with 10-mL ethylene glycol-1 mol L(-1) NaCl solution, 7:3, by irradiation with 120 W for 40 min (the same as the extraction time), and collection with a PDMS-DVB fiber at 35 degrees C, resulted in the best extraction efficiency. Recovery was more than 80% and RSD was less than 14%. Optimum desorption was achieved by heating at 290 degrees C for 5 min. Detection limits varied from 0.02 to 1.0 ng for different PAHs. A real sample was obtained by using XAD-2 to collect smoke from indoor burning of joss sticks. The amounts of PAHs measured varied from 0.795 to 2.53 ng. The method is a simple and rapid procedure for determination of PAHs on XAD-2 absorbent, and is free from toxic organic solvents.

  13. D-101大孔吸附树脂对黄花蒿黄酮的吸附热力学和动力学研究%ADSORPTION THERMODYNAMICS AND KINETICS OF ARTEMISIA ANNUA FLAVONOIDS ADSORBED ON MACROPOROUS ADSORBENT RESINS D101

    Institute of Scientific and Technical Information of China (English)

    熊利芝; 李佳焱; 王家坚; 欧阳文; 朱杰英

    2014-01-01

    通过静态吸附实验,研究了D-101大孔吸附树脂对黄花蒿黄酮的吸附热力学和动力学过程.结果表明,当温度在298~318K和在实验研究浓度范围内,D-101大孔吸附树脂对黄花蒿黄酮的吸附符合Freundlich等温吸附方程;ΔG<0,吸附过程能自发进行;ΔH<0,为放热过程;ΔS<0,D-101大孔吸附树脂吸附黄花蒿黄酮的作用大于水的解吸过程,导致熵减.分别采用准一级动力学方程、准二级动力学方程和粒内扩散动力学模型探讨其吸附特性,研究结果表明,吸附过程符合准二级动力学方程,粒内扩散与膜扩散交互控制黄花蒿黄酮在D-101大孔吸附树脂上的吸附.%The adsorption thermodynamics and kinetics of artemisia annua flavonoids absorbed on macroporous adsorbent resins D101 were studied by static adsorption experiments.The results showed that the adsorption equilibrium data were agreed with Freundlich adsorption isotherm well in the temperature range of 298~318K and concentration range in the experiment.Thermodynamic analysis suggested ΔG<0,ΔH<0 and ΔS<0,which indicated the adsorption procedure was a spontaneously exothermic reaction with entropy decrease.The adsorption of artemisia annua flavonoids on the macroporous adsorbent resins D101 could be described well by Pseudo-second-order rate equation,and the rate-determining step of the adsorption was the combined action of film diffusion and intraparticle diffusion.

  14. Study on the Separation and Purification of Elaeagnus Angustifolia Polysaccharide by Using the DM-18 Macroporous Resins%DM-18型大孔树脂分离纯化新疆沙枣果肉中多糖的工艺

    Institute of Scientific and Technical Information of China (English)

    杨魁; 陈晴晴; 杨金凤; 杨静; 陈景堃; 刘红

    2014-01-01

    To research and optimize the best conditions of the DM-18 macroporous resins,a dynamic absorption and desorption experiment was designed.The result showed that the best conditions as follows:2.0 mg /mL of concentration and 7.0 of pH of the solution of Elaeagnus angustifolia polysaccharide,the sample loading amount of 3.0 BV,1.5 BV/h of the rate,the eluent concentration of 35%,the total quantity of eluent of 4.0 BV and eluent rate of 1.0 BV/h.The rates of absorption and desorption could achieve 90.13% and 92.17% under the conditions above.It concludes that the DM-18 macroporous resins is a good material to separae and purificate the Elaeagnus angustifolia polysaccharide.%本文研究了DM-18型大孔树脂分离纯化沙枣多糖的工艺条件,考察了各因素对分离、纯化沙枣多糖效果的影响,确定了分离沙枣多糖的最佳分离条件。结果表明:在沙枣多糖样品溶液2.0 mg /mL,上样速率为1.5 BV/h,上样液pH 值为7.0,上样量为3.0 BV、洗脱剂乙醇浓度为35%、洗脱剂用量为4.0 BV、洗脱速率为1.0 BV/h时,DM-18型大孔树脂对沙枣多糖的动态吸附率和解吸率分别达到90.13%和92.17%,表明该大孔树脂是一种较好的分离纯化沙枣多糖的材料。

  15. Isolation and purification of polyphenols in pre-germinated brown rice by macroporous resin%树脂分离纯化萌发糙米中多酚的研究

    Institute of Scientific and Technical Information of China (English)

    侯会绒; 孙兆远

    2012-01-01

    比较了AB-8、X-5、NKA、NKA-2、S-85种大孔树脂对萌发糙米多酚的吸附和解吸性能,结果表明,AB-8树脂具有较好的吸附性能和解吸效果;确定了AB-8树脂分离萌发糙米多酚的适宜操作条件为:上柱料液浓度为O.4716mg/mL,流速为2.0mL/min,以蒸馏水和浓度为70%乙醇进行洗脱,解吸速率N2.0mL/min,得到萌发糙米多酚纯度为63.25%。AB-8树脂可用于萌发糙米多酚的分离纯化。%Adsorption capacity and static desorption rate of adsorption resins such as AB-8, X-5, NKA, NKA-2, S-8 for polyphenols of pre-germinated brown rice were assayed. AB-8 resin had the best adsorption capacity and static desorption rate for polyphenols. The optimal conditions of isolation and purification for polyphenols of pre-germinated brown rice by AB-8 resin were obtained. The crude polyphenols extract solution with the concentration of 0.4716 mg/mL was first subjected to AB-8 resin adsorption at the flow rate of 2.0 mL/min. Then the impurities were eluted down by distilled water and 70% ethanol at the desorption rate of 2.0 mL/min. The purity of resulting polyphenols of pre-germinated brown rice was 63.25%. The polyphenols of pre-germinated brown rice could be isolated and purified by AB-8 resin.

  16. Study on the Antioxidant and AntimicrobiaI Activity and Purification with Macroporous Resin of TotaI FIavonoids from Coriandrumsativum L.%大孔树脂纯化芫荽总黄酮及芫荽总黄酮抗氧化和抗菌活性研究

    Institute of Scientific and Technical Information of China (English)

    刘芸; 任慧婧; 黄锴; 王珂佳; 胡美忠

    2015-01-01

    Obj ective:To investigate the purification technology of total flavonoids with macroporous resin and to study the antibacterial and antioxidant activity of total flavonoids from Coriandrum sativum L..Method:Screen the optimal macroporous resin and optimize the purification technology of total flavonoids from Coriandrumsativum L.,then use the DPPH method to test the antioxidant activity and agar-diffusion method to test the antibacterial activity of total flavonoids from Coriandrum sativum L..Results:AB-8 resin has excellent effect on the adsorption and desorption of total flavonoids from Coriandrumsativum L..The sample concentration is 1 .5 mg/mL and the rate is 2 mL/min,the eluent is 70% ethanol of 4 BV and rate of 2 mL/min,which are the optimal purification process conditions.The total flavonoids from Coriandrumsativum L.also has excellent antioxidant activity (EC50 = 1 .5 mg/mL ),and the antibacterial activity against Bacillussubtilis, Staphylococcusaureus,Escherichiacoli,Pesudomonasaeruginosa,Aspergillusniger, but not against Saccharomycescerevisiae.%目的:研究芫荽总黄酮的大孔树脂纯化工艺及总黄酮抗氧化、抗菌活性。方法:通过筛选优化大孔树脂型号,优化大孔树脂提取芫荽总黄酮条件,利用DPP H 芫荽总黄酮抗氧化活性,琼脂扩散法测试芫荽总黄酮抗菌活性。结果:AB-8树脂对芫荽总黄酮有较好的吸附和解吸效果,最优工艺条件为:芫荽总黄酮上样液的质量浓度为1.5 mg/mL,上样速率为2 mL/min,洗脱剂为70%乙醇,洗脱剂用量为4 BV,洗脱速率为2 mL/min,芫荽黄酮提取物清除DPPH ·自由基的EC50为1.5 mg/mL。对枯草芽孢杆菌、金黄色葡萄球菌、大肠杆菌、绿脓杆菌、黑曲霉均有抗菌活性,但是对酿酒酵母无效。结论:AB-8型大孔树脂富集芫荽总黄酮效果最佳。

  17. 大孔树脂纯化五味子总木脂素、总三萜工艺研究%Study on purification of total lignans and total triterpenes from Schisandra Chinensis (Turcz.) Baill by AB-8 macroporous resin

    Institute of Scientific and Technical Information of China (English)

    莫永俊; 汪春泉; 王琦; 赵晓宏

    2013-01-01

    Objective To establish a technical process for the purification of total lignans,total triterpenes from Schisandra Chinensis (Turcz.) Baill. Methods The adsorption and desorption rate of five types of macroporous resins was calculated to determine the best resin. The dynamic experiments of adsorption and desorption were carried to obtain the optimal parameters. Results The adsorption and isolation effect of AB-8 type resin was the best. The optimal conditions were that: the density of sample solution was 1.5 mg/mL,the maximum loading amount was 7 BV as well as distilled water was taken 9BV,solvent of elution was 30% of alcohol (9BV) + 80% of alcohol (10BV). The content of total lignans,total triterpenes,Schisandrin in the final production could reach 39.55%,13.96%,8.95% respectively. Conclusion The method of gradient elution is a better way to purify total lignans and triterpenes. It is possible that this method be used in the industrial production.%目的 考察大孔树脂纯化五味子总木脂素总三萜的最佳工艺.方法 比较了5种不同类型大孔树脂对五味子总木脂素、总三萜、五味子醇甲的吸附解析性能,确定适宜的树脂类型和最佳纯化工艺条件.结果 AB-8型树脂吸附解析效果最好;最佳工艺条件:上样液浓度1.5 mg/mL,最大上样量7BV,蒸馏水洗脱体积9BV,洗脱溶剂为30%乙醇(9BV)+80%乙醇(10BV);纯化后终产品中总木脂素、总三萜、五味子醇甲的质量分数分别为39.55%、13.96%、8.95%.结论 本文所报道的梯度洗脱法可显著提高终产品中总木脂素、总三萜、五味子醇甲的质量分数,验证了其工业生产的可能.

  18. Synthesis of N-Doped meso-macroporous carbon and its application to SO2 absorption

    Science.gov (United States)

    Liu, Chao; Zhang, Lei; Hu, Yongqi; Chen, Aibing; Wang, Xiaojing

    2014-12-01

    N-Doped meso-macroporous carbon materials were synthesized using melamine-formaldehyde resin as carbon precursor and silica spheres as a removable template. The as-synthesized carbon materials with a bimodal pores structure (about 3.9 and ˜50-200 nm) display a high surface nitrogen content of 30 wt %. The macropores of carbon materials can be modulated by changing the diameter of template. The SO2 adsorption experiments demonstrate a high adsorption capacity of 78.6 mg g-1 and a considerable stability even over 9 cycles for the carbon materials.

  19. Resin screening for the removal of pyridine-derivatives from waste-water by solvent impregnated resin technology

    NARCIS (Netherlands)

    Bokhove, J.; Schuur, B.; Haan, de A.B.

    2013-01-01

    The selective removal of pyridine derivatives by solvent impregnated resins has been studied. A solvent impregnated resin consists of a macro-porous particle that is impregnated with a solvent. This technology allows the use liquid–liquid extraction in fixed-bed operation, and prevents problems like

  20. Study on adsorption effect of rebaudioside A and stevioside onto D392 macroporous resin%大孔树脂D392对莱鲍迪苷A和甜菊苷吸附作用的研究

    Institute of Scientific and Technical Information of China (English)

    叶发银; 杨瑞金; 华霄; 赵伟; 张文斌

    2012-01-01

    根据莱鲍迪苷A(RA)比甜菊苷(S)多一个葡萄糖基的特点,针对性地选择了14种工业树脂,分别考察了它们对RA和S的吸附能力和吸附选择性。在此基础上,研究了吸附选择性较高的大孔树脂D392的吸附动力学和吸附热力学,并考察了温度、甜菊糖苷水溶液浓度、pH、溶剂对D392吸附选择性的影响规律。结果表明,D392在水相中对S的吸附能力大于对RA的吸附能力,吸附为放热过程,且在较低温度下吸附选择性较好。在298.15K,pH7.0,混合糖苷(RA/S=1:1)浓度为5g/L时,经D392吸附6h,吸附残液中RA/S达到最大值。进一步以RA含量70.3%的甜菊糖苷作供试液,经D392吸附6h,吸附残液中RA含量可提高到88.4%,RA保留率为68.0%.%Based on the difference of molecular structure between rebaudioside A and other steviol glycosides,the performance and separation characteristics of fourteen selected commercial adsorbent resins for the separation and purification of RA had been evaluated.According to the results, D392 offered higher adsorption selectivity than other resins.Influential factors such as adsorption kinetics,adsorption isotherm,temperature,concentration and pH value of adsorption solution,and solvents to the adsorption selectivity were successively investigated on D392.The results showed that the ability of adsorption of S with D392 was stronger than that of RA.The adsorption process was exothermic in aqueous solution,and higher adsorption selectivity was found at lower temperatures.The RA/S ratio of the raffinate attained the maximum when the adsorption was conducted at 298.15K,pH 7.0,and 5g/L of the feeding solution( RA/S = 1:1).After the treatment on D392,the content of RA in the product increased from 70.3% to 88.4% ,and the recovery yield of RA was 68.0%.

  1. In Situ Preconcentration and Determination of Trace Lead in Water Sample with Amberlite XAD-2 Functionalized with Dithizone%Amberlite XAD-2键合双硫腙螯合树脂现场预富集测定水中痕量铅

    Institute of Scientific and Technical Information of China (English)

    王爱霞; 吴冬梅; 谢文兵; 郭黎平

    2006-01-01

    以Amberlite XAD-2树脂与双硫腙通过NN基键合的形式合成了一种新型螯合树脂(XAD-H2DZ),采用IR和TGA技术对其特性进行了表征,并将其应用于微柱现场在线采样(MFS)新技术中,实现了环境水样中痕量铅的在线原位预富集和实验室中流动注射-火焰原子吸收(FI-FAAS)系统的联机测定.当采样体积为10和50 mL时,其富集因子分别为78和384倍;检出限(3σ)分别为0.32和0.079 μg/L;相对标准偏差(n=7)分别为2.0%和1.9%.对环境水样标准物质(GBW08608)、海水中微量元素标准物质(GBW(E) 080040)和实际样品(大连老虎滩区域海水以及南湖水)中铅进行分析,均获得了满意的结果.

  2. Optimisation and application of accelerated solvent extraction and flash chromatography for quantification of PCBs in tree barks and XAD-2 passive samplers using GC-ECD with dual columns.

    Science.gov (United States)

    Guéguen, Florence; Stille, Peter; Millet, Maurice

    2013-07-15

    An analytical method for the quantification of Polychlorinated biphenyls (PCBs) concentrations in XAD-2 passive air samplers (PAS) and tree barks collected close to the Rhine River between France and Germany was developed. This method used Accelerated Solvent Extraction (ASE) followed by a purification step by flash chromatography using a 4gr cartridge (3 g of silica gel and 1 g of 44% acidified silica) and analysis by GC-ECD with dual columns. Quantification (QL) and detection (DL) limits varied 0.5 from and 5.7 ng PAS(-1) and from 0.5 and 3.0 ng PAS(-1) respectively. For tree barks, quantification and detection limits were calculated for each congener on washed tree bark sample with a signal to noise ratio of 3:1 and 10:1 (corresponding to a LQ in the range of 1-4 ng per bark sample by congeners). Uncertainties on each congener concentration were calculated to be in the range of 3-20% XAD-2 passive samplers were field calibrated by using Hi-vol. Samplers. Sampling rates of 4.2, 11.5, 1.6, and 7.9 m(3) PAS(-1) d(-1) for tri-, tetra-, penta- hexa-PCBs, respectively were obtained and are comparable to those already obtained with PUF-PAS for gas phase only (gas/particle distribution was 90/10). Method was applied to real atmospheric samples collected by XAD-2 passive samplers and tree barks in the east of France.

  3. 超声提取白刺中总生物碱及大孔树脂纯化的工艺研究%Ultrasound extraction total alkaloids from Nitraria sibirica Pall and process research of macroporous resin purification

    Institute of Scientific and Technical Information of China (English)

    王玉玲; 曾会明; 张建秋; 马挺军

    2013-01-01

    为优化西伯利亚白刺种籽中总生物碱的提取工艺,采用超声波提取总碱,以硫酸阿托品为对照品,酸性染料比色法测定白刺中总生物碱的含量,探讨料液比、提取温度、时间、乙醇浓度4个因素的影响,确定最佳提取参数.从7种大孔吸附树脂中筛选出对白刺生物碱有最佳分离纯化效果的一种树脂,研究其对生物碱静态、动态吸附、解析效果.研究结果表明,当料液比为1∶20,温度60℃,时间40 min,乙醇浓度70%时,总生物碱提取率(生物碱/种籽重)最高,217.372 9 μg/g D101对白刺总生物碱的吸附、解析效果最好,对其进行动态吸附,可知最佳的工艺条件为上样液pH值为5,流速为0.75 mL/min,乙醇的洗脱浓度为80%.%In order to optimize the extract condition, total alkaloids in Nitraria sibirica was extracted by ultrasound and the content of total alkaloids was determined by the acidic dye colorimetry, the effects of solid-liquid ratio, temperature, time and ethanol concentration on the optimum extraction parameters were investigated, thereby determining the optimal extraction parameters; the best one of isolation and purification from seven kinds of resin were screened out to research its effects on the alkaloids of static, dynamic adsorption. The results show that with the conditions of solid-liquid ratio of 1:20, temperature 60 ℃, time 40 minutes, ethanol concentration of 70%, the highest total alkaloid extract rate was 217.372 9 μg/g; the adsorption and resolution effects of D101 on N. sibirica's total alkaloids were the best, the dynamic adsorption tests proved that the optimum process conditions were: sample solution pH 5, flow rate 0.75mL/min, ethanol concentration 80%.

  4. 多花勾儿茶中儿茶素的提取分离与HPLC测定%Separation and Characterization of Catechin in man-Made Green Tea, the Fruits and Leaves of Berchemia Floribunda with Macroporous Resin and HPLC

    Institute of Scientific and Technical Information of China (English)

    姚姝凤; 唐克华; 刘小攀; 成江; 董爱文

    2015-01-01

    以多花勾儿茶果实、叶及自制绿茶为原料,采用水浴法提取儿茶素,研究其最佳提取工艺.提取液经石油醚脱脂溶性色素后,采用大孔吸附树脂D941进行吸附分离,静态吸附和解析条件研究得出纯净水洗脱效果较好.多花勾儿茶果实、叶及自制绿茶吸附分离的纯化液,用色谱柱:Boston Green ODS PC18(4.6×250 mm ,5μm),检测波长279 nm ,流动相乙腈0.4%磷酸(w (乙腈)∶ w (0.4%磷酸)=13∶87),柱温35℃,流速1 mL/min ,一次进样10μL来进行高效液相色谱(HPLC)检测,其结果显示,多花勾儿茶果实中儿茶素含量最低,自制绿茶中的儿茶素含量最高.%In this study ,the extraction process of catechins was investigated with a certain concentration of ethanol as solvent from man‐made green tea ,fruits and leaves of Berchemia floribunda ,using the method of waterbath .After the fat soluble pigment was removed by petroleum ether from extracting solution ,the catechins was purified by porous resin adsorption method .The static adsorption and desorption tests of catechin with macroporous resin showed that D941 was the optimal resin for purification and the pure water was the optimum eluant .Purified liquid of fruit ,leaves and home‐made green tea extracts were de‐tected by HPLC .The catechins was separated on PC18 chromatographic column (4 .6 × 250 mm ,5 μm) at 35 ℃ ,with nitrile‐0 .4% phosphoric acid (13∶87) as mobile phase at a flow rate of 1 mL/min ,and de‐tected at the wavelength of 279 nm (UV scan) .The results showed that the catechin content of fruit was the lowest ,while the content of man‐made green tea was significantly higher than that of both the fruit and leaves through the optimized extraction processes .

  5. Sulfo cation-exchange resins as heterogeneous catalysts for the reaction of styrene with formaldehyde

    Energy Technology Data Exchange (ETDEWEB)

    Kasymova, K.A.; Sharf, V.Z.; Litvin, E.F.; Grigor' eva, E.N.

    1987-07-20

    Macroporous and gel sulfo cation-exchange resins are active catalysts for the condensation of styrene with formaldehyde. The product, 4-phenyl-1,3-dioxane was obtained in up to 97% yield. The activity of macroporous sulfo cation-exchange resins increases with decreasing particle diameter but in the case of the gel samples, granule size has only a slight effect on the reaction rate. The enhanced activity of sulfo cation-exchange resins is presumably a result of the high value of the acidity function H/sub 0/ of the sulfonic acid groups of the cation-exchange resin.

  6. Template synthesis of ordered macroporous hydroxyapatite bioceramics.

    Science.gov (United States)

    Ji, Lijun; Jell, Gavin; Dong, Yixiang; Jones, Julian R; Stevens, Molly M

    2011-08-28

    Hydroxyapatite has found wide application in bone tissue engineering. Here we use a macroporous carbon template to generate highly ordered macroporous hydroxyapatite bioceramics composed of close-packed hollow spherical pores with interconnected channels. The template has advantages for the preparation of ordered materials.

  7. Use of Cation Exchange Resins for Production of U{sub 3}O{sub 8} Suitable for the Al-U{sub 3}O{sub 8} Powder Metallurgy Process

    Energy Technology Data Exchange (ETDEWEB)

    Mosley, W.C.

    2001-09-17

    This report describes the production of U{sub 3}O{sub 8} powders from three types of cation exchange resins: Dowex 50W, a strong acid, sulfonate resin; AG MP-50, a macroporous form of sulfonate resin; and Bio-Rex 70, a weak acid, carboxylic resin.

  8. Soil Macropore Structure Characterized by X-Ray Computed Tomography

    Institute of Scientific and Technical Information of China (English)

    FENG Jie; ZHANG Jia-Bao; ZHU An-Ning; BI Jing-Wei

    2003-01-01

    Undisturbed soil core with many macropores and disturbed soil core with only one macropore (diameter is 10 mm) were probed by x-ray computed tomography (CT). The size, number, shape and continuity of macropores in the transverse and vertical sections of soil were characterized using CT scanning images. The probability densities of macropores in the transverse section of soil core exhibited a logarithmic Γ distribution.Results indicated that CT scanning was a promising nondestructive method for characterizing macropores in soils.

  9. Assessing the Bioaccessibility of High Molecular Weight PAHs in Soils from a Coking Plant Using XAD-2 Assisted Desorption Method%XAD-2树脂表征焦化厂土壤中高环PAHs的生物可给性

    Institute of Scientific and Technical Information of China (English)

    钟茂生; 姜登登; 王颖; 姜林; 夏天翔; 韩丹

    2015-01-01

    利用Amberlite XAD-2树脂辅助解吸技术表征某焦化厂土样中高环PAHs的解吸特征及其生物可给性,分析风险评估过程中考虑污染物生物可给性的可行性;采用傅里叶红外光谱法测试解吸前、后土样的红外光谱特征,判断不同土壤有机官能团对PAHs的吸附强弱.结果表明:土样中PAHs前30 d的解吸速率明显大于后60 d(前者的解吸速率比后者高2~3个数量级),60 d后污染物解吸基本已达到平衡,整个过程符合两阶段解吸模型.渗漏污染途径下土样中高环PAHs的生物可给性为0.18 ~0.47,低于大气沉降污染途径下表层土样中对应PAHs的生物可给性(1.00),表明在开展场地健康风险评估过程中,应考虑具体场地土壤中PAHs的生物可给性,以在一定程度上降低评估结果的保守性.解吸前、后土样红外光谱特征整体无明显变化,解吸过程不改变土壤主要有机官能团类型,但解吸后土壤中羟基和羧基的峰强明显减弱,吸附于羟基及羧基上的PAHs可能更易解吸.

  10. Scaling hydraulic properties of a macroporous soil

    Science.gov (United States)

    Mohanty, Binayak P.

    1999-06-01

    Macroporous soils exhibit significant differences in their hydraulic properties for different pore domains. Multimodal hydraulic functions may be used to describe the characteristics of multiporosity media. I investigated the usefulness of scaling to describe the spatial variability of hydraulic conductivity (K(-h)) functions of a macroporous soil in Las Nutrias, New Mexico. Piecewise-continuous hydraulic conductivity functions suitable for macroporous soils in conjunction with a hybrid similar media-functional normalization scaling approach were used. Results showed that gravity-dominated flow and the related hydraulic conductivity (K(minus;h) functions of the macropore region are more readily scalable than capillary-dominated flow properties of the mesopore and micropore regions. A possible reason for this behavior is that gravity-dominated flow in the larger pores is mostly influenced by the pore diameter which remains more uniform as compared to tortuous mesopores and micropores with variable neck and body sizes along the pore length.

  11. Deep Ultraviolet Macroporous Silicon Filters Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase I proposal describes a novel method to make deep and far UV optical filters from macroporous silicon. This type of filter consists of an array of...

  12. Macroporous ultramicroelectrodes for improved electroanalytical measurements.

    Science.gov (United States)

    Szamocki, Rafael; Velichko, Alexandra; Holzapfel, Christian; Mücklich, Frank; Ravaine, Serge; Garrigue, Patrick; Sojic, Neso; Hempelmann, Rolf; Kuhn, Alexander

    2007-01-15

    Recent work on the preparation of highly organized macroporous electrodes and nanoporous ultramicroelectrodes has been combined and extended to elaborate macroporous ultramicroelectrodes (UMEs) by template synthesis using colloidal crystals and following two different and complementary methods. On the one hand, arched porous UMEs were prepared, and on the other hand, cylindrical porous UMEs were obtained by using cavity UMEs. These macroporous UMEs have an active surface area which is up to 2 orders of magnitude higher compared to that of a classical disk UME as characterized by cyclic voltammetry. To study their analytical performance, the macroporous UMEs have been modified with a redox-active thiol and also a model bioelectrocatalytical system containing a redox mediator, a cofactor, and glucose-dehydrogenase. In both cases the electrochemical signal is amplified by up to 2 orders of magnitude, which increases significantly the analytical performance of such electrodes and therefore opens up new applications for this kind of miniaturized electrochemical system.

  13. Studies concerning the anion ex-change resins catalyzed esterification of epichlorohydrin with organic acids

    Directory of Open Access Journals (Sweden)

    E.I. Muresan

    2009-09-01

    Full Text Available The paper studies the esterification of carboxylic acids with epichlorohydrin over two macroporous strong base anion exchange resins with different polymer matrix. For both resins, the influence of reaction parameters (temperature, catalyst loading, molar ratio on the reaction rate and the yields of the two isomeric esters were investigated.

  14. Carbon nanofibers encapsulated in macropores in silicon

    Energy Technology Data Exchange (ETDEWEB)

    Starkov, V.; Red' kin, A. [Institute of Microelectronics Technology and High Purity Materials, RAS, Institutskaya str. 6, Chernogolovka 142432 (Russian Federation)

    2007-05-15

    This work reports on the development of fuel cells electrodes with a porous silicon structure and carbon nanofibers encapsulated in macropores in silicon. It is demonstrated that decomposition of carbon on a Ni catalyst deposited on the pore walls can be used to create a homogeneous carbon nanotube layer that dramatically increases the specific surface area while simultaneously reducing the resistivity of the macroporous silicon layer. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  15. Modified ion exchange resins - synthesis and properties. Pt. 1

    Energy Technology Data Exchange (ETDEWEB)

    Doescher, F.; Klein, J.; Pohl, F.; Widdecke, H.

    1982-01-22

    Sulfomethylated resins are prepared by polymer analogous reactions, starting from macroporous poly(styrene-co-divinylbenzene) matrices. Different reaction paths are discussed and used in the synthesis. Sulfomethylation can be achieved by reaction of a chloromethylated resin with dimethyl sulfide and sodium sulfonate or alternatively by oxidation of polymer-bound thiol groups. Both methods give high conversions as shown by IR spectra and titration of the sulfonic acid groups. Poly(1-(4-hydroxysulfomethylphenyl)ethylene) (3) is obtained by reaction of poly(1-(4-hydroxyphenyl)ethylene) (2) resin with formaldehyde/sodium sulfonate. The thermal stability, catalytic activity, and ion exchange equilibria of the sulfomethylated resin are investigated.

  16. Elaboration of extracting, incinerable and/or conducting resins, for the grouped conversion of actinides; Conception de resines extractantes, incinerables et/ou conductrices, pour la conversion groupee d'actinides

    Energy Technology Data Exchange (ETDEWEB)

    Mokhtari, H. [Paris-11 Univ., 91 - Orsay (France)]|[CEA Valrho, Lab. de Chimie des Actinides (LCA), 30 - Marcoule (France)

    2006-07-01

    The first results obtained in the framework of the study called PEACE (Process for the Elaboration of Actinide Carbide from ion Exchange resin) concern the fixation of neodymium(III) (simulating trivalent actinides) on two carboxylic resins: the first one is of gel type and the second one of macroporous type. A kinetic study of the exchange NH{sub 4}{sup +}/Nd{sup 3+} has shown that: 1)neodymium is fixed under the form of a complexed or hydrolyzed specie of neodymium of charge 2+ 2)a high charge rate is reached (40% in mass for the dried resin which corresponds to an exchange capacity of 11 meq/g dry of introduced resin) 3)the exchange kinetics is better for the macroporous resin than for the gel resin. A heat treatment of the macroporous resin charged in neodymium has been carried out until the carbonization by the mean of thermal gravimetric analyses carried out under air and argon. A carbon/neodymium ratio of about 5 is obtained after carbonization under argon. Scanning electron microscopy analyses carried out on the macroporous resin charged in neodymium have revealed a conservation of the sphericity and a consequent reduction of the resin balls diameter after heat treatment and an homogeneous distribution of neodymium inside the sphere. (O.M.)

  17. [Fracture of macroporous hydroxyapatite prosthesis].

    Science.gov (United States)

    Adetchessi, A T; Pech-Gourg, G; Metellus, P; Fuentes, S

    2012-12-01

    Different prosthesis implants are offered to perform a cranioplasty after a decompressive craniectomy when autologous bone graft cannot be used. The authors report the case of a 25-year-old man who benefited a unilateral decompressive craniectomy after a severe head trauma. Seven months later, a cranioplasty using custom macroporous hydroxyapatite prosthesis was performed. The postoperative course was marked by a generalized seizure leading to a traumatic head injury. The CT-scan showed a comminutive fracture of the prosthesis and an extradural hematoma. The patient underwent a removal of the fractured prosthesis and an evacuation of the extradural clot. The postoperative course was uneventful with a Glasgow outcome scale score at 5. A second cranioplasty using a polyether ether ketone (PEEK) implant was performed. Among cranioplasty prosthesis solutions, hydroxyapatite implants seem to have similar property to the bone. However, its weak mechanic resistance is an actual problem in patients susceptible to present generalized seizures with consecutive head impact. Hence, in patients with decompressive craniectomy who are exposed to potential brain injury, we favor the use of more resistant implant as PEEK prosthesis.

  18. Study on sorption of D155 resin for gadolinium

    Institute of Scientific and Technical Information of China (English)

    XIONG Chunhua

    2008-01-01

    The sorption behavior and mechanism of a Macroporous weak acid resin,(D155 resin,)for Gd(III) were investigated. The statically saturated sorption capacity is 283 mg/g resin at 298 K in HAc-NaAc medium. The Gd(III) adsorbed on macroporous weak acid resin,(D155 resin,)could be reductively eluted with the mixed solution of HCl and NaCl, and the elution percentage was as high as 100%. The resin could be regenerated and reused without remarkable decrease in sorption capacity. The apparent sorption rate constant was k298=1.98×10-5 s-1. The apparent activation energy was Ea=2.78 kJ/mol. The sorption behavior of D155 resin for Gd(III) obeyed the Langmuir isotherm. The thermodynamic sorption parameters were (H=33.0 kJ/mol, (S=192 J/mol/K, and (G298=-24.3 kJ/mol. The sorption mechanism of D155 resin for Gd(III) was examined by using chemical method and IR spectrometry. The coordination compound was formed between oxygen atoms in the functional group of D155 resin and Gd (III).

  19. Synthesis and Adsorption Properties of Polystyrene-supported Chelating Resins Containing Heterocyclic Functional Groups

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A series of new chelating resins with incorporating heterocyclic functional groups:pyridine, thiadizole, benzothizole into macroporous chloromethylated polystyrene were synthesized via hydrophilic spacer arm of polyethylene glycol co ntaining sulfur. These chelating resins were found to show high adsorption capacities for Ag+, Hg2+, Au3+ and Pd2+, and the presence of spacer arm can enhance adsorption ability due to increase the hydrophilicity of the chelating resins.

  20. INVESTIGATION ON PRODUCTION OF REFINED BRINE USED IN CHLORO—ALKALI MEMBRANE BY D 412 CHELATING RESIN

    Institute of Scientific and Technical Information of China (English)

    LIUFengzhi; LIHexian

    2001-01-01

    The adsorption property,the operating life,the operating exchange capacity and regeneration of D412 macroporous phosphonomethylamina chelating resin for removing Ca2+,Mg2+ and Fe2+ from high pH brine of alkali production by ionic membrane were investigated.The resin showed good physical-chemical and kinetic propoerty,high exchange capacity.excellent durability.

  1. INVESTIGATION ON PRODUCTION OF REFINED BRINE USED IN CHLORO-ALKALI MEMBRANE BY D412 CHELATING RESIN

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The adsorption property the operating life, the operating exchange capacity and regeneration of D412 macroporous phosphonomethylamina chelating resin for removing Ca2+,Mg2+ and Fe2+ from high pH brine of alkali production by ionic membrane were investigated The resin showed good physical-chemical and kinetic property, high exchange capacity, excellent durability.

  2. Chemically modified polymeric resins for separation of cations, organic acids, and small polar moleculea by high performance liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Morris, John B. [Iowa State Univ., Ames, IA (United States)

    1993-07-01

    This thesis is divided into 4 parts: a review, ion chromatography of metal cations on carboxylic resins, separation of hydrophilic organic acids and small polar compounds on macroporous resin columns, and use of eluent modifiers for liquid chromatographic separation of carboxylic acids using conductivity detection.

  3. STUDY ON THE SYNTHESIS OF POLYSTYRENE SUPPORTED MACROCYCLIC MERCAPTAL CHELATING RESIN AND ITS PROPERTIES

    Institute of Scientific and Technical Information of China (English)

    SUN Qiang; ZHANG Jinlan; XU Jiping

    1984-01-01

    Chelating resin with macrocyclic mercaptal group supported on macroporous polystyrene beads was synthesized, which showed good selectivity to Hg2+: its complexing capacity amounted to 30-60 mg Hg2+/g resin, two orders of magnitude greater than for other metal ions such as Ca2+, Zn2+,Cd2+, Pb2+ etc. This resin could restore the activity of urease which had been deactivated by poisoning with Hg2+. Its restoring power was far better than that of the mercapto-resin and common anionic exchange resins. It showed some promising use as an oral polymeric detoxifying drug for mercury poisoning.

  4. Scalable synthesis of hierarchical macropore-rich activated carbon microspheres assembled by carbon nanoparticles for high rate performance supercapacitors

    Science.gov (United States)

    Zhang, Dongdong; Zhao, Jianghong; Feng, Chong; Zhao, Rijie; Sun, Yahui; Guan, Taotao; Han, Baixin; Tang, Nan; Wang, Jianlong; Li, Kaixi; Qiao, Jinli; Zhang, Jiujun

    2017-02-01

    A scalable inverse-microemulsion-polymerization-phase-separation coupling method is applied to successfully prepare hierarchical macropore-rich activated carbon microspheres (ACS) using a phenolic resin (PR) precursor followed by carbonization and KOH activation for the first time. The formed ACS materials are assembled by carbon nanoparticles (CNPs). The macropores interspersed among the component CNPs are formed after removing the non-reactive solvent phase in the course of the polymerization of the reactive PR phase, which occupies ∼64% of the total pore volume (∼2.779 cm3 g-1) of the optimized ACS. In combination with mesopores (∼18% of the total pore volume), the ACS possesses meso/macropores approaching 82% of the total pore volume. Micropores are created in the component CNPs via KOH activation, showing shortened ion transport distances in the nanoscale dimension. Both the hierarchical micro/meso/macroporous structure and the inner nanoparticle morphology (short ion diffusion pathways) can significantly contribute to the rapid transport of electrolyte ions throughout the carbonaceous matrix, resulting in superior rate performance of ACS-based supercapacitors. More importantly, the energy densities of the ACS supercapacitors operating in both aqueous and organic electrolyte retain steady over a wide range of power densities varying dramatically from 0.25 to 14.5 kW kg-1 and to 7.0 kW kg-1, respectively.

  5. Novel macroporous amphoteric gels: Preparation and characterization

    Directory of Open Access Journals (Sweden)

    S. Kudaibergenov

    2012-05-01

    Full Text Available Macroporous amphoteric gels based on allylamine, methacrylic acid and acrylamide crosslinked by N,N'-methylenebisacrylamide were synthesized by radical copolymerization of monomers in cryoconditions. The composition of cryogels was determined by combination of potentiometric and conductimetric titrations. The morphology of cryogels was evaluated by scanning electron microscope (SEM. Cryogels exhibited sponge-like porous structure with pore size ranging from 50 to 200 μm. The values of the isoelectric points (IEPs determined from the swelling experiments arranged between 3.5 and 4.3. The high adsorption-desorption capacity of amphoteric cryogels with respect to mM and trace concentrations of copper, nickel, and cobalt ions was demonstrated. It was shown that the macroporous amphoteric cryogels are able to adsorb up to 99.9% of copper, nickel, and cobalt ions from 10–3 mol•L–1 aqueous solution.

  6. Macroporous Monolithic Polymers: Preparation and Applications

    Directory of Open Access Journals (Sweden)

    Cecilia Inés Alvarez Igarzabal

    2009-12-01

    Full Text Available In the last years, macroporous monolithic materials have been introduced as a new and useful generation of polymers used in different fields. These polymers may be prepared in a simple way from a homogenous mixture into a mold and contain large interconnected pores or channels allowing for high flow rates at moderate pressures. Due to their porous characteristics, they could be used in different processes, such as stationary phases for different types of chromatography, high-throughput bioreactors and in microfluidic chip applications. This review reports the contributions of several groups working in the preparation of different macroporous monoliths and their modification by immobilization of specific ligands on the products for specific purposes.

  7. Sampling of organophosphorus pesticides at trace levels in the atmosphere using XAD-2 adsorbent and analysis by gas chromatography coupled with nitrogen-phosphorus and ion-trap mass spectrometry detectors.

    Science.gov (United States)

    Russo, Mario Vincenzo; Avino, Pasquale; Cinelli, Giuseppe; Notardonato, Ivan

    2012-09-01

    This paper shows an analytical methodology based on solid-phase extraction by XAD-2 adsorbent and gas chromatography (GC) coupled with nitrogen-phosphorus (NPD) and ion-trap mass spectrometry detectors (ITMS) in negative chemical ionization (NCI) mode analyses for investigating organophosphorus pesticides (OPs) at trace levels (in nanograms per cubic meter) in the atmosphere: in particular, we set up a procedure for analyzing 38 OPs. For the analytical methodology linearity responses have been obtained in GC-NPD (r > 0.9982) and GC-NCI/ITMS (r > 0.9974) in a large linearity range (0.10-500 pg μL(-1) in both cases) whereas the limits of detection range between 0.01 and 0.03 pg μL(-1) in both the techniques with a relative standard deviation (RSD) below 9.0 in both cases. Particular attention has been devoted to investigate the effect of different solvents (n-hexane, benzene, chloroform, carbon disulfide, acetonitrile) on the OP recovery as well the breakthrough volumes have been evaluated (100% recovery up to 4,286 L g(-1)). The study has also investigated the OP recoveries at different sampling flow rates (1.5 and 2.0 L min(-1)) for determining the optimal conditions for sample collection. Finally, the whole approach has been successfully applied to real samples collected in four different areas in the Molise region (Central Italy) during different seasons: the results show that parathion-ethyl, dimethoate, omethoate, and malathion are present in all periods at low levels (ranging between 70 and 10 ng m(-3)): their levels in such periods can be correlated with spraying as well atmospheric conditions favoring the dispersion/accumulation of these pollutants.

  8. XAD-2树脂对油菜蜂蜜中黄酮类物质分离条件的优化%Isolation and identification of flavonoids on rape honey through column chromatography and LC/MS/MS

    Institute of Scientific and Technical Information of China (English)

    邢建军; 杨洁; 郑国伟; 王炎; 刘睿

    2010-01-01

    以华中农业大学康思农实验蜂场油菜蜂蜜为材料,研究了XAD-2树脂对油菜蜂蜜中黄酮类物质的柱层析分离条件.在考察4种不同因素对分离效果影响的基础上,得出的最佳分离条件是:蜂蜜上样量与树脂量的比为1.2:1;上样液pH=2;90%的甲醇为洗脱溶剂,并采用3倍柱床体积的甲醇量(洗脱速度为4.5ml/min),其加标回收率为82.8%.对柱层析分离得到蜂蜜黄酮样品采用LC/MS/MS(液质联用)分析,发现康思农油菜蜂蜜样品中含有槲皮素、异鼠李素、山萘酚、木樨草素、白杨黄酮、高良姜黄素、短叶松素、芹菜素、5,7一二羟基双氢黄酮和汉黄芩素等10种黄酮类物质.

  9. Macroporous nanowire nanoelectronic scaffolds for synthetic tissues

    Science.gov (United States)

    Tian, Bozhi; Liu, Jia; Dvir, Tal; Jin, Lihua; Tsui, Jonathan H.; Qing, Quan; Suo, Zhigang; Langer, Robert; Kohane, Daniel S.; Lieber, Charles M.

    2012-11-01

    The development of three-dimensional (3D) synthetic biomaterials as structural and bioactive scaffolds is central to fields ranging from cellular biophysics to regenerative medicine. As of yet, these scaffolds cannot electrically probe the physicochemical and biological microenvironments throughout their 3D and macroporous interior, although this capability could have a marked impact in both electronics and biomaterials. Here, we address this challenge using macroporous, flexible and free-standing nanowire nanoelectronic scaffolds (nanoES), and their hybrids with synthetic or natural biomaterials. 3D macroporous nanoES mimic the structure of natural tissue scaffolds, and they were formed by self-organization of coplanar reticular networks with built-in strain and by manipulation of 2D mesh matrices. NanoES exhibited robust electronic properties and have been used alone or combined with other biomaterials as biocompatible extracellular scaffolds for 3D culture of neurons, cardiomyocytes and smooth muscle cells. Furthermore, we show the integrated sensory capability of the nanoES by real-time monitoring of the local electrical activity within 3D nanoES/cardiomyocyte constructs, the response of 3D-nanoES-based neural and cardiac tissue models to drugs, and distinct pH changes inside and outside tubular vascular smooth muscle constructs.

  10. Hierarchically Structured Monolithic ZSM-5 through Macroporous Silica Gel Zeolitization

    Institute of Scientific and Technical Information of China (English)

    Lei Qian; Zhao Tianbo; Li Fengyan; Zong Baoning; Tong Yangchuan

    2006-01-01

    The hierarchically structured ZSM-5 monolith was prepared through transforming the skeletons of the macroporous silica gel into ZSM-5 by the steam-assisted conversion method. The morphology and monolithic shapes of macroporous silica gel were well preserved. The hierarchically structured ZSM-5 monolith exhibited the hierarchical porosity, with mesopores and macropores existing inside the macroporous silica gel, and micropores formed by the ZSM-5. The products have been characterized properly by using the XRD, SEM and N2 adsorption-desorption methods.

  11. Batch and column study: sorption of perfluorinated surfactants from water and cosolvent systems by Amberlite XAD resins.

    Science.gov (United States)

    Xiao, Feng; Davidsavor, Kerry Jade; Park, Sangyoo; Nakayama, Michio; Phillips, Brian Ray

    2012-02-15

    Amberlite XAD resins have been employed to a great extent as the sorbent for removing or concentrating organic compounds from different matrices. We present for the first time a systematic study on the sorption of perfluorochemical (PFC) surfactants, an emerging class of environmental contaminants, by XAD-7HP (moderately polar) and XAD-2 (nonpolar). The results show that XAD-7HP can strongly sorb PFCs at circumneutral pH; the isotherm-determined linear sorption coefficient can reach 10(6)L/kg. On the other hand, the sorption coefficient for XAD-2 was two orders of magnitude lower than that for XAD-7HP. PFC sorption on XAD-7HP increased with an increase of the perfluorocarbon chain length of PFC and a decrease of the solution pH, indicating the importance of hydrophobic and electrostatic effects. The sorption coefficient for XAD-7HP reduced markedly with increasing fraction of the organic cosolvent (methanol) in the water-cosolvent mixture; however, the trend could not be predicted by a log-linear cosolvency model. Furthermore, the statistical analysis of column test results showed that after regeneration XAD-7HP can be used at least eight times without significant loss of performance. Finally, the experimental results imply that XAD-7HP sorption of shorter-chained PFCs (≤5 perfluorinated carbons) from water can be thermodynamically favorable.

  12. Resin catalysts and method of preparation

    Science.gov (United States)

    Smith, L.A. Jr.

    1986-12-16

    Heat stabilized catalyst compositions are prepared from nuclear sulfonic acid, for example, macroporous crosslinked polyvinyl aromatic compounds containing sulfonic acid groups are neutralized with a metal of Al, Fe, Zn, Cu, Ni, ions or mixtures and alkali, alkaline earth metals or ammonium ions by contacting the resin containing the sulfonic acid with aqueous solutions of the metals salts and alkali, alkaline earth metal or ammonium salts. The catalysts have at least 50% of the sulfonic acid groups neutralized with metal ions and the balance of the sulfonic acid groups neutralized with alkali, alkaline earth ions or ammonium ions.

  13. Pesticide leaching in macroporous clay soils: field experiment and modeling

    NARCIS (Netherlands)

    Scorza Júnior, R.P.

    2002-01-01

    Keywords : pesticide leaching, macropores, preferential flow, preferential transport, cracked clay soil, pesticide leaching models, groundwater contamination, inverse modeling, bentazone and imidacloprid. The presence of macropores (i.e. shrinkage c

  14. DIFFUSIVITY OF ARRE EARTH ION IN POROUS ION EXCHANGE RESINS

    Institute of Scientific and Technical Information of China (English)

    LingDaren; LiuYucheng; 等

    1997-01-01

    The self-diffusion of Eu3+ ion in porous resins D72 and D751 was studied by isotope exchange reaction.Applying Kataoka's bidisperse pore model,the intraparticle effective diffusivity De were resolved into a solid diffusivity Dg and a macropore diffusivity Dp.The experiments show that De.Dp and Dg all increase with the increase of reaction temperature;the response Dp and Dg of D751 resin is smaller than that of D72 resin;the diffusivity of Eu3+ ion in solution is larger than Dp,which leads to the conclusion that the diffusion of ion in the pore of resin can not completely be equal to that in solution.

  15. Epoxy resins.

    Science.gov (United States)

    Bray, P G

    1999-01-01

    Epoxy resins have an extraordinarily broad range of commercial applications, especially as protective surface coatings and adhesives. Epoxy resin systems include combinations of epoxy monomers, hardeners, reactive diluents, and/or a vast array of other additives. As a result, an epoxy resin system may have a number of chemical ingredients with the potential for attendant health hazards. Most, but not all, of these health hazards arise in the occupational setting. The most frequent adverse effects are irritation or allergic mechanisms involving the dermal and respiratory systems. Sensitization usually is caused by low molecular weight or short-chain compounds. This review discusses the diagnosis, treatment, and prevention of epoxy resin-related adverse health effects.

  16. Macroporous synthetic hydroxyapatite bioceramics for bone substitute applications

    CSIR Research Space (South Africa)

    Thomas, ME

    1999-08-01

    Full Text Available An improved strategy is described for the manufacture of macroporous hydroxyapatite bioceramics for bone substitute applications. This is based on a modified fugitive phase technique, which allows production of relatively open, high-strength devices...

  17. Resin composites

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Peutzfeldt, Anne; Lussi, Adrian;

    2014-01-01

    OBJECTIVE: To investigate how the modulus of elasticity of resin composites influences marginal quality in restorations submitted to thermocyclic and mechanical loading. METHODS: Charisma, Filtek Supreme XTE and Grandio were selected as they were found to possess different moduli of elasticity...... of resin composite (p=0.81) on the quality of dentine margins was observed, before or after loading. Deterioration of all margins was evident after loading (p....008). CONCLUSIONS: The resin composite with the highest modulus of elasticity resulted in the highest number of gap-free enamel margins but with an increased incidence of paramarginal enamel fractures. CLINICAL SIGNIFICANCE: The results from this study suggest that the marginal quality of restorations can...

  18. Adsorption of polyethylene-glycolated bovine serum albumin on macroporous and polymer-grafted anion exchangers.

    Science.gov (United States)

    Zhu, Mimi; Carta, Giorgio

    2014-01-24

    The chromatographic and adsorptive properties of BSA and BSA conjugated with 10 and 30kDa PEG polymers are determined for a macroporous anion exchanger (UNOsphere™ Diol Q) and for a polymer-grafted material having the same backbone matrix (Nuvia Q™). Chromatographic retention, adsorption capacity, and adsorption kinetics are enhanced in the polymer-grafted resin for both BSA and 10kDa PEG-BSA as a result of interactions with the grafted polymers. However, the difference between the two resins diminishes for 30kDa PEG-BSA indicating that size exclusion effects strongly affect binding in the polymer-grafted material for this larger conjugate. Images of intraparticle concentration profiles obtained by confocal scanning laser microscopy show that the transport mechanisms of both BSA and PEGylated BSA are very different in the two resins. The protein binding kinetics are dominated by ordinary pore diffusion and are essentially independent of the direction of transport for UNOsphere Diol Q as a result of its large pore size. Thus, for this material, displacement of PEGylated BSA by BSA is clearly evident at the intraparticle scale. On the other hand, the protein binding kinetics in Nuvia Q are consistent with a solid diffusion mechanism driven by the adsorbed protein concentration. For this material, protein transport is very fast for one component or two-component co-adsorption of BSA and PEGylated BSA but slows down dramatically for sequential adsorption of these species as a result of heightened diffusional hindrance when the two components counterdiffuse within the resin.

  19. 对甲基苯甲酸在大孔吸附树脂上的吸附热力学及动力学研究%Study on adsorption thermodynamics and kinetics of p-toluic acid onto macroporous adsorption resin

    Institute of Scientific and Technical Information of China (English)

    代喃喃; 刘玉林; 董庆华; 唐树和

    2012-01-01

    Experimental investigations were conducted to study the adsorption characteristics of p-toluic acid,with NDA-1800 and JX-101 resins as adsorbents. The results indicated that the equilibrium adsorption data was fitted well with Freundlich adsorption isotherm model in the temperature range of 283 ~ 313 K. The changes of enthalpy, free energy, entropy indicated an exothermic, spontaneous and disorder decreasing process happened in the adsorption,with low activation energy. The adsorption kinetics parameters were drawn from the experiment data and increased with raising temperature.%研究了对甲基苯甲酸在NDA-1800和JX-101大孔吸附树脂上的静态吸附热力学和动力学行为.结果表明,在283 ~313 K和研究的浓度范围内,两种大孔吸附树脂吸附对甲基苯甲酸的行为符合Freundlich吸附等温方程.对甲基苯甲酸在两种大孔吸附树脂上的吸附焓变△H<0,为放热过程;自由能变△G<0,吸附过程能自发进行;吸附熵变△S<0,这是因为吸附质分子从水溶液中被吸附到树脂表面后,其分子运动受到了限制,使吸附熵减少.两种大孔树脂吸附对甲基苯甲酸的速率常数都比较大,且随着温度的升高而增大.吸附活化能都比较低,吸附较容易进行.

  20. Estudos de adsorção de di-2-piridil cetona saliciloilhidrazona (DPKSH) em resinas amberlite xad-2 e xad-7. Extração de íons cobre em fase sólida envolvendo a xad-7 modificada com DPKSH

    OpenAIRE

    Patricia Antonio de Menezes Freitas

    2007-01-01

    Di-2-piridil cetona saliciloilhidrazona (DPKSH) é uma hidrazona que forma compostos de coordenação com diversos íons metálicos. As resinas Amberlite XAD-2 e XAD-7 são polímeros não-iônicos que podem ser usados para a pré-concentração de íons metálicos. A adsorção de DPKSH nessas matrizes poliméricas foi etudada utilizando a espectrofotometria. A quantidade de DPKSH adsorvida nessas resinas foi calculada a partir da diferença entre a concentração inicial a concentração remanescente na solução ...

  1. Molecularly imprinted macroporous monolithic materials for protein recognition

    Institute of Scientific and Technical Information of China (English)

    Qi Liang Deng; Yan Li Li; Li Hua Zhang; Yu Kui Zhang

    2011-01-01

    Synthetic materials that can specifically recognize proteins will find wide application in many fields. In this report, bovine serum albumin was chosen as the template protein. Acrylamide and N, N'-methylenebisacrylamide were employed as the functional and cross-linker monomers, respectively. Molecularly imprinted macroporous monolithic materials that can preferentially bind the template protein in an aqueous environment were prepared by combination of molecular imprinting technique and freezing/thawing preparation method. The resulted imprinted macroporous monolithic columns were evaluated by utilizing as stationary phase in high performance liquid chromatography and solid-phase extraction materials. The experimental results indicated that the imprinted macroporous monolithic column exhibited good recognition for template protein, as compared with the control protein (hemoglobin), whereas the non-imprinted polymer (prepared under the same conditions except without addition template protein) had no selective properties.

  2. Quantifying macropore recharge: Examples from a semi-arid area

    Science.gov (United States)

    Wood, W.W.; Rainwater, K.A.; Thompson, D.B.

    1997-01-01

    The purpose of this paper is to illustrate the significantly increased resolution of determining macropore recharge by combining physical, chemical, and isotopic methods of analysis. Techniques for quantifying macropore recharge were developed for both small-scale (1 to 10 km2) and regional-scale areas in and semi-arid areas. The Southern High Plains region of Texas and New Mexico was used as a representative field site to test these methods. Macropore recharge in small-scale areas is considered to be the difference between total recharge through floors of topographically dosed basins and interstitial recharge through the same area. On the regional scale, macropore recharge was considered to be the difference between regional average annual recharge and interstitial recharge measured in the unsaturated zone. Stable isotopic composition of ground water and precipitation was used us an independent estimate of macropore recharge on the regional scale. Results of this analysis suggest that in the Southern High Plains recharge flux through macropores is between 60 and 80 percent of the total 11 mm/y. Between 15 and 35 percent of the recharge occurs by interstitial recharge through the basin floors. Approximately 5 percent of the total recharge occurs as either interstitial or matrix recharge between the basin floors, representing approximately 95 percent of the area. The approach is applicable to other arid and semi-arid areas that focus rainfall into depressions or valleys.The purpose of this paper is to illustrate the significantly increased resolution of determining macropore recharge by combining physical, chemical, and isotopic methods of analysis. Techniques for quantifying macropore recharge were developed for both small-scale (1 to 10 km2) and regional-scale areas in arid and semi-arid areas. The Southern High Plains region of Texas and New Mexico was used as a representative field site to test these methods. Macropore recharge in small-scale areas is considered

  3. Review: Resin Composite Filling

    OpenAIRE

    Desmond Ng; Jimmy C. M. Hsiao; Keith C. T. Tong; Harry Kim; Yanjie Mai; Keith H. S. Chan

    2010-01-01

    The leading cause of oral pain and tooth loss is from caries and their treatment include restoration using amalgam, resin, porcelain and gold, endodontic therapy and extraction. Resin composite restorations have grown popular over the last half a century because it can take shades more similar to enamel. Here, we discuss the history and use of resin, comparison between amalgam and resin, clinical procedures involved and finishing and polishing techniques for resin restoration. Although resin ...

  4. SOLVENT EFFECTS ON THE HYDRATION OF CYCLOHEXENE CATALYZED BY A STRONG ACID ION-EXCHANGE RESIN .3. EFFECT OF SULFOLANE ON THE EQUILIBRIUM CONVERSION

    NARCIS (Netherlands)

    PANNEMAN, HJ; BEENACKERS, AACM

    1992-01-01

    The liquid-phase hydration of cyclohexene, a pseudo-first-order reversible reaction catalyzed by a strong acid ion-exchange resin, was investigated in solvent mixtures of water and sulfolane. Macroporous Amberlite XE 307 was used because of its superior catalytic activity. Chemical equilibrium conve

  5. A convenient synthesis of pyrroles catalyzed by acidic resin under solvent-free condition

    Institute of Scientific and Technical Information of China (English)

    Shi

    2010-01-01

    A convenient and effective Paal-Knorr condensations of 2,5-hexanedione with most amines have been carried out at room temperature under solvent-free condition. Macroporous strongly acidic styrol resin (D001) as a novel, efficient, cost-effective, and reusable solid acid catalyst for the synthesis of pyrroles under the same conditions. The pyrroles were obtained in high yields in short reaction times.

  6. Fabrication and Characteristics of Macroporous TiO2 Photocatalyst

    Directory of Open Access Journals (Sweden)

    Guiyun Yi

    2014-01-01

    Full Text Available Macroporous TiO2 photocatalyst was synthesized by a facile nanocasting method using polystyrene (PS spherical particles as the hard template. The synthesized photocatalyst was characterized by transmission electron microscope (TEM, scanning electron microscopy (SEM, thermogravimetry-differential thermogravimetry (TG-DTG, X-ray diffraction (XRD, and N2-sorption. TEM, SEM, and XRD characterizations confirmed that the macroporous TiO2 photocatalyst is composed of anatase phase. The high specific surface area of 87.85 m2/g can be achieved according to the N2-sorption analysis. Rhodamine B (RhB was chosen as probe molecule to evaluate the photocatalytic activity of the TiO2 catalysts. Compared with the TiO2 materials synthesized in the absence of PS spherical template, the macroporous TiO2 photocatalyst sintered at 500°C exhibits much higher activity on the degradation of RhB under the UV irradiation, which can be assigned to the well-structured macroporosity. The macroporous TiO2 material presents great potential in the fields of environmental remediation and energy conversion and storage.

  7. Dye tracer infiltration technique to investigate macropore flow paths in Maka Mountain, Yunnan Province, China

    Institute of Scientific and Technical Information of China (English)

    张家明; 徐则民

    2016-01-01

    In order to investigate the differences of macropores vertical distribution under different surface plants, and to assess the influences of root systems, organic matter and texture on macropore flow paths, two dye tracer infiltration experiments were performed in slopes under two different plants (Campylotropis polyantha (Franch.) Schindl vs.Cynodon dactylon(Linn.) Pers). Dye tracer infiltration experiments with field observations and measurements of soil properties were combined. Results show that the discrepancy in macropores distribution between two slopes under different plants is significant. Root systems have significant effects on macropore flow paths distribution and the effect become more pronounced as the diameter of roots become larger. Organic matter and stone are important factors to affect macropores distribution. Root-soil interface, inter-aggregate macropore and stone-soil interface are important macropore flow paths in well vegetated slopes.

  8. Synthesis and Adsorption Properties of Chelating Resins Containing Sulfoxide and Heterocyclic Functional Groups

    Institute of Scientific and Technical Information of China (English)

    Chun Nuan JI; Xiu Juan ZHANG; Rong Jun QU; Hou CHEN; Chun Hua WANG; Chang Mei SUN

    2006-01-01

    Several of new chelating resins containing sulfoxide and heterocyclic functional groups (3-aminopyridine and 2-mercaptobenzothiazole) based on macroporous chloromethylated polystyrene were synthesized and characterized by elemental analysis and infrared spectra. Their adsorption capacities towards Zn2+, Cu2+, Pb2+, Hg2+ and Ag+ at pH 3.0 and 6.0 were investigated in detail. It was found that the adsorption capacities of the resins containing bis[(3-pyridylaminoethyl)sulfoxide or (2-benzothiazolylthioethyl)sulfoxide for the above ions were higher than that on ones containing single above-mentioned groups.

  9. Resin Catalyst Hybrids

    Institute of Scientific and Technical Information of China (English)

    S. Asaoka

    2005-01-01

    @@ 1Introduction: What are resin catalyst hybrids? There are typically two types of resin catalyst. One is acidic resin which representative is polystyrene sulfonic acid. The other is basic resin which is availed as metal complex support. The objective items of this study on resin catalyst are consisting of pellet hybrid, equilibrium hybrid and function hybrid of acid and base,as shown in Fig. 1[1-5].

  10. 1-Butanol absorption in poly(styrene-divinylbenzene) ion exchange resins for catalysis.

    Science.gov (United States)

    Pérez-Maciá, M A; Curcó, D; Bringué, R; Iborra, M; Rodríguez-Ropero, F; van der Vegt, N F A; Aleman, Carlos

    2015-12-21

    The swelling behaviour of poly(styrene-co-divinylbenzene), P(S-DVB), ion exchange resins in 1-butanol (BuOH) has been studied by means of atomistic classical molecular dynamics simulations (MD). The topological characteristics reported for the resin in the dry state, which exhibited complex internal loops (macropores), were considered for the starting models used to examine the swelling induced by BuOH contents ranging from 10% to 50% w/w. Experimental measurements using a laser diffraction particle size analyzer indicate that swelling causes a volume variation with respect to the dry resin of 21%. According to MD simulations, such a volume increment corresponds to a BuOH absorption of 31-32% w/w, which is in excellent agreement with the indirect experimental estimation (i.e. 31% w/w). Simulations reveal that, independently of the content of BuOH, the density of the swelled resin is higher than that of the dry resin, evidencing that the alcohol provokes important structural changes in the polymeric matrix. Thus, BuOH molecules cause a collapse of the resin macropores when the content of alcohol is ≤20% w/w. In contrast, when the concentration of BuOH is close to the experimental value (∼30% w/w), P(S-DVB) chains remain separated by pores faciliting the access of the reactants to the reaction centers. On the other hand, evaluation of both bonding and non-bonding interactions indicates that the mixing energy is the most important contribution to the absorption of BuOH into the P(S-DVB) resin. Overall, the results displayed in this work represent a starting point for the theoretical study of the catalytic conversion of BuOH into di-n-butyl ether in P(S-DVB) ion exchange resins using sophisticated electronic methods.

  11. Treatment of drilling wastewater using a weakly Dasic resin

    Institute of Scientific and Technical Information of China (English)

    Lü Ronghu; Mu Bo; Zhang Hongyan; Guo Shaohui

    2008-01-01

    Macroporous weak basic anion exchanger(D301R)was used to remove organic substances from drilling wastewater.The effect of pH,temperature and contact time on adsorption behavior was investigated in batch experiments,which indicated that the COD(Chemical Oxygen Demand)removal ratio of drilling wastewater was approximately 90%.and the COD of treated wastewater was below 70 mg/L under appropriate operating conditions.A mixed liquor of NaOH and NaCl was selected as desorbent because of its better elution performance.The results of column dynamic adsorption and regeneration showed that the COD of wastewater could be efficiently removed bv D301R resin,and the resin was easily regenerated by the selected desorbent.

  12. Review: Resin Composite Filling

    Science.gov (United States)

    Chan, Keith H. S.; Mai, Yanjie; Kim, Harry; Tong, Keith C. T.; Ng, Desmond; Hsiao, Jimmy C. M.

    2010-01-01

    The leading cause of oral pain and tooth loss is from caries and their treatment include restoration using amalgam, resin, porcelain and gold, endodontic therapy and extraction. Resin composite restorations have grown popular over the last half a century because it can take shades more similar to enamel. Here, we discuss the history and use of resin, comparison between amalgam and resin, clinical procedures involved and finishing and polishing techniques for resin restoration. Although resin composite has aesthetic advantages over amalgam, one of the major disadvantage include polymerization shrinkage and future research is needed on reaction kinetics and viscoelastic behaviour to minimize shrinkage stress.

  13. Macroporous bioceramics: a remarkable material for bone regeneration.

    Science.gov (United States)

    Lew, Kien-Seng; Othman, Radzali; Ishikawa, Kunio; Yeoh, Fei-Yee

    2012-09-01

    This review summarises the major developments of macroporous bioceramics used mainly for repairing bone defects. Porous bioceramics have been receiving attention ever since their larger surface area was reported to be beneficial for the formation of more rigid bonds with host tissues. The study of porous bioceramics is important to overcome the less favourable bonds formed between dense bioceramics and host tissues, especially in healing bone defects. Macroporous bioceramics, which have been studied extensively, include hydroxyapatite, tricalcium phosphate, alumina, and zirconia. The pore size and interconnections both have significant effects on the growth rate of bone tissues. The optimum pore size of hydroxyapatite scaffolds for bone growth was found to be 300 µm. The existence of interconnections between pores is critical during the initial stage of tissue ingrowth on porous hydroxyapatite scaffolds. Furthermore, pore formation on β-tricalcium phosphate scaffolds also allowed the impregnation of growth factors and cells to improve bone tissues growth significantly. The formation of vascularised tissues was observed on macroporous alumina but did not take place in the case of dense alumina due to its bioinert nature. A macroporous alumina coating on scaffolds was able to improve the overall mechanical properties, and it enabled the impregnation of bioactive materials that could increase the bone growth rate. Despite the bioinertness of zirconia, porous zirconia was useful in designing scaffolds with superior mechanical properties after being coated with bioactive materials. The pores in zirconia were believed to improve the bone growth on the coated system. In summary, although the formation of pores in bioceramics may adversely affect mechanical properties, the advantages provided by the pores are crucial in repairing bone defects.

  14. Ordered coalescence of nanocrystals: a path to strong macroporous nanoceramics

    Energy Technology Data Exchange (ETDEWEB)

    Shen Zhijian; Xiong Yan [Berzelii Center EXSELENT for Porous Materials and Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, Stockholm S-106 91 (Sweden); Hoeche, Thomas [Leibniz-Institut fuer Oberflaechenmodifizierung e.V., Permoserstrasse 15, Leipzig D-04318 (Germany); Salamon, David [Membrane Technology Group, University of Twente, PO Box 217, 7500 AE Enschede (Netherlands); Fu Zhengyi [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China); Belova, Lyubov, E-mail: shen@mmk.su.se [Department of Materials Science and Engineering, Royal Institute of Technology, Stockholm S-100 44 (Sweden)

    2010-05-21

    A versatile approach for integrating two apparently conflicting physical properties, high porosity and high mechanical strength, in polycrystalline bulks is established and demonstrated for the case of alumina ceramics. Macroporous alumina nanoceramics are synthesized by stimulating coalescence-mediated necking, which enables the formation of strong crystallographically coherent necks between adjacent grains. The work places a general emphasis on manipulating crystal growth on the nanoscale and on preparing highly porous polycrystalline bulk ceramics with improved mechanical rigidity.

  15. Macropore-mesopore model of water flow through aggregated porous media

    Energy Technology Data Exchange (ETDEWEB)

    Fong, L.; Appelbaum, H.R.

    1980-12-01

    A combined, one-dimensional, macropore-mesopore, hydrologic model was developed for simulating water flow through soils for analysis of data related to water and chemical flow in soils. Flows within the macroporous system as well as interactive flows between macroporous and mesoporous systems were modeled. Computer subroutines were written and incorporated into the existing one-dimensional Terrestrial Ecosystem Hydrologic Model (TEHM) developed at ORNL. Simulation showed that macropore flow effects are important during heavy precipitation and are more significant in soils of comparatively low hydraulic conductivity (5 to 10 cm/d). Increased drainage and decreased lateral flow result from the addition of the macropore model. The effect was more pronounced in soils of large macroporosity. Preliminary results indicate that the model is insensitive to geometrical properties of macropores.

  16. [Sizes of soil macropores and related main affecting factors on a vegetated basalt slope].

    Science.gov (United States)

    Guan, Qi; Xu, Ze-Min; Tian, Lin

    2013-10-01

    The landslide on vegetated slopes caused by extreme weather has being increased steadily, and the preferential flow in soil macropores plays an important role in the landslide. By using water breakthrough curve and Poiseuille equation, this paper estimated the radius range, amount, and average volume of soil macropores on a vegetated basalt slope of Maka Mountain, Southwest China, and analyzed the distribution of the soil macropores and the main affecting factors. In the study area, the radius of soil macropores ranged from 0.3 to 1.8 mm, mainly between 0.5 and 1.2 mm. The large-radius macropores (1.4-1.8 mm) were lesser, while the small-radius macropores (< 1.4 mm) were more. With the development of soil profile, soil macropores were more in upper layers and lesser in deeper layers. The average volume of the macropores contributed 84.7% to the variance of steady effluent rate. Among the factors affecting the average volume of the large macropores, vegetations root mass had a linear relationship, with the correlation coefficient being 0.70, and soil organic matter content also had a linear relationship, with the correlation coefficient being 0.64.

  17. [Macropore characteristics and its relationships with the preferential flow in broadleaved forest soils of Simian Mountains].

    Science.gov (United States)

    Wang, Wei; Zhang, Hong-jiang; Cheng, Jin-hua; Wu, Yu-he; Du, Shi-cai; Wang, Ran

    2010-05-01

    Brilliant blue dyeing and water breakthrough curve were applied to study the number and distribution of macropores and their relations to the preferential flow in typical sub-tropic broad-leaved forest soils of Simian Mountains. The radii of the macropores were mainly between 0. 3 and 3.0 mm, with the macroporosities in the range of 6.3% to 10.5%, and the macropores were always distributed in aggregation with increasing soil depth. The number of the macropores in each radius interval of dye-stained areas was tenfold increase than that of blank areas. The number of the macropores with radius larger than 0.3 mm, especially larger than 1.5 mm, was the most important factor affecting the occurrence of preferential flow. Significant correlations were found between the number of macropores and the water steady effluent volume, with the highest correlation coefficients of 0.842 and 0.879 for the radii intervals of 0.7-1.5 mm and 1.5-3.0 mm, respectively. Macro-pore continuity in dye-stained areas was better than that in blank areas, especially in the radius interval of 1.5-3.0 mm, with the biggest difference of 78.31%. In dye-stained areas, the number of macropores decreased gradually with soil depth. The filler-like distribution of macropores formed an effective water pressure gradient, which resulted in the preferential transport of water.

  18. Ordered macroporous bimetallic nanostructures: design, characterization, and applications.

    Science.gov (United States)

    Lu, Lehui; Eychmüller, Alexander

    2008-02-01

    Ordered porous metal nanomaterials have current and future potential applications, for example, as catalysts, as photonic crystals, as sensors, as porous electrodes, as substrates for surface-enhanced Raman scattering (SERS), in separation technology, and in other emerging nanotechnologies. Methods for creating such materials are commonly characterized as "templating", a technique that involves first the creation of a sacrificial template with a specific porous structure, followed by the filling of these pores with desired metal materials and finally the removal of the starting template, leaving behind a metal replica of the original template. From the viewpoint of practical applications, ordered metal nanostructures with hierarchical porosity, namely, macropores in combination with micropores or mesopores, are of particular interest because macropores allow large guest molecules to access and an efficient mass transport through the porous structures is enabled while the micropores or mesopores enhance the selectivity and the surface area of the metal nanostructures. For this objective, colloidal crystals (or artificial opals) consisting of three-dimensional (3D) long-range ordered arrays of silica or polymer microspheres are ideal starting templates. However, with respect to the colloidal crystal templating strategies for production of ordered porous metal nanostructures, there are two challenging questions for materials scientists: (1) how to uniformly and controllably fill the interstitial space of the colloidal crystal templates and (2) how to generate ordered composite metal nanostructures with hierarchical porosity. This Account reports on recent work in the development and applications of ordered macroporous bimetallic nanostructures in our laboratories. A series of strategies have been explored to address the challenges in colloidal crystal template techniques. By rationally tailoring experimental parameters, we could readily and selectively design

  19. Evaluation of salinity effect on quantitative analysis of aquatic humic substances using nonionic DAX-8 resin.

    Science.gov (United States)

    Kida, Morimaru; Ohtsuka, Toshiyuki; Kato, Taku; Suzuki, Takeshi; Fujitake, Nobuhide

    2016-03-01

    A nonionic macroporous resin, Amberlite(®) XAD-8, or its substitute, Supelite™ DAX-8, is used when isolating or quantifying aquatic humic substances (AHS). However, the effect of salinity on the adsorption behavior of AHS onto the resin is yet to be confirmed, rendering the possibility of salinity-induced changes in the values of quantified amounts or characteristics of AHS obtained from a salty system. To verify the results of quantification and isolation of AHS using the resin in different salinity systems, the effect of salinity on such quantitative analyses of AHS has been examined. It has been concluded that the salinity effect is in general trivial and will not hinder comparison of results regardless of sample solution salinity.

  20. RELATION BETWEEN MECHANICAL PROPERTIES AND PYROLYSIS TEMPERATURE OF PHENOL FORMALDEHYDE RESIN FOR GAS SEPARATION MEMBRANES

    Directory of Open Access Journals (Sweden)

    MONIKA ŠUPOVÁ

    2012-03-01

    Full Text Available The aim of this paper has been to characterize the relation between the pyrolysis temperature of phenol-formaldehyde resin, the development of a porous structure, and the mechanical properties for the application of semipermeable membranes for gas separation. No previous study has dealt with this problem in its entirety. Phenol-formaldehyde resin showed an increasing trend toward micropore porosity in the temperature range from 500 till 1000°C, together with closure of mesopores and macropores. Samples cured and pyrolyzed at 1000°C pronounced hysteresis of desorption branch. The ultimate bending strength was measured using a four-point arrangement that is more suitable for measuring of brittle materials. The chevron notch technique was used for determination the fracture toughness. The results for mechanical properties indicated that phenol-formaldehyde resin pyrolyzates behaved similarly to ceramic materials. The data obtained for the material can be used for calculating the technical design of gas separation membranes.

  1. ADSORPTION OF 2,4-D ON MODIFIED HYPERCROSSLINKED POLYSTYRENE (NDA-99) AND XAD-4 RESIN

    Institute of Scientific and Technical Information of China (English)

    Yu-ping Qiu; Jin-long Chen; Ai-min Li; Quan-xing Zhang; Min-sheng Huang

    2005-01-01

    The adsorption behavior of pesticide 2,4-dichlorophenoxyacetic acid (2,4-D) in aqueous solution has been investigated using a hypercrosslinked polystyrene adsorbent (NDA-99) modified by dimethylamine group as well as a nonionic macroporous adsorbent (XAD-4). The Langmuir and Freundlich isotherm models were employed to fit the experimental data to describe adsorption mechanism. It shows that NDA-99 resin exhibits an adsorption affinity for 2,4-D higher than XAD-4 resin owing to its exceptional micropore structure and the amine group of the hypercrosslinked matrix.Further studies indicate that the hydrogen bonding interaction and the stronger π-π conjugation play a significant role in the course of the adsorption of 2,4-D on NDA-99 resin, which is in agreement with the IR spectroscopic results and the AE values of HOMO (the highest occupied molecular orbit) of adsorbent and LUMO (the lowest unoccupied molecular orbit) of adsorbate calculated from the MINDO/3 model.

  2. Mechanically robust, rapidly actuating, and biologically functionalized macroporous poly(N-isopropylacrylamide)/silk hybrid hydrogels.

    Science.gov (United States)

    Gil, Eun Seok; Park, Sang-Hyug; Tien, Lee W; Trimmer, Barry; Hudson, Samuel M; Kaplan, David L

    2010-10-05

    A route toward mechanically robust, rapidly actuating, and biologically functionalized polymeric actuators using macroporous soft materials is described. The materials were prepared by combining silk protein and a synthetic polymer (poly(N-isopropylacrylamide) (PNIAPPm)) to form interpenetrating network materials and macroporous structures by freeze-drying, with hundreds of micrometer diameter pores and exploiting the features of both polymers related to dynamic materials and structures. The chemically cross-linked PNIPAAm networks provided stimuli-responsive features, while the silk interpenetrating network formed by inducing protein β-sheet crystallinity in situ for physical cross-links provided material robustness, improved expansion force, and enzymatic degradability. The macroporous hybrid hydrogels showed enhanced thermal-responsive properties in comparison to pure PNIPAAm hydrogels, nonporous silk/PNIPAAm hybrid hydrogels, and previously reported macroporous PNIPAAm hydrogels. These new systems reach near equilibrium sizes in shrunken/swollen states in less than 1 min, with the structural features providing improved actuation rates and stable oscillatory properties due to the macroporous transport and the mechanically robust silk network. Confocal images of the hydrated hydrogels around the lower critical solution temperature (LCST) revealed macropores that could be used to track changes in the real time morphology upon thermal stimulus. The material system transformed from a macroporous to a nonporous structure upon enzymatic degradation. To extend the utility of the system, an affinity platform for a switchable or tunable system was developed by immobilizing biotin and avidin on the macropore surfaces.

  3. Direct access to macroporous chromium nitride and chromium titanium nitride with inverse opal structure.

    Science.gov (United States)

    Zhao, Weitian; DiSalvo, Francis J

    2015-03-21

    We report a facile synthesis of single-phase, nanocrystalline macroporous chromium nitride and chromium titanium nitride with an inverse opal morphology. The material is characterized using XRD, SEM, HR-TEM/STEM, TGA and XPS. Interconversion of macroporous CrN to Cr2O3 and back to CrN while retaining the inverse opal morphology is also demonstrated.

  4. Highly Ordered TiO2 Macropore Arrays as Transparent Photocatalysts

    OpenAIRE

    Yuan Dong; Junfeng Chao; Zhong Xie; Xin Xu; Zhuoran Wang; Di Chen

    2012-01-01

    Highly ordered transparent TiO2 macropore arrays were synthesized via a simple glass-clamping method at room temperature. The as-synthesized TiO2 macropore arrays show high transmittance in the visible light region and can be used as transparent photocatalysts for degradation of organic dyes.

  5. Artificial macropores attract crop roots and enhance plant productivity on compacted soils.

    Science.gov (United States)

    Colombi, Tino; Braun, Serge; Keller, Thomas; Walter, Achim

    2017-01-01

    The structure of compacted soils is characterised by decreased (macro-)porosity, which leads to increased mechanical impedance and decreased fluid transport rates, resulting in reduced root growth and crop productivity. Particularly in soils with high mechanical impedance, macropores can be used by roots as pathways of least resistance. This study investigated how different soil physical states relate to whole plant growth and whether roots grow towards spots with favourable soil physical conditions. Experiments were conducted under controlled and field conditions. Soybean (Glycine max L.), wheat (Triticum aestivum L.) and maize (Zea mays L.) were grown on uncompacted soil, compacted soil and compacted soil with artificial macropores. The interactions between roots and artificial macropores were quantified using X-ray computed tomography. Active growth of roots towards artificial macropores was observed for all three species. Roots grew either into macropores (predominantly in maize) or crossed them (predominantly in wheat). The presence of artificial macropores in compacted soil enabled all three species to compensate for decreased early vigour at later developmental stages. These results show that roots sense their physical environment, enabling them to grow towards spots with favourable soil conditions. The different kinds of root-macropore interaction indicated that macropores serve as a path of least resistance and a source of oxygen, both resulting in increased crop productivity on compacted soils. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Macroporous silica–alumina composites with mesoporous walls

    Indian Academy of Sciences (India)

    Gautam Gundiah

    2001-04-01

    Macroporous silica–alumina composites with mesopores have been prepared by employing polymethylmethacrylate beads as templates in the presence of the cationic surfactant, N-cetyl-N,N,N-trimethylammonium bromide. The Si/Al ratio in the composites has been varied between 4.5 and 48 and the occurrence of mesopores has been verified by X-ray diffraction. The surface areas of the samples vary between 676 and 1038 m2g–1, with the highest value in the sample with Si/Al = 48.

  7. Preferential flow in macroporous swelling soil with internal catchment: model development and applications

    Science.gov (United States)

    Greco, Roberto

    2002-12-01

    A new model of infiltration in swelling and shrinking clay soil was developed. The model consisted of two flow domains: soil matrix, with flow modelled by means of Darcy equation, and macropores; the latter was divided in turn into two sub-domains: shrinkage cracks, with aperture dynamically depending on matrix water content, and permanent macropores, independent of matrix saturation. In the shrinkage cracks sub-domain, a kinematic wave equation was derived by considering laminar motion of thin water films, along two parallel nearly vertical walls; in the permanent macropores sub-domain, a kinematic wave equation was assumed, with parameters physically related with macropores shape and dimension. Exchange of water between macropore domains and matrix was introduced in form of sink terms in the macropores mass balance equations, and as source terms in the matrix continuity equation. Infiltration through macropore walls was modelled using a diffusivity function derived from aggregates sorptivity measurements. The internal catchment was included by considering at each layer a fraction of dead end permanent macropores. Water ponding at the bottom of dead end macropores, infiltrated into the corresponding matrix layer. The model was tested against the results of infiltration transients through a large undisturbed swelling and shrinking clay soil column. Outflow rate from column bottom surface was constantly measured, while water content profile was registered at regular time intervals by means of five TDR horizontal probes. In order to quantify model parameters, characterisation of soil matrix was carried out, providing hydraulic conductivity curve, water retention curve, shrinkage characteristic and aggregates diffusivity. All of the other model parameters, thanks to their clear physical meaning, were estimated from direct observation of soil structure, except macropores morphologic parameters, some of which, although measurable, were obtained by calibration due to

  8. [Radiopacity of composite resins].

    Science.gov (United States)

    Tamburús, J R

    1990-01-01

    The author studied the radiopacity of six composite resins, submitted to radiographic examination in standardized conditions, only with kilovoltage variations. Along with resins it was radiographed an aluminium penetrometer, to compare their optical densities. The results showed that kilovoltagem variations interfered in optical densities of the resins, being more pronounced in 50-55, 55-60 and 60-65 kilovoltages. Despite this, the relations of optical densities as compared with that of penetrometer steps kept unaltered most fo the kilovoltages used.

  9. Biocompatibility of composite resins

    OpenAIRE

    Sayed Mostafa Mousavinasab

    2011-01-01

    Dental materials that are used in dentistry should be harmless to oral tissues, so they should not contain any leachable toxic and diffusible substances that can cause some side effects. Reports about probable biologic hazards, in relation to dental resins, have increased interest to this topic in dentists. The present paper reviews the articles published about biocompatibility of resin-restorative materials specially resin composites and monomers which are mainly based on Bis-GMA and concern...

  10. New 3-D microarray platform based on macroporous polymer monoliths.

    Science.gov (United States)

    Rober, M; Walter, J; Vlakh, E; Stahl, F; Kasper, C; Tennikova, T

    2009-06-30

    Polymer macroporous monoliths are widely used as efficient sorbents in different, mostly dynamic, interphase processes. In this paper, monolithic materials strongly bound to the inert glass surface are suggested as operative matrices at the development of three-dimensional (3-D) microarrays. For this purpose, several rigid macroporous copolymers differed by reactivity and hydrophobic-hydrophilic properties were synthesized and tested: (1) glycidyl methacrylate-co-ethylene dimethacrylate (poly(GMA-co-EDMA)), (2) glycidyl methacrylate-co-glycerol dimethacrylate (poly(GMA-co-GDMA)), (3) N-hydroxyphthalimide ester of acrylic acid-co-glycidyl methacrylate-co-ethylene dimethacrylate (poly(HPIEAA-co-GMA-co-EDMA)), (4) 2-cyanoethyl methacrylate-co-ethylene dimethacrylate (poly(CEMA-co-EDMA)), and (5) 2-cyanoethyl methacrylate-co-2-hydroxyethyl methacrylate-co-ethylene dimethacrylate (poly(CEMA-co-HEMA-co-EDMA)). The constructed devices were used as platforms for protein microarrays construction and model mouse IgG-goat anti-mouse IgG affinity pair was used to demonstrate the potential of developed test-systems, as well as to optimize microanalytical conditions. The offered microarray platforms were applied to detect the bone tissue marker osteopontin directly in cell culture medium.

  11. Effects of hydrophilic macropore fillings and coatings on the infiltration into water repellent porous media

    Science.gov (United States)

    Suetsugu, A.; Mori, Y.

    2012-12-01

    Macropores generate rapid flow paths in the surface soils by their high permeability under saturated/near-saturated moisture conditions. In natural soils, some macropores are filled/coated with various materials including decayed plant roots (Meek et al., 1989), exudates from plants/soil organisms (Jegou et al., 2001), iron oxides or other precipitates from preferentially-introduced solutes/colloids to the macropores (Rasmussen et al., 2001), or the surrounding soils with reduced bulk density (Ela et al., 1992). When we expect infiltration into water repellent soils through macropores or hydrophilic patches created from the macropore cementation processes, hydrophilicity of the macropore fillings/coatings should be understood. In the present study, we conducted an infiltration experiment with water repellent porous media and some macropore fillings/coatings, in order to clarify the roles of hydrophilic macropore fillings/coatings in infiltration. Ponding depth and flow distribution were monitored with a micro-focus X-ray computational tomography apparatus (SMX-90CT, Shimadzu Corp., Kyoto, Japan) at 90 kV and 110 μA. Dilute CsCl(aq) (density: 1.04 Mg m-3) was used as the contrast media to avoid density-driven alteration of the flows. Water repellency of the samples was evaluated by the water drop penetration time (WDPT, Van't Woudt, 1959). A glass beads (mean diameter: 0.46 mm, BZ-04, ASONE Corp., Osaka, Japan) was used as water repellent porous media. The glass beads sample was packed in 50-mL polypropylene centrifugation tubes at 1.55 Mg m-3 bulk density. A 2-mm hole was made at the bottom of each centrifugation tube for ventilation. The hole was covered with mesh cloth. Macroporous structure was made at the center of each tube from the surface. Each macroporous structure had 4-mm diameter and 30-mm length. Six types of macropores were prepared including 1) no macropore, 2) empty macropore, 3) an aluminum (Al) pipe (4-mm inner diameter, 5-mm outer diameter), 4) a

  12. RESEARCH ON IMPROVED EPOXY RESINS.

    Science.gov (United States)

    another ’million-modulus’ epoxy resin. Cast resin properties from a series of epoxy resins hardened with several aromatic diamines are reported, but these data are sufficient to advance only speculative conclusions. (Author)

  13. BINARY COMPETITIVE AND COOPERATIVE ADSORPTION OF AROMATIC COMPOUNDS ON POLYMERIC RESINS

    Institute of Scientific and Technical Information of China (English)

    Wei-ming Zhang; Jin-long Chen; Bing-cai Pan; Quan-xing Zhang

    2005-01-01

    The adsorption behaviors of 2-naphthalenesulfonic acid and aniline on a conventional macroporous resin Amberlite XAD4 and the other two newly-developed hypercrosslinked resins NDA101 and NDA100 were investigated in a single or binary batch system at 293 K and 313 K, respectively. All the adsorption isotherms of 2-naphthalenesulfonic acid and aniline on the test resins in both systems can fit well with the Langmuir equation, indicating that the adsorption is a favorable process. At the identical equilibrium concentration, the amount of aniline adsorbed on polymeric resins in the single system is higher than that in the binary system because of the competitive adsorption between 2-naphthalenesulfonic acid and aniline on the resin surface. However, the uptake amount of 2-naphthalenesulfonic acid in the binary system is markedly larger than that in the single system, which is presumably due to the cooperative effect arisen from the electrostatic interaction between 2-naphthalenesulfonic acid and aniline adsorbed on the resin surface. The simultaneous adsorption system was proven to be helpful for the selective adsorption toward 2-naphthalenesulfonic acid due to its larger selective index.

  14. Effect of resin charged functional group, porosity, and chemical matrix on the long-term pharmaceutical removal mechanism by conventional ion exchange resins.

    Science.gov (United States)

    Wang, Wei; Li, Xiaofeng; Yuan, Shengliu; Sun, Jian; Zheng, Shaokui

    2016-10-01

    This study attempted to clarify the long-term pharmaceutical removal mechanism from sewage treatment plant effluent during the cyclical adsorption-regeneration operation of 5 commercial resin-based fixed-bed reactors with the simultaneous occurrence of electrostatic interactions and complex non-electrostatic interactions. It examined 12 pharmaceuticals belonging to 10 therapeutic classes with different predominant existing forms and hydrophobicities. Furthermore, the effect of the resin charged functional group (strong-base vs. strong-acid vs. non-ionic), porosity (macroporous vs. gel), and chemical matrix (polystyrenic vs. polyacrylic) on the mechanism was investigated to optimize resin properties and achieve higher pharmaceutical removal. The results reported herein indicate the importance of non-electrostatic interactions between pharmaceuticals and the resin backbone during short-term cyclical operation (i.e., the 1st adsorption-regeneration cycle). With the development of cyclical operation, however, non-electrostatic interaction-induced pharmaceutical removal generally decreased and even disappeared when equilibrium was achieved between the influent and the resin. Despite pharmaceutical therapeutic class or hydrophilicity, anion (or cation) exchange resin preferentially removed those pharmaceuticals that were predominantly present as organic anions (or cations) by ion exchange process during long-term cyclical operation (i.e., ≥6 adsorption-regeneration cycles). Besides pharmaceuticals predominantly present as undissociated molecules, some amphoteric pharmaceuticals containing large amounts of zwitterions were also difficult to remove by ion exchange resin. Additionally, neither resin porosity nor chemical matrix had any significant effect on the long-term pharmaceutical removal mechanism.

  15. Links between matrix bulk density, macropore characteristics and hydraulic behavior of soils

    DEFF Research Database (Denmark)

    Katuwal, Sheela; Møldrup, Per; Lamandé, Mathieu

    2013-01-01

    The relationship of soil bulk density with the hydraulic behavior of soil and the role of macropores in preferential flow and transport has been extensively studied in literatures. Yet, the influence of soil structural heterogeneity as simultaneous variation of bulk density and macropore characte......The relationship of soil bulk density with the hydraulic behavior of soil and the role of macropores in preferential flow and transport has been extensively studied in literatures. Yet, the influence of soil structural heterogeneity as simultaneous variation of bulk density and macropore...... resolution X-ray CT and linked them with laboratory measurements of air permeability and leaching experiment. In addition to macropore characteristics, we also quantified the CT-number of the matrix as a measure of the bulk density of the matrix, i.e., excluding macropores in the soil. Soils from the two...... field sites had similar texture (loam or sandy loam), yet the sand content was higher in Faardrup soils and clay and organic carbon content were higher in Silstrup soils. In general, Silstrup soil had more macropores (>1.2mm) than Faardrup soils but both the soils exhibited similar relationships between...

  16. Synthesis of 3D ordered macroporous indium tin oxide using polymer colloidal crystal template

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Xue'ao; MAN; Yahui; WANG; Jianfang; LIU; Changli; WU; Wenjian

    2006-01-01

    Three-dimensional (3D) ordered macroporous indium tin oxide (ITO) is prepared using a polymer colloidal crystal template that is formed by self-assembly of the monodisperse poly(methyl methacrylate) (PMMA) microspheres. The morphologies and BET surface area of the macroporous material is examined by scanning electron microscope, transmission electron microscopy and N2 adsorption/desorption. Results indicate that the macroporous material has highly ordered arrays of the uniform pores replicated from the PMMA colloidal crystal template when the polymer colloidal crystal template is removed by calcinations at 500℃. The pore diameter (about 450 nm) of macroporous ITO slightly shrank to the PMMA microspheres. The BET surface area and pore volume of the macroporous material are 389 m2·g-1 and 0.36 cm3·g-1, respectively. Moreover, the macroporous ITO, containing 5 mol% Sn and after annealing under vacuum, shows the minimum resistivity of ρ= 8.2×10-3 Ω· cm. The conductive mechanism of macroporous ITO is discussed, and it is believed that the oxygen vacancies are the major factor for excellent electrical properties.

  17. Adsorption behavior and mechanism of D113 resin for lanthanum

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The sorption properties of macroporous weak acid resin (Dl13) for La3+ ion were studied by chemical analysis and IR spectra. Experimental results indicate that the D113 resin has a good adsorption ability for La3+ at pH = 6.0 in the HAc-NaAc medium. The statically saturated adsorption capacity is 273.3 mg/g. Separation coefficients of βLa3+/ Ce3+, βLa3+/ Gd3+, βLa3+/ Er3+, and βLa3+/γ3+ are 2.29, 3.64,4.27, and 0.627, respectively. The apparent activation energy of adsorption, Ea is 18.4 kJ/mol, the thermodynamics parameters △H, △S, and △G of Sorption are 4.53 kJ/mol, 61.8 J/(mol·K), -13.9 kJ/mol, respectively. The adsorption behavior of Dl13 for La3+ obeys the Freundlich isotherm. La3+ adsorbed on resin can be eluted by 2.0 mol/LHC1 quantitatively.

  18. Rainfall Simulator Experiments to Investigate Macropore Impacts on Hillslope Hydrological Response

    Directory of Open Access Journals (Sweden)

    Yvonne Smit

    2016-11-01

    Full Text Available Understanding hillslope runoff response to intense rainfall is an important topic in hydrology, and is key to correct prediction of extreme stream flow, erosion and landslides. Although it is known that preferential flow processes activated by macropores are an important phenomena in understanding runoff processes inside a hillslope, hydrological models have generally not embraced the concept of an extra parameter that represents ‘macropores’ because of the complexity of the phenomenon. Therefore, it is relevant to investigate the influence of macropores on runoff processes in an experimental small artificial hillslope. Here, we report on a controlled experiment where we could isolate the influence of macropores without the need for assumptions regarding their characteristics. Two identical hillslopes were designed, of which one was filled with artificial macropores. Twelve artificial rainfall events were applied to the two hillslopes and results of drainage and soil moisture were investigated. After the experiments, it could be concluded that the influence of macropores on runoff processes was minimal. The S90 sand used for this research caused runoff to respond fast to rainfall, leading to little or no development of saturation near the macropores. In addition, soil moisture data showed a large amount of pendular water in the hillslopes, which implies that the soil has a low air entry value, and, in combination with the lack of vertical flow, could have caused the pressure difference between the matrix and the macropores to vanish sooner and result in equilibrium being reached in a relatively short time. Nevertheless, a better outline is given to determine a correct sand type for these types of experiments and, by using drainage recession analysis to investigate the influences of macropores on runoff, heterogeneity in rainfall intensity can be overcome. This study is a good point of reference to start future experiments from concerning

  19. Fabrication of Macro-porous β-zeolite by Using Colloidal Polystyrene Spheres as a Template

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A β-zeolite/polystyrene composite material was synthesized by co-deposition of mono-disperse polystyrene spheres and nano β-zeolite particles in aqueous suspension on a vertical substrate. Macro-porous β-zeolite was obtained after the polystyrene template was removed by calcination. The micro/macro-pore structure of the prepared β-zeolite was highly ordered. In comparison with other assembly methods, the co-deposition method could obtain a highly ordered macro-porous material with relatively large zeolite filling particles, and therefore the co-deposition of particles with different size is a promising method for the fabrication of macro-porous materials.

  20. Immobilization of bacteria in microgel grafted onto macroporous polyethylene

    Energy Technology Data Exchange (ETDEWEB)

    Trelles, J.A.; Quiroga, F.; Britos, C. [Dpto. de Ciencia y Tecnologia, Universidad Nacional de Quilmes, Roque Saenz Pena 352, (B1876BXD) Bernal, Buenos Aires (Argentina); Smolko, Eduardo E. [Comision Nacional de Energia Atomica, Buenos Aires (Argentina); Grasselli, Mariano, E-mail: mgrasse@unq.edu.a [Dpto. de Ciencia y Tecnologia, Universidad Nacional de Quilmes, Roque Saenz Pena 352, (B1876BXD) Bernal, Buenos Aires (Argentina)

    2010-03-15

    The development of 'Green Chemistry' requires new materials to replace the conventional organic chemistry by biological catalysts, to produce fine chemicals in an environmentally friendly manner. Microbial whole cells can be directly used as biocatalysts, providing a simple and cheap methodology since enzyme isolation and purification are avoided. High-density polyethylene (HDPE) is a very stable polymer though it can be activated by gamma radiation to induce grafting. Glycidyl methacrylate was grafted onto macroporous HDPE and PP in the range of 1-6%, proportional to the initial monomer concentration. Grafted polymers were further chemically modified with ethylenediamine to generate a cationic hydrogel of micron-size thickness onto the internal polymer surfaces. Modified polymers were able to immobilize Gram-positive and Gram-negative bacteria that can catalyze a chemical reaction as efficient as free cells do.

  1. Immobilization of bacteria in microgel grafted onto macroporous polyethylene

    Science.gov (United States)

    Trelles, J. A.; Quiroga, F.; Britos, C.; Smolko, Eduardo E.; Grasselli, Mariano

    2010-03-01

    The development of " Green Chemistry" requires new materials to replace the conventional organic chemistry by biological catalysts, to produce fine chemicals in an environmentally friendly manner. Microbial whole cells can be directly used as biocatalysts, providing a simple and cheap methodology since enzyme isolation and purification are avoided. High-density polyethylene (HDPE) is a very stable polymer though it can be activated by gamma radiation to induce grafting. Glycidyl methacrylate was grafted onto macroporous HDPE and PP in the range of 1-6%, proportional to the initial monomer concentration. Grafted polymers were further chemically modified with ethylenediamine to generate a cationic hydrogel of micron-size thickness onto the internal polymer surfaces. Modified polymers were able to immobilize Gram-positive and Gram-negative bacteria that can catalyze a chemical reaction as efficient as free cells do.

  2. Pillaring effects in macroporous carrageenan-silica composite microspheres.

    Science.gov (United States)

    Boissière, M; Tourrette, A; Devoisselle, J M; Di Renzo, F; Quignard, F

    2006-02-01

    The impregnation of a carrageenan gel by a silica sol is an efficient method to form a composite material which can be conveniently activated by CO2 supercritical drying. The textural properties of the solids have been characterized by nitrogen adsorption-desorption at 77 K and their composition by thermogravimetric analysis and EDX microprobe. Morphology was examined by SEM. The silica-carrageenan composites present an open macroporous structure. Silica particles retained inside the gel behaved as pillars between the polysaccharide fibrils and form a stick-and-ball network. The stiffening of the carrageenan gel by silica prevented its shrinkage upon drying. The nature of the alkali cations affected the retention of silica particles inside the gel. In the absence of silica, carrageenan fibrils rearrange under supercritical drying and form an aerogel with cavities in the mesopore range.

  3. Macroporous hydrogels with tailored morphology and mechanical properties

    Science.gov (United States)

    Bignotti, Fabio; Agnelli, Silvia; Baldi, Francesco; Sartore, Luciana; Peroni, Isabella

    2016-05-01

    In this work it is shown that hydroxyethylcellulose (HEC) can be employed for preparing macroporous polyacrylamide (PAAm) hydrogels with tailored morphology and mechanical properties. By changing the HEC content in the reaction mixture hydrogels with different pore sizes and degrees of interconnectivity can be synthesized. The equilibrium swelling ratio in 0.1 M NaCl increases with the amount of HEC employed. Tensile tests run on equilibrated hydrogels show that these materials behave as rubber-like materials. Their mechanical stiffness decreases regularly as the amount of HEC, and therefore their porosity, is increased. A more complex trend is observed for elongation and stress at break, which display a maximum at intermediate contents of HEC.

  4. Electro-responsive macroporous polypyrrole scaffolds for triggered dexamethasone delivery.

    Science.gov (United States)

    Seyfoddin, A; Chan, A; Chen, W-T; Rupenthal, I D; Waterhouse, G I N; Svirskis, D

    2015-08-01

    Corticosteroids such as dexamethasone are first line ophthalmic treatment for non-infectious posterior uveitis. Corticosteroids are often administered via intravitreal injection to treat this condition with frequent injections associated with poor treatment adherence and complications such as endophthalmitis. Current ocular implants provide sustained corticosteroid release at predetermined rates and lack the ability for dose individualisation. This study describes the successful fabrication of electrically responsive macroporous polypyrrole (PPy) thin films, and their subsequent application to triggered dexamethasone release. Colloidal crystal films composed of 370nm polymethylmethacrylate colloids were first deposited on ITO coated glass substrates, and subsequently used as sacrificial templates for the fabrication of high surface area, 3-dimensionally ordered macroporous PPy inverse opal (PPy IO) thin films. SEM, UV-Vis reflectance and cyclic voltammetry measurements established that the redox state of the PPy IO films could be controlled via electrical stimulation, which in turn influences both porosity and optical properties of the films. Incorporation of the anti-inflammatory corticosteroid, dexamethasone phosphate (DexP), in the PPy IO films during their fabrication resulted in an effective delivery platform for triggered DexP release. A sustained release profile was observed for the PPy IO-DexP films, bursts of release could be triggered by electrical stimulation. The amount of DexP released from the PPy IO-DexP films was significantly higher than that released from the conventional non-porous PPy-DexP films of comparable mass. Results suggest that electrically responsive PPy IO structures are highly suitable for on-demand drug delivery applications. This technology may enable physicians to fine-tune the required dose according to disease state and patients' needs to enhance the safety and efficacy of corticosteroid treatment. Copyright © 2015 Elsevier B

  5. Pesticide transport to tile-drained fields in SWAT model – macropore flow and sediment

    DEFF Research Database (Denmark)

    Lu, Shenglan; Trolle, Dennis; Blicher-Mathiesen, Gitte;

    2015-01-01

    as a fraction of effective rainfall and transported to the tile drains directly. Macropore sediment transport is calculated similarly to the MACRO model (Jarvis et al., 1999). Mobile pesticide transport is calculated with a decay function with the flow, whereas sorbed pesticides transport is associated...... Tool (SWAT) to simulate transport of both mobile (e.g. Bentazon) and strongly sorbed (e.g. Diuron) pesticides in tile drains. Macropore flow is initiated when soil water content exceeds a threshold and rainfall intensity exceeds infiltration capacity. The amount of macropore flow is calculated......Preferential flow and colloidal facilitated transport via macopores connected to tile drains are the main pathways for pesticide transport from agricultural areas to surface waters in some area. We developed a macropore flow module and a sediment transport module for the Soil and Water Assessment...

  6. Flow and transport processes in a macroporous subsurface-drained glacial till soil

    DEFF Research Database (Denmark)

    Villholth, Karen G.; Jensen, Karsten Høgh

    1998-01-01

    -scale concentration gradients, is questioned. Decreasing the domain exchange resulted in an improved model correspondence with the drainage chemograph. The drainage flow pattern was altered between drainage seasons owing to the changes in hydraulic efficiency of surface-vented macropores influenced by the physical......The experimental results from a field-scale tracer experiment in a subsurface-drained glacial till soil were analyzed by the application of a single/dual porosity model (MACRO), optionally accounting for concurrent and interacting flow and transport in the bulk soil porosity as well...... as in the macropores. The model analysis showed that macropore flow is essential in describing the observed transport phenomenon on a short as well as a longer time scale. The diffusive exchange of solute between the matrix and the macropores was very sensitive and critical for the model prediction of the drainage...

  7. Oscillations of light absorption in 2D macroporous silicon structures with surface nanocoatings

    Energy Technology Data Exchange (ETDEWEB)

    Karachevtseva, L., E-mail: lakar@isp.kiev.ua [V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine, 41 Nauki Pr., 03028 Kyiv (Ukraine); Kuchmii, S. [L.V. Pisarzhevskii Institute of Physical Chemistry, National Academy of Sciences of Ukraine, 31 Nauki Pr., 03028 Kyiv (Ukraine); Lytvynenko, O.; Sizov, F.; Stronska, O. [V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine, 41 Nauki Pr., 03028 Kyiv (Ukraine); Stroyuk, A. [L.V. Pisarzhevskii Institute of Physical Chemistry, National Academy of Sciences of Ukraine, 31 Nauki Pr., 03028 Kyiv (Ukraine)

    2011-02-01

    We investigated the near-IR light absorption oscillations in 2D macroporous silicon structures with microporous silicon layers and CdTe, ZnO surface nanocrystals. The electro-optical effect was taken into account within the strong electric field approximation. Well-separated oscillations were observed in the spectral ranges of the surface bonds of macroporous silicon structures with surface nanocrystals. The model of the resonant electron scattering on impurity states in electric field of heterojunction 'silicon-nanocoating' on macropore surface as well as realization of Wannier-Stark effect on the randomly distributed surface bonds were considered. The Wannier-Stark ladders are not broken by impurities because of the longer scattering lifetime as compared with the period of electron oscillations in an external electric field, in all spectral regions considered for macroporous silicon structures with CdTe and ZnO surface nanocrystals.

  8. Synthesis and application of nano-, meso- and macroporous sorbents based on lignin for detoxication of biological fluids

    Science.gov (United States)

    Chopabayeva, Nazira N.; Mukanov, Kanatbek N.; Tasmagambet, Amandyk T.

    2014-05-01

    Novel nano-, meso- and macroporous sorbents based on hydrolysis lignin have been synthesized by catalytic o-alkylation of biolpolymer with epoxy resin ED-20 and subsequent amination of formed α-oxyde derivative. Composition, structure, morphology and physical, chemical properties of ion-exchangers were investigated by FTIR, SEM, TEM, porosimetry and potentiometric titration method. It has been established that alkaline activated lignin shows an increase of SBET to 20.9 m2/g while modification leads to decrease of SBET more than double (from 9.2 to 5.2 m2/g) that of an untreared sample (14.5 m2/g). Synthesized sorbents are characterized by approximately identical mesoporous structure and mainly contained a pore size of 10-14 nm. The results clearly demonstrate the efficiency of lignin based sorbents for the removal of water and lipid soluble toxic metabolites from blood serum of diabetic retinopathy patients. Samples reduced the high level of total cholesterol, including its most atherogenic fractions (LDL-C, VLDL-C), triglyceride to the level of optimum compensated diabetes without significant removal of HDL-C. Concentration of glucose was decreased to physiological norms.

  9. MACROPORE FLOW AND MASS WASTING OF GULLIES IN THE LOESS PLATEAU, CHINA

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Due to the extensive gullying from historically excessive erosion in the loess plateau of China, much of this region is being converted to native grass and shrub vegetation. Tunnel scour and mass wasting are important gully erosion processes resulting from preferential flow through macropores ( pores > 1 mm diameter). The objective of this study is to assess the changes with time in macropore flow characteristics of soils on the Loess Plateau following conversion to grass vegetation and the associated degree of mass wasting of gully faces. Ridge areas that had been revegetated for 1 year, 6 years, and > 15 years following tilling, and for 6 years following contour-ditching and the adjacent gully faces were characterized for their macropore and soil matrix properties on a 50 cm by 50 cm area. The total number of macropores increased from 11.6/m2 to 39.6/m2 from 1 to 6 years and to 51.6/m2 after 15 years of revegetation following tillage. The macroporosity increased from 0.0008 m3/m3 to 0.0018 m3/m3 from 1 to 6 years of revegetation following tillage but the lowest macroporosity (0.0005 m3/m3) was 6 years of revegetation following contour-ditching. The contour-ditched area had the lowest infiltration rate (95 m/d) through the soil matrix (areas without macropores) with the tilled areas having similar infiltration rates regardless of the number of years of revegetation (averaged 146 m/d). Due to tunnel scour erosion of macropores during infiltration into the area revegetated for 1 year, pore diameters enlarged by more than 200% resulting in this condition having the highest individual macropore infiltration rates (7967 m/d). Macropores in all other areas were stable with no tunnel scour erosion of macropores. The total capacity for infiltration through macropores increased significantly with time following revegetation. The number of macropores on the gully faces was triple (92.8/m2) and the macroporosity quadruple (0.004 m3/m3) that of the ridge surfaces. The upper

  10. Biocidal quaternary ammonium resin

    Science.gov (United States)

    Janauer, G. E.

    1983-01-01

    Activated carbon (charcoal) and polymeric resin sorbents are widely used in the filtration and treatment of drinking water, mainly to remove dissolved organic and inorganic impurities and to improve the taste. Earlier hopes that activated carbon might "disinfect' water proved to be unfounded. The feasibility of protecting against microbial infestation in charcoal and resin beds such as those to be incorporated into total water reuse systems in spacecraft was investigated. The biocidal effect of IPCD (insoluable polymeric contact disinfectants) in combination with a representative charcoal was assessed. The ion exchange resins (IPCD) were shown to adequately protect charcoal and ion exchange beds.

  11. Biocompatibility of composite resins

    Directory of Open Access Journals (Sweden)

    Sayed Mostafa Mousavinasab

    2011-01-01

    Full Text Available Dental materials that are used in dentistry should be harmless to oral tissues, so they should not contain any leachable toxic and diffusible substances that can cause some side effects. Reports about probable biologic hazards, in relation to dental resins, have increased interest to this topic in dentists. The present paper reviews the articles published about biocompatibility of resin-restorative materials specially resin composites and monomers which are mainly based on Bis-GMA and concerns about their degradation and substances which may be segregated into oral cavity.

  12. Preparation and characterization of polystyrene-based monolith with ordered macroporous structure

    Institute of Scientific and Technical Information of China (English)

    Quan Zhou Wu; Jian Feng He; Ji Ming Ou

    2012-01-01

    In this paper,polystyrene-based monoliths with highly ordered macroporous structure were synthesized by using SiO2 colloidal crystal as template.SEM observation shows that the macropores are highly ordered and are interconnected by small windows.The BET surface area of PS monolith is about 36.17 m2/g.The polymer monoliths can resist 5 MPa pressure,showing high mechanical and compressive strength.

  13. Unfolding and aggregation of monoclonal antibodies on cation exchange columns: effects of resin type, load buffer, and protein stability.

    Science.gov (United States)

    Guo, Jing; Carta, Giorgio

    2015-04-03

    The chromatographic behavior of a monoclonal antibody (mAb) that exhibits a pronounced two-peak elution behavior is studied for a range of strong cation exchange resins and with varying load buffer pH and composition. Six stationary phases are considered, including two tentacle-type resins (Fractogel EMD SO3-(M) and Eshmuno S), a resin with grafted polymeric surface extenders (Nuvia S), a resin with a bimodal pore size distribution (POROS HS 50), and two macroporous resins without polymer grafts (Source 30S and UNOsphere Rapid S). The two-peak elution behavior is very pronounced for the tentacle and polymer-grafted resins and for POROS HS 50, but is essentially absent for the two macroporous resins. The extent of this behavior decreases as the buffer pH and concentration increase and, consequently, mAb binding becomes weaker. Replacing sodium with arginine as the buffer counterion, which is expected to decrease the mAb binding strength, nearly completely eliminates the two-peak behavior, while replacing sodium with tetra-n-butylammonium hydroxide, which is expected to increase the mAb binding strength, dramatically exacerbate the effect. As shown by hydrogen-deuterium exchange mass spectrometry (HX-MS), the two-peak elution behavior is related to conformational changes that occur when the mAb binds. These changes result in increased solvent exposure of specific peptides in the Fc-region for either the Fractogel or the Nuvia resin. No significant conformational changes were seen by HX-MS when the mAb was bound to the UNOsphere resin or on the Fractogel resin when arginine was used in lieu of sodium as the load buffer counterion. Experiments with two additional mAbs on the Fractogel resin show that the two-peak elution behavior is dependent on the particular antibody. Circular dichroism suggests that the propensity of different mAbs to either precipitate directly or to form stabilizing intermolecular structures upon exposure to thermal stress can be related to their

  14. Resin composite repair: Quantitative microleakage evaluation of resin-resin and resin-tooth interfaces with different surface treatments

    OpenAIRE

    Celik, Cigdem; Cehreli, Sevi Burcak; Arhun, Neslihan

    2015-01-01

    Objective: The aim was to evaluate the effect of different adhesive systems and surface treatments on the integrity of resin-resin and resin-tooth interfaces after partial removal of preexisting resin composites using quantitative image analysis for microleakage testing protocol. Materials and Methods: A total of 80 human molar teeth were restored with either of the resin composites (Filtek Z250/GrandioSO) occlusally. The teeth were thermocycled (1000×). Mesial and distal 1/3 parts of the res...

  15. Ordered macroporous quercetin molecularly imprinted polymers: Preparation, characterization, and separation performance.

    Science.gov (United States)

    Feng, Yonggang; Liu, Qin; Ye, Lifang; Wu, Quanzhou; He, Jianfeng

    2017-02-01

    Ordered macroporous molecularly imprinted polymers were prepared by a combination of the colloidal crystal templating method and the molecular imprinting technique by using SiO2 colloidal crystal as the macroporogen, quercetin as the imprinting template, acrylamide as the functional monomer, ethylene glycol dimethacrylate as the cross-linker and tetrahydrofuran as the solvent. Scanning electron microscopy and Brunauer-Emmett-Teller measurements show that the ordered macroporous molecularly imprinted polymers have a more regular macroporous structure, a narrower pore distribution and a greater porosity compared with the traditional bulk molecularly imprinted polymers. The kinetic and isothermal adsorption behaviors of the polymers were investigated. The results indicate that the ordered macroporous molecularly imprinted polymers have a faster intraparticle mass transfer process and a higher adsorption capacity than the traditional bulk molecularly imprinted polymers. The ordered macroporous molecularly imprinted polymers were further employed as a sorbent for a solid-phase extraction. The results show that the ordered macroporous molecularly imprinted polymers can effectively separate quercetin from the Gingko hydrolysate.

  16. Separation of hemicellulose-derived saccharides from wood hydrolysate by lime and ion exchange resin.

    Science.gov (United States)

    Wang, Xiaojun; Zhuang, Jingshun; Fu, Yingjuan; Tian, Guoyu; Wang, Zhaojiang; Qin, Menghua

    2016-04-01

    A combined process of lime treatment and mixed bed ion exchange was proposed to separate hemicellulose-derived saccharides (HDS) from prehydrolysis liquor (PHL) of lignocellulose as value added products. The optimization of lime treatment achieved up to 44.2% removal of non-saccharide organic compounds (NSOC), mainly colloidal substances, with negligible HDS degradation at 0.5% lime level and subsequent neutralization by phosphoric acid. The residual NSOC and calcium ions in lime-treated PHL were eliminated by mixed bed ion exchange. The breakthrough curves of HDS and NSOC showed selective retention toward NSOC, leading to 75% HDS recovery with 95% purity at 17 bed volumes of exchange capacity. In addition, macroporous resin showed higher exchange capacity than gel resin as indicated by the triple processing volume. The remarkable selectivity of the combined process suggested the feasibility for HDS separation from PHL.

  17. Soil organic carbon, macropore networks and preferential transport

    Science.gov (United States)

    Larsbo, Mats; Koestel, John; Kätterer, Thomas; Jarvis, Nick

    2016-04-01

    Agricultural management practices such as tillage, crop rotations, residue management and fertilization can have a strong influence on soil organic carbon (SOC) stocks. An increase in SOC content will generally improve soil structure, which in turn determines the solute transport pathways through the soil. The aim of this study was to quantify the architecture of macropore networks in undisturbed soil columns (15 cm high, 12.7 cm diameter) sampled along a transect with natural variations in SOC using X-ray tomography and to relate the network characteristics to the degree of preferential transport in the columns. Two tracer experiments were carried out at constant irrigation rates of 2 and 5 mm h-1. We used the normalised 5% arrival time which reflects the tendency for early arrival of the solutes as a measure of the degree of preferential transport. The soil macropore networks were analysed in cylindrical sub-volumes (8 cm high, 10 cm diameter) located centrally within the soil columns. These sub-volumes were considered unaffected by sampling artefacts. Analyses were also carried out the for whole sample volumes to enable comparisons with the results from the transport experiments. Image processing and analysis were carried out in ImageJ and R. The same grey value threshold was applied to all images after harmonisation of grey values using the PVC column walls and the air outside the columns. This approach resulted in a satisfactory separation between the pore space and the surrounding soil matrix and organic matter. The SOC content along the transect, which varied from 4.2 to 15% , was correlated to all measures of the pore network for the sub-volumes except for the connectivity probability. Columns with high SOC content were associated with large macroporosities (both total and connected), large specific surface areas, large fractal dimensions and small mean pore thicknesses. The SOC content for whole sample volumes was positively correlated to 5% arrival times

  18. Macropore system characteristics controls on non-reactive solute transport at different flow rates

    Science.gov (United States)

    Larsbo, Mats; Koestel, John

    2014-05-01

    Preferential flow and transport in macroporous soils are important pathways for the leaching of agrochemicals through soils. Preferential solute transport in soil is to a large extent determined by the macropore system characteristics and the water flow conditions. The importance of different characteristics of the macropore system is likely to vary with the flow conditions. The objective of this study was to determine which properties of the macropore system that control the shape of non-reactive tracer solute breakthrough curves at different steady-state flow rates. We sampled five undisturbed columns (20 cm high, 20 cm diameter) from the soil surface of four soils with clay contents between 21 and 50 %. Solute transport experiments were carried out under unsaturated conditions at 2, 4, 6, 8 and 12 mm h-1 flow rates. For each flow rate a pulse of potassium bromide solution was applied at the soil surface and the electrical conductivity was measured with high temporal resolution in the column effluent. We used the 5 % arrival time and the holdback factor to estimate the degree of preferential transport from the resulting breakthrough curves. Unsaturated hydraulic conductivities were measured at the soil surface of the columns using a tension disc infiltrometer. The macropore system was imaged by industrial X-ray computed tomography at a resolution of 125 μm in all directions. Measures of the macropore system characteristics including measures of pore continuity were calculated from these images using the ImageJ software. Results show that the degree of preferential transport is generally increasing with flow rate when larger pores become active in the transport. The degree of preferential flow was correlated to measures of macropore topology. This study show that conclusions drawn from experiments carried out at one flow rate should generally not be extrapolated to other flow rates.

  19. Facile fabrication of egg white macroporous sponges for tissue regeneration.

    Science.gov (United States)

    Jalili-Firoozinezhad, Sasan; Rajabi-Zeleti, Sareh; Mohammadi, Parvaneh; Gaudiello, Emanuele; Bonakdar, Shahin; Solati-Hashjin, Mehran; Marsano, Anna; Aghdami, Nasser; Scherberich, Arnaud; Baharvand, Hossein; Martin, Ivan

    2015-10-28

    The availability of 3D sponges combining proper biochemical, biophysical, and biomechanical properties with enhanced capacity of in vivo engraftment and vascularization is crucial in regenerative medicine. A simple process is developed to generate macroporous scaffolds with a well-defined architecture of interconnected pores from chicken egg white (EW), a material with protein- and growth factor-binding features which has not yet been employed in regenerative medicine. The physicomechanical properties and degradation rates of the scaffold are finely tuned by using varying concentrations of the cross-linker, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride, without alteration of the biochemical traits. In vitro, EW scaffolds supported active metabolism, proliferation, and migration of human dermal fibroblasts, thereby generating uniform cellular constructs. In vivo, subcutaneous implantation in mice reveals negligible immune reaction and efficient cell and tissue ingrowth. Angiogenesis into EW scaffolds is enhanced as compared to standard collagen type I sponges used as reference material, likely due to significantly higher adsorption of the proangiogenic factor vascular endothelial growth factor. In summary, a material is presented derived by facile processing of a highly abundant natural product. Due to the efficient subcutaneous engraftment capacity, the sponges can find utilization for soft tissue regeneration.

  20. Preparation and bioactivity of sol-gel macroporous bioactive glass

    Institute of Scientific and Technical Information of China (English)

    Zhihua Zhou; Jianming Ruan; Jianpeng Zou; Zhongcheng Zhou

    2008-01-01

    Bioactive glass is well known for its ability of bone regeneration, and sol-gel bioactive glass has many advantages com-pared with melt-derived bioactive glass. 3-D scaffold prepared by the sol-gel method is a promising substrate material for bone tissue engineering and large-scale bone repair. Porous sol-gel glass in the CaO-SiO2-P2O5 system with macropores larger than 100 μm was prepared by the addition of stearic acid as a pore former. The diameter of the pore created by the pore former varied from 100 to 300μm. The formation of a hydroxyapatite layer on the glass was analyzed by studying the surface of the porous glass by scanning elec-tron microscopy, energy dispersive spectroscopy, X-ray diffraction, and Raman spectra after they had been immersed in simulated body fluid (SBF) for some time, and the porous glass shows good bioactivity.

  1. Macroporous monoliths for trace metal extraction from seawater

    Energy Technology Data Exchange (ETDEWEB)

    Yue, Yanfeng; Mayes, Richard; Gill, Gary A.; Kuo, Li-Jung; Wood, Jordana R.; Binder, Andrew; Brown, Suree; Dai, Sheng

    2015-05-29

    The viability of seawater-based uranium recovery depends on the uranium adsorption rate and capacity, since the concentration of uranium in the oceans is relatively low (3.3 μgL⁻¹). An important consideration for a fast adsorption is to maximize the adsorption properties of adsorbents such as surface areas and pore structures, which can greatly improve the kinetics of uranium extraction and the adsorption capacity simultaneously. Following this consideration, macroporous monolith adsorbents were prepared from the copolymerization of acrylonitrile (AN) and N,N’-methylenebis(acrylamide) (MBAAm) based on a cryogel method using both hydrophobic and hydrophilic monomers. The monolithic sorbents were tested with simulated seawater containing a high uranyl concentration (–6 ppm) and the uranium adsorption results showed that the adsorption capacities are strongly influenced by the ratio of monomer to the crosslinker, i.e., the density of the amidoxime groups. The preliminary seawater testing indicates the high salinity content of seawater does not hinder the adsorption of uranium.

  2. High energy density supercapacitors using macroporous kitchen sponges

    KAUST Repository

    Chen, Wei

    2012-01-01

    Macroporous, low-cost and recyclable kitchen sponges are explored as effective electrode platforms for supercapacitor devices. A simple and scalable process has been developed to fabricate MnO 2-carbon nanotube (CNT)-sponge supercapacitor electrodes using ordinary kitchen sponges. Two organic electrolytes (1 M of tetraethylammonium tetrafluoroborate (Et 4NBF 4) in propylene carbonate (PC), 1 M of LiClO 4 in PC) are utilized with the sponge-based electrodes to improve the energy density of the symmetrical supercapacitors. Compared to aqueous electrolyte (1 M of Na 2SO 4 in H 2O), the energy density of supercapacitors tripled in Et 4NBF 4 electrolyte, and further increased by six times in LiClO 4 electrolyte. The long-term cycling performance in different electrolytes was examined and the morphology changes of the electrode materials were also studied. The good electrochemical performance in both aqueous and organic electrolytes indicates that the MnO 2-CNT-sponge is a promising low-cost electrode for energy storage systems. © 2012 The Royal Society of Chemistry.

  3. Performance of nitrogen-containing macroporous carbon supported cobalt catalyst synthesized through in-situ construction of catalytic sites for oxygen reduction reaction

    Science.gov (United States)

    He, Fan; Yang, Jun; Li, Rui; Liu, Bin Hong; Li, Zhou Peng

    2015-01-01

    A novel method of in-situ catalytic site (CoNx) construction in macroporous carbon (MPC) is developed. The nitrogen-containing MPC-supported cobalt (Co/N-MPC) catalysts are synthesized via the pyrolysis of a mixture of glucose-urea resin, nano-CaCO3, and cobalt nitrate. The nano-CaCO3 functions as a template to fabricate MPC that provides high electric conductivity and large specific surface area. The catalytic CoNx sites are simultaneously created during the formation of N-MPC. The use of glucose-urea resin as the carbon and nitrogen sources significantly increases the nitrogen content as high as 8.8 at% in the MPC. The synthesized Co/N-MPC demonstrates superb catalytic activity toward oxygen reduction reaction. The direct borohydride fuel cell using the Co/N-MPC shows a power density as high as 170 mW cm-2 which is much higher than the cell using 10 wt.% Pt/C but slightly lower than the cell using 20 wt.% Pt/C as the cathode catalyst at ambient conditions.

  4. Fractionation of fulvic acid extracted from lake sediments using XAD resins and the metal complexing ability. Kosho taisekibutsuchu kara chushutsusareta furubosan no XAD jushi kyuchaku ni yoru bunkaku to sakka noryoku

    Energy Technology Data Exchange (ETDEWEB)

    Usui, K.; Kishino, T. (Ube Colege, Yamaguchi (Japan). laboratory of Environmental Science); Higashi, T.; Shindo, H.; Marumoto, T. (Yamaguchi University, Yamaguchi (Japan). Faculty of Agriculture)

    1993-10-10

    Fulvic acid was extracted from lake sediments, and given an adsorption treatment with Amberlite XAD-2 and XAD-8 resins. The copper complexing ability of the treated liquid was discussed using a two binding site model. As a result of deriving the condition stability constants of the treated liquid, it was learned that the fulvic acid can be divided largely into two kinds with different complexing ability by about 100 times, having log K1 = 6.33 to 7.12 and log K2 = 4.35 to 4.66. The majority was composed of fulvic acid having weak complexing ability. The resin treatment separated the fulvic acid nearly completely into an adsorption fraction and a non-adsorption fraction. The fulvic acid in the adsorption fraction showed very little complexing ability. On the other hand, the fulvic acid in the non-adsorption fraction, which is nearly colorless, exhibited a complexing ability of 33 to 45 [mu] mol/g as copper complexing capacity. Further, the amount of the non-adsorption fraction appeared to account for 52% to 69% of the total fulvic acid as judged from the TOC value. 19 refs., 1 fig., 1 tab.

  5. Direct Electrospinning of Ultrafine Fibers with Interconnected Macropores Enabled by in Situ Mixing Microfluidics.

    Science.gov (United States)

    Liu, Wanjun; Zhu, Lei; Huang, Chen; Jin, Xiangyu

    2016-12-21

    Porous ultrafine fibers are of great importance to various applications. Herein, we report a method to directly fabricate macro-porous ultrafine fibers by an in situ mixing microfluidics which allows for the simultaneous electrospinning of solution immediately after mixing. The formation mechanism of macro-pores should be attributed to the incomplete mixing coupled with nonsolvent-induced phase separation, which was elucidated by systematical investigation of various solvent systems and mixing solvents. The diameter of the macro-porous fibers can be tuned from 1.80 ± 0.40 to 6.75 ± 0.48 μm by adjusting the solution concentration and the feeding rate of mixing solvent. The results indicated that macro-porous fibers exhibited higher specific surface area (48.66 ± 8.30 m(2) g(-1)), larger pore size (116.73 nm) and pore volume (0.169 ± 0.007 cm(3) g(-1)) than conventional electrospun porous fibers, enabling the high oil absorption capacities of 95.68, 57.98, and 34.82 g g(-1) for silicon oil, motor oil, and peanut oil, respectively. Our method has greatly expanded the solution scope for electrospinning from stable solution systems to unstable or substable solution systems, thus providing intriguing opportunities for the investigation and fabrication of heterogeneous fibers by in situ mixing of various immiscible solvents/solutions. Our findings can serve as guidelines for the electrospinning of ultrafine fibers with interconnected macro-pores (>50 nm).

  6. Reusable macroporous photonic crystal-based ethanol vapor detectors by doctor blade coating.

    Science.gov (United States)

    Ko, Ya-Ling; Tsai, Hui-Ping; Lin, Kun-Yi; Chen, Ying-Chu; Yang, Hongta

    2017-02-01

    This research reports the development of sensitive and reversible vapor detection by using three-dimensional macroporous photonic crystals. A scalable and roll-to-roll compatible doctor blade coating technology is utilized to fabricate flexible macroporous poly(ethoxylated trimethylolpropane triacrylate) (PETPTA) films with hexagonal close-packed pores which are interconnected. The pores are then coated with a layer of poly(2-hydroxyethyl methacrylate) (PHEMA) to create macroporous PHEMA/PETPTA films. The condensation of vapors in the PHEMA coated macroporous films leads to the increase of both the PHEMA swelling degree and the effective refractive index of the diffractive medium, resulting in the red-shift and amplitude reduction of the optical stop bands. The optical measurements reveal that the diffraction from the as-prepared macroporous photonic crystals sensitively monitors the vapor pressure of ethanol since the PHEMA layer displays a great volume dependence on ethanol due to a decreased Flory-Huggins mixing parameter. The dependence of the diffraction wavelength on vapor pressure and the reproducibility of vapor sensing have also been investigated in this study.

  7. Preparation of Macro-Porous Tin Oxide for Sensing of Sulfur Compound.

    Science.gov (United States)

    Park, No-Kuk; Lee, Tae Hoon; Sung, Yeon Baek; Kim, Yong Sul; Lee, Tae Jin

    2016-03-01

    Macro-porous tin oxide was prepared as an enhanced sensing material for sulfur compounds, such as hydrogen sulfide. Poly-methyl-methacrylate (PMMA) was used as a template for the formation of macro-pores. Tin chloride was used as a precursor for the synthesis of tin oxide, and was impregnated over PMMA beads using a rotary vacuum evaporator. The solid Sn/PMMA material was treated thermally for 4 h at 600 degrees C. The porous morphology of tin oxide prepared in this study was observed by scanning electron microscopy. The surface area of this material measured by the nitrogen adsorption method was approximately 56 m2/g. The crystal structure of the porous material analyzed by XRD was a typical structure of tin oxide. The response of macro-porous tin oxide as a chemical gas sensor was measured using an I-V source meter and the change in signal was observed with the repeated injection of hydrogen sulfide and air. The sensing tests for macro-porous tin oxide were carried out at 200 degrees C and the fast response of macro-porous sensing material was also confirmed.

  8. Organic matter composition of soil macropore surfaces under different agricultural management practices

    Science.gov (United States)

    Glæsner, Nadia; Leue, Marin; Magid, Jacob; Gerke, Horst H.

    2016-04-01

    Understanding the heterogeneous nature of soil, i.e. properties and processes occurring specifically at local scales is essential for best managing our soil resources for agricultural production. Examination of intact soil structures in order to obtain an increased understanding of how soil systems operate from small to large scale represents a large gap within soil science research. Dissolved chemicals, nutrients and particles are transported through the disturbed plow layer of agricultural soil, where after flow through the lower soil layers occur by preferential flow via macropores. Rapid movement of water through macropores limit the contact between the preferentially moving water and the surrounding soil matrix, therefore contact and exchange of solutes in the water is largely restricted to the surface area of the macropores. Organomineral complex coated surfaces control sorption and exchange properties of solutes, as well as availability of essential nutrients to plant roots and to the preferentially flowing water. DRIFT (Diffuse Reflectance infrared Fourier Transform) Mapping has been developed to examine composition of organic matter coated macropores. In this study macropore surfaces structures will be determined for organic matter composition using DRIFT from a long-term field experiment on waste application to agricultural soil (CRUCIAL, close to Copenhagen, Denmark). Parcels with 5 treatments; accelerated household waste, accelerated sewage sludge, accelerated cattle manure, NPK and unfertilized, will be examined in order to study whether agricultural management have an impact on the organic matter composition of intact structures.

  9. Adsorption behaviors of a novel carbonyl and hydroxyl groups modified hyper-cross-linked poly(styrene-co-divinylbenzene) resin for beta-naphthol from aqueous solution.

    Science.gov (United States)

    He, Chunlian; Huang, Jianhan; Yan, Cheng; Liu, Jianbo; Deng, Linbei; Huang, Kelong

    2010-08-15

    A series of novel hyper-cross-linked resins were synthesized from macroporous cross-linked chloromethylated poly(styrene-co-divinylbenzene) by adding different dosage of hydroquinone in Friedel-Crafts reaction. The results of the pore structures revealed that the prepared resins possessed micropores, mesopores and macropores, and the chloromethyl groups and the uploaded hydroquinone were partly oxidized according to the results of Fourier-transformed infrared ray spectra. Among these hydroquinone modified resins, HJ-Y06 resin held the largest adsorption capacity for beta-naphthol, and its adsorption capacity was comparable with XAD-4 while much larger than X-5. The adsorption kinetics could be characterized by pseudo-second-order rate equation and intra-particle diffusion model was the rate-limiting step at the initial process. The adsorption was favorable at solution pH lower than 6.5. The adsorption isotherms could be fitted by Langmuir model and the adsorption was an endothermic process. Hydrogen bonding between formaldehyde carbonyl and quinone carbonyl groups on HJ-Y06 and phenolic hydroxyl groups of beta-naphthol was the main driving force for the adsorption.

  10. Characterization, visualization and quantification of soil macropores and preferential flow using SPECT and X-ray CAT scanning

    Science.gov (United States)

    Perret, Johan Sebastien

    The presence of soil macropores provides an opportunity for water and associated chemicals to move preferentially through the vadose zone. Most studies on the characterization of macropore flow consider the soil system to be a "black-box". Thus, efforts to describe macropores in quantitative terms have not yet resulted in a comprehensive theoretical framework that allows for a complete representation of their geometry and their effect on preferential flow. Macropore networks in four large undisturbed soil columns (850 mm x 77 mm diameter), were quantified and visualized, both in 2-D and 3-D, using X-ray Computer Assisted Tomography (CAT). Macropore quantification included two-dimensional parameters (i.e., number of macropores, macropore size, hydraulic radius, rectangularity and circularity), and three-dimensional and topological parameters (i.e., macropore length, volume, 3-D hydraulic radius, tortuosity, numerical density, coordination number, and connectivity). Pores larger or equal to 1.0 mm in equivalent diameter were readily detected, visualized and quantified. It was found that the average macroporosity of four soil columns varied between 2.1 and 3.8%. From the hydraulic radius distribution, it was inferred that about 20% of macropore throats have a diameter of 1.6 mm. It was found that the majority of macropore networks had a length of 40 mm, a volume of 60 mm 3 and a wall area of 175 mm2. Breakthrough of potassium iodide was monitored with X-ray CAT scanning. This approach allowed for real-time examination of flow mechanisms through the macropore and matrix flow domains at various depths along the soil column. Flow in the matrix domain suggested that part of the matrix contains small pores (mesopores) that were connected to macropore networks. It is suggested that the matrix domain should be subdivided into two regions: mesopores and micropores. In addition, the macropore domain should be defined both in terms of macropore geometry and its ability to

  11. Flow and transport processes in a macroporous subsurface-drained glacial till soil

    DEFF Research Database (Denmark)

    Villholth, Karen Grothe; Jensen, Karsten Høgh; Fredericia, Johnny

    1998-01-01

    The qualitative and quantitative effects of macropore flow and transport in an agricultural subsurface-drained glacial till soil in eastern Denmark have been investigated. Three controlled tracer experiments on individual field plots (each approximately 1000 m(2)) were carried out by surface...... was evidenced directly by the rapid (within 10 mm of water input) and abrupt chloride breakthrough in the drainage water at 1.2 m depth in two of the tracer experiments. In the third experiment, the effect of macropore transport was obvious from the rapid and relatively deep penetration of the tracer...... into the soil profile. Dye infiltration experiments in the field as well as in the laboratory supported the recognition of the dominant contribution of macropores to the infiltration and transport process. The soil matrix significantly influenced the tracer distribution by acting as a source or sink...

  12. DLTS of p-type Czochralski Si wafers containing processing-induced macropores

    Science.gov (United States)

    Simoen, E.; Depauw, V.; Gordon, I.; Poortmans, J.

    2012-01-01

    The deep levels present in p-type Czochralski silicon with processing-induced macropores in the depletion region have been studied by the deep-level transient (DLT) spectroscopy technique. It is shown that a broad band is present for a bias pulse close to the interface with the Al Schottky contact, which exhibits anomalously slow hole capture and is ascribed to the internal interface states of the macropores. For depths beyond the pore region, other deep levels, associated with point defects—possibly metal contamination during the high-temperature annealing step under H2 ambient--have been observed. The impact of the observed defects on the lifetime of thin-film solar cells, fabricated using macropore-based layer transfer is discussed. Finally, it is shown that the presence of pores in the depletion region, which also affects the DLT-spectrum, alters the capacitance-voltage characteristics.

  13. Production and in vitro evaluation of macroporous, cell-encapsulating alginate fibres for nerve repair.

    Science.gov (United States)

    Lin, Sharon Chien-Yu; Wang, Yiwei; Wertheim, David F; Coombes, Allan G A

    2017-04-01

    The prospects for successful peripheral nerve repair using fibre guides are considered to be enhanced by the use of a scaffold material, which promotes attachment and proliferation of glial cells and axonal regeneration. Macroporous alginate fibres were produced by extraction of gelatin particle porogens from wet spun fibres produced using a suspension of gelatin particles in 1.5% w/v alginate solution. Gelatin loading of the starting suspension of 40.0, 57.0, and 62.5% w/w resulted in gelatin loading of the dried alginate fibres of 16, 21, and 24% w/w respectively. Between 45 and 60% of the gelatin content of hydrated fibres was released in 1h in distilled water at 37°C, leading to rapid formation of a macroporous structure. Confocal laser scanning microscopy (CLSM) and image processing provided qualitative and quantitative analysis of mean equivalent macropore diameter (48-69μm), pore size distribution, estimates of maximum porosity (14.6%) and pore connectivity. CLSM also revealed that gelatin residues lined the macropore cavities and infiltrated into the body of the alginate scaffolds, thus, providing cell adhesion molecules, which are potentially advantageous for promoting growth of glial cells and axonal extension. Macroporous alginate fibres encapsulating nerve cells [primary rat dorsal root ganglia (DRGs)] were produced by wet spinning alginate solution containing dispersed gelatin particles and DRGs. Marked outgrowth was evident over a distance of 150μm at day 11 in cell culture, indicating that pores and channels created within the alginate hydrogel were providing a favourable environment for neurite development. These findings indicate that macroporous alginate fibres encapsulating nerve cells may provide the basis of a useful strategy for nerve repair. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. In vitro biological characterization of macroporous 3D Bonelike structures prepared through a 3D machining technique

    Energy Technology Data Exchange (ETDEWEB)

    Laranjeira, M.S.; Dias, A.G. [INEB - Instituto de Engenharia Biomedica, Divisao de Biomateriais, Universidade do Porto, Rua do Campo Alegre, 823, 4150-180 Porto (Portugal); Santos, J.D. [INEB - Instituto de Engenharia Biomedica, Divisao de Biomateriais, Universidade do Porto, Rua do Campo Alegre, 823, 4150-180 Porto (Portugal); Universidade do Porto, Faculdade de Engenharia, Departamento de Engenharia Metalurgica e Materiais, Rua Dr. Roberto Frias, 4200-465 Porto - Portugal (Portugal); Fernandes, M.H., E-mail: mhrf@portugalmail.pt [Universidade do Porto, Faculdade de Medicina Dentaria, Laboratorio de Farmacologia e Biocompatibilidade Celular, Rua Dr. Manuel Pereira da Silva, 4200-392 Porto (Portugal)

    2009-04-30

    3D bioactive macroporous structures were prepared using a 3D machining technique. A virtual 3D structure model was created and a computer numerically controlled (CNC) milling device machined Bonelike samples. The resulting structures showed a reproducible macroporosity and interconnective structure. Macropores size after sintering was approximately 2000 {mu}m. In vitro testing using human bone marrow stroma showed that cells were able to adhere and proliferate on 3D structures surface and migrate into all macropore channels. In addition, these cells were able to differentiate, since mineralized globular structures associated with cell layer were identified. Results obtained showed that 3D structures of Bonelike successfully allow cell migration into all macropores, and allow human bone marrow stromal cells to proliferate and differentiate. This innovative technique may be considered as a step-forward preparation for 3D interconnective macroporous structures that allow bone ingrowth while maintaining mechanical integrity.

  15. Sol-gel synthesis of macroporous barium zirconate monoliths from ionic precursors via a phase separation route

    Science.gov (United States)

    Guo, Xingzhong; Wang, Zichen; Song, Jie; Yang, Hui

    2017-03-01

    Monolithic macroporous barium zirconate derived from ionic precursors has been successfully prepared via a phase separation route in the presence of poly(ethylene oxide) (PEO) and propyleneoxide (PO). Poly(ethylene oxide) (PEO) acts as a phase separation inducer, while propyleneoxide (PO) acts as a gelation accelerant in the sol-gel process. Appropriate choice of poly(ethylene oxide) (PEO) and propyleneoxide (PO) allows the production of continuous macroporous monolithic gel with a porosity of ca. 63% and a macropore size of 1.8 μm. Some BaCl2 recrystallizes in the dried gel, and subsequently tetragonal ZrO2 phase precipitates after heat-treated at 800 °C. The crystalline phase barium zirconate forms after heat treatment at 1100 °C in air, while the macroporous structure is preserved with a slight increase of porosity and a decrease of macropore size.

  16. Macroporous Titania Monolith Prepared via Sol-gel Process with Polymer Foam as the Template

    Institute of Scientific and Technical Information of China (English)

    REN, Jian; DU, Zhong-Jie; ZHANG, Chen; LI, Hang-Quan

    2006-01-01

    Macroporous titania monoliths were prepared via sol-gel method using polymer foam as templates. The polymer foam polymerized via concentrated emulsion polymerization was immerged in a solution of titanium(Ⅳ) isopropoxide in 2-propanol, which underwent a sol-gel process. The organic components were subsequently removed by calcination. The effects of various parameters, including the nature of the monomer, the volume fraction of dispersed phase of the concentrated emulsion, and concentration of the sol-gel solution were investigated. The SEM micrographs of the macroporous titania monoliths thus obtained showed that the porous structure of the final material was effectively controllable.

  17. Silica-supported Macroporous Chitosan Bead for Affinity Purification of Trypsin Inhibitor

    Institute of Scientific and Technical Information of China (English)

    Feng Na XI; Jian Min WU; Ming Ming LUAN

    2005-01-01

    Macroporous cross-linking chitosan layer coated on silica gel (CTS-SiO2) was prepared by phase inversion and polyethylene glycol (PEG) molecular imprinting methods. Formation of macroporous surface was investigated by scanning electron microscopy (SEM) and BET analysis.The prepared bead was activated by reacting with 1,2-ethylene diglycidyl ether for introducing epoxy groups, and trypsin could be efficiently immobilized on the bead as a biospecific ligand.The bead bearing trypsin was employed to purify trypsin inhibitor (TIs) from egg white as affinity adsorbent.

  18. Resin composite repair: Quantitative microleakage evaluation of resin-resin and resin-tooth interfaces with different surface treatments.

    Science.gov (United States)

    Celik, Cigdem; Cehreli, Sevi Burcak; Arhun, Neslihan

    2015-01-01

    The aim was to evaluate the effect of different adhesive systems and surface treatments on the integrity of resin-resin and resin-tooth interfaces after partial removal of preexisting resin composites using quantitative image analysis for microleakage testing protocol. A total of 80 human molar teeth were restored with either of the resin composites (Filtek Z250/GrandioSO) occlusally. The teeth were thermocycled (1000×). Mesial and distal 1/3 parts of the restorations were removed out leaving only middle part. One side of the cavity was finished with course diamond bur and the other was air-abraded with 50 μm Al2O3. They were randomly divided into four groups (n = 10) to receive: Group 1: Adper Single Bond 2; Group 2: All Bond 3; Group 3: ClearfilSE; Group 4: BeautiBond, before being repaired with the same resin composite (Filtek Z250). The specimens were re-thermocycled (1000×), sealed with nail varnish, stained with 0.5% basic fuchsin, sectioned mesiodistally and photographed digitally. The extent of dye penetration was measured by image analysis software (ImageJ) for both bur-finished and air-abraded surfaces at resin-tooth and resin-resin interfaces. The data were analyzed statistically. BeautiBond exhibited the most microleakage at every site. Irrespective of adhesive and initial composite type, air-abrasion showed less microleakage except for BeautiBond. The type of initial repaired restorative material did not affect the microleakage. BeautiBond adhesive may not be preferred in resin composite repair in terms of microleakage prevention. Surface treatment with air-abrasion produced the lowest microleakage scores, independent of the adhesive systems and the pre-existing resin composite type. Pre-existing composite type does not affect the microleakage issue. All-in-one adhesive resin (BeautiBond) may not be preferred in resin composite repair in terms of microleakage prevention.

  19. System for removing contaminants from plastic resin

    Science.gov (United States)

    Bohnert, George W.; Hand, Thomas E.; DeLaurentiis, Gary M.

    2010-11-23

    A resin recycling system that produces essentially contaminant-free synthetic resin material in an environmentally safe and economical manner. The system includes receiving the resin in container form. A grinder grinds the containers into resin particles. The particles are exposed to a solvent in one or more solvent wash vessels, the solvent contacting the resin particles and substantially removing contaminants on the resin particles. A separator is used to separate the resin particles and the solvent. The resin particles are then placed in solvent removing element where they are exposed to a solvent removing agent which removes any residual solvent remaining on the resin particles after separation.

  20. Recovery of naringin from kinnow (Citrus reticulata Blanco) peels by adsorption–desorption technique using an indigenous resin

    Indian Academy of Sciences (India)

    M LAXMI DEEPAK BHATLU; SATYA VIR SINGH; ASHOK KUMAR VERMA

    2017-01-01

    A process technology has been developed for recovery of naringin from kinnow (citrus) peels,which is a waste. The kinnow peels were boiled with water to extract naringin into water. It was adsorbed on an indigenous macroporous resin, Indion PA-500. Naringin was recovered from the saturated resin by desorption with ethanol as a solvent. The equilibrium and kinetic studies for both adsorption and desorption are presented.The Langmuir isotherm described the adsorption equilibrium data. However, desorption data were best described by the Toth isotherm. Adsorption and desorption kinetic data were found to follow a pseudo-secondorder rate equation and second-order rate equation, respectively. Recovery of naringin was about 49% w/w (based on naringin present in peel-boiled extract). The purity of final products was 91–94% w/w.

  1. Flame Retardant Epoxy Resins

    Science.gov (United States)

    Thompson, C. M.; Smith, J. G., Jr.; Connell, J. W.; Hergenrother, P. M.; Lyon, R. E.

    2004-01-01

    As part of a program to develop fire resistant exterior composite structures for future subsonic commercial aircraft, flame retardant epoxy resins are under investigation. Epoxies and their curing agents (aromatic diamines) containing phosphorus were synthesized and used to prepare epoxy formulations. Phosphorus was incorporated within the backbone of the epoxy resin and not used as an additive. The resulting cured epoxies were characterized by thermogravimetric analysis, propane torch test, elemental analysis and microscale combustion calorimetry. Several formulations showed excellent flame retardation with phosphorous contents as low as 1.5% by weight. The fracture toughness of plaques of several cured formulations was determined on single-edge notched bend specimens. The chemistry and properties of these new epoxy formulations are discussed.

  2. Metal-induced fluorescence properties of three-dimensionally ordered macroporous silver inverse opal platforms

    Science.gov (United States)

    Chae, Weon-Sik; Lee, Myung-Jin; Kim, Kisun; Hyun, Jerome K.; Jeon, Seokwoo

    2016-02-01

    This study examined the metal-induced fluorescence properties of three-dimensionally ordered macroporous silver inverse opal (IO) films. Electrochemically synthesized silver IO films with a micrometer cavity exhibited notable fluorescence enhancement at the silver frame, and a decrease in fluorescence lifetime. Numerical calculations supported the observations of a higher fluorescence efficiency at the frame than in the cavity.

  3. Polymer-in-a-Silica-Crust Membranes: Macroporous Materials with Tunable Surface Functionality

    NARCIS (Netherlands)

    Urmenyi, Ana M.; Philipse, Albert P.; Lammertink, Rob G.H.; Wessling, Matthias

    2006-01-01

    We report on alkaline hydrolysis of tetraethoxysilane (Stöber synthesis) inside a macroporous polymer matrix resulting in a homogeneous coverage of silica onto the polymer surface. The encapsulation of the polymer struts by a continuous silica crust allows further functionalization with hydrophilic

  4. [Kinetics of serum albumin adsorption on the macroporous glass MPS-250 GKH].

    Science.gov (United States)

    Naumova, L V; El'Kin, G E; Dmitrenko, L V

    1996-01-01

    Intrinsic diffusion (defined as diffusion within micropores or microgranules) was shown to be a major factor that determines the kinetics of bovine serum albumin adsorption to macroporous silica MPS-250 GKh. The effective coefficient of intrinsic diffusion (within the silica phase) was calculated (Def = 7 x 10(-7) cm2/s).

  5. Activity and Spatial Distribution of Candida antarctica Lipase B Immobilized on Macroporous Organic Polymeric Adsorbents

    DEFF Research Database (Denmark)

    Nielsen, Anne Veller Friis; Andric, Pavle; Munk Nielsen, Per

    2014-01-01

    A systematic study of the influence of carrier particle size (500 − 850 μ m) and enzyme load (26 200 − 66 100 lipase activity units (LU)/g dry carrier) on the content and activity of Candida antarctica lipase B (CALB) immobilized by adsorption onto macroporous poly(methyl methacrylate) (PMM...

  6. Fabrication of Ordered Macroporous CdS and ZnS by Colloidal Crystal Template

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Ordered macroporous semiconductors CdS and ZnS with regular arrays of spherical pores have been fabricated by poly (styrene-acrylic) (PSA) colloidal crystal template. It was found that the exact three-dimensional (3D) structure of the template had been imprinted in the final material.

  7. Interconnected macroporous poly(ethylene glycol) cryogels as a cell scaffold for cartilage tissue engineering.

    Science.gov (United States)

    Hwang, Yongsung; Sangaj, Nivedita; Varghese, Shyni

    2010-10-01

    Macroporous networks of poly(ethylene glycol) (PEG) with interconnected pores can be created by cryogelation techniques. In this study, we describe the potential application of such PEG cryogels as scaffolds for cartilage tissue engineering. Three-dimensional macroporous cryogels were evaluated for chondrocyte growth and production of cartilage-specific extracellular matrix (ECM). Seeded primary bovine chondrocytes showed homogeneous distribution throughout the cryogels. DNA content suggests continuous cell proliferation over 4 weeks of in vitro culture. Analysis of the composition of cell-secreted ECM showed a culture-time-dependent increase in the amount of glycosaminoglycan and collagen. The production of ECM by chondrocytes was confirmed using scanning electron microscopy analysis. Further histological and immunohistological analysis of the cell-laden scaffold confirmed the presence of accumulated cartilage-specific ECM within the scaffold. The interconnected macroporous network promoted diffusion of cell-secreted matrix within the cryogels. Our results indicated that interconnected macroporous PEG cryogels successfully supported attachment, viability, proliferation, and biosynthetic activity of seeded chondrocytes.

  8. Immobilization of denatured DNA to macroporous supports: I. Efficiency of different coupling procedures.

    Science.gov (United States)

    Bünemann, H; Westhoff, P; Herrmann, R G

    1982-11-25

    Methods commonly used for covalent immobilization of single stranded DNA have been applied to several solid supports (Sephadex G-25 and Cellex 410) as well as to a number of macroporous materials (Sepharose C1-6B, C1-2B; Sephacryl S-500 and S-1000). Coupling efficiencies and stability of covalently bound DNA are compared for both classes of materials. The yields of the immobilization reaction for sonicated DNA are only 10-40% for G-25 and Cellex 410 in contrast to 60-80% for C1-6B and S-500. Under optimal conditions, up to 0.5 mg of DNA can be coupled initially per g of wet macroporous material. The immobilized DNAs are lost from the supports in a biphasic manner, with about 10-20% loss per day during the first 2-3 days at 45 degrees C, followed by only about 1% loss per day at the same temperature thereafter. The influence of the coupling procedure on the generation of mismatch effects has been studied in 2.4 M tetraethylammonium chloride solution for the hybrid formation between immobilized and mobile DNA. The degree of mismatch ranged from 0-3% and depended on the method of immobilization. The unspecific absorption of DNA on macroporous materials is sufficiently low to allow efficient hybrid selection. No size limitations have been observed when plastid mRNAs are selected by cloned fragments of plastid DNA immobilized to macroporous Sephacryl S-500.

  9. Rainfall Simulator Experiments to Investigate Macropore Impacts on Hillslope Hydrological Response

    NARCIS (Netherlands)

    Smit, Y.; Teuling, Adriaan J.; van der Ploeg, Martine J.

    2016-01-01

    Understanding hillslope runoff response to intense rainfall is an important topic in hydrology, and is key to correct prediction of extreme stream flow, erosion and landslides. Although it is known that preferential flow processes activated by macropores are an important phenomena in understanding

  10. Macroporous p-GaP Photocathodes Prepared by Anodic Etching and Atomic Layer Deposition Doping.

    Science.gov (United States)

    Lee, Sudarat; Bielinski, Ashley R; Fahrenkrug, Eli; Dasgupta, Neil P; Maldonado, Stephen

    2016-06-29

    P-type macroporous gallium phosphide (GaP) photoelectrodes have been prepared by anodic etching of an undoped, intrinsically n-type GaP(100) wafer and followed by drive-in doping with Zn from conformal ZnO films prepared by atomic layer deposition (ALD). Specifically, 30 nm ALD ZnO films were coated on GaP macroporous films and then annealed at T = 650 °C for various times to diffuse Zn in GaP. Under 100 mW cm(-2) white light illumination, the resulting Zn-doped macroporous GaP consistently exhibit strong cathodic photocurrent when measured in aqueous electrolyte containing methyl viologen. Wavelength-dependent photoresponse measurements of the Zn-doped macroporous GaP revealed enhanced collection efficiency at wavelengths longer than 460 nm, indicating that the ALD doping step rendered the entire material p-type and imparted the ability to sustain a strong internal electric field that preferentially drove photogenerated electrons to the GaP/electrolyte interface. Collectively, this work presents a doping strategy with a potentially high degree of controllability for high-aspect ratio III-V materials, where the ZnO ALD film is a practical dopant source for Zn.

  11. A Hierarchically Micro-Meso-Macroporous Zeolite CaA for Methanol Conversion to Dimethyl Ether

    Directory of Open Access Journals (Sweden)

    Yan Wang

    2016-11-01

    Full Text Available A hierarchical zeolite CaA with microporous, mesoporous and macroporous structure was hydrothermally synthesized by a ”Bond-Blocking” method using organo-functionalized mesoporous silica (MS as a silica source. The characterization by XRD, SEM/TEM and N2 adsorption/desorption techniques showed that the prepared material had well-crystalline zeolite Linde Type A (LTA topological structure, microspherical particle morphologies, and hierarchically intracrystalline micro-meso-macropores structure. With the Bond-Blocking principle, the external surface area and macro-mesoporosity of the hierarchical zeolite CaA can be adjusted by varying the organo-functionalized degree of the mesoporous silica surface. Similarly, the distribution of the micro-meso-macroporous structure in the zeolite CaA can be controlled purposely. Compared with the conventional microporous zeolite CaA, the hierarchical zeolite CaA as a catalyst in the conversion of methanol to dimethyl ether (DME, exhibited complete DME selectivity and stable catalytic activity with high methanol conversion. The catalytic performances of the hierarchical zeolite CaA results clearly from the micro-meso-macroporous structure, improving diffusion properties, favoring the access to the active surface and avoiding secondary reactions (no hydrocarbon products were detected after 3 h of reaction.

  12. A model for simulating the influence of a spatial distribution of large circular macropores on surface runoff

    Science.gov (United States)

    Léonard, J.; Perrier, E.; de Marsily, G.

    2001-12-01

    This paper reports the development and test, at the scale of 1 m2, of an event- based model that aims at simulating the influence of a spatial distribution of large circular macropores on surface runoff. The main originality of this model is that it focuses on the way macropores are supplied with water at the soil surface, by coupling an original model for water interception by individual macropores to a high-resolution spatialized overland flow model. A three-step evaluation of the model was carried out, involving (1) an experimental test of the model for water interception by macropores; (2) a sensitivity analysis of the model to time and space discretization; and (3) a comparison between numerical and field results in the case of runoff on a crusted soil surface with a population of large macropores made by termites in the Sahel. The model was found to accurately simulate the effect of a spatial distribution of large macropores on runoff, and it showed that small heterogeneities, like macropores or areas where a crust has been destroyed, which cover a very limited proportion of the soil surface, can have a high impact on runoff.

  13. Paramagnetic epoxy resin

    Directory of Open Access Journals (Sweden)

    E. C. Vazquez Barreiro

    2017-01-01

    Full Text Available This work illustrates that macrocycles can be used as crosslinking agents for curing epoxy resins, provided that they have appropriate organic functionalities. As macrocycles can complex metal ions in their structure, this curing reaction allows for the introduction of that metal ion into the resin network. As a result, some characteristic physical properties of the metallomacrocycle could be transferred to the new material. The bisphenol A diglycidyl ether (BADGE, n = 0 and hemin (a protoporphyrin IX containing the Fe(III ion, and an additional chloride ligand have been chosen. The new material has been characterized by differential scanning calorimetry (DSC, thermogravimetric analysis (TGA, Fourier Transform Infrared (FT-IR, Nuclear Magnetic Resonance (NMR, Transmission Electron Microscopy (TEM, and magnetic susceptibility measurements. Fe(III remains in the high-spin state during the curing process and, consequently, the final material exhibits the magnetic characteristics of hemin. The loss of the chlorine atom ligand during the cure of the resin allows that Fe(III can act as Lewis acid, catalyzing the crosslinking reactions. At high BADGE n = 0/hemin ratios, the formation of ether and ester bonds occurs simultaneously during the process.

  14. Fast plasma sintering delivers functional graded materials components with macroporous structures and osseointegration properties.

    Science.gov (United States)

    Godoy, R F; Coathup, M J; Blunn, G W; Alves, A L; Robotti, P; Goodship, A E

    2016-04-13

    We explored the osseointegration potential of two macroporous titanium surfaces obtained using fast plasma sintering (FPS): Ti macroporous structures with 400-600 µmØ pores (TiMac400) and 850-1000 µmØ pores (TiMac850). They were compared against two surfaces currently in clinical use: Ti-Growth® and air plasma spray (Ti-Y367). Each surface was tested, once placed over a Ti-alloy and once onto a CoCr bulk substrate. Implants were placed in medial femoral condyles in 24 sheep. Samples were explanted at four and eight weeks after surgery. Push-out loads were measured using a material-testing system. Bone contact and ingrowth were assessed by histomorphometry and SEM and EDX analyses. Histology showed early osseointegration for all the surfaces tested. At 8 weeks, TiMac400, TiMac850 and Ti-Growth® showed deep bone ingrowth and extended colonisation with newly formed bone. The mechanical push-out force was equal in all tested surfaces. Plasma spray surfaces showed greater bone-implant contact and higher level of pores colonisation with new bone than FPS produced surfaces. However, the void pore area in FPS specimens was significantly higher, yet the FPS porous surfaces allowed a deeper osseointegration of bone to implant. FPS manufactured specimens showed similar osseointegration potential to the plasma spray surfaces for orthopaedic implants. FPS is a useful technology for manufacturing macroporous titanium surfaces. Furthermore, its capability to combine two implantable materials, using bulk CoCr with macroporous titanium surfaces, could be of interest as it enables designers to conceive and manufacture innovative components. FPS delivers functional graded materials components with macroporous structures optimised for osseointegration.

  15. Dry PMR-15 Resin Powders

    Science.gov (United States)

    Vannucci, Raymond D.; Roberts, Gary D.

    1988-01-01

    Shelf lives of PMR-15 polymides lengthened. Procedure involves quenching of monomer reactions by vacuum drying of PRM-15 resin solutions at 70 to 90 degree F immediately after preparation of solutions. Absence of solvent eliminates formation of higher esters and reduces formation of imides to negligible level. Provides fully-formulated dry PMR-15 resin powder readily dissolvable in solvent at room temperature immediately before use. Resins used in variety of aerospace, aeronautical, and commercial applications.

  16. Linking air and water transport in intact soils to macropore characteristics inferred from X-ray computed tomography

    DEFF Research Database (Denmark)

    Katuwal, S.; Nørgaard, Trine; Møldrup, Per

    2015-01-01

    Soil macropores often control fluid flow and solute transport, and quantification of macropore characteristics including their variability in space and time are essential to predict soil hydraulic and hydrogeochemical functions. In this study, measurements of air and solute transport properties...... and direct macropore visualization by X-ray CT scanning were carried out on 17 large (19-cm diam.; 20-cm length) undisturbed soil columns sampled across a field site (Silstrup, Denmark) with natural gradients in texture and density. Air permeability (ka) at in-situ water content and -20 hPa of matric...

  17. Resin regeneration device for condensate desalter

    Energy Technology Data Exchange (ETDEWEB)

    Segawa, Yoshihiro [Toshiba Engineering Co. Ltd., Kawasaki, Kanagawa (Japan); Hirose, Yuki

    1998-07-28

    The present invention provides a resin regeneration device for a condensate desalter of a nuclear power plant. Namely, both anionic and cationic exchange resins are supplied in a mixed state from a forwarding water desalting tower to an anionic resin regeneration tower. In the anionic resin generation tower, the resin is once separated to an anionic exchange region layer, a mixed resin layer and an cationic exchange resin layer in this order from the upper portion by water injected from a stirring water injection tube disposed at the bottom. Then, water is injected from a developing water injection tube disposed at the lower portion of the mixed resin layer to develop the cationic exchange resin layer and the mixed resin layer to the upper portion of the cationic resin regeneration tower. Subsequently, the amount of the injection of the developing water is reduced to such a flow rate that only the anionic exchange resin is precipitated. Then, a cationic exchange resin layer is formed at the upper portion and an anion exchange resin layer is formed at the lower portion of the developing water injection tube of the cationic resin regeneration tower. The anionic exchange resin is transferred to the anionic exchange resin regeneration tower in this state. According to the present invention, the mixed resin layer can be separated to anionic and cationic exchange resins easily and reliably. (I.S.)

  18. Hierarchically macroporous silver monoliths using Pluronic F127: Facile synthesis, characterization and its application as an efficient biomaterial for pathogens

    Directory of Open Access Journals (Sweden)

    Gowhar Ahmad Naikoo

    2016-03-01

    Full Text Available Herein we report the facile synthesis of three dimensional macroporous (MP silver monoliths serving as intelligent biomaterials against Gram negative (Escherichia coli, Salmonella typhimurium and Gram positive (Bacillus subtilis bacteria with more efficacy against Gram negative bacteria. The macroporous silver monoliths were examined by Fourier transform infra red (FTIR spectroscopy, thermogravimetric analysis (TGA, X-ray diffraction (XRD study, field emission scanning electron microscopy (FESEM, energy dispersion X-ray spectroscopy analysis (EDX and Brunauer–Emmet–Teller (BET adsorption technique. From the antibacterial activity results, it was concluded that macroporous silver monoliths can serve as efficient disinfection agents. The enhanced antibacterial properties of macroporous silver monoliths was possibly due to high surface free energy of the surface Ag+ atoms leading to cell membrane damage followed by cell death.

  19. [Acrylic resin removable partial dentures

    NARCIS (Netherlands)

    Baat, C. de; Witter, D.J.; Creugers, N.H.J.

    2011-01-01

    An acrylic resin removable partial denture is distinguished from other types of removable partial dentures by an all-acrylic resin base which is, in principle, solely supported by the edentulous regions of the tooth arch and in the maxilla also by the hard palate. When compared to the other types of

  20. Biocompatibility, degradability, bioactivity and osteogenesis of mesoporous/macroporous scaffolds of mesoporous diopside/poly(l-lactide) composite

    OpenAIRE

    Liu, Zhulin; Ji, Jiajin; Tang, Songchao; Qian, Jun; Yan, Yonggang; Yu, Baoqing; Su, Jiacan; Wei, Jie

    2015-01-01

    Bioactive mesoporous diopside (m-DP) and poly(l-lactide) (PLLA) composite scaffolds with mesoporous/macroporous structure were prepared by the solution-casting and particulate-leaching method. The results demonstrated that the degradability and bioactivity of the mesoporous/macroporous scaffolds were significantly improved by incorporating m-DP into PLLA, and that the improvement was m-DP content-dependent. In addition, the scaffolds containing m-DP showed the ability to neutralize acidic deg...

  1. A Macroporous TiO2 Oxygen Sensor Fabricated Using Anodic Aluminium Oxide as an Etching Mask

    Directory of Open Access Journals (Sweden)

    Sheng-Po Wu

    2010-01-01

    Full Text Available An innovative fabrication method to produce a macroporous Si surface by employing an anodic aluminium oxide (AAO nanopore array layer as an etching template is presented. Combining AAO with a reactive ion etching (RIE processes, a homogeneous and macroporous silicon surface can be effectively configured by modulating AAO process parameters and alumina film thickness, thus hopefully replacing conventional photolithography and electrochemical etch methods. The hybrid process integration is considered fully CMOS compatible thanks to the low-temperature AAO and CMOS processes. The gas-sensing characteristics of 50 nm TiO2 nanofilms deposited on the macroporous surface are compared with those of conventional plain (or non-porous nanofilms to verify reduced response noise and improved sensitivity as a result of their macroporosity. Our experimental results reveal that macroporous geometry of the TiO2 chemoresistive gas sensor demonstrates 2-fold higher (~33% improved sensitivity than a non-porous sensor at different levels of oxygen exposure. In addition, the macroporous device exhibits excellent discrimination capability and significantly lessened response noise at 500 °C. Experimental results indicate that the hybrid process of such miniature and macroporous devices are compatible as well as applicable to integrated next generation bio-chemical sensors.

  2. A macroporous TiO2 oxygen sensor fabricated using anodic aluminium oxide as an etching mask.

    Science.gov (United States)

    Lu, Chih-Cheng; Huang, Yong-Sheng; Huang, Jun-Wei; Chang, Chien-Kuo; Wu, Sheng-Po

    2010-01-01

    An innovative fabrication method to produce a macroporous Si surface by employing an anodic aluminium oxide (AAO) nanopore array layer as an etching template is presented. Combining AAO with a reactive ion etching (RIE) processes, a homogeneous and macroporous silicon surface can be effectively configured by modulating AAO process parameters and alumina film thickness, thus hopefully replacing conventional photolithography and electrochemical etch methods. The hybrid process integration is considered fully CMOS compatible thanks to the low-temperature AAO and CMOS processes. The gas-sensing characteristics of 50 nm TiO(2) nanofilms deposited on the macroporous surface are compared with those of conventional plain (or non-porous) nanofilms to verify reduced response noise and improved sensitivity as a result of their macroporosity. Our experimental results reveal that macroporous geometry of the TiO(2) chemoresistive gas sensor demonstrates 2-fold higher (∼33%) improved sensitivity than a non-porous sensor at different levels of oxygen exposure. In addition, the macroporous device exhibits excellent discrimination capability and significantly lessened response noise at 500 °C. Experimental results indicate that the hybrid process of such miniature and macroporous devices are compatible as well as applicable to integrated next generation bio-chemical sensors.

  3. Three-dimensional ordered macroporous platinum-based electrode for methanol oxidation

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In this paper, three-dimensional ordered macroporous platinum catalysts with high real surface area were synthesized using the inverted colloidal crystals template technique and have been employed for the electrooxidation of methanol. The morphology and electrocatalytic behavior of the porous Pt electrodes were investigated with atomic force microscopy and electrochemical techniques. For the same amount of Pt deposited, the real surface areas of the electrodes are 9.16 and 8.00 cm2 for the porous electrodes with pore size of 320 and 500 nm respectively, which are more than 5 times larger than the directly deposited Pt electrode (1.4 cm2). The pore size effect on the methanol electrooxidation was investigated by testing low concentration solution of methanol and porous materials with different pore sizes. The synthesized macroporous Pt electrode shows high stability toward the electrooxidation of methanol and is promising for the direct methanol fuel cell.

  4. Macroporous glass monoliths prepared from powdered niobium phosphate glass by fast sintering

    Energy Technology Data Exchange (ETDEWEB)

    Lacerda Mauricio, Vitor; Alves, Oswaldo Luiz; Odone Mazali, Italo, E-mail: mazali@iqm.unicamp.br

    2011-03-15

    Macroporous monoliths were prepared by very fast sintering (between 3 and 15 min) of niobophosphate glass powders at low temperature (1018 K) using cellulose as a foaming agent. The porous materials were analyzed by thermal analysis, Raman spectroscopy, scanning electron microscopy and powder X-ray diffraction, and further investigated using X-ray microtomography, a non-destructive technique capable of reconstructing three-dimensional models of samples and providing structural measurements. The progression of the porosity of the monoliths depends on the sintering time (3 to 15 min) and the amount (up to 50% in mass) of cellulose used. The macroporous glass monoliths may find application in integrated chemical systems and in filtering processes.

  5. Ordered macroporous platinum electrode and enhanced mass transfer in fuel cells using inverse opal structure.

    Science.gov (United States)

    Kim, Ok-Hee; Cho, Yong-Hun; Kang, Soon Hyung; Park, Hee-Young; Kim, Minhyoung; Lim, Ju Wan; Chung, Dong Young; Lee, Myeong Jae; Choe, Heeman; Sung, Yung-Eun

    2013-01-01

    Three-dimensional, ordered macroporous materials such as inverse opal structures are attractive materials for various applications in electrochemical devices because of the benefits derived from their periodic structures: relatively large surface areas, large voidage, low tortuosity and interconnected macropores. However, a direct application of an inverse opal structure in membrane electrode assemblies has been considered impractical because of the limitations in fabrication routes including an unsuitable substrate. Here we report the demonstration of a single cell that maintains an inverse opal structure entirely within a membrane electrode assembly. Compared with the conventional catalyst slurry, an ink-based assembly, this modified assembly has a robust and integrated configuration of catalyst layers; therefore, the loss of catalyst particles can be minimized. Furthermore, the inverse-opal-structure electrode maintains an effective porosity, an enhanced performance, as well as an improved mass transfer and more effective water management, owing to its morphological advantages.

  6. Nitrogen Doped Macroporous Carbon as Electrode Materials for High Capacity of Supercapacitor

    Directory of Open Access Journals (Sweden)

    Yudong Li

    2017-01-01

    Full Text Available Nitrogen doped carbon materials as electrodes of supercapacitors have attracted abundant attention. Herein, we demonstrated a method to synthesize N-doped macroporous carbon materials (NMC with continuous channels and large size pores carbonized from polyaniline using multiporous silica beads as sacrificial templates to act as electrode materials in supercapacitors. By the nice carbonized process, i.e., pre-carbonization at 400 °C and then pyrolysis at 700/800/900/1000 °C, NMC replicas with high BET specific surface areas exhibit excellent stability and recyclability as well as superb capacitance behavior (~413 F ⋅ g−1 in alkaline electrolyte. This research may provide a method to synthesize macroporous materials with continuous channels and hierarchical pores to enhance the infiltration and mass transfer not only used as electrode, but also as catalyst somewhere micro- or mesopores do not work well.

  7. Enhanced Electrocatalytic Activity of Pt/3D Hierarchical Bimodal Macroporous Carbon Nanospheres.

    Science.gov (United States)

    Balgis, Ratna; Widiyastuti, W; Ogi, Takashi; Okuyama, Kikuo

    2017-07-19

    Proton exchange membrane fuel cells require electrocatalysts with a high platinum (Pt) loading, large active surface area, and favorable hydrodynamic profile for practical applications. Here, we report the design of three-dimensional hierarchical bimodal macroporous carbon nanospheres with an interconnected pore system, which are applied as an electrocatalyst support. Carbon-supported Pt (Pt/C) catalysts were prepared by aerosol spray pyrolysis followed by microwave chemical deposition. The hierarchical porous structures not only increased the dispersion of Pt nanoparticles but also improved catalytic performance. A hierarchical bimodal macroporous Pt/C catalyst with a mixture of 30 and 120 nm size pores showed the best performance. The electrochemical surface area and mass activity values of this support were 96 m(2) g(-1)-Pt and 378 mA mg(-1)-Pt, respectively at a Pt loading of 15 wt %.

  8. Double Emulsion Droplets as Microreactors for Synthesis of Magnetic Macroporous Polymer Beads

    Institute of Scientific and Technical Information of China (English)

    Wei-cai Wang; Chao Peng; Kai Shi; Yan-xiong Pan; Hai-shan Zhang; Xiang-ling Ji

    2014-01-01

    An easy method is presented to fabricate monodisperse magnetic macroporous polymer beads (MMPBs).Waterin-oil high intemal phase emulsion (HIPE) is prepared by emulsifying aqueous iron ions solution in an oil phase containing monomers.The HIPE is introduced into a simple microfluidic device to fabricate monodisperse (water-in-oil)-in-water double emulsion droplets.The droplets serve as microreactors to synthesize Fe3O4 nanoparticles and are on-line polymerized to form MMPBs.The prepared MMPBs display uniform size,interconnected porous structure,superparamagnetic behavior and uniform distribution of Fe3O4 in polymer matrix.The MMPBs are characterized by scanning electron microscopy (SEM),Fourier transform infrared spectroscopy (FTIR),X-ray diffraction (XRD),transmission electron microscopy (TEM),vibrating sample magnetometry (VSM).We believe that this method is a universal technique in preparing macroporous nanocomposite beads.

  9. Thermoresponsive composite hydrogels with aligned macroporous structure by ice-templated assembly.

    Science.gov (United States)

    Bai, Hao; Polini, Alessandro; Delattre, Benjamin; Tomsia, Antoni P

    2013-10-26

    Natural tissues, such as bone, tendon, and muscle, have well defined hierarchical structures, which are crucial for their biological and mechanical functions. However, mimicking these structural features still remains a great challenge. In this study, we use ice-templated assembly and UV-initiated cryo-polymerization to fabricate a novel kind of composite hydrogel which have both aligned macroporous structure at micrometer scale and a nacre-like layered structure at nanoscale. Such hydrogels are macroporous, thermoresponsive, and exhibit excellent mechanical performance (tough and high stretchable), attractive properties that are of significant impact on the wide applications of composite hydrogels, especially as tissue-engineering scaffolds. The fabrication method in this study including freeze-casting and cryo-polymerization can also be applied to other materials, which makes it promising for designing and developing smart and multifunctional composite hydrogels with hierar chical structures.

  10. Bioethanol production by reusable Saccharomyces cerevisiae immobilized in a macroporous monolithic hydrogel matrices.

    Science.gov (United States)

    Mulko, Lucinda; Rivarola, Claudia R; Barbero, Cesar A; Acevedo, Diego F

    2016-09-10

    Performance of yeasts on industrial processes can be dramatically improved by immobilization of the biocatalyst. The immobilization of Saccharomyces cerevisiae inside monolithic macroporous hydrogels were produced by in-situ polymerization of acrylamide around a live yeast suspension under cryogelation conditions. Preculture of the yeasts was not necessary and this innovative and simple procedure is amenable to scaling-up to industrial production. The yeasts were efficiently retained in monolithic hydrogels, presenting excellent mechanical properties and high cell viability. Macroporous hydrogels showed a fast mass transport allowing the hydrogel-yeast complexes achieved similar ethanol yield and productivity than free yeasts, which is larger than those reached with yeasts immobilized in compact hydrogels. Moreover, the same yeasts were able to maintain its activity by up to five reaction cycles with a cell single batch during fermentation reactions.

  11. Synthesis and Textural Characterization of Mesoporous and Meso-/Macroporous Silica Monoliths Obtained by Spinodal Decomposition

    Directory of Open Access Journals (Sweden)

    Anne Galarneau

    2016-04-01

    Full Text Available Silica monoliths featuring either mesopores or flow-through macropores and mesopores in their skeleton are prepared by combining spinodal phase separation and sol-gel condensation. The macroporous network is first generated by phase separation in acidic medium in the presence of polyethyleneoxides while mesoporosity is engineered in a second step in alkaline medium, possibly in the presence of alkylammonium cations as surfactants. The mesoporous monoliths, also referred as aerogels, are obtained in the presence of alkylpolyethylene oxides in acidic medium without the use of supercritical drying. The impact of the experimental conditions on pore architecture of the monoliths regarding the shape, the ordering, the size and the connectivity of the mesopores is comprehensively discussed based on a critical appraisal of the different models used for textural analysis.

  12. Preparation of spherical macroporous poly(lactic-co-glycolic acid) for bone tissue regeneration.

    Science.gov (United States)

    Bian, Chunhui; Lin, Huiming; Li, Xiaofeng; Ma, Jie; Jiang, Pingping; Qu, Fengyu

    2015-02-01

    Spherical macroporous poly(lactic-co-glycolic acid) (PLGA) has been synthesised using an emulsion method. Polyvinyl alcohol and Pluronic F127 have been used as dispersing and porogen agent, respectively. The diameter of the spherical PLGA is about 20 μm and the pore size of the PLGA macroporous is about 2-2.5 μm observed by scanning electron microscopy. After immersing in simulated body fluid, the PLGA materials can induce the formation of hydroxyapatite (HAP) on their surface. The HAP-PLGA has been obtained and used as the host for drug release. Furthermore, the drug-loaded samples possess the various drug release performance by adjusting the thickness of the HAP layer. This highly satisfied composite material is expected to be promising in the applications in tissue regeneration engineering.

  13. Development of macropore arrays in silicon and related technologies for X-ray imaging applications

    OpenAIRE

    Badel, Xavier

    2003-01-01

    Digital devices have started to replace photographic film inX-ray imaging applications. As compared to photographic films,these devices are more convenient to obtain images and tohandle, treat and store these images. The goal of the presentstudy is to develop macropore arrays and related silicontechnologies in order to fabricate X-ray imaging detectors formedical applications, and in particular for dentistry. Althougha few detectors are already available on the market, theirperformances, such...

  14. Hierarchically microporous/macroporous scaffold of magnesium-calcium phosphate for bone tissue regeneration.

    Science.gov (United States)

    Wei, Jie; Jia, Junfeng; Wu, Fan; Wei, Shicheng; Zhou, Huanjun; Zhang, Hongbo; Shin, Jung-Woog; Liu, Changsheng

    2010-02-01

    Hierarchically 3D microporous/macroporous magnesium-calcium phosphate (micro/ma-MCP) scaffolds containing magnesium ammonium phosphate hexahydrate [NH(4)MgPO(4).6H(2)O] and hydroxyapatite [Ca(10)(PO(4))(6)(OH)(2)] were fabricated from cement utilizing leaching method in the presence of sodium chloride (NaCl) particles and NaCl saturated water solution. NaCl particles produced macroporosity, and NaCl solution acted as both cement liquid and porogens, inducing the formation of microporosity. The micro/ma-MCP scaffolds with porosities varied from 52 to 78% showed well interconnected and open macropores with the sizes of 400-500 microm, and degradation of the scaffolds was significantly enhanced in Tris-HCl solution compared with macroporous MCP (ma-MCP) and corresponding calcium phosphate cement (CPC) scaffolds. Cell attachment and proliferation of MG(63) on micro/ma-MCP were significantly better than ma-MCP and CPC scaffolds because of the presence of microporosity, which enhanced the surface area of the scaffolds. Moreover, the alkaline phosphatase (ALP) activity of the MG(63) cells on micro/ma-MCP was significantly higher than ma-MCP and CPC scaffolds at 7 days, and the MG(63) cells with normal phenotype spread well and formed confluent layers across the macroporous walls of the micro/ma-MCP scaffolds. Histological evaluation confirmed that the micro/ma-MCP scaffolds improved the efficiency of new bone regeneration, and exhibited excellent biocompatibility, biodegradability and faster and more effective osteogenesis in vivo.

  15. Monodisperse spherical meso-macroporous silica particles: Synthesis and adsorption of biological macromolecules

    Science.gov (United States)

    Stovpiaga, E. Yu.; Grudinkin, S. A.; Kurdyukov, D. A.; Kukushkina, Yu. A.; Nashchekin, A. V.; Sokolov, V. V.; Yakovlev, D. R.; Golubev, V. G.

    2016-11-01

    Monodispersed spherical silica particles, including large mesopores (over 10 nm) and macropores (up to 100 nm) were obtained by chemical etching in an autoclave. A method for introducing globular protein myoglobin molecules into the pores is developed. The method of filling is based on a high adsorption capacity of the developed internal pore structure of the particles. The structure and adsorption properties of the materials are studied.

  16. Current-voltage characteristics in macroporous silicon/SiOx/SnO2:F heterojunctions.

    Science.gov (United States)

    Garcés, Felipe A; Urteaga, Raul; Acquaroli, Leandro N; Koropecki, Roberto R; Arce, Roberto D

    2012-07-25

    We study the electrical characteristics of macroporous silicon/transparent conductor oxide junctions obtained by the deposition of fluorine doped-SnO2 onto macroporous silicon thin films using the spray pyrolysis technique. Macroporous silicon was prepared by the electrochemical anodization of a silicon wafer to produce pore sizes ranging between 0.9 to 1.2 μm in diameter. Scanning electronic microscopy was performed to confirm the pore filling and surface coverage. The transport of charge carriers through the interface was studied by measuring the current-voltage curves in the dark and under illumination. In the best configuration, we obtain a modest open-circuit voltage of about 70 mV and a short-circuit current of 3.5 mA/cm2 at an illumination of 110 mW/cm2. In order to analyze the effects of the illumination on the electrical properties of the junction, we proposed a model of two opposing diodes, each one associated with an independent current source. We obtain a good accordance between the experimental data and the model. The current-voltage curves in illuminated conditions are well fitted with the same parameters obtained in the dark where only the photocurrent intensities in the diodes are free parameters.

  17. Macroporous Composite Cryogels with Embedded Polystyrene Divinylbenzene Microparticles for the Adsorption of Toxic Metabolites from Blood

    Directory of Open Access Journals (Sweden)

    Tanja Eichhorn

    2013-01-01

    Full Text Available Composite monolithic adsorbents were prepared by the incorporation of neutral polystyrene divinylbenzene (PS-DVB microparticles into macroporous polymer structures produced by cryogelation of agarose or poly(vinyl alcohol. The composite materials exhibited excellent flow-through properties. Scanning electron microscopy of the composite cryogels revealed that the microparticles were covered by thin films of poly(vinyl alcohol or agarose and thus were withheld in the monolith structure. Plain PS-DVB microparticles showed efficient adsorption of albumin-bound toxins related to liver failure (bilirubin and cholic acid and of cytokines (tumor necrosis factor-alpha and interleukin-6. The rates of adsorption and the amount of adsorbed factors were lower for the embedded microparticles as compared to the parent PS-DVB microparticles, indicating the importance of the accessibility of the adsorbent pores. Still, the macroporous composite materials showed efficient adsorption of albumin-bound toxins related to liver failure as well as efficient binding of cytokines, combined with good blood compatibility. Thus, the incorporation of microparticles into macroporous polymer structures may provide an option for the development of adsorption modules for extracorporeal blood purification.

  18. Fully Accessible Ag Nanoparticles within Three-dimensionally Ordered Macroporous SiO2

    Institute of Scientific and Technical Information of China (English)

    邬泉周; 尹强; 廖菊芳; 邓景衡; 李玉光

    2005-01-01

    A multi-step process was used for preparation of three-dimensionally ordered macroporous (3DOM) SiO2, in which fully accessible Ag nanoparticles are incorporated. The method involves the processes of assembly of polystyrene colloidal crystal, preparation of 3DOM SiO2, and incorporation of Ag nanoparticles within 3DOM SiO2 through in situ Tollens' reaction. XRD, SEM and EDXS determination show that the Ag particles deposited on the macroporous walls in nano dimension. The results indicate that lower concentration of silver ammoniate and for-maldehyde in the solution is favorable for forming a very narrow size distribution and uniform shape of nanoparticles. However, the higher the concentration of the solution and the more the loading times, the larger the possibility to form un-uniform particles. Ag nanoparticles can be sintered into larger and spheral particles by calcination at 600℃, but can resist sintering owing to their high dispersivity when loading amount is small. The study provided a simple approach to tailor Ag/3DOM SiO2 composite materials with desired morphology and size of Ag particles within the macropores.

  19. Ionic liquid-regenerated macroporous cellulose monolith: Fabrication, characterization and its protein chromatography.

    Science.gov (United States)

    Du, Kaifeng

    2017-04-21

    Macroporous cellulose monolith as chromatographic support was successfully fabricated from an ionic liquid dissolved cellulose solution by an emulsification method and followed by the cross-linking reaction and DEAE modification. With the physical characterization, the cellulose monolith featured by both the interconnected macropores in range of 0.5-2.5μm and the diffusion pores centered at about 10nm. Given the bimodal pore system, the monolith possessed the specific surface area of 36.4m(2)g(-1) and the column permeability of about 7.45×10(-14)m(2). After the DEAE modification, the anion cellulose monolith was evaluated for its chromatography performances. It demonstrated that the static and dynamic adsorption capacity of BSA reached about 66.7mgmL(-1) and 43.9mgmL(-1) at 10% breakthrough point, respectively. The results were comparable to other chromatographic adsorbent. In addition, the proteins mixture with different pI was well separated at high flow velocity (611.0cmh(-1)) and high protein recovery (over 97%), proving the macroporous cellulose monolith had excellent separation performance. In this way, the prepared cellulose monolith with bimodal pores system is expected for the potential application in high-speed chromatography. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Human umbilical cord stem cell encapsulation in novel macroporous and injectable fibrin for muscle tissue engineering

    Science.gov (United States)

    Liu, Jun; Xu, Hockin H.K.; Zhou, Hongzhi; Weir, Michael D.; Chen, Qianming; Trotman, Carroll Ann

    2012-01-01

    There has been little research on the seeding of human umbilical cord mesenchymal stem cells (hUCMSCs) in three-dimensional scaffolds for muscle tissue engineering. The objectives of this study were: (i) to seed hUCMSCs in a fibrin hydrogel containing fast-degradable microbeads (dMBs) to create macropores to enhance cell viability; and (ii) to investigate the encapsulated cell proliferation and myogenic differentiation for muscle tissue engineering. Mass fractions of 0–80% of dMBs were tested, and 35% of dMBs in fibrin was shown to avoid fibrin shrinkage while creating macropores and promoting cell viability. This construct was referred to as “dMB35”. Fibrin without dMBs was termed “dMB0”. Microbead degradation created macropores in fibrin and improved cell viability. The percentage of live cells in dMB35 reached 91% at 16 days, higher than the 81% in dMB0 (p muscle tissue engineering applications. PMID:22902812

  1. Preparation of ZIF-8 membranes supported on macroporous carbon tubes via a dipcoating-rubbing method

    Science.gov (United States)

    Kong, Lingyin; Zhang, Xiongfu; Liu, Haiou; Wang, Tonghua; Qiu, Jieshan

    2015-02-01

    In the present work, a new dipcoating-rubbing method (DCRM) was developed to seed the surface of a macroporous carbon tube with a mixture of graphite and ZIF-8 nanoparticles. A continuous and low-defect ZIF-8 membrane was well formed on the seeded carbon tube by solvothermal growth. The DCRM involved a two-step process including first dipcoating a thin layer of the composite of graphite and ZIF-8 nanoparticles on the carbon surface and then rubbing the layer to form a stable seed layer. The graphite in the composite acting as binding agent could have two functions: (1) anchoring the ZIF-8 seeds onto the carbon surface; (2) smoothing the coarse surface of the macroporous carbon tube, thus forming a high quality ZIF-8 membrane. The as-prepared membrane was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and single gas permeation and was proved to be continuous and low-defect. The ideal selectivity of H2/CH4 is 7.9 with a H2 permeance of 7.15×10-8 mol Pa-1 s-1 m-2, which is higher than its corresponding Knudsen diffusion value. We could therefore expect the ZIF-8 membrane supported on macroporous tubular carbon to achieve a high selectivity of H2 over CH4 through a molecular sieving effect.

  2. 21 CFR 177.1500 - Nylon resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Nylon resins. 177.1500 Section 177.1500 Food and... Repeated Use Food Contact Surfaces § 177.1500 Nylon resins. The nylon resins listed in paragraph (a) of... packaging food, subject to the provisions of this section: (a) The nylon resins are manufactured...

  3. 21 CFR 177.2440 - Polyethersulfone resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyethersulfone resins. 177.2440 Section 177.2440... Components of Articles Intended for Repeated Use § 177.2440 Polyethersulfone resins. Polyethersulfone resins... the purpose of this section, polyethersulfone resins are: (1)...

  4. 21 CFR 177.1655 - Polysulfone resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polysulfone resins. 177.1655 Section 177.1655 Food... of Single and Repeated Use Food Contact Surfaces § 177.1655 Polysulfone resins. Polysulfone resins... purpose of this section, polysulfone resins are: (1)...

  5. 21 CFR 177.1585 - Polyestercarbonate resins.

    Science.gov (United States)

    2010-04-01

    .... Polyestercarbonate resins may be safely used as articles or components of articles intended for use in producing... chloride such that the finished resins are composed of 45 to 85 molepercent ester, of which up to 55 mole... the resins. (3) Residual methylene chloride levels in poly-ester-carbonate resins. Poly-ester...

  6. 21 CFR 178.3930 - Terpene resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Terpene resins. 178.3930 Section 178.3930 Food and... and Production Aids § 178.3930 Terpene resins. The terpene resins identified in paragraph (a) of this... the terpene resins identified in paragraph (b) of this section may be safely used as components...

  7. Indirect resin composites

    Directory of Open Access Journals (Sweden)

    Nandini Suresh

    2010-01-01

    Full Text Available Aesthetic dentistry continues to evolve through innovations in bonding agents, restorative materials, and conservative preparation techniques. The use of direct composite restoration in posterior teeth is limited to relatively small cavities due to polymerization stresses. Indirect composites offer an esthetic alternative to ceramics for posterior teeth. This review article focuses on the material aspect of the newer generation of composites. This review was based on a PubMed database search which we limited to peer-reviewed articles in English that were published between 1990 and 2010 in dental journals. The key words used were ′indirect resin composites,′ composite inlays,′ and ′fiber-reinforced composites.′

  8. Chromatography resin support

    Science.gov (United States)

    Dobos, James G.

    2002-01-01

    An apparatus and method of using an improved chromatography resin support is disclosed. The chromatography support platform is provided by a stainless steel hollow cylinder adapted for being inserted into a chromatography column. An exterior wall of the stainless steel cylinder defines a groove for carrying therein an "O"-ring. The upper surface of the stainless steel column is covered by a fine stainless steel mesh welded to the edges of the stainless steel cylinder. When placed upon a receiving ledge defined within a chromatography column, the "O"-ring provides a fluid tight seal with the inner edge wall of the chromatography cylinder. The stainless steel mesh supports the chromatography matrix and provides a back flushable support which is economical and simple to construct.

  9. Contact allergy to epoxy resin

    DEFF Research Database (Denmark)

    Bangsgaard, Nannie; Thyssen, Jacob Pontoppidan; Menné, Torkil

    2012-01-01

    . Objectives. To evaluate the prevalence of contact allergy to epoxy resin monomer (diglycidyl ether of bisphenol A; MW 340) among patients with suspected contact dermatitis and relate this to occupation and work-related consequences. Patients/methods. The dataset comprised 20 808 consecutive dermatitis...... in an educational programme. Conclusion. The 1% prevalence of epoxy resin contact allergy is equivalent to reports from other countries. The high occurrence of epoxy resin exposure at work, and the limited use of protective measures, indicate that reinforcement of the law is required....

  10. Macroporous perovskite-type complex oxide catalysts of La_(1-x)K_xCo_(1-y)Fe_yO_3 for diesel soot combustion

    Institute of Scientific and Technical Information of China (English)

    张桂臻; 赵震; 刘坚; 徐俊峰; 荆延妮; 段爱军; 姜桂元

    2009-01-01

    A facile procedure was carried out to prepare macroporous perovskite-type complex oxide catalysts of La1-xKxCo1-yFeyO3(x=0,0.1,y=0,0.1) by using the combined method of organic ligation and solution combustion.This method could ensure the formation of the desired macroporous structures and the desired crystal phases of the prepared catalysts.It was found that the macroporous catalysts showed higher catalytic activities for soot combustion than that of the corresponding nanometric samples,and the macroporous ...

  11. EPOXY RESIN TOUGHENED BY THERMOPLASTICS

    Institute of Scientific and Technical Information of China (English)

    FU Zengli; SUN Yishi

    1989-01-01

    Two kinds of tough ductile heatresisting thermoplastic, namely bisphenol A polysulfone (PSF) and polyethersulfone (PES) were used to toughen thermoset epoxy resin. A systematic study on the relationship between the molecular weight and the terminal group of the thermoplastic modifier and the fracture toughness of the modified resin was carried out. The morphology of PSF modified epoxy resin was surveyed. With the same kind of PSF the structure of the epoxy resin and the toughening effect of PSF was also investigated. The fractography of PSF, particle modified epoxy was examined in detail with SEM. The contribution of every possible energy absorption process has been discussed. Crack pinning mechanism seems to be the most important toughening mechanism for tough ductile thermoplastic PSF particle modified epoxy system.

  12. Bending characteristics of resin concretes

    Directory of Open Access Journals (Sweden)

    Ribeiro Maria Cristina Santos

    2003-01-01

    Full Text Available In this research work the influence of composition and curing conditions in bending strength of polyester and epoxy concrete is analyzed. Various mixtures of resin and aggregates were considered in view of an optimal combination. The Taguchi methodology was applied in order to reduce the number of tests, and in order to evaluate the influence of various parameters in concrete properties. This methodology is very useful for the planning of experiments. Test results, analyzed by this methodology, shown that the most significant factors affecting bending strength properties of resin concretes are the type of resin, resin content and charge content. An optimal formulation leading to a maximum bending strength was achieved in terms of material parameters.

  13. Bulk-Fill Resin Composites

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Havndrup-Pedersen, Cæcilie; Honoré, Daniel;

    2015-01-01

    the restorative procedure. The aim of this study, therefore, was to compare the depth of cure, polymerization contraction, and gap formation in bulk-fill resin composites with those of a conventional resin composite. To achieve this, the depth of cure was assessed in accordance with the International Organization...... for Standardization 4049 standard, and the polymerization contraction was determined using the bonded-disc method. The gap formation was measured at the dentin margin of Class II cavities. Five bulk-fill resin composites were investigated: two high-viscosity (Tetric EvoCeram Bulk Fill, SonicFill) and three low......-viscosity (x-tra base, Venus Bulk Fill, SDR) materials. Compared with the conventional resin composite, the high-viscosity bulk-fill materials exhibited only a small increase (but significant for Tetric EvoCeram Bulk Fill) in depth of cure and polymerization contraction, whereas the low-viscosity bulk...

  14. Epoxy hydantoins as matrix resins

    Science.gov (United States)

    Weiss, J.

    1983-01-01

    Tensile strength and fracture toughness of castings of the hydantoin resins cured with methylenedianiline are significantly higher than MY 720 control castings. Water absorption of an ethyl, amyl hydantoin formulation is 2.1 percent at equilibrium and Tg's are about 160 C, approximately 15 deg below the final cure temperature. Two series of urethane and ester-extended hydantoin epoxy resins were synthesized to determine the effect of crosslink density and functional groups on properties. Castings cured with methylenedianiline or with hexahydrophthalic anhydride were made from these compounds and evaluated. The glass transition temperatures, tensile strengths and moduli, and fracture toughness values were all much lower than that of the simple hydantoin epoxy resins. Using a methylene bishydantoin epoxy with a more rigid structure gave brittle, low-energy fractures, while a more flexible, ethoxy-extended hydantoin epoxy resin gave a very low Tg.

  15. Karakteristik Komposit Resin Berkemampuan Mengalir

    Directory of Open Access Journals (Sweden)

    Bambang Irawan

    2015-10-01

    Full Text Available The use of resin composites as posterior restoratives has markedly increased over the past decade. The patients demand for better esthetics, concerns related to possible mercury toxicity from amalgam and improvements in resin composite materials have significantly contributed the popularity of these materials. Early problems related to composites included excessive wear, less of anatomic form, post operative sensitivity, secondary caries and marginal leakage. Marginal adaptation still remains an unavoidable problem for composite restoration, especially at the gingival wall of cervical or Class II restoration. In an attempt to improve marginal sealing, many techniques and lining materials have been designed. To reduce stress generated by polymerization shrinkage, applying and curing of resin composites in layers is often recommended. Using a thick adhesive layer or low-viscosity resin may, due to its elastic properties, serve as a flexible intermediate layer and compensate for the polymerization stress created in resin composite. Flowable composites were created by retaining the same small particle size of traditional hybrid composite but reducing the filler content and allowing the increased resin to reduce the viscosity of the mixture. Flowable composites were introduced in 1996 as liners, fissure sealants and also in tunnel preparations. They have been suggested for Class I, II, III and V cavity restorations, preventive resin restorations and composite, porcelain and amalgam repairing. Their usage as a liner under high filled resins in posterior restorations has been shown to improve the adaptation of composites and effectively achieve clinically acceptable results. This article attempts to give a broad characteristics of different types of flowable composites. 

  16. Karakteristik Komposit Resin Berkemampuan Mengalir

    OpenAIRE

    Bambang Irawan

    2015-01-01

    The use of resin composites as posterior restoratives has markedly increased over the past decade. The patients demand for better esthetics, concerns related to possible mercury toxicity from amalgam and improvements in resin composite materials have significantly contributed the popularity of these materials. Early problems related to composites included excessive wear, less of anatomic form, post operative sensitivity, secondary caries and marginal leakage. Marginal adaptation still remains...

  17. New Low Cost Resin Systems

    Science.gov (United States)

    2006-05-31

    DGEBA ). 30 % of the epoxy groups of RDGE were reacted with the dihydroxyl acid and resulted 3.2 wt% phosphorous and a new epoxide equivalent weight...of 207. Adducts were also made with DGEBA and the dihydroxyl phosphorous based acid but resulted in a substantial increased viscosity and therefore...70 wt% with a standard DGEBA resin, this material accelerated the epoxy reaction too much to make a VaRTM processable resin. Due to the processing

  18. Effects of the hydraulic conductivity of the matrix/macropore interface on cumulative infiltrations into dual-permeability media

    Science.gov (United States)

    Lassabatere, L.; Peyrard, X.; Angulo-Jaramillo, R.; Simunek, J.

    2009-12-01

    Modeling of water infiltration into the vadose zone is important for better understanding of movement of water-transported contaminants. There is a great need to take into account the soil heterogeneity and, in particular, the presence of macropores or cracks that could generate preferential flow. Several mathematical models have been proposed to describe unsaturated flow through heterogeneous soils. The dual-permeability model (referred to as the 2K model) assumes that flow is governed by Richards equation in both porous regions (matrix and macropores). Water can be exchanged between the two regions following a first-order rate law. Although several studies have dealt with such modeling, no study has evaluated the influence of the hydraulic conductivity of the matrix/macropore interface on water cumulative infiltration. And this is the focus of this study. An analytical scaling method reveals the role of the following main parameters for given boundary and initial conditions: the saturated hydraulic conductivity ratio (R_Ks), the water pressure scale parameter ratio (R_hg), the saturated volumetric water content ratio (R_θs), and the shape parameters of the water retention and hydraulic conductivity functions. The last essential parameter is related to the interfacial hydraulic conductivity (Ka) between the macropore and matrix regions. The scaled 2K flow equations were solved using HYDRUS-1D 4.09 for the specific case of water infiltrating into an initially uniform soil profile and a zero pressure head at the soil surface. A sensitivity of water infiltration was studied for different sets of scale parameters (R_Ks, R_hg, R_θs, and shape parameters) and the scaled interfacial conductivity (Ka). Numerical results illustrate two extreme behaviors. When the interfacial conductivity is zero (i.e., no water exchange), water infiltrates separately into matrix and macropore regions, producing a much deeper moisture front in the macropore domain. In the opposite case

  19. Quantification of 3D macropore networks in forest soils in Touzhai valley (Yunnan, China) using X-ray computed tomography and image analysis

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jia-ming; XU Ze-min; LI Feng; HOU Ru-ji; REN Zhe

    2017-01-01

    The three dimensional (3D) geometry of soil macropores largely controls preferential flow,which is a significant infiltrating mechanism for rainfall in forest soils and affects slope stability.However,detailed studies on the 3D geometry of macropore networks in forest soils are rare.The intense rainfall-triggered potentially unstable slopes were threatening the villages at the downstream of Touzhai valley (Yunnan,China).We visualized and quantified the 3D macropore networks in undisturbed soil columns (Histosols) taken from a forest hillslope in Touzhai valley,and compared them with those in agricultural soils (corn and soybean in USA;barley,fodder beet and red fescue in Denmark) and grassland soils in USA.We took two large undisturbed soil columns (250 mmx250 mm×500 mm),and scanned the soil columns at in-situ soil water content conditions using X-ray computed tomography at a voxel resolution of 0.945 x 0.945 × 1.500 mm3.After reconstruction and visualization,we quantified the characteristics of macropore networks.In the studied forest soils,the main types of macropores were root channels,inter-aggregate voids,macropores without knowing origin,root-soil interface and stone-soil interface.While macropore networks tend to be more complex,larger,deeper and longer.The forest soils have high macroporosity,total macropore wall area density,node density,and large macropore volume,hydraulic radius,mean macropore length,angle,and low tortuosity.The findings suggest that macropore networks in the forest soils have high interconnectivity,vertical continuity,linearity and less vertically oriented.

  20. TRANSPLANTATION OF CRYOPRESERVED FETAL LIVER CELLS SEEDED INTO MACROPOROUS ALGINATE-GELATIN SCAFFOLDS IN RATS WITH LIVER FAILURE

    Directory of Open Access Journals (Sweden)

    D. V. Grizay

    2015-01-01

    Full Text Available Aim. To study the therapeutic potential of cryopreserved fetal liver cells seeded into macroporous alginategelatin scaffolds after implantation to omentum of rats with hepatic failure.Materials and methods.Hepatic failure was simulated by administration of 2-acetyl aminofl uorene followed partial hepatectomy. Macroporous alginate-gelatin scaffolds, seeded with allogenic cryopreserved fetal liver cells (FLCs were implanted into rat omentum. To prevent from colonization of host cells scaffolds were coated with alginate gel shell. Serum transaminase activity, levels of albumin and bilirubin as markers of hepatic function were determined during 4 weeks after failure model formation and scaffold implantation. Morphology of liver and scaffolds after implantation were examined histologically. Results. Macroporous alginate-gelatin scaffolds after implantation to healthy rats were colonized by host cells. Additional formation of alginate gel shell around scaffolds prevented the colonization. Implantation of macroporous scaffolds seeded with cryopreserved rat FLCs and additionally coated with alginate gel shell into omentum of rats with hepatic failure resulted in signifi cant improvement of hepatospecifi c parameters of the blood serum and positive changes of liver morphology. The presence of cells with their extracellular matrix within the scaffolds was confi rmed after 4 weeks post implantation.Conclusion. The data above indicate that macroporous alginate-gelatin scaffolds coated with alginate gel shell are promising cell carriers for the development of bioengineered liver equivalents.

  1. A simple method for the production of large volume 3D macroporous hydrogels for advanced biotechnological, medical and environmental applications

    Science.gov (United States)

    Savina, Irina N.; Ingavle, Ganesh C.; Cundy, Andrew B.; Mikhalovsky, Sergey V.

    2016-02-01

    The development of bulk, three-dimensional (3D), macroporous polymers with high permeability, large surface area and large volume is highly desirable for a range of applications in the biomedical, biotechnological and environmental areas. The experimental techniques currently used are limited to the production of small size and volume cryogel material. In this work we propose a novel, versatile, simple and reproducible method for the synthesis of large volume porous polymer hydrogels by cryogelation. By controlling the freezing process of the reagent/polymer solution, large-scale 3D macroporous gels with wide interconnected pores (up to 200 μm in diameter) and large accessible surface area have been synthesized. For the first time, macroporous gels (of up to 400 ml bulk volume) with controlled porous structure were manufactured, with potential for scale up to much larger gel dimensions. This method can be used for production of novel 3D multi-component macroporous composite materials with a uniform distribution of embedded particles. The proposed method provides better control of freezing conditions and thus overcomes existing drawbacks limiting production of large gel-based devices and matrices. The proposed method could serve as a new design concept for functional 3D macroporous gels and composites preparation for biomedical, biotechnological and environmental applications.

  2. Nanocomposite synthesis by absorption of nanoparticles into macroporous hydrogels. Building a chemomechanical actuator driven by electromagnetic radiation.

    Science.gov (United States)

    Molina, M A; Rivarola, C R; Miras, M C; Lescano, D; Barbero, C A

    2011-06-17

    Macroporous hydrogels irreversibly absorb solid nanoparticles from aqueous dispersions. A nanocomposite is made using a macroporous thermosensitive hydrogel (poly(N-isopropylacrylamide-co-(2-acrylamido-2-methyl propane sulfonic acid)) (poly(NIPAm-co-AMPS)) and conductive polymer (polyaniline, PANI) nanoparticles (PANI NPs). Macroporous gels of poly(NIPAm-co-AMPS) were made by a cryogelation technique. NPs of PANI were produced by precipitation polymerization. It is found that PANI NPs are easily absorbed into the macroporous hydrogels while conventional non-porous hydrogels do not incorporate NPs. It is shown that PANI NPs, dispersed in water, absorb NIR laser light or microwave radiation, increasing their temperature. Upon irradiation of the nanocomposite with microwaves or NIR laser light, the PANI NPs heat up and induce the phase transition of the thermosensitive hydrogel matrix and the internal solution is released. Other nano-objects, such as gold nanorods and PANI nanofibers, are also easily incorporated into the macroporous gel. The resulting nanocomposites also suffer a phase transition upon irradiation with electromagnetic waves. The results suggest that, using a thermosensitive matrix and conducting nanoparticles, mechanical/chemical actuators driven at a distance by electromagnetic radiation can be built. The sensitivity of the nanocomposite to electromagnetic radiation can be modulated by the pH, depending on the nature of the incorporated nanoparticles. Additionally, it is possible to make systems which absorb either NIR or microwaves or both.

  3. Nanocomposite synthesis by absorption of nanoparticles into macroporous hydrogels. Building a chemomechanical actuator driven by electromagnetic radiation

    Energy Technology Data Exchange (ETDEWEB)

    Molina, M A; Rivarola, C R; Miras, M C; Lescano, D; Barbero, C A, E-mail: cbarbero@exa.unrc.edu.ar [Programa de Materiales Avanzados, Departamento de Quimica, Universidad Nacional de Rio Cuarto, Ruta 8, km 601, Agencia postal No 3, 5800 Rio Cuarto (Argentina)

    2011-06-17

    Macroporous hydrogels irreversibly absorb solid nanoparticles from aqueous dispersions. A nanocomposite is made using a macroporous thermosensitive hydrogel (poly(N-isopropylacrylamide-co-(2-acrylamido-2-methyl propane sulfonic acid)) (poly(NIPAm-co-AMPS)) and conductive polymer (polyaniline, PANI) nanoparticles (PANI NPs). Macroporous gels of poly(NIPAm-co-AMPS) were made by a cryogelation technique. NPs of PANI were produced by precipitation polymerization. It is found that PANI NPs are easily absorbed into the macroporous hydrogels while conventional non-porous hydrogels do not incorporate NPs. It is shown that PANI NPs, dispersed in water, absorb NIR laser light or microwave radiation, increasing their temperature. Upon irradiation of the nanocomposite with microwaves or NIR laser light, the PANI NPs heat up and induce the phase transition of the thermosensitive hydrogel matrix and the internal solution is released. Other nano-objects, such as gold nanorods and PANI nanofibers, are also easily incorporated into the macroporous gel. The resulting nanocomposites also suffer a phase transition upon irradiation with electromagnetic waves. The results suggest that, using a thermosensitive matrix and conducting nanoparticles, mechanical/chemical actuators driven at a distance by electromagnetic radiation can be built. The sensitivity of the nanocomposite to electromagnetic radiation can be modulated by the pH, depending on the nature of the incorporated nanoparticles. Additionally, it is possible to make systems which absorb either NIR or microwaves or both.

  4. Formation of a macro-porous SiO2 layer as an anti-reflective coating on glass substrates.

    Science.gov (United States)

    Park, No-Kuk; Kim, Yong Sul; Kim, Min Jung; Lee, Tae Jin; Lee, Seung Hyun; Lee, Seung Hun

    2013-11-01

    A macro-porous silica layer, consisting of a silica layer with macro-sized pores, was formed as an antireflective material on glass substrates. The silica layer and macro-pores were formed by the oxidative thermal decomposition of tetra-ethylorthorsilicate (TEOS) used as the precursor and polystyrene (PS) spherical beads used as the polymer template for the macro-pores at high temperatures. The size of pores was determined by the size of PS beads in the antireflective agent solution. The size of the PS spherical beads can be controlled by changing the concentration of styrene monomer, and the porosity of the macro pore in the silica layer could be controlled by the TEOS/PS ratio. The optimal thermal treating temperature for the formation of a macro-porous silica layer was found to be 650 degrees C. The size of the spherical type macro pores formed in the silica layer on the glass substrate was 100-150 nm. UV-Vis spectrophotometry confirmed the improved antireflective properties of the glass substrate with the macro-porous silica layer.

  5. Preparation of Chitosan Nanocompositeswith a Macroporous Structure by Unidirectional Freezing and Subsequent Freeze-Drying

    Directory of Open Access Journals (Sweden)

    Inmaculada Aranaz

    2014-11-01

    Full Text Available Chitosan is the N-deacetylated derivative of chitin, a naturally abundant mucopolysaccharide that consists of 2-acetamido-2-deoxy-β-d-glucose through a β (1→4 linkage and is found in nature as the supporting material of crustaceans, insects, etc. Chitosan has been strongly recommended as a suitable functional material because of its excellent biocompatibility, biodegradability, non-toxicity, and adsorption properties. Boosting all these excellent properties to obtain unprecedented performances requires the core competences of materials chemists to design and develop novel processing strategies that ultimately allow tailoring the structure and/or the composition of the resulting chitosan-based materials. For instance, the preparation of macroporous materials is challenging in catalysis, biocatalysis and biomedicine, because the resulting materials will offer a desirable combination of high internal reactive surface area and straightforward molecular transport through broad “highways” leading to such a surface. Moreover, chitosan-based composites made of two or more distinct components will produce structural or functional properties not present in materials composed of one single component. Our group has been working lately on cryogenic processes based on the unidirectional freezing of water slurries and/or hydrogels, the subsequent freeze-drying of which produce macroporous materials with a well-patterned structure. We have applied this process to different gels and colloidal suspensions of inorganic, organic, and hybrid materials. In this review, we will describe the application of the process to chitosan solutions and gels typically containing a second component (e.g., metal and ceramic nanoparticles, or carbon nanotubes for the formation of chitosan nanocomposites with a macroporous structure. We will also discuss the role played by this tailored composition and structure in the ultimate performance of these materials.

  6. Impedance measurement for microstructure characterization and internal surface estimation of macroporous silicon

    Energy Technology Data Exchange (ETDEWEB)

    RoyChaudhuri, C. [Department of Electronics and Telecommunication Engineering, Bengal Engineering and Science University, Shibpur, Botanic Garden, Howrah 711103 (India); Jana, M.; Bandopadhyay, N.R. [School of Materials Science and Engineering, Bengal Engineering and Science University, Shibpur, Botanic Garden, Howrah 711103 (India)

    2010-09-15

    In this paper, a simple and convenient method based on impedance measurement has been proposed for the first time to evaluate the average porosity, pore radius, and internal surface area of macroporous silicon structure fabricated by electrochemical method. The porosity and the average pore radius have been obtained by developing a geometrical model and applying the generalized effective medium approximation theory to the dc and ac impedance measurement of both unoxidized and thermally oxidized macroporous silicon. The internal surface area per unit volume is then computed from the porosity and the pore radius using the same model. The method has been applied to a wide range of porosity from 30 to 58% fabricated on p-type <100> silicon with a resistivity of 10-20 {omega} cm. Experimental verification of porosity, mean pore radius, and internal surface area have been performed by standard gravimetric technique and by top-view and cross-section SEM imaging, respectively. A typical mean pore radius, porosity, and internal surface area of a macroporous silicon sample has been obtained to be 1.52 {mu}m, 54.2%, and 3565.7 cm{sup 2}/cm{sup 3}, respectively, from the impedance measurement and 1.5 {mu}m, 55%, and 3666.7 cm{sup 2}/cm{sup 3} from SEM and gravimetric analysis which shows that the results are within 2% of the values obtained by conventional methods. The advantages of this method over the other recently reported techniques for similar characterization have been discussed. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  7. PREPARATION OF MACROPOROUS TIO2 BY STARCH MICROSPHERES TEMPLATE WITH ASSISTANCE OF SUPERCRITICAL CO2

    Directory of Open Access Journals (Sweden)

    Lin-Qi Tang

    2009-02-01

    Full Text Available In this work a green route is reported to prepare a TiO2 macroporous network using corn starch microspheres flake as a bio-template. The starch microspheres prepared by emulsion technology were used as a template into which precursor tetrabutyl titanate (TBOT was permeated using supercritical carbon dioxide (scCO2 as a forceful carrier or infiltration media, resulting in the formation of an organic/inorganic hybrid material; then the coated template was gelled and dried during the scCO2-coating and the depressurization processes, followed by removal of the template by calcination at 700°C; finally, TiO2 inverse-opals-like material reversely replicating the starch microspheres template was obtained. Scanning electron microscopy (SEM, nitrogen sorption measurements, and X-ray diffraction (XRD indicated that the products were the inverse replicas from their templates. The obtained TiO2 inverse opals-like material showed a wide dispersion of pore sizes from mesopores to macropores – a few nanometers to several micrometers –with the BET surface area up to 103 m2/g, and a predominantly anatase crystalline phase. In addition, the wall thickness of the macropores varied with tunable pressure for closed cells or open-cell foams. So this facile and environmentally friendly process for the preparation of high-surface area, thermally-stable, metal-oxide catalysts and supports by a starch microsphere templating approach may have widespread potential applications in catalysis, absorbents, photoelectric materials, and so on.

  8. Development of macroporous calcium phosphate scaffold processed via microwave rapid drying

    Energy Technology Data Exchange (ETDEWEB)

    Jamuna-Thevi, K., E-mail: jamuna@sirim.my [Advanced Materials Research Centre (AMREC), SIRIM Berhad, Lot 34, Jalan Hi-Tech 2/3, Kulim Hi-Tech Park, 09000 Kulim, Kedah (Malaysia); Zakaria, F.A. [Advanced Materials Research Centre (AMREC), SIRIM Berhad, Lot 34, Jalan Hi-Tech 2/3, Kulim Hi-Tech Park, 09000 Kulim, Kedah (Malaysia); Othman, R. [Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia, Seri Ampangan, 14300 Nibong Tebal, Penang (Malaysia); Muhamad, S. [Bioassay Unit, Herbal Medicine Research Centre (HMRC), Institute for Medical Research (IMR), Jalan Pahang, 50588 Kuala Lumpur (Malaysia)

    2009-06-01

    Porous hydroxyapatite (HA) scaffold has great potential in bone tissue engineering applications. A new method to fabricate macroporous calcium phosphate (CP) scaffold via microwave irradiation, followed by conventional sintering to form HA scaffold was developed. Incorporation of trisodium citrate dihydrate and citric acid in the CP mixture gave macroporous scaffolds upon microwave rapid drying. In this work, a mixture of {beta}-tricalcium phosphate ({beta}-TCP), calcium carbonate (CaCO{sub 3}), trisodium citrate dihydrate, citric acid and double distilled de-ionised water (DDI) was exposed to microwave radiation to form a macroporous structure. Based on gross eye examinations, addition of trisodium citrate at 30 and 40 wt.% in the CP mixture ({beta}-TCP and CaCO{sub 3}) without citric acid indicates increasing order of pore volume where the highest porosity yield was observed at 40 wt.% of trisodium citrate addition and the pore size was detected at several millimeters. Therefore, optimization of pore size was performed by adding 3-7 wt.% of citric acid in the CP mixture which was separately mixed with 30 and 40 wt.% of trisodium citrate for comparison purposes. Fabricated scaffolds were calcined at 600 deg. C and washed with DDI water to remove the sodium hydroxycarbonate and sintered at 1250 deg. C to form HA phase as confirmed in the X-ray diffraction (XRD) results. Based on Archimedes method, HA scaffolds prepared from 40 wt.% of trisodium citrate with 3-7 wt.% of citric acid added CP mixture have an open and interconnected porous structure ranging from 51 to 53 vol.% and observation using Scanning electron microscope (SEM) showed the pore size distribution between 100 and 500 {mu}m. The cytotoxicity tests revealed that the porous HA scaffolds have no cytotoxic potential on MG63 osteoblast-like cells which might allow for their use as biomaterials.

  9. Method development for thermal analyses testing on Reillex HPQ resin using the advanced reactive system screening tool (ARSST)

    Energy Technology Data Exchange (ETDEWEB)

    Best, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-03-01

    Reillex™ HPQ resin was developed by Los Alamos Laboratory and Reilly Industries Inc. in an effort to increase safety and process efficiency during the recovery and purification of plutonium. Ionac™ A-641, another strong base macroporous anion exchange resin used in the nuclear industry, was known to undergo a runaway reaction in hot nitric acid solutions. Because of this, an extensive amount of thermal analyses testing on the Reillex™ HPQ resin in SRNL was performed in 1999-2001 prior to use. A report on the thermal stability qualification of the Reillex™ HPQ resin in 8M (35%) and 12M (53%) HNO3 was reported in 2000. In 2001, the reactivity of Reillex™ HPQ resin in 14.4M (64%) HNO3 was evaluated. In January of 2001, thermal stability scoping tests were performed on irradiated Reillex™ HPQ resin in 14.4M (64%) HNO3 (as a worst case scenario) and the results sent to Fauske and Associates to calculate a rupture disk size for the HB-Line resin column. A technical report by Fauske and Associates was issued in February 2001 recommending a 2.0” vent line with a rupture disk set pressure of 60 psig. This calculation was based on ARSST thermal analyses scoping tests at SRNL in which 4 grams of dried resin and 6.0 grams of 64% nitric acid in a 10 gram test cell, produced a maximum pressure rate (dP/dt) of 720 psi/min (12 psi/sec) and a maximum temperature of 250 °C. In 2015, a new batch of Reillex™ HPQ resin was manufactured by Vertellus Industries. A test sample of the resin was sent to SRNL to perform acceptance and qualification thermal stability testing using the ARSST. During these tests, method development was performed to ensure that a representative resin to acid ratios were used while running the tests in the ARSST. Fauske and Associates recommended to either use a full test cell representative of the HB-Line column or a 10 gram sample in the test cell that was representative of the ratios of resin to nitric acid in

  10. Macroporous silicon membranes as electron and x-ray transmissive windows

    OpenAIRE

    Schilling, J.; Scherer, A; Gösele, U; Kolbe, M.

    2004-01-01

    Macroporous silicon membranes are fabricated whose pores are terminated with 60 nm thin silicon dioxide shells. The transmission of electrons with energies of 5 kV-25 kV through these membranes was investigated reaching a maximum of 22% for 25 kV. Furthermore, the transmission of electromagnetic radiation ranging from the far-infrared to the x-ray region was determined. The results suggest the application of the membrane as window material for electron optics and energy dispersive x-ray detec...

  11. Synthesis of 3-D ordered macroporous silicate using the template formed from monodispersed polystyrene latex

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Based on the template formed from monodispersed polystyrene (PS) latex, a modified fast sol-gel process was employed to synthesize a three-dimensional ( 3-D ) ordered macroporous silica material after removing the template by calcination at high temperature. It was indicated that there existed highly ordered packed pores within the whole silica material by SEM morphology observation. It was also found that the pores were interconnected. The pore size could be controlled mainly by varying the particle size of the latex ranging from 101 to 102 nm. The formation process of the ordered pores was also preliminarily discussed.

  12. Electrochemical synthesis of macroporous zinc oxide layers by employing hydrogen peroxide as oxygen precursor

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez, Daniel [Laboratoire d' Electrochimie et Chimie Analytique (UMR CNRS 7575), Ecole Nationale Superieure de Chimie de Paris (ENSCP) (France); Instituto de Quimica, Pontificia Universidad Catolica de Valparaiso, Valparaiso (Chile); Bartlett, Philip; Abdelsalam, Mamdouh [School of Chemistry, University of Southampton (United Kingdom); Gomez, Humberto [Instituto de Quimica, Pontificia Universidad Catolica de Valparaiso, Valparaiso (Chile); Lincot, Daniel [Laboratoire d' Electrochimie et Chimie Analytique (UMR CNRS 7575), Ecole Nationale Superieure de Chimie de Paris (ENSCP) (France)

    2008-10-15

    Two- and three-dimensional ordered porous zinc oxide (ZnO) films were prepared by electrodeposition on Indium Tin Oxide coated glass, using two- and three-dimensional poly(styrene) opal templates. The oxide was formed by electrochemical reduction of hydrogen peroxide in aqueous zinc perchlorate solution. Scanning electron microscopy measurements showed well ordered inverse opal structures for macroporous ZnO. At high hydrogen peroxide concentration, dense inner conformal filling was achieved for 2D and 3D structures. The formation of nanocrystalline ZnO was checked by X-ray diffraction. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  13. SYNTHESIS OF SPHERICAL MACROPOROUS ADSORBENT BASED ON UREA—FORMALDEHYDE CONDENSED POLYMER

    Institute of Scientific and Technical Information of China (English)

    XUMingcheng; XUMancai; 等

    2000-01-01

    Spherical macroporous adsorbents with active sites capable of hydrogen bonding adsorption based on urea-formaldehyde condensed polymer were synthesized via reversed suspension polymerization.The properties of the obtained adsorbent were also investigated in detail.The results showed that the water permeability could be improved by adding hydroxyl-contatining organic compound moiety into the adsorbent.The specific surface area and average pore diameter of these adsorbents increaswed while the porosity first increased then decreased with the increase of the amount of the added hydroxyl-containing compound.

  14. Macroporous hydrogels based on 2-hydroxyethyl methacrylate. Part III. Hydrogels as carriers for immobilization of proteins.

    Science.gov (United States)

    Michálek, J; Prádný, M; Artyukhov, A; Slouf, M; Smetana, K

    2005-08-01

    Four series of macroporous hydrogels based on crosslinked copolymers of 2-hydroxyethyl methacrylate (HEMA)-sodium methacrylate (MANa), copolymer HEMA-[2-(methacryloyloxy)ethyl]trimethylammonium chloride (MOETACl), terpolymer HEMA-MANa-MOETACl and on a polyelectrolyte complex were used as carriers for immobilization of proteins, chicken egg white albumin and avidin. The adsorption capacity of the hydrogels for the two proteins, kinetics and pH dependence of albumin adsorption and desorption were studied. The morphology of the hydrogels with and without immobilized albumin was studied by low-vacuum scanning electron microscopy.

  15. Immobilization of denatured DNA to macroporous supports: II. Steric and kinetic parameters of heterogeneous hybridization reactions.

    OpenAIRE

    Bünemann, H

    1982-01-01

    The accessibility of immobilized DNA has been shown to depend more crucially on the method of immobilization than on the type of support used for fixation. When sonicated denatured DNA is coupled via diazotization or via cyanogen bromide reaction to solid Sephadex G-25 and Cellex 410 or to macroporous Sephacryl S-500 and Sepharose C1-6B its accessibility varies from 100 to 24 percent. Generally the loss of accessibility is linked to a depression of the melting temperature of DNA helices forme...

  16. Immobilization of denatured DNA to macroporous supports: I. Efficiency of different coupling procedures.

    OpenAIRE

    Bünemann, H; Westhoff, P; Herrmann, R. G.

    1982-01-01

    Methods commonly used for covalent immobilization of single stranded DNA have been applied to several solid supports (Sephadex G-25 and Cellex 410) as well as to a number of macroporous materials (Sepharose C1-6B, C1-2B; Sephacryl S-500 and S-1000). Coupling efficiencies and stability of covalently bound DNA are compared for both classes of materials. The yields of the immobilization reaction for sonicated DNA are only 10-40% for G-25 and Cellex 410 in contrast to 60-80% for C1-6B and S-500. ...

  17. Nanoporous walls on macroporous foam: rational design of electrodes to push areal pseudocapacitance

    Energy Technology Data Exchange (ETDEWEB)

    Guan, Cao; Fan, Hong Jin [Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University (Singapore); Energy Research Institute, NTU (ERIAN), Nanyang Technological University (Singapore); Li, Xianglin; Wang, Zilong; Soci, Cesare [Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University (Singapore); Cao, Xiehong; Zhang, Hua [School of Materials Science and Engineering, Nanyang Technological University (Singapore)

    2012-08-08

    For application as a pseudocapacitor electrode, highly porous CoO nanowalls are fabricated directly on 3D macroporous nickel foam (see images). A relatively high areal capacitance is achieved because of the porous structure. By grafting the porous nanowalls with another pseudocapacitive oxide, the areal capacitance can be further significantly boosted, owing to the increased surface area caused by the hierarchically porous structure as well as a possible synergetic effect between the two oxides. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Quantification of small-scale physicochemical properties of intact macropore surfaces in Bt-horizons of Luvisols

    Science.gov (United States)

    Leue, Martin; Gerke, Horst H.

    2017-04-01

    During preferential flow in structured soils, the interaction of percolating water and reactive solutes with the soil matrix is mostly restricted to surfaces of preferential flow paths which affect mass exchange processes by the physical and chemical properties. These properties can strongly differ from bulk soil properties with respect to texture, organic matter (OM), pore geometry, density, and porosity. The aim of our work was to identify and to quantify effective macropore properties which concurrently are appropriate to represent physical mechanisms for entire soil horizons with respect to preferential flow. We studied physical and chemical properties of intact surfaces of soil aggregates, biopores (root channels, worm burrows), and coated cracks from Luvisol Bt-horizons. The spatial distribution of the OM composition and related physical properties such as wettability, the organic carbon content, and the cation exchange capacity of these macropores as characterized by DRIFT spectroscopy and complementary techniques were found spatially distributed at the mm-scale. Differences could be observed for loess and glacial till as parent materials, land use, and macropore types, in particular for cracks and biopores. The geometrical properties (pore volume, diameter, surfaces area, connectivity, and tortuosity) of all potentially available macropores, in particular the differences between cracks and biopores, were quantified in large soil columns using X-ray computed tomography (µCT). Dye tracer experiments at the cm-to-m-scale showed substrate-specific and macropore-specific differences between the active preferential flow paths. In a summarizing step we aim to combine the chemical and physical surface properties with the geometrical properties of the macropores in order to estimate the effects of the surface properties on preferential flow in Bt-horizons. The specific surface areas and chemical compositions may help explain differences in the staining patterns

  19. Sorption of Ni(II) ions from aqueous solution by Lewatit cation-exchange resin.

    Science.gov (United States)

    Dizge, Nadir; Keskinler, Bülent; Barlas, Hulusi

    2009-08-15

    Ion-exchange is an alternative process for uptake of heavy metals from aqueous solutions. In the present study, the sorption of nickel(II) ions from aqueous solution was investigated by using Lewatit MonoPlus SP 112 (strongly acidic, macroporous cation-exchange resin) in a batch adsorption system as a function of pH (2.0-8.0), initial nickel concentration (50-200 mg/L), resin dosage (0.5-2.0 g/L), contact time (0.5-3h), and temperatures (298-318K). The data were analyzed on the basis of Lagergren pseudo-first order, pseudo-second order (Types 1-5), Elovich and external, Weber-Morris intraparticle, pore-surface mass diffusion models. The experimental data showed that the maximum pH for efficient sorption of nickel(II) was 6.0. At the optimal conditions, nickel(II) ions sorption on the resin was decreased when the initial metal concentration increased. The results indicated that the resin dosage strongly affected the amount of nickel(II) ions removed from aqueous solution. The adsorption process was very fast due to 80% of nickel(II) sorption was occurred within 30 min and equilibrium was reached at about 90 min. Freundlich and Langmuir adsorption isotherm models were used for sorption equilibrium data and the maximum adsorption capacity (171 mg/g) of Lewatit MonoPlus SP 112 was obtained from Langmuir isotherm. The thermodynamic parameters (DeltaG degrees, free energy change; DeltaS degrees, enthalpy change; and DeltaH degrees, entropy change) for sorption of nickel(II) ions were evaluated. The rise in temperature caused a partly increase in the value of the equilibrium constant (K(c)) for the sorption of nickel(II) ions. Moreover, column flow adsorption study was also studied. Breakthrough curves were obtained from column flow studies by using both synthetic solution and rinsing bath water of filter industry. The column regeneration was carried out for two sorption-desorption cycles. The eluant used for regeneration of the cation-exchange resin was 7% (w/w) HCl. The

  20. THE SYNTHESIS OF MODIFIED DIPHENYL OXIDE RESIN

    Institute of Scientific and Technical Information of China (English)

    MAOMingfei; LIUZhifang; 等

    2002-01-01

    Modified diphenyl oxide resin was synthesized by co-polymerization of unsaturated acid and diphenyl oxide derivants.And then modified bismaleimide resin and expoxide linear phenolic resin were added into modified diphenyl oxide resin to co-polymerized and modify once more.The system was applied in composites.Their properties wrer investigated and found that they met the requirements as a heat-resisting adhesive.

  1. 静态吸附杜仲叶中绿原酸较合适树脂的研究%More appropriate resins on the static adsorption of chlorogenic acid from eucommia leaf

    Institute of Scientific and Technical Information of China (English)

    罗剑; 吴海振; 年四辉

    2011-01-01

    目的 以静态吸附法从杜仲叶提取液中筛选吸附、纯化绿原酸的最佳树脂.方法 以绿原酸静态吸附量、解析率、纯度为评价指标分别对NKA-Ⅱ、NKA-9、D-101-1、HPD-100、HPD-600、HPD826、330、AB-8 8种树脂进行考察.结果 NKA-Ⅱ吸附量为18.63 mg·g-1,60%与95%乙醇加合解析率达到70.2%,绿原酸在样品中纯度大于20.30%.结论 NKA-Ⅱ是绿原酸较合适的吸附树脂,可供参考.%Aim To select the hest macroporous resin which absorbs chlorogenic acid from the extract of Eucommia Leaf by static ahsorption. Methods The static absorption, desorption capacities and purity of chlorogenic acid were the indexes to evaluate eight macroporous resins NKA- Ⅱ , NKA-9 , D-101-1 . HPD-100 , HPD-600 , HPD826 , 330 and AB-8. Results Among these eight resins, the polar resin NKA- Ⅱ possessed suitable absorption and desorption c.apacities. with the absorption and desorption rates being 18. 63 mg· g-1 and 70. 2% . The purity of chlorogenic acid in the samples was above 20. 30% . Conclusion NKA- Ⅱ is a suitable resin to absorh chlorogenic acid.

  2. 21 CFR 872.3140 - Resin applicator.

    Science.gov (United States)

    2010-04-01

    ... DEVICES DENTAL DEVICES Prosthetic Devices § 872.3140 Resin applicator. (a) Identification. A resin applicator is a brushlike device intended for use in spreading dental resin on a tooth during application of tooth shade material. (b) Classification. Class I (general controls). The device is exempt from...

  3. Method of removing contaminants from plastic resins

    Science.gov (United States)

    Bohnert,George W.; Hand,Thomas E.; Delaurentiis,Gary M.

    2007-08-07

    A method for removing contaminants from synthetic resin material containers using a first organic solvent system and a second carbon dioxide system. The organic solvent is utilized for removing the contaminants from the synthetic resin material and the carbon dioxide is used to separate any residual organic solvent from the synthetic resin material.

  4. Method for removing contaminants from plastic resin

    Science.gov (United States)

    Bohnert, George W.; Hand, Thomas E.; DeLaurentiis, Gary M.

    2008-12-30

    A method for removing contaminants from synthetic resin material containers using a first organic solvent system and a second carbon dioxide system. The organic solvent is utilized for removing the contaminants from the synthetic resin material and the carbon dioxide is used to separate any residual organic solvent from the synthetic resin material.

  5. 21 CFR 177.1595 - Polyetherimide resin.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyetherimide resin. 177.1595 Section 177.1595... Components of Single and Repeated Use Food Contact Surfaces § 177.1595 Polyetherimide resin. The polyetherimide resin identified in this section may be safely used as an article or component of an...

  6. 21 CFR 177.1556 - Polyaryletherketone resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyaryletherketone resins. 177.1556 Section 177... Components of Single and Repeated Use Food Contact Surfaces § 177.1556 Polyaryletherketone resins. The poly...) resins (CAS Reg. No. 55088-54-5 and CAS Reg. No. 60015-05-6 and commonly referred to...

  7. 21 CFR 177.1555 - Polyarylate resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyarylate resins. 177.1555 Section 177.1555 Food... of Single and Repeated Use Food Contact Surfaces § 177.1555 Polyarylate resins. Polyarylate resins... contact with food in accordance with the following prescribed conditions: (a) Identity. Polyarylate...

  8. 21 CFR 177.1560 - Polyarylsulfone resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyarylsulfone resins. 177.1560 Section 177.1560... Components of Single and Repeated Use Food Contact Surfaces § 177.1560 Polyarylsulfone resins. Polyarylsulfone resins (CAS Reg. No. 79293-56-4) may be safely used as articles or components of articles...

  9. 40 CFR 721.9495 - Acrylosilane resins.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Acrylosilane resins. 721.9495 Section... Substances § 721.9495 Acrylosilane resins. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substances identified as acrylosilane resins (PMNs P-95-1024/1040) are...

  10. 21 CFR 172.280 - Terpene resin.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Terpene resin. 172.280 Section 172.280 Food and..., Films and Related Substances § 172.280 Terpene resin. The food additive terpene resin may be safely used... polymer obtained by polymerizing terpene hydrocarbons derived from wood. It has a softening point of...

  11. 21 CFR 177.1680 - Polyurethane resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyurethane resins. 177.1680 Section 177.1680 Food... of Single and Repeated Use Food Contact Surfaces § 177.1680 Polyurethane resins. The polyurethane...) For the purpose of this section, polyurethane resins are those produced when one or more of...

  12. Delivery of ibuprofen by natural macroporous sporopollenin exine capsules extracted from Phoenix dactylifera L.

    Science.gov (United States)

    Alshehri, Saad M; Al-Lohedan, Hamad A; Chaudhary, Anis Ahmad; Al-Farraj, Eida; Alhokbany, Norah; Issa, Zuheir; Alhousine, Sami; Ahamad, Tansir

    2016-06-10

    Sporopollenin macroporous capsules (SMCs) were extracted from date palm (Phoenix dactylifera L.) spores and coated by a natural polymer composite (chitosan with glutaraldehyde). The polymer coated macroporous capsules SMC@poly were used in the in vitro-controlled delivery of ibuprofen. The materials obtained were characterized through spectral, thermal, scanning electron microscopy (SEM), X-ray diffraction (XRD), and nitrogen adsorption-desorption isotherms. The IBU loading and releasing was studied by investigating the changes in various factors such as pH, temperature, and initial concentration. The results revealed that the loading of IBU increased when the concentration of IBU was decreased, following the Langmuir adsorption isotherm. The maximum loading of the IBU was observed at pH6.0 (97.2%, with 50mg/mL). The releasing results indicate that IBU was released faster when the pH was changed from 1.4 to 7.4. In addition, the cytotoxicity of the SMC, SMC@poly, and SMC@poly-IBU were tested against human intestinal Caco-2 cell line using MTT assay, and the results revea'led that all the materials in this study were biocompatible.

  13. Detachment of affinity-captured bioparticles by elastic deformation of a macroporous hydrogel

    Science.gov (United States)

    Dainiak, Maria B.; Kumar, Ashok; Galaev, Igor Yu.; Mattiasson, Bo

    2006-01-01

    Adsorption of bioparticles to affinity surfaces involves polyvalent interactions, complicating greatly the recovery of the adsorbed material. A unique system for the efficient binding and release of different cells and particles is described. Affinity-bound bioparticles and synthetic particles are detached from the macroporous hydrogel matrix, a so-called cryogel, when the cryogel undergoes elastic deformation. The particle detachment upon elastic deformation is believed to be due to breaking of many of the multipoint attachments between the particles and the affinity matrix and the change in the distance between affinity ligands when the matrix is deformed. However, no release of affinity-bound protein occurred upon elastic deformation. The phenomenon of particle detachment upon elastic deformation is believed to be of a generic nature, because it was demonstrated for a variety of bioparticles of different sizes and for synthetic particles, for different ligand–receptor pairs (IgG–protein A, sugar–ConA, metal ion–chelating ligand), and when the deformation was caused by either external forces (mechanical deformation) or internal forces (the shrinkage of thermosensitive, macroporous hydrogel upon an increase in temperature). The elasticity of cryogel monoliths ensures high recovery of captured cells under mild conditions, with highly retained viability. This property, along with their continuous porous structure makes cryogel monoliths very attractive for applications in affinity cell separation. PMID:16418282

  14. Tension free monofilament macropore polypropylene mesh (Gynemesh PS in female genital prolapse repair

    Directory of Open Access Journals (Sweden)

    Vicente Sola

    2006-08-01

    Full Text Available OBJECTIVES: To review intraoperative and postoperative complications associated to the correction of cystocele and rectocele with polypropylene mesh macropore monofilament (Gynemesh PS using transvaginal free tension technique. MATERIALS AND METHODS: Prospective study of patients that have been submitted to correction of cystocele and/or rectocele between November 2004 and August 2005 in the Urogynecology and Vaginal Surgery Unit of Gynecology and Obstetrics Department, Las Condes Clinic. Mesh was used in 31 patients: 9 for cystocele, 11 for rectocele, and 11 for concomitant meshes. Total mesh used 42. Media age 55 years old, weight 64 kilograms. In 7 patients we used a third mesh for correction of urinary incontinence by TVT-O technique. RESULTS: They did not present intraoperative complications, neither in immediate or delayed postoperative time. We did not observe hematoma, infection, erosion or exposition mesh. Healing of cystocele and rectocele was obtained in 100% of patients, with a pursuit between 1 and 8 months. DISCUSSION: The use of prosthetic polypropylene monofilament macropore mesh in the correction of cystocele and/or rectocele, by transvaginal route with tension free technique seems to be a safe and effective surgery procedure.

  15. Sapropel-based supports as novel macroporous carbon-mineral adsorbents for enzymatic active substances

    Directory of Open Access Journals (Sweden)

    G.A. Kovalenko

    2016-12-01

    Full Text Available The novel macroporous carbon-mineral Sapropel supports were obtained from lacustrine sapropel silts of freshwater lakes by annealing of semi-coke in the inert atmosphere. The specific surface area of these supports varied from 10 to 100 m2/g, the total pore volume from 0.3 cm3/g till 1.6 cm3/g; macropores of diameters more than 2 µm were predominating. The Sapropel supports were studied for the adsorption/adhesion of enzymatic active substances, such as whole bacterial cells, and invertase-active fully destroyed baker's yeast cells (autolysates, and purified enzyme nitrilase. The heterogeneous biocatalysts with required enzymatic activity were prepared and their properties were studied in the corresponding bioconversion processes. The invertase-active biocatalysts exhibited high activity, 120–135 U/g, and stability; the half-times of their inactivation (t½ were more than 1000 h in the continuous process of sucrose hydrolysis at 50 °C. The nitrilase-active biocatalysts for “green” chemistry of nitriles possessed high activity, 350–500 U/g, and the t½ were estimated to be more than 100 h in the periodic process of hydration of acrylonitrile to acrylic acid at 22 °C.

  16. Polymeric macroporous formulations for the control release of mosquitocidal Bacillus sphaericus ISPC-8.

    Science.gov (United States)

    Tripathi, Anuj; Hadapad, Ashok B; Hire, Ramesh S; Melo, Jose S; D'Souza, Stanislaus F

    2013-12-10

    Bio-polymeric mosquitocidal formulations were developed for the control release of Bacillus sphaericus ISPC-8 by the immobilization of its spore-crystal complex onto the macroporous polymeric matrices. The biodegradable formulations were synthesized at sub-zero temperature using natural polymeric substrates like agarose, alginate, cellulose, non-adsorbent cotton, wooden cork powder and also magnetite nanoparticles. The obtained polymeric matrices were morphologically characterized, which showed 85-90% porosity, uniform pores distribution, high permeability and controlled degradation (19-30%) in 4 weeks depending upon the composition of formulations. Further, the polymeric macroporous formulations were tested for persistence of mosquitocidal activity against Culex quinquefasciatus larvae. Unformulated B. sphaericus ISPC-8 spores retained 54% of larvicidal activity after 7 days, which completely reduced after 35 days of treatment. However, the immobilized B. sphaericus spores in agarose-alginate formulations showed high larvicidal activity on day 7 and retained about 45% activity even after 35 days of treatments. Studies on UV-B and pH dependent inactivation of toxins and spore viability showed that these formulations were significantly protecting the spores as compared to the unformulated spores, which suggest its potential application for the mosquito control program.

  17. Preparation of macroporous methacrylate-based monoliths for chromatographic applications by the Reactive Gelation Process.

    Science.gov (United States)

    Bechtle, M; Butté, A; Storti, G; Morbidelli, M

    2010-07-09

    Polymeric monoliths are a relatively new separation medium for chromatographic applications. The innovative approach to produce such monoliths, the Reactive Gelation Process, presented by Marti et al. [1] for polystyrene macroporous materials is applied to a methacrylate-based material. It is shown that it is possible to create a macroporous structure by Reactive Gelation also with this polymer even if the properties of the material are different. Besides the analysis of the material by SEM and BET, several chromatographic methods are used to analyze the material properties. The ISEC experiments showed a much smaller size exclusion effect than in conventional packed beds. The permeability of the material is comparable to a packed bed with 4.13 μm particles. The column efficiency is not changing for increasing flow rates. Because of the high efficiency of the material, shorter columns are needed and therefore the comparatively low permeability is compensated. The monolith also exhibits a significant adsorption capacity for hydrophobic interaction, which makes it suitable for chromatographic purification processes.

  18. A composite chitosan-gelatin bi-layered, biomimetic macroporous scaffold for blood vessel tissue engineering.

    Science.gov (United States)

    Badhe, Ravindra V; Bijukumar, Divya; Chejara, Dharmesh R; Mabrouk, Mostafa; Choonara, Yahya E; Kumar, Pradeep; du Toit, Lisa C; Kondiah, Pierre P D; Pillay, Viness

    2017-02-10

    A composite chitosan-gelatin macroporous hydrogel-based scaffold with bi-layered tubular architecture was engineered by solvent casting-co-particulate leaching. The scaffold constituted an inner macroporous layer concealed by a non-porous outer layer mimicking the 3D matrix of blood vessels with cellular adhesion and proliferation. The scaffold was evaluated for its morphological, physicochemical, physicomechanical and biodurability properties employing SEM, FTIR, DSC, XRD, porositometry, rheology and texture analysis. The fluid uptake and biodegradation in the presence of lysozymes was also investigated. Cellular attachment and proliferation was analysed using human dermal fibroblasts (HDF-a) seeded onto the scaffold and evaluated by MTT assay, SEM, and confocal microscopy. Results demonstrated that the scaffold had a desirable tensile strength=95.81±11kPa, elongation at break 112.5±13%, porosity 82% and pores between 100 and 230μm, 50% in vitro biodegradation at day 16 and proliferated fibroblasts over 20 days. These results demonstrate that scaffold may be an excellent tubular archetype for blood vessel tissue engineering.

  19. Ground Organic Monolith Particles Having a Large Volume of Macropores as Chromatographic Separation Media

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jin Wook; Ali, Faiz; Kim, Yune Sung; Cheong, Won Jo [Inha Univ., Incheon (Korea, Republic of)

    2014-07-15

    A reaction mixture was developed for formation of soft organic monolith that was easily smashed, rinsed, refluxed, filtered, and dried to give monolith particles having high pore volume of macropores. This phase was almost without mesopores. The reaction mixture was composed of methacrylic acid, ethylene glycol dimethacrylate, polyethylene glycol (porogen), and an initiator in a mixed solvent of toluene and isooctane. The selection of porogen and its amount was carefully carried out to obtain the optimized separation efficiency of the resultant phase. The median macropore size was 1.6 μm, and the total pore volume was 3.0-3.4 mL/g. The median particle size (volume based) was 15 μm, and the range of particle size distribution was very broad. Nevertheless the column (1 Χ 300 mm) packed with this phase showed good separation efficiency (N∼10,000-16,000) comparable to that of a commercial column packed with 5 μm C18 silica particles.

  20. Immobilization of denatured DNA to macroporous supports: II. Steric and kinetic parameters of heterogeneous hybridization reactions.

    Science.gov (United States)

    Bünemann, H

    1982-11-25

    The accessibility of immobilized DNA has been shown to depend more crucially on the method of immobilization than on the type of support used for fixation. When sonicated denatured DNA is coupled via diazotization or via cyanogen bromide reaction to solid Sephadex G-25 and Cellex 410 or to macroporous Sephacryl S-500 and Sepharose C1-6B its accessibility varies from 100 to 24 percent. Generally the loss of accessibility is linked to a depression of the melting temperature of DNA helices formed on the support. This correlation shows a characteristic course for a particular coupling method. DNA coupled under denaturing conditions may become totally inaccessible when only 3 percent of its bases are involved in the covalent linkage. Kinetic experiments with sonicated E.coli DNA have shown that the rate constants for renaturation or hybridization reactions are very similar for DNA immobilized by different methods to solid or macroporous supports. Generally the second order rate constant for a heterogeneous reaction (between mobile and immobilized DNA) is about one order of magnitude smaller than that of the analogous homogeneous reaction (in solution).

  1. EFFECTS OF DIFFUSION ON THE KINETICS OF MALTOSE HYDROLYSIS USING GLUCOAMYLASE IMMOBILIZED ON MACROPOROUS SILICA

    Directory of Open Access Journals (Sweden)

    L.R.B. Gonçalves

    1997-12-01

    Full Text Available In this work the effects of diffusion on the hydrolysis of maltose using glucoamylase immobilized on macroporous silica at 30o C are studied. Two different kinds of experimental assays are carried out: one using free enzyme and the other using an enzyme covalently linked to macroporous silica, preactivated with glutaraldehyde. Free enzyme assays are used to estimate the kinetic parameters for hydrolysis of maltose at 30ºC, according to a Michaelis-Menten equation, with inhibition by the product. Runs with the immobilized enzyme enable us to estimate dextrin diffusivities in silica, assuming that the inherent kinetic parameters are equal to the intrinsic ones. The values of kinetic and mass transfer parameters are: K3 = 0.90x10-5 g/U.s, Km = 0.61x10-3 g/ml, Ki = 1.23x10-1 g/ml, DMs = 0.50x10-6 cm2 /s and DGs = 0.55x10-6 cm2 /s

  2. Occupational exposure to epoxy resins

    NARCIS (Netherlands)

    Terwoert, J.; Kersting, K.

    2014-01-01

    Products based on epoxy resins as a binder have become popular in various settings, among which the construction industry and in windmill blade production, as a result of their excellent technical properties. However, due to the same properties epoxy products are a notorious cause of allergic skin d

  3. Stochastic resin transfer molding process

    CERN Document Server

    Park, M

    2016-01-01

    We consider one-dimensional and two-dimensional models of stochastic resin transfer molding process, which are formulated as random moving boundary problems. We study their properties, analytically in the one-dimensional case and numerically in the two-dimensional case. We show how variability of time to fill depends on correlation lengths and smoothness of a random permeability field.

  4. Occupational exposure to epoxy resins

    NARCIS (Netherlands)

    Terwoert, J.; Kersting, K.

    2014-01-01

    Products based on epoxy resins as a binder have become popular in various settings, among which the construction industry and in windmill blade production, as a result of their excellent technical properties. However, due to the same properties epoxy products are a notorious cause of allergic skin

  5. [Epoxy resin systems and contact dermatitis].

    Science.gov (United States)

    Pietranek, Jolanta Eliza

    2007-01-01

    Contact dermatitis is the major chronic skin disease that represents a global health problem. Its prevalence has been significant increasing in the latest decades. Contact dermatitis substantially alters the social life of patients and affects their work productivity. Epoxy resin systems are a frequent cause of occupational allergic contact dermatitis. Epoxy resins have an extremely wide range of commercial applications. Epoxy resin systems include combinations of epoxy monomers, hardeners, reactive diluents, and/or a vast array of other additives. In occupational settings, sensitization occurs not only to resins, but also to hardeners and reactive diluents. In this article adverse effects of epoxy resin systems are discussed.

  6. Lattice Boltzmann Modeling of Macro-Porous Flow: Effects of Image Segmentation Algorithms and Comparisons with Observed Data

    Science.gov (United States)

    In this presentation we simulate saturated flow through macroporous soil columns (7.62x18 cm) with a lattice Boltzmann model and compare results with measured saturated hydraulic conductivities. Porous geometry was obtained with an industrial CT scanner yielding a resolution of 119 microns (656x656x...

  7. One-step preparation of macroporous polymer particles with multiple interconnected chambers: a candidate for trapping biomacromolecules.

    Science.gov (United States)

    Qian, Qiuping; Huang, Xiaopeng; Zhang, Xinyue; Xie, Zhigang; Wang, Yapei

    2013-09-27

    Taking advantage of photothermal conversion, the surface pores of water-dispersible single-walled carbon nanotubes assembled on polymer particles were rapidly closed by NIR irradiation to produce macroporous polymeric microspheres with multiple interconnected chambers. These particles can act as smart containers to encapsulate and hold DNA molecules.

  8. Conjunction of Conducting Polymer Nanostructures with Macroporous Structured Graphene Thin Films for High-Performance Flexible Supercapacitors.

    Science.gov (United States)

    Memon, Mushtaque A; Bai, Wei; Sun, Jinhua; Imran, Muhammad; Phulpoto, Shah Nawaz; Yan, Shouke; Huang, Yong; Geng, Jianxin

    2016-05-11

    Fabrication of hybridized structures is an effective strategy to promote the performances of graphene-based composites for energy storage/conversion applications. In this work, macroporous structured graphene thin films (MGTFs) are fabricated on various substrates including flexible graphene papers (GPs) through an ice-crystal-induced phase separation process. The MGTFs prepared on GPs (MGTF@GPs) are recognized with remarkable features such as interconnected macroporous configuration, sufficient exfoliation of the conductive RGO sheets, and good mechanical flexibility. As such, the flexible MGTF@GPs are demonstrated as a versatile conductive platform for depositing conducting polymers (CPs), e.g., polyaniline (PAn), polypyrrole, and polythiophene, through in situ electropolymerization. The contents of the CPs in the composite films are readily controlled by varying the electropolymerization time. Notably, electrodeposition of PAn leads to the formation of nanostructures of PAn nanofibers on the walls of the macroporous structured RGO framework (PAn@MGTF@GPs): thereafter, the PAn@MGTF@GPs display a unique structural feature that combine the nanostructures of PAn nanofibers and the macroporous structures of RGO sheets. Being used as binder-free electrodes for flexible supercapacitors, the PAn@MGTF@GPs exhibit excellent electrochemical performance, in particular a high areal specific capacity (538 mF cm(-2)), high cycling stability, and remarkable capacitive stability to deformation, due to the unique electrode structures.

  9. Meso-Molding Three-Dimensional Macroporous Perovskites: A New Approach to Generate High-Performance Nanohybrid Catalysts

    DEFF Research Database (Denmark)

    Arandiyan, Hamidreza; Scott, Jason; Wang, Yuan

    2016-01-01

    Newly designed 3D highly ordered macro/mesoporous multifunctional La1-xCexCoO3 nanohybrid frameworks with a 2D hexagonal mesostructure were fabricated via facile meso-molding in a three-dimensionally macroporous perovskite (MTMP) route. The nanohybrid framework exhibited excellent catalytic...

  10. Meso-macroporous Al2O3 supported Ru catalysts for CO preferential oxidation in hydrogen-rich gases

    Institute of Scientific and Technical Information of China (English)

    Limiao Shen; Cheng Zhang; Yuan Liu

    2012-01-01

    Series of meso-macroporous Al2O3 supported Ru catalysts with different loadings were prepared by incipient wetness method and applied to preferential oxidation of CO in hydrogen-rich gases.N2 adsorption-desorption,SEM,XRD,TEM,CO chemisorption and H2-TPR techniques were employed to characterize the catalysts.The results indicate that Ru/Al2O3 catalysts have meso-macroporous structure,high surface area and high metal dispersion.The characterization results of XRD and CO chemisorption indicate the entry of Ru ions into Al2O3 lattice.The results of catalytic performance tests indicate that the meso-macroporous Al2O3 supported Ru catalysts for CO preferential oxidation showed good activity under high space velocity.It is proposed that the macropores in the Ru/Al2O3 catalyst favor mass transfer and mesopores help to improve the dispersion of metal,resulting in the excellent catalytic performance.

  11. Facile synthesis of a Cu-based MOF confined in macroporous carbon hybrid material with enhanced electrocatalytic ability.

    Science.gov (United States)

    Zhang, Yufan; Bo, Xiangjie; Luhana, Charles; Wang, Huan; Li, Mian; Guo, Liping

    2013-08-07

    The Cu-based MOF loaded on macroporous carbon (MPC) creates novel Cu-MOF-MPC hybrids for the first time. The obtained Cu-MOF-MPC composites are used as electrocatalysts for the oxidation of NADH and reduction of H2O2 in neutral solution.

  12. Cm-scale Heterogeneity in Degradation - Potential Impact on Leaching of MCPA through a Variably-Saturated Macroporous Clayey Till

    DEFF Research Database (Denmark)

    Rosenbom, Annette Elisabeth; Johnsen, Anders R.; Aamand, Jens;

    both flow and degradation are associated with macropores/wormholes. Results show that cm-scale heterogeneity in degradation potential with simple matrix flow has a negligible effect on MCPA leaching at one meter below soil surface. By introducing a wormhole in the low-permeable 3D-soil modeling domain...

  13. [Dimensional accuracy of microwave-cured denture base resin].

    Science.gov (United States)

    Uchida, K; Okamoto, F; Ogata, K; Sato, T

    1989-02-01

    Recently, microwave-cured denture base resin was developed, and the resin solved the problem of internal porosity which had been generated by curing the conventional denture base resins with microwave irradiation. In this study, the dimensional accuracy of microwave-cured denture base resin was compared with that of other denture base resins, such as pour-type resin, heat-cured resin and heat-shock resin. From the experiment, the following results were obtained. 1. Dimensional accuracy of microwave-cured denture base resin was better than that of heat-cured resin and heat-shock resin, and was similar to that of pour-type resin. 2. Dimensional accuracy of microwave-cured denture base resin by slow cooling method and rapid cooling method was almost the same. Those findings suggest that microwave-cured denture base resin is valuable in clinic.

  14. Prediction of biopore- and matrix-dominated flow from X-ray CT-derived macropore network characteristics

    Science.gov (United States)

    Naveed, Muhammad; Moldrup, Per; Schaap, Marcel G.; Tuller, Markus; Kulkarni, Ramaprasad; Vogel, Hans-Jörg; Wollesen de Jonge, Lis

    2016-10-01

    Prediction and modeling of localized flow processes in macropores is of crucial importance for sustaining both soil and water quality. However, currently there are no reliable means to predict preferential flow due to its inherently large spatial variability. The aim of this study was to investigate the predictive performance of previously developed empirical models for both water and air flow and to explore the potential applicability of X-ray computed tomography (CT)-derived macropore network characteristics. For this purpose, 65 cylindrical soil columns (6 cm diameter and 3.5 cm height) were extracted from the topsoil (5 cm to 8.5 cm depth) in a 15 m × 15 m grid from an agricultural field located in Silstrup, Denmark. All soil columns were scanned with an industrial X-ray CT scanner (129 µm resolution) and later employed for measurement of saturated hydraulic conductivity, air permeability at -30 and -100 cm matric potential, and gas diffusivity at -30 and -100 cm matric potential. Distribution maps for saturated hydraulic conductivity, air permeability, and gas diffusivity reflected no autocorrelation irrespective of soil texture and organic matter content. Existing empirical predictive models for saturated hydraulic conductivity and air permeability showed poor performance, as they were not able to realistically capture macropore flow. The tested empirical model for gas diffusivity predicted measurements at -100 cm matric potential reasonably well, but failed at -30 cm matric potential, particularly for soil columns with biopore-dominated flow. X-ray CT-derived macroporosity matched the measured air-filled porosity at -30 cm matric potential well. Many of the CT-derived macropore network characteristics were strongly interrelated. Most of the macropore network characteristics were also significantly correlated with saturated hydraulic conductivity, air permeability, and gas diffusivity. The predictive Ahuja et al. (1984) model for saturated hydraulic

  15. Photoacoustic analysis of dental resin polymerization

    Science.gov (United States)

    Coloiano, E. C. R.; Rocha, R.; Martin, A. A.; da Silva, M. D.; Acosta-Avalos, D.; Barja, P. R.

    2005-06-01

    In this work, we use the photoacoustic technique to monitor the curing process of diverse dental materials, as the resins chemically activated (RCA). The results obtained reveal that the composition of a determined RCA significantly alters its activation kinetics. Photoacoustic data also show that temperature is a significant parameter in the activation kinetics of resins. The photoacoustic technique was also applied to evaluate the polymerization kinetics of photoactivated resins. Such resins are photoactivated by incidence of continuous light from a photodiode. This leads to the polymerization of the resin, modifying its thermal properties and, consequently, the level of the photoacoustic signal. Measurements show that the polymerization of the resin changes the photoacoustic signal amplitude, indicating that photoacoustic measurements can be utilized to monitor the polymerization kinetic and the degree of polymerization of photoactivated dental resins.

  16. Adsorption and Desorption of Praseodymium (Ⅲ) from Aqueous Solution Using D72 Resin%Adsorption and Desorption of Praseodymium (Ⅲ) from Aqueous Solution Using D72 Resin

    Institute of Scientific and Technical Information of China (English)

    熊春华; 朱京妃; 沈忱; 陈青

    2012-01-01

    In this work, the feasibility of using a macroporous strong acid ion exchange resin (D72) as an adsorbent for praseodymium (Ⅲ) was examined. The adsorption behavior and mechanism were investigated with various chemical methods and IR spectrometry. The results showed that the loading of Pr (III) ions was strongly dependent on pH of the medium and the optimal adsorption condition is in HAc-NaAc medium with pH value of 3.0. Adsorption kinetics of Pr (III) ions onto D72 resin could be best described by pseudo-second-order model. The maximum adsorption capacity of D72 for Pr (Ⅲ) was evaluated to be 294 mg·g 1 for the Langmuir model at 298K. The apparent activation energy, E a , was 14.71 kJ·mol 1 . The calculated data of thermodynamic parameters, ΔSΘ value of 100 J·mol 1 ·K 1 and ΔHΘ value of 8.89 kJ·mol 1 , indicate the endothermic nature of the adsorption process, while a decrease of ΔGΘ with increasing temperature indicates the spontaneous nature of the adsorption process. Finally, Pr (Ⅲ) can be eluted by using 1.00 mol·L 1 HCl-0.50 mol·L 1 NaCl solution and the D72 resin can be regenerated and reused. Thomas model was successfully applied to experimental data to predict the breakthrough curves and to determine the characteristic parameters of the column useful for process design. The characterization before and after adsorption of Pr (Ⅲ) ions on D72 resin was conformed by IR.

  17. Hydrothermal synthesis of 2D ordered macroporous ZnO films

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The ZnO films with two-dimensional ordered macroporous structure were successfully fabricated through hydrothermal crystal growth of ZnO on the ZnO substrate covered with a mouolayer of polystyrene (PS) spheres as template.The precursor solution of hydrothermal crystal growth of ZnO were prepared by equitramine (HMT).The confinement effect of the PS spheres template on the growth of ZnO nanorods and the influence of sodium citrate on the crystal growth of ZnO had been studied.The film surface morphology and the preferential growth of ZnO crystal were investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD),respectively.Also,the photoluminescence spectrum of ZnO films had been measured,and the corresponding mechanism was discussed.

  18. Noble metals binding on macroporous poly(GMA-co-EGDMA modified with ethylenediamine

    Directory of Open Access Journals (Sweden)

    ANTONIJE ONJIA

    2004-06-01

    Full Text Available Macroporous crosslinked poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate, p(GME, was synthesized by suspension copolymerization and modified by reaction of the pendant epoxy groups with ethylenediamine. The sorption rate and capacity of the modified copolymer, p(GME-en for Rh(III, Au(III and Pt(IV ions were determined in batch experiments under non-competitive conditions. The uptake of Rh(III was faster than those of Au(III and Pt(IV. The sorption capacity for Pt(IV was determined in the pH range 0.9–6.0. The maximum Pt(IV uptake capacity onto p(GME-en at pH 5.5 was 1.30 mmol/g.

  19. Pore-filling Three-dimensionally Ordered Macroporous Polyimide Composite Proton Conducting Membranes

    Institute of Scientific and Technical Information of China (English)

    DAI Xin; GENG Lei; LIU Dan; L(U) Chang-li; YANG Bai

    2011-01-01

    The silica opal templates were prepared from three silica colloids of different diameters of 230 nm,500nm and 1.5 μm by a filtration route.The large-scale stable opal template membranes after sintering the deposited SiO2 opal template can be successfully obtained by optimizing the pH value and NaCl concentration in silica colloidal solutions.The three-dimensionally ordered macroporous(3DOM) polyimide membranes without crack were fabricated by reproducing the structure of silica opal template.We prepared the pore-filling composite proton exchange membranes by filling the 3DOM structure with proton conducting organosilane sol.The result indicates that the composite membranes exhibit higher water uptake than pure filling organosilane gel.The proton conductivity increased with the increasing of pore cell in composite membranes.

  20. Preparation and Properties of Macroporous Silicon Nitride Ceramics by Gelcasting and Carbonthermal Reaction

    Institute of Scientific and Technical Information of China (English)

    Wen ZHANG; Hongjie WANG; Zhihao JIN

    2005-01-01

    Macroporous silicon nitride (Si3N4) ceramics with high strength, uniform structure and relatively high porosity were obtained by gelcasting and carbonthermal reaction in a two-step sintering technique. Microstructure and composition were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction(XRD). Open porosity, pore size distribution and basic mechanical performance were measured by Archimedes method,mercury intrusion porosimetry and three-point bending methods, respectively. SEM and TEM results revealed that pores were formed by elongated β-Si3N4. SADP measurement proved the formation of SiC particles. The SiC granules were beneficial for the formation of high ratio elongated β-Si3N4, and at proper amount, they also acted as reinforcement phase. Thermodynamic analysis indicated that the mechanisms of the reactions were mainly associated with liquid-solid reaction and gas-liquid reaction.

  1. Visual and reversible carbon dioxide sensing enabled by doctor blade coated macroporous photonic crystals.

    Science.gov (United States)

    Lin, Yi-Han; Suen, Shing-Yi; Yang, Hongta

    2017-11-15

    With significant impacts of carbon dioxide on global climate change, carbon dioxide sensing is of great importance. However, most of the existing sensing technologies are prone to interferences from carbon monoxide, or suffer from the use of sophisticated instruments. This research reports the development of reproducible carbon dioxide sensor using roll-to-roll compatible doctor blade coated three-dimensional macroporous photonic crystals. The pores are functionalized with amine groups to allow the reaction with carbon dioxide in the presence of humidity. The adsorption of carbon dioxide leads to red-shift and amplitude reduction of the optical stop bands, resulting in carbon dioxide detection with visible readout. The dependences of the diffraction wavelength on carbon dioxide partial pressure for various amine-functionalized photonic crystals and different humidities in the environment are systematically investigated. In addition, the reproducibility of carbon dioxide sensing has also been demonstrated in this research. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Risk predicting of macropore flow using pedotransfer functions, textural maps and modeling

    DEFF Research Database (Denmark)

    Iversen, Bo Vangsø; Børgesen, Christen Duus; Lægdsmand, Mette;

    2011-01-01

    using combinations of different soil physical parameters. The neural network was able to develop reasonably accurate PTFs predicting log[k(−1)], whereas the prediction of log(Ks) was less accurate. Using the distributed data of the hydraulic properties derived from the PTFs, outputs of water flow...... of this study were first to develop pedotransfer functions (PTFs) predicting near-saturated [k(−1)] and saturated (Ks) hydraulic conductivity using simple soil parameters as predictors and second to use this information and a newly developed rasterbased soil property map of Denmark to identify risk areas...... for macropore flow. The data set was based on hydraulic measurements on large, undisturbed soil columns from different localities in Denmark. Unsaturated [k(h)] and saturated hydraulic conductivity were measured in the laboratory; k(−1) representing the hydraulic conductivity of the soil matrix...

  3. Formation of photoluminescent n-type macroporous silicon: Effect of magnetic field and lateral electric potential

    Energy Technology Data Exchange (ETDEWEB)

    Antunez, E.E. [Centro de Investigación en Ingeniería y Ciencias Aplicadas, UAEM, Av. Universidad 1001, Col. Chamilpa, Cuernavaca, Morelos, CP 62210 (Mexico); Estevez, J.O. [Instituto de Física, B. Universidad Autónoma de Puebla, A.P. J-48, Puebla 72570 (Mexico); Campos, J. [Instituto de Energías Renovables, UNAM, Priv. Xochicalco S/N, Temixco, Morelos, CP 62580 (Mexico); Basurto-Pensado, M.A. [Centro de Investigación en Ingeniería y Ciencias Aplicadas, UAEM, Av. Universidad 1001, Col. Chamilpa, Cuernavaca, Morelos, CP 62210 (Mexico); Agarwal, V., E-mail: vagarwal@uaem.mx [Centro de Investigación en Ingeniería y Ciencias Aplicadas, UAEM, Av. Universidad 1001, Col. Chamilpa, Cuernavaca, Morelos, CP 62210 (Mexico)

    2014-11-15

    Metal electrode-free electrochemical etching of low doped n-type silicon substrates, under the combined effect of magnetic and lateral electric field, is used to fabricate photoluminescent n-type porous silicon structures in dark conditions. A lateral gradient in terms of structural characteristics (i.e. thickness and pore dimensions) along the electric field direction is formed. Enhancement of electric and magnetic field resulted in the increase of pore density and a change in the shape of the macropore structure, from circular to square morphology. Broad photoluminescence (PL) emission from 500 to 800 nm, with a PL peak wavelength ranging from 571 to 642 nm, is attributed to the wide range of microporous features present on the porous silicon layer.

  4. Effect of tillage on macropore flow and phosphorus transport to tile drains

    Science.gov (United States)

    Williams, Mark R.; King, Kevin W.; Ford, William; Buda, Anthony R.; Kennedy, Casey D.

    2016-04-01

    Elevated phosphorus (P) concentrations in subsurface drainage water are thought to be the result of P bypassing the soil matrix via macropore flow. The objectives of this study were to quantify event water delivery to tile drains via macropore flow paths during storm events and to determine the effect of tillage practices on event water and P delivery to tiles. Tile discharge, total dissolved P (DP) and total P (TP) concentrations, and stable oxygen and deuterium isotopic signatures were measured from two adjacent tile-drained fields in Ohio, USA during seven spring storms. Fertilizer was surface-applied to both fields and disk tillage was used to incorporate the fertilizer on one field while the other remained in no-till. Median DP concentration in tile discharge prior to fertilizer application was 0.08 mg L-1 in both fields. Following fertilizer application, median DP concentration was significantly greater in the no-tilled field (1.19 mg L-1) compared to the tilled field (0.66 mg L-1), with concentrations remaining significantly greater in the no-till field for the remainder of the monitored storms. Both DP and TP concentrations in the no-till field were significantly related to event water contributions to tile discharge, while only TP concentration was significantly related to event water in the tilled field. Event water accounted for between 26 and 69% of total tile discharge from both fields, but tillage substantially reduced maximum contributions of event water. Collectively, these results suggest that incorporating surface-applied fertilizers has the potential to substantially reduce the risk of P transport from tile-drained fields.

  5. A macroporous bioreactor super activated by the recombinant human transforming growth factor-beta 3

    Directory of Open Access Journals (Sweden)

    Ugo eRipamonti

    2012-06-01

    Full Text Available Macroporous single-phase hydroxyapatite (HA and biphasic HA/β-tricalcium phosphate with 33% post-sinter hydroxyapatite (HA/β-TCP were combined with 25 or 125 µg recombinant human transforming growth factor-β3 (hTGF-β3 to engineer a super activated bioreactor implanted in orthotopic calvarial and heterotopic rectus abdominis muscle sites and harvested on day 30 and 90. Coral-derived calcium carbonate fully converted (100% and partially converted to 5% and 13% hydroxyapatite/calcium carbonate (HA/CC preloaded with 125 and 250 µg hTGF-β3, and 1:5 and 5:1 binary applications of hTGF-β3: hOP-1 by weight, were implanted in the rectus abdominis and harvested on day 20 and 30, respectively, to monitor spatial/temporal morphogenesis by high doses of hTGF-β3. Bone formation was assessed on decalcified paraffin-embedded sections by measuring the fractional volume of newly-formed bone. On day 30 and 90, single phase HA implants showed greater amounts of bone when compared to biphasic specimens; 5 % and 13 % HA/CC pre-loaded with 125 and 250 µg hTGF-β3 showed substantial induction of bone formation; 250 µg hTGF-β3 induced as yet unreported massive induction of bone formation as early as 20 days prominently outside the profile of the macroporous constructs. The induction of bone formation is controlled by the implanted ratio of the recombinant morphogens, i.e. the 1:5 hTGF-β3:hOP-1 ratio by weight was greater than the inverse ratio. The unprecedented tissue induction by single doses of 250 µg hTGF-β3 resulting in rapid bone morphogenesis of vast mineralized ossicles with multiple trabeculations surfaced by contiguous secreting osteoblasts is the novel molecular and morphological frontier for the induction of bone formation in clinical contexts.

  6. Delta-sleep inducing peptide entrapment in the charged macroporous matrices

    Energy Technology Data Exchange (ETDEWEB)

    Sukhanova, Tatiana V., E-mail: sukhanovat@mail.ru [Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Laboratory of Cell Interactions, Miklukho-Maklaya st., 16/10 Moscow (Russian Federation); Artyukhov, Alexander A.; Gurevich, Yakov M.; Semenikhina, Marina A. [Mendeleyev University of Chemical Technology of Russia, Research and Teaching Center “Biomaterials”, Miusskaya sq., 9 Moscow (Russian Federation); Prudchenko, Igor A. [Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Laboratory of Peptide Chemistry, Miklukho-Maklaya st., 16/10 Moscow (Russian Federation); Shtilman, Mikhail I. [Mendeleyev University of Chemical Technology of Russia, Research and Teaching Center “Biomaterials”, Miusskaya sq., 9 Moscow (Russian Federation); Markvicheva, Elena A. [Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Laboratory Polymers for Biology, Miklukho-Maklaya st., 16/10 Moscow (Russian Federation)

    2014-09-01

    Various biomolecules, for example proteins, peptides etc., entrapped in polymer matrices, impact interactions between matrix and cells, including stimulation of cell adhesion and proliferation. Delta-sleep inducing peptide (DSIP) possesses numerous beneficial properties, including its abilities in burn treatment and neuronal protection. DSIP entrapment in two macroporous polymer matrices based on copolymer of dimethylaminoethyl methacrylate and methylen-bis-acrylamide (Co-DMAEMA-MBAA) and copolymer of acrylic acid and methylen-bis-acrylamide (Co-AA-MBAA) has been studied. Quite 100% of DSIP has been entrapped into positively charged Co-DMAEMA-MBAA matrix, while the quantity of DSIP adsorbed on negatively charged Co-AA-MBAA was only 2–6%. DSIP release from Co-DMAEMA-MBAA was observed in saline solutions (0.9% NaCl and PBS) while there was no DSIP release in water or 25% ethanol, thus ionic strength was a reason of this process. - Graphical abstract: Delta-sleep inducing peptide possessing neuroprotective and wound healing properties was adsorbed on positively charged polymer matrix Co-DMAEMA-MBAA for tissue engineering. The peptide released from Co-DMAEMA-MBAA matrix in function of ionic strength of solution, pH decreasing stimulated peptide release from Co-DMAEMA-MBAA matrix for 3 h. This construction could be a base of new bioactive implants. - Highlights: • Macroporous positively charged Co-DMAEMA-MBAA matrix pore size was 20–35 μm. • DSIP was adsorbed on Co-DMAEMA-MBAA totally in 16 h. • Its release depends on ionic strength of solution (no release in 25% ethanol or water). • Co-DMAEMA-MBAA matrix swelling depends on pH and ionic strength of solution. • DSIP is destroyed in PBS and 0.9% NaCl in 5 days, but in water it was more stable.

  7. NMR imaging of fluid exchange between macropores and matrix in eogenetic karst

    Science.gov (United States)

    Florea, L.J.; Cunningham, K.J.; Altobelli, S.

    2009-01-01

    Sequential time-step images acquired using nuclear magnetic resonance (NMR) show the displacement of deuterated water (D2O) by fresh water within two limestone samples characterized by a porous and permeable limestone matrix of peloids and ooids. These samples were selected because they have a macropore system representative of some parts of the eogenetic karst limestone of the Biscayne Aquifer in southeastern Florida. The macroporosity, created by the trace fossil Ophiomorpha, is principally well connected and of centimeter scale. These macropores occur in broadly continuous stratiform zones that create preferential flow layers within the hydrogeologic units of the Biscayne. This arrangement of porosity is important because in coastal areas, it could produce a preferential pathway for salt water intrusion. Two experiments were conducted in which samples saturated with D2O were placed in acrylic chambers filled with fresh water and examined with NMR. Results reveal a substantial flux of fresh water into the matrix porosity with a simultaneous loss of D 2O. Specifically, we measured rates upward of 0.001 mL/h/g of sample in static conditions, and perhaps as great as 0.07 mL/h/g of sample when fresh water continuously flows past a sample at velocities less than those found within stressed areas of the Biscayne. These experiments illustrate how fresh water and D2O, with different chemical properties, migrate within one type of matrix porosity found in the Biscayne. Furthermore, these experiments are a comparative exercise in the displacement of sea water by fresh water in the matrix of a coastal, karst aquifer since D2O has a greater density than fresh water. ?? 2008 National Ground Water Association.

  8. Hierarchically oriented macroporous anode-supported solid oxide fuel cell with thin ceria electrolyte film.

    Science.gov (United States)

    Chen, Yu; Zhang, Yanxiang; Baker, Jeffrey; Majumdar, Prasun; Yang, Zhibin; Han, Minfang; Chen, Fanglin

    2014-04-09

    Application of anode-supported solid oxide fuel cell (SOFC) with ceria based electrolyte has often been limited by high cost of electrolyte film fabrication and high electrode polarization. In this study, dense Gd0.1Ce0.9O2 (GDC) thin film electrolytes have been fabricated on hierarchically oriented macroporous NiO-GDC anodes by a combination of freeze-drying tape-casting of the NiO-GDC anode, drop-coating GDC slurry on NiO-GDC anode, and co-firing the electrolyte/anode bilayers. Using 3D X-ray microscopy and subsequent analysis, it has been determined that the NiO-GDC anode substrates have a porosity of around 42% and channel size from around 10 μm at the electrolyte side to around 20 μm at the other side of the NiO-GDC (away from the electrolyte), indicating a hierarchically oriented macroporous NiO-GDC microstructure. Such NiO-GDC microstructure shows a tortuosity factor of ∼1.3 along the thickness direction, expecting to facilitate gas diffusion in the anode during fuel cell operation. SOFCs with such Ni-GDC anode, GDC film (30 μm) electrolyte, and La0.6Sr0.4Co0.2Fe0.8O3-GDC (LSCF-GDC) cathode show significantly enhanced cell power output of 1.021 W cm(-2) at 600 °C using H2 as fuel and ambient air as oxidant. Electrochemical Impedance Spectroscopy (EIS) analysis indicates a decrease in both activation and concentration polarizations. This study has demonstrated that freeze-drying tape-casting is a very promising approach to fabricate hierarchically oriented porous substrate for SOFC and other applications.

  9. Rhombohedral iron trifluoride with a hierarchized macroporous/mesoporous texture from gaseous fluorination of iron disilicide

    Energy Technology Data Exchange (ETDEWEB)

    Guérin, Katia, E-mail: katia.araujo_da_silva@univ-bpclermont.fr [Université Clermont Auvergne, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, BP 10448, F-63000 Clermont-Ferrand (France); CNRS, UMR 6296, ICCF, F-63171 Aubière (France); Delbègue, Diane; Louvain, Nicolas; Doubtsof, Léa; Hamwi, André [Université Clermont Auvergne, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, BP 10448, F-63000 Clermont-Ferrand (France); CNRS, UMR 6296, ICCF, F-63171 Aubière (France); Laik, Barbara; Pereira-Ramos, Jean-Pierre [Université Paris Est Créteil, Institut de Chimie et des Matériaux Paris-Est, UMR CNRS 7182, Thiais (France); Tahar-sougrati, Moulay; Jumas, Jean-Claude [Université Montpellier II, Institut Charles Gerhardt de Montpellier, UMR CNRS 5253, Montpellier (France); Willmann, Patrick; Cénac-Morthe, Céline [Centre National d' Etudes Spatiales, Toulouse (France)

    2016-04-15

    Stable low temperature rhombohedral iron trifluoride has been obtained by the fluorination under the pure fluorine gas of iron disilicide. The combination of both unusual fluorination process and precursor avoids to get unhydrated crystalline FeF{sub 3} particles and allows the formation of hierarchized channels of mesoporous/macroporous texture favorable for lithium diffusion. The fluorination mechanism proceeds by temperature steps from the formation, for a fluorination temperature below 200 °C, of an amorphous phase and an intermediate iron difluoride identified mainly by {sup 57}Fe Mössbauer spectroscopy before getting, as soon as a fluorination temperature of 260 °C is reached, the rhombohedral FeF{sub 3}. Both amorphous and crystallized samples display good ability for electrochemical process when used as cathode in lithium-ion battery. The low diameter of rhombohedral structure channels is balanced by an appropriate mesoporous texture and a capacity of 225 mAh.g{sup −1} after 5 cycles for a discharge cut-off of 2.5 V vs. Li{sup +}/Li at a current density of C/20 has been obtained and stabilized at 95 mAh.g{sup −1} after 116 cycles. - Highlights: • We investigated the synthesis of rhombohedral FeF{sub 3} by solid–gas reaction from iron disilicide. • We demonstrated that depending on the fluorination temperature various phases are stabilized. • We got a hierarchized macroporous/mesoporous texture. • We studied the electrochemical performances of amorphous and crystallized FeF{sub 3}. • Crystallized FeF{sub 3} presents a high faradic yield at first cycle focusing on insertion process.

  10. Surface functionalization of macroporous polymeric materials by treatment with air low temperature plasma.

    Science.gov (United States)

    Molina, R; Sole, I; Vílchez, A; Bertran, E; Solans, C; Esquena, J

    2013-04-01

    Polystyrene/divinylbenzene (PS-DVB) macroporous monoliths obtained using highly concentrated emulsions as templates show a superhydrophobic behaviour, restricting their potential technological applications, especially those related to adhesion and wetting. Air plasma treatments were carried out in order to modulate wetting properties, modifying the surface chemical composition of macroporous polystyrene/divinylbenzene materials. The superhydrophobic behaviour was rapidly suppressed by air plasma treatment, greatly reducing the water contact angle, from approximately 150 degrees to approximately 90 degrees, in only 10 seconds of treatment. The new surface chemical groups, promoted by plasma active species, were characterized by surface analysis techniques with different depth penetration specificity (contact angle, XPS, FTIR and SEM). Results demonstrated that very short treatment times produced different chemical functionalities, mainly C-O, C=O, O-C=O and C-N, which provide the materials with predominantly acidic surface properties. However, plasma active species did not penetrate deeply through the interconnected pores of the material. FTIR analysis evidenced that the new hydrophilic surface groups promoted by plasma active species are in a negligibly concentration compared to bulk chemical groups, and are located in a very thin surface region on the PS-DVB monolith surface (significantly below 2 microm). XPS analysis of treated monoliths revealed a progressive increase of oxygen and nitrogen content as a function of plasma treatment time. However, oxidation of the PS-DVB monoliths surface prevails over the incorporation of nitrogen atoms. Finally, SEM studies indicated that the morphology of the plasma treated PS-DVB does not significantly change even for the longest air plasma treatment time studied (120 s).

  11. Silicon microtubes made by immersing macroporous silicon into ammonium fluoride solution

    Energy Technology Data Exchange (ETDEWEB)

    Huanca, Danilo Roque, E-mail: droqueh@usp.br [Laboratorio de sensores e Dispositivos do Instituto de Física e Química da Universidade Federal de Itajubá, Avenida BPS, 1303, CEP 37500 903 Itajubá, MG (Brazil); Laboratório de Microeletrônica da Escola Politécnica da USP, Avenida Prof. Luciano Gualberto, travessa 3 n° 380, CEP 05508-900 São Paulo, SP (Brazil); Kim, Hae Yong [Laboratório de Processamento de Sinais da Escola Politécnica da USP, Avenida Prof. Luciano Gualberto, travessa 3 n° 380, CEP 05508-900 São Paulo, SP (Brazil); Salcedo, Walter Jaimes [Laboratório de Microeletrônica da Escola Politécnica da USP, Avenida Prof. Luciano Gualberto, travessa 3 n° 380, CEP 05508-900 São Paulo, SP (Brazil)

    2015-06-15

    In this paper, we report the fabrication of silicon microtubes (SMT) by electrochemical dissolution of macroporous silicon layers immersed into aqueous solution of NH{sub 4}F mixed with Na{sub 2}SO{sub 4}, at different pH levels (4.5–9.5). Well-defined SMT have been obtained at pH 6.5, 7.5 and 9.5, whereas for other pH levels, the surface of the porous structure becomes passivated or formation of needle-like structure occurs. The mean inner diameter and the thickness of walls of the tubes shown to be depended on the pH level of the solutions. In this investigation, we obtained silicon tubes with inner diameter from 0.2 to 2.0 μm with thickness wall from about 0.23 to 0.50 μm. The investigation of these structures indicates that for tube formation the pH level and predominance of the anisotropic dissolution are necessary conditions. The tube formation cannot be explained regarding the silicon dissolution mechanism. For this aim, the role of the space charge region must be regarded. The structural characterization of silicon tubes was achieved by X-ray diffraction (XRD), X-ray energy dispersive Spectroscopy (EDS) and Raman spectroscopy and the results pointed out that these tubes are constituted by crystalline silicon structures covered by a very thin silicon oxide film. In this paper, the formation mechanism of the SMT is also discussed, highlighting the role of the space charge region (SCR) and the pH level for tube formation. - Highlights: • We fabricate silicon microtubes using macroporous silicon as a starting material. • Depending on the pH level, well-defined tubes are formed or the surface is passivate. • It was identified that the key factors for tube formation are the pH level and the space charge region.

  12. Fate and transport of selected estrogen compounds in Hawaii soils: Effect of soil type and macropores

    Science.gov (United States)

    D'Alessio, Matteo; Vasudevan, Dharni; Lichwa, Joseph; Mohanty, Sanjay K.; Ray, Chittaranjan

    2014-10-01

    The fate and transport of estrogen compounds in the environment is of increasing concern due to their potential impact on freshwater organisms, ecosystems and human health. The behavior of these compounds in batch experiments suggests low mobility, while field studies indicate the persistence of estrogen compounds in the soil with the possibility of migration to surface water as well as groundwater. To better understand the movement of these chemicals through soils, we examined their transport in three different Hawaiian soils and two aqueous matrices. The three different soils used were an Oxisol, a Mollisol and a cinder, characterized by different mineralogical properties and collected at depths of 60-90 cm and 210-240 cm. Two liquid matrices were used; deionized (DI) water containing calcium chloride (CaCl2), and recycled water collected from a wastewater treatment facility. The experiments were conducted in packed and structured columns. Non-equilibrium conditions were observed during the study, especially in the structured soil. This is believed to be primarily related to the presence of macropores in the soil. The presence of macropores resulted in reduced contact time between soil and estrogens, which facilitated their transport. We found that the organic carbon content and mineralogical composition of the soils had a profound effect on the transport of the estrogens. The mobility of estrone (E1) and 17β-estradiol (E2) was greater in cinder than in the other soils. In column experiments with recycled water, earlier breakthrough peaks and longer tails of estrogens were produced compared to those observed using DI water. The use of recycled water for agricultural purposes and the siting of septic tanks and cesspools should be critically reviewed in light of these findings, especially in areas where groundwater is the primary source of potable water, such as Hawaii.

  13. Fate and transport of selected estrogen compounds in Hawaii soils: effect of soil type and macropores.

    Science.gov (United States)

    D'Alessio, Matteo; Vasudevan, Dharni; Lichwa, Joseph; Mohanty, Sanjay K; Ray, Chittaranjan

    2014-10-01

    The fate and transport of estrogen compounds in the environment is of increasing concern due to their potential impact on freshwater organisms, ecosystems and human health. The behavior of these compounds in batch experiments suggests low mobility, while field studies indicate the persistence of estrogen compounds in the soil with the possibility of migration to surface water as well as groundwater. To better understand the movement of these chemicals through soils, we examined their transport in three different Hawaiian soils and two aqueous matrices. The three different soils used were an Oxisol, a Mollisol and a cinder, characterized by different mineralogical properties and collected at depths of 60-90 cm and 210-240 cm. Two liquid matrices were used; deionized (DI) water containing calcium chloride (CaCl2), and recycled water collected from a wastewater treatment facility. The experiments were conducted in packed and structured columns. Non-equilibrium conditions were observed during the study, especially in the structured soil. This is believed to be primarily related to the presence of macropores in the soil. The presence of macropores resulted in reduced contact time between soil and estrogens, which facilitated their transport. We found that the organic carbon content and mineralogical composition of the soils had a profound effect on the transport of the estrogens. The mobility of estrone (E1) and 17β-estradiol (E2) was greater in cinder than in the other soils. In column experiments with recycled water, earlier breakthrough peaks and longer tails of estrogens were produced compared to those observed using DI water. The use of recycled water for agricultural purposes and the siting of septic tanks and cesspools should be critically reviewed in light of these findings, especially in areas where groundwater is the primary source of potable water, such as Hawaii.

  14. Color difference of composite resins after cementation with different shades of resin luting cement.

    Science.gov (United States)

    Cengiz, Esra; Kurtulmus-Yilmaz, Sevcan; Karakaya, Izgen; Aktore, Huseyin

    2017-07-26

    The purpose of this study was to evaluate the color difference of nanohybrid and ormocer-based composite resins with different thicknesses when 4 different shades of resin luting cement were used. 56 disc specimens of each composite resin (Aelite aesthetic enamel, Ceram-X mono) with 0.5 and 1 mm thicknesses were fabricated. Baseline color measurements were performed using a clinical spectrophotometer. The specimens of each thicknesses of each resin were randomly divided into 4 groups according to the shades of resin luting cement (white/A1, yellow/universal/A3, transparent and white opaque) (n = 7). Mixed resin cement was applied onto the resin specimens using a Teflon mold in 0.1 mm thickness. Color measurements of cemented composite resin specimens were repeated and color difference (∆E) between baseline and after cementation measurements was calculated. ANOVA and Tukey's test were used for statistical analysis. The opaque shade had significantly increased ∆E values as compared to the other shades (p resins in terms of ∆E values. The shade of resin cement and the type of the resin affected the final color; however, the thickness of composite resin had no influence on the final color of restoration. Selecting the shade of resin luting cement before cementation of indirect composite laminate restoration is important to achieve final color match.

  15. TREATMENT AND RESOURCE REUSE OF 1,2,4-ACID PRODUCING EFFLUENT WITH MACROPOROUS POLYMERIC ADSORBENT

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The treatment and resource reuse of 1,2,4-acid producing wastewater by self-mademacroporous adsorption resin ND,A-107 was studied in this paper. Optimum adsorption anddesorption process parameters were acquired by systematically study. The polymeric resin NDA-10 7indicated good adsorption & desorption of 1,2, 4-acid in the wastewater. The removal efficiency of1,2,4-acid, CODer is about 78%, 72% respectively. It is evident that this adsorption process is anefficient treatment method for 1,2,4-acid producing wastewater. At the same time, the accumulationand resource reuse of l,2, 4-acid can be realized in this process.

  16. Resin Diterpenes from Austrocedrus chilensis

    Directory of Open Access Journals (Sweden)

    Verónica Rachel Olate

    2011-12-01

    Full Text Available Seventeen diterpenes belonging to the labdane, abietane and isopimarane skeleton classes were isolated from the resin of the Chilean gymnosperm Austrocedrus chilensis and identified by spectroscopic and spectrometric methods. The diterpene 12-oxo-labda-8(17,13E-dien-19 oic acid is reported for the first time as a natural product and 14 diterpenes are reported for the first time for the species.

  17. High-throughput sequential injection method for simultaneous determination of plutonium and neptunium in environmental solids using macroporous anion-exchange chromatography, followed by inductively coupled plasma mass spectrometric detection.

    Science.gov (United States)

    Qiao, Jixin; Hou, Xiaolin; Roos, Per; Miró, Manuel

    2011-01-01

    This paper reports an automated analytical method for rapid and simultaneous determination of plutonium and neptunium in soil, sediment, and seaweed, with detection via inductively coupled plasma mass spectrometry (ICP-MS). A chromatographic column packed with a macroporous anion exchanger (AG MP-1 M) was incorporated in a sequential injection (SI) system for the efficient retrieval of plutonium, along with neptunium, from matrix elements and potential interfering nuclides. The sorption and elution behavior of plutonium and neptunium onto AG MP-1 M resin was compared with a commonly utilized AG 1-gel-type anion exchanger. Experimental results reveal that the pore structure of the anion exchanger plays a pivotal role in ensuring similar separation behavior of plutonium and neptunium along the separation protocol. It is proven that plutonium-242 ((242)Pu) performs well as a tracer for monitoring the chemical yield of neptunium when using AG MP-1 M resin, whereby the difficulties in obtaining a reliable and practicable isotopic neptunium tracer are overcome. An important asset of the SI setup is the feasibility of processing up to 100 g of solid substrates using a small-sized (ca. 2 mL) column with chemical yields of neptunium and plutonium being ≥79%. Analytical results of three certified/standard reference materials and two solid samples from intercomparison exercises are in good agreement with the reference values at the 0.05 significance level. The overall on-column separation can be completed within 3.5 h for 10 g of soil samples. Most importantly, the anion-exchange mini-column suffices to be reused up to 10-fold with satisfactory chemical yields (>70%), as demanded in environmental monitoring and emergency scenarios, making the proposed automated assembly well-suited for unattended and high-throughput analysis.

  18. Adhesion Analysis of Resin/Resin Interface by Molecular Dynamics Simulation

    National Research Council Canada - National Science Library

    MIYAZAKI, Mariko; KANEGAE, Yoshiharu; IWASAKI, Tomio

    2012-01-01

    .... In this paper, a technique for using a molecular dynamics simulation to analyze the adhesion of the interface between adhesive and polyimide, that is the resin/resin interface, has been proposed...

  19. Wannier-Stark electro-optical effect, quasi-guided and photonic modes in 2D macroporous silicon structures with SiO2 coatings

    Science.gov (United States)

    Karachevtseva, L.; Goltviansky, Yu.; Sapelnikova, O.; Lytvynenko, O.; Stronska, O.; Bo, Wang; Kartel, M.

    2016-12-01

    Opportunities to enhance the properties of structured surfaces were demonstrated on 2D macroporous silicon structures with SiO2 coatings. We investigated the IR light absorption oscillations in macroporous silicon structures with SiO2 coatings 0-800 nm thick. The Wannier-Stark electro-optical effect due to strong electric field on Si-SiO2boundary and an additional electric field of quasi-guided optical modes were taken into account. The photonic modes and band gaps were also considered as peculiarities in absorbance spectra of macroporous silicon structures with a thick SiO2 coating. The photonic modes do not coincide with the quasi-guided modes in the silicon matrix and do not appear in absorption spectra of 2D macroporous silicon structures with surface nanocrystals.

  20. Scintillating 99Tc Selective Ion Exchange Resins

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell Greenhalgh; Richard D. Tillotson

    2012-07-01

    Scintillating technetium (99Tc) selective ion exchange resins have been developed and evaluated for equilibrium capacities and detection efficiencies. These resins can be utilized for the in-situ concentration and detection of low levels of pertechnetate anions (99TcO4-) in natural waters. Three different polystyrene type resin support materials were impregnated with varying amounts of tricaprylmethylammonium chloride (Aliquat 336) extractant, several different scintillating fluors and wavelength shifters. The prepared resins were contacted batch-wise to equilibrium over a wide range of 99TcO4- concentrations in natural water. The measured capacities were used to develop Langmuir adsorption isotherms for each resin. 99Tc detection efficiencies were determined and up to 71.4 ± 2.6% was achieved with some resins. The results demonstrate that a low level detection limit for 99TcO4- in natural waters can be realized.

  1. Gold Loading on Ion Exchange Resins in Non-Ammoniacal Resin-Solution Systems

    OpenAIRE

    Abrar Muslim

    2010-01-01

    The loading of gold using strong base anion exchange resin in non-ammoniac resin-solution (NARS) systems has been studied. The loading of gold onto ion exchange resins is affected by polythionate concentration, and trithionate can be used as the baseline in the system. The results also show that resin capacity on gold loading increases due to the increase in the equilibrium thiosulfate concentration in the NARS system. Gold loading performances show the need of optimization the equilibrium co...

  2. Release and toxicity of dental resin composite

    OpenAIRE

    Saurabh K Gupta; Saxena, Payal; Pant, Vandana A.; Pant, Aditya B.

    2012-01-01

    Dental resin composite that are tooth-colored materials have been considered as possible substitutes to mercury-containing silver amalgam filling. Despite the fact that dental resin composites have improved their physico-chemical properties, the concern for its intrinsic toxicity remains high. Some components of restorative composite resins are released in the oral environment initially during polymerization reaction and later due to degradation of the material. In vitro and in vivo studies h...

  3. Color stability of different composite resin materials.

    Science.gov (United States)

    Falkensammer, Frank; Arnetzl, Gerwin Vincent; Wildburger, Angelika; Freudenthaler, Josef

    2013-06-01

    Data are needed to better predict the color stability of current composite resin materials. The purpose of this study was to evaluate the impact of different storage solutions on the color stability of different composite resin materials. Different restorative and adhesive composite resin specimens (dual-polymerizing self-adhesive resin cement, autopolymerizing resin-based composite resin, dual-polymerizing resin-based composite resin, nanohybrid composite resin, and microhybrid composite resin) were fabricated and stored in red wine, black tea, chlorhexidine, sodium fluoride, tea tree oil, or distilled water for 4 weeks at 37°C. Color parameters were measured with a colorimeter before and after storage. Total color differences and specific coordinate differences were expressed as ΔE, ΔL, Δa, and Δb. A 2-way and 1-way analysis of variance (ANOVA) with Bonferroni adjustment for multiple comparisons were applied for statistical calculations (α=.05). Red wine caused the most severe discoloration (ΔE >10), followed by black tea with perceptible (ΔE >2.6) to clinically unacceptable discoloration (ΔE >5.5). Colored mouth rinses discolored the materials to a lesser extent with clinically acceptable values. Dual-polymerizing resin adhesives showed a higher amount of discoloration. Current restorative and adhesive composite resin materials discolor over time under the influence of different storage solutions. The composition related to the polymerizing mode seemed to be a causative factor. Copyright © 2013 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

  4. Relative Molecular Mass Distribution of BG Resins

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Benzoguanamine-formaldehyde (BG-F) resins are a class of amino resins, which are important cross-linking agents for epoxy, alkyol and acrylic resins, etc. The cross-linking performance is the best one when the polymerization degree is 2-4. This paper discusses the effects of the pH value for polycondensation and the formaldehyde to benzoguanamine mole ratio in a methanol system, and compares the relative molecular mass distribution using the Flory statistics method.

  5. Epoxy Resins Modified with Vegetable Oils

    Institute of Scientific and Technical Information of China (English)

    P.Czub

    2007-01-01

    1 Results The application of modified natural oils, nontoxic, biodegradable and renewable materials, for the modification and the synthesis of epoxy resins were presented. Firstly, the application of epoxidized vegetable oils (soybean, rapeseed, linseed and sunflower):as reactive diluents for epoxy resins was proposed and studied[1-2]. Viscosity reducing ability of epoxidized oils was tested in the compositions with Bisphenol A based low-molecular-weight epoxy resins. The rheological behaviour of the mi...

  6. Damping Properties of Flexible Epoxy Resin

    Institute of Scientific and Technical Information of China (English)

    WANG Xiang; LIU Hanxing; OUYANG Shixi

    2008-01-01

    Amino-terminated polyethers and amino-terminated polyurethane were used as curing agent to cure the epoxy resin together and get a series of cured products. The damping properties of the composites were studied by DMA test at different measurement frequencies. Damping mechanical tests show that the flexible epoxy resin has higher loss factor than common epoxy. The highest loss factor reaches 1.57. Also the height and position of loss factor peak of the flexible epoxy resin varies by changing the content of amino-terminated polyethers. Results shows that the flexible epoxy resin can be used as damping polymer materials at room temperature or in common frequency range.

  7. Resin composites in minimally invasive dentistry.

    Science.gov (United States)

    Jacobsen, Thomas

    2004-01-01

    The concept of minimally invasive dentistry will provide favorable conditions for the use of composite resin. However, a number of factors must be considered when placing composite resins in conservatively prepared cavities, including: aspects on the adaptation of the composite resin to the cavity walls; the use of adhesives; and techniques for obtaining adequate proximal contacts. The clinician must also adopt an equally conservative approach when treating failed restorations. The quality of the composite resin restoration will not only be affected by the outline form of the preparation but also by the clinician's technique and understanding of the materials.

  8. Advanced resin systems for graphite epoxy composites

    Science.gov (United States)

    Gilwee, W. J.; Jayarajan, A.

    1980-01-01

    The value of resin/carbon fiber composites as lightweight structures for aircraft and other vehicle applications is dependent on many properties: environmental stability, strength, toughness, resistance to burning, smoke produced when burning, raw material costs, and complexity of processing. A number of woven carbon fiber and epoxy resin composites were made. The epoxy resin was commercially available tetraglycidylmethylene dianiline. In addition, composites were made using epoxy resin modified with amine and carboxyl terminated butadiene acrylonitrile copolymer. Strength and toughness in flexure as well as oxygen index flammability and NBS smoke chamber tests of the composites are reported.

  9. Novel silica-based ion exchange resin

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-11-01

    Eichrom`s highly successful Diphonixo resin resembles a conventional ion exchange resin in its use of sulfonic acid ligands on a styrene- divinylbenzene matrix. Diphonix resin exhibits rapid exchange kinetics that allow economical operation of ion exchange systems. Unlike conventional resins, Diphonix resin contains chelating ligands that are diphosphonic acid groups that recognize and remove the targeted metals and reject the more common elements such as sodium, calcium and magnesium. This latter property makes Diphonix ideal for many industrial scale applications, including those involving waste treatment. For treatment of low-level, transuranic (TRU) and high- level radioactive wastes, Diphonix`s polystyrene backbone hinders its application due to radiolytic stability of the carbon-hydrogen bonds and lack of compatibility with expected vitrification schemes. Polystyrene-based Diphonix is approximately 60% carbon- hydrogen. In response to an identified need within the Department of Energy for a resin with the positive attributes of Diphonix that also exhibits greater radiolytic stability and final waste form compatibility, Eichrom has successfully developed a new, silica-based resin version of Diphonix. Target application for this new resin is for use in environmental restoration and waste management situations involving the processing of low-level, transuranic and high-level radioactive wastes. The resin can also be used for processing liquid mixed waste (waste that contains low level radioactivity and hazardous constituents) including mixed wastes contaminated with organic compounds. Silica-based Diphonix is only 10% carbon-hydrogen, with the bulk of the matrix silica.

  10. Curing Mechanism of Condensed Polynuclear Aromatic Resin and Thermal Stability of Cured Resin

    Institute of Scientific and Technical Information of China (English)

    Li Shibin; Sun Qiqian; Wang Yuwei; Wu Mingbo; Zhang Zailong

    2015-01-01

    In order to improve the thermal stability of condensed polynuclear aromatic (COPNA) resin synthesized from vacuum residue, 1,4-benzenedimethanol was added to cure COPNA resin. The curing mechanism was investigated by pro-ton nuclear magnetic resonance spectrometry, solid carbon-13 nuclear magnetic resonance spectrometry and Fourier trans-form infrared spectroscopy. Microstructures of the uncured and the cured COPNA resins were studied by scanning electron microscopy and X-ray diffractometry. The thermal stability of COPNA resins before and after curing was tested by thermo-gravimetric analysis. The element composition of the cured COPNA resin heated at different temperatures was analyzed by an element analyzer. The results showed that the uncured COPNA resin reacted with the cross-linking agent during the cur-ing process, and the curing mechanism was conifrmed to be the electrophilic substitution reaction. Compared with the un-cured COPNA resin, the cured COPNA resin had a smooth surface, well-ordered and streamlined sheet structure with more crystalline solids, better molecular arrangement and orientation. The weight loss process of the uncured and cured COPNA resins was divided into three stages. Carbon residue of the cured COPNA resin was 41.65%at 600℃, which was much higher than 25.02%of the uncured COPNA resin, which indicated that the cured COPNA resin had higher thermal stability.

  11. Effects of CT Number-Derived Matrix Density on Preferential Flow and Transport in Macroporous Agricultural Soil

    DEFF Research Database (Denmark)

    Katuwal, Sheela; Møldrup, Per; Lamande, Mathieu André Maurice;

    2015-01-01

    permeability, saturated hydraulic conductivity, and solute transport. This was due to the limited CT scan resolution and large structural variability below this resolution. However, CTmatrix, a new parameter derived from the CT number of the matrix excluding stones and large mostly air-filled macropores...... risks to public health. This study focused on establishing links between the structural pore space and preferential transport using a combination of standard physical measurement methods for air and water permeabilities, breakthrough experiments, and X-ray computed tomography (CT) on large soil columns....... Substantial structural heterogeneity that resulted in significant variations in flow and tracer transport was observed, despite the textural similarity of the investigated samples. Quantification of macropore characteristics with X-ray CT was useful but not sufficient to explain the variability in air...

  12. Perspectives of treatment of anemias with cells of fetal liver, immobilized in macroporous alginate-gelatin carriers

    Directory of Open Access Journals (Sweden)

    Gritsay D.V.

    2014-06-01

    Full Text Available Aim of the work was to study possibility of erythropoiesis stimulation by transplantation of fetal liver cells, seeded into macro¬porous carriers to the rats with post-hemorrhargic anemia, induced by 70% hepatectomy. Fetal liver cells (FLC were isolated from fetuses of rats with 15 days’ gestation and were cryopreserved. Decryopreserved FLC were seeded into macroporous spongy alginate-gelatin scaffolds, which were covered by alginate capsule and implanted into omentum of rats with modeled liver insufficiency. It was shown that fetal liver cells, immobilized in macroporous scaffolds after implantation have positive effect on red blood count and hemoglobin content, indicating that this approach is promising for the development of new methods of anemia treatment.

  13. ADSORPTION DYNAMICS OF MACROPOROUS POLYMERIC ADSORBENT 1.The Studies on the Particle Diffusion Mass—Transfer Process

    Institute of Scientific and Technical Information of China (English)

    WANGChunhong; XUMingcheng; 等

    2000-01-01

    The adsorption dynamics for phenol in aqueous solution of the adsorbent based on polystyrene was studied.In order to distinguish with the Boyd quasi-homogeneous model of the inner structure of ion-exchanger,the particle diffusion model including surface diffustion model and porediffusion model was suggested which is suitable to the macroporous adsorbent.The diffusiondetermination step of the adsorption pocess was established and the effective diffusion coefficient was also determined.The influence of surface diffusion and pore difusion on the particle diffusion rate was investigated qualitatively.All of these were very important to improve the structure of the macroporous adsorbent in order to improve the mass-transfer rate.

  14. Prediction of biopore- and matrix-dominated flow from X-ray CT-derived macropore network characteristics

    DEFF Research Database (Denmark)

    Naveed, Muhammad; Møldrup, Per; Schaap, Marcel G

    2016-01-01

    at 􀀀30 and 􀀀100 cm matric potential, and gas diffusivity at 􀀀30 and 􀀀100 cm matric potential. Distribution maps for saturated hydraulic conductivity, air permeability, and gas diffusivity reflected no autocorrelation irrespective of soil texture and organic matter...... content. Existing empirical predictive models for saturated hydraulic conductivity and air permeability showed poor performance, as they were not able to realistically capture macropore flow. The tested empirical model for gas diffusivity predicted measurements at 􀀀100 cm matric potential...... interrelated. Most of the macropore network characteristics were also significantly correlated with saturated hydraulic conductivity, air permeability, and gas diffusivity. The predictive Ahuja et al. (1984) model for saturated hydraulic conductivity, air permeability, and gas diffusivity performed reasonably...

  15. 大孔吸附树脂纯化黄精小分子糖的工艺研究%Purification of Low Molecular Weight Saccharide in Rhizoma Polygonati by Macroorous Absorption Resins

    Institute of Scientific and Technical Information of China (English)

    李晓坤; 董晶晶; 贺海花; 杨云

    2011-01-01

    Objective: To study the optimal conditions and parameters of purifying lnw molecular weight saccharide in Rhizoma polygonati with macroporous resins. Method; With the yield and purily as the indices,the absorption characteristics of four resins for low molecular weight saccharide purification were compared. The optimal conditions of the; purification technology were investigated. Result; The AB-8 resin was the best of the four resins and the optimum conditions were the following;solution concentration of 36. 32 mg·ml-1, sample volume of 4 times of resin volume, eluting cubage of 8 times of resin volume, distilled water as eluling solvent with eluting rate of 1.0 ml·min-1. The yield was 97. 56% ,and the purity reached 90. 93%. Conclusion: The process of macroporous absorption resins to purify low molecular weight saccharide is simple,feasible and suitable for industrial production.%目的:研究大孔树脂吸附纯化黄精小分子糖的最佳工艺条件及参数.方法:以小分子糖保留率和纯度为考察指标,比较四种大孔树脂对黄精小分子糖的吸附性能,考察上样浓度、上样量、洗脱流速和洗脱剂用量等因素对优选树脂纯化工艺的影响,确定最佳工艺参数.结果:最佳工艺条件为选用AB-8大孔吸附树脂,上样浓度36.32 mg·ml-1,最大上样量4倍柱床体积,以蒸馏水8倍柱床体积洗脱,洗脱流速为1.0 ml·min-1.通过本工艺纯化的黄精小分子糖保留率达97.56%,纯度达90.93%.结论:大孔吸附树脂对黄精小分子糖有较好的纯化作用,该工艺简单可行,适合干工业化生产.

  16. Subnanomolar Detection Limit Application of Ion-Selective Electrodes with Three-Dimensionally Ordered Macroporous (3DOM) Carbon Solid Contacts

    OpenAIRE

    2009-01-01

    Solid-contact ion-selective electrodes (SC-ISEs) can exhibit very low detection limits and, in contrast to conventional ISEs, do not require an optimization of the inner filling solution. This work shows that subnanomolar detection limits can also be achieved with SC-ISEs with three-dimensionally ordered macroporous (3DOM) carbon contacts, which have been shown recently to exhibit excellent long-term stabilities and good resistance to the interferences from oxygen and light. The detection lim...

  17. Simple preparation of lotus-root shaped meso-/macroporous TiO₂ and their DSSC performances.

    Science.gov (United States)

    Hong, Jin-Yeon; Bae, Sang-Eun; Won, Yong Sun; Huh, Seong

    2015-06-15

    In pursuit of superior TiO2 photoanode materials for dye-sensitized solar cells (DSSCs), we prepared lotus-root shaped meso-/macroporous TiO2. The lotus-root shaped meso-/macroporous TiO2 was easily prepared by using a cetyltrimethylammonium hydroxide (CTAOH) template in aqueous solution. The crystallization of the as-prepared amorphous lotus-root shaped TiO2 was performed at 700 °C in air. Crystalline anatase phase with a very small portion of rutile phase was generated after the heat treatment at 700 °C and the BET surface area of crystalline lotus-root shaped meso-/macroporous TiO2 material (LR-700) was 30.0 m(2) g(-1). The wall of LR-700 displayed well-developed mesoporosity with a pore dimension of 28.3 nm. Periodically arranged microscale one-dimensional (1D) macropores were also observed in the particles. The photon-to-current conversion efficiencies (η) of LR-700 photoanodes in Grätzel type DSSCs were examined. The conversion efficiency of DSSC prepared by mixing nanoparticulate Evonik P25 and LR-700 (ratio=85:150 by mass) was 28% greater compared to the reference electrode using P25. Incident photon-to-current efficiencies (IPCE) of the DSSCs were dramatically improved by employing the photoanodes composed of a mixture of P25 and LR-700 but impedance analysis indicated that P25/LR-700 mixed cells have resistances similar to the standard P25 reference cell. Thus, photovoltaic performances could be improved mainly due to the increases of dye uptake and external quantum efficiency by using a mixed photoanode composed of LR-700 and nanocrystalline P25 particles.

  18. Evaluation of the in vitro degradation of macroporous hydrogels using gravimetry, confined compression testing, and microcomputed tomography.

    Science.gov (United States)

    Behravesh, Esfandiar; Timmer, Mark D; Lemoine, Jeremy J; Liebschner, Michael A K; Mikos, Antonios G

    2002-01-01

    This study investigated the in vitro degradation characteristics of macroporous hydrogels based on poly(propylene fumarate-co-ethylene glycol) (P(PF-co-EG)). Four formulations were fabricated to test the effect of porosity and cross-linking density on the degradation of the resulting macroporous hydrogels. Macroporosity was introduced by the addition of sodium bicarbonate and ascorbic acid, the precursors of the carbon dioxide porogen, in the initiation system for the hydrogel cross-linking. Macroporous hydrogels with porosities of 0.80 +/- 0.03 and 0.89 +/- 0.03 were synthesized by the addition of sodium bicarbonate of concentrations 40 and 80 mg/mL and ascorbic acid of concentrations 0.05 and 0.1 mol/L, respectively. Poly(ethylene glycol) diacrylate (PEG-DA) was utilized as a cross-linker. The molecular weight between cross-links had a significant effect on weight loss after 12 weeks, where samples with M(C) of 1,880 +/- 320 synthesized with a P(PF-co-EG):PEG-DA ratio of 3:1 had a significantly greater mass loss due to degradation than those with M(C) of 1,000 +/- 100 synthesized with a P(PF-co-EG):PEG-DA ratio of 1:1. In contrast, porosity played a minimal role in determining the weight loss. Mechanical testing of the hydrogels under confined compression showed a decrease in compressive modulus over the degradation time for all formulations. In addition, an increase in hydrogel equilibrium water content and pore wall thickness was observed with degradation time, whereas the hydrogel porosity and surface area density remained invariant. The results from microcomputed tomography corroborated with the rest of the measurements and indicated a bulk degradation mechanism of the macroporous hydrogels.

  19. ASSESSING THE BIOAVAILABILITY OF PAHS IN FIELD-CONTAMINATED SEDIMENT USING XAD-2 ASSISTED DESORPTION

    Science.gov (United States)

    In the bioremediation of soils/sediments contaminated with polycyclic aromatic hydrocarbons (PAHs) it is imperative to determine the fraction of the PAHs that is amenable to remediation. For example, what fraction of the PAHs is available to the indigenous microorganisms, i.e. bi...

  20. Study on Separation of Lanthanum from Praseodymium Complexes with IMDA by Gel and Macroporous Anion-Exchangers

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    During our studies on separation of rare earth complexes with aminopolycarboxylic acids on anion-exchangers, it is found that the affinity series of these elements with IMDA (Ln3+:IMDA=1:2) for the anion-exchanger Dowex 1 in the acetate and IMDA forms is non-typical: Dy3+> Ho3+> Gd3+>Eu3+>Er3+>Y3+>Sm3+>Tm3+>Nd3+>Pr3+>>La3+. In the affinity series La3+ is characterised as the lowest affinity in omparison with other rare earth elements, which indicates possibility ofpurification of La3+ from all remaining lanthanides as well as Pr3+ in the macro-micro systems by the frontal analysis technique. In the investigations strongly basic gel anion-exchangers Dowex 1×8 (type 1) and Dowex 2×8 (type 2) and strongly basic and weakly basic macroporous anion-exchangers Dowex MSA-1 and Dowex MWA-1 were used. Macroporous ion-exchangers have a sponge-like matrix which contains pores larger than molecules in size and the exchange of large ions is faster. The studies indicate that both the gel and macroporous anion-exchangers are useful for purification of La3+ from Pr3+ complexes with iminodiacetic acid.

  1. Optimization of macropore evolution towards high photocatalytic activity enhancement in meso/macro porous Anatase TiO2

    Science.gov (United States)

    Nair, Radhika V.; Gayathri, P. K.; Siva Gummaluri, Venkata; Vijayan, C.

    2017-01-01

    We report on an optimization strategy for macro pore evolution leading to the design of highly photocatalytic 3D hierarchical meso/macroporous TiO2 via much simpler, faster and cost effective synthesis scheme. Meso/macro porous TiO2 is an excellent candidate material for photocatalytic applications owing to the availability of internal surfaces as active sites for redox reactions. The current research scenario focuses on the design of highly efficient photocatalytic systems as well as rapid, facile and cost effective methods of synthesis and optimization of parameters. The present report is on the gradual evolution of macropores in anatase TiO2 by the effective control of pH of the solvent, reaction time, temperature, solvent ratio and reactant concentration via a facile hydrothermal method in this regard. 3D hierarchical macroporous structures are obtained at pH 7 within a comparatively short reaction time of 5 h and demonstrated to be highly photocatalytic (with rate constant four times that of P25 nanoparticles) through photodegradation of Rhodamine B dye.

  2. A simple method for preparation of macroporous polydimethylsiloxane membrane for microfluidic chip-based isoelectric focusing applications

    Energy Technology Data Exchange (ETDEWEB)

    Ou Junjie [Department of Mechanical and Mechatronics Engineering, University of Waterloo, 200 University Ave West, Waterloo, Ontario, N2L 3G1 (Canada); Department of Chemistry, University of Waterloo, 200 University Ave West, Waterloo, Ontario, N2L 3G1 (Canada); Ren, Carolyn L., E-mail: c3ren@mecheng1.uwaterloo.ca [Department of Mechanical and Mechatronics Engineering, University of Waterloo, 200 University Ave West, Waterloo, Ontario, N2L 3G1 (Canada); Pawliszyn, Janusz [Department of Chemistry, University of Waterloo, 200 University Ave West, Waterloo, Ontario, N2L 3G1 (Canada)

    2010-03-10

    A new, simple method was reported to prepare PDMS membranes with micrometer size pores for microfluidic chip applications. The pores were formed by adding polystyrene and toluene into PDMS prepolymer solution prior to spin-coating and curing. The resulting PDMS membrane has a thickness of around 10 {mu}m and macropores with a diameter ranging from 1 to 2 {mu}m measured using scanning electron microscope (SEM) imaging. This PDMS membrane was validated by integrating it with PDMS microfluidic chips for protein separation using isoelectric focusing mechanism coupled with whole channel imaging detection (IEF-WCID). It has been shown that five standard pI markers and a mixture of two proteins, myoglobin and {beta}-lactoglobulin, can be separated using these chips. The results indicated that this macroporous PDMS membrane can replace the dialysis membrane in PDMS chips for the IEF-WCID technique. The preparation method of macroporous PDMS membrane may be potentially applied in other fields of microfluidic chips.

  3. Fabrication of macroporous carbonate apatite foam by hydrothermal conversion of alpha-tricalcium phosphate in carbonate solutions.

    Science.gov (United States)

    Wakae, H; Takeuchi, A; Udoh, K; Matsuya, S; Munar, M L; LeGeros, R Z; Nakasima, A; Ishikawa, K

    2008-12-15

    Bone consists of a mineral phase (carbonate apatite) and an organic phase (principally collagen). Cancellous bone is characterized by interconnecting porosity necessary for tissue ingrowth and nourishment of bone cells. The purpose of the present study was to fabricate macroporous carbonate apatite (CAP) blocks with interconnecting porosity as potential bone substitute biomaterials by hydrothermal conversion of alpha-TCP foam in carbonate solution. The fabrication of the macroporous CAP was accomplished in two steps: (1) preparation of alpha-TCP foams using polyurethane foams as templates, and (2) hydrothermal conversion at 200 degrees C of alpha-TCP foam in the presence of ammonium carbonate solutions of different concentrations. The maximum carbonate content of the resultant CAP foam was approximately 7.4 wt %. The mean porosity of the CAP foam was as high as 93 vol %. The macroporous CAP blocks or granules prepared in this manner has properties similar to that of bone in mineral composition and in having interconnecting macroporosity necessary for osteoconductivity and tissue ingrowth. On the basis of composition and interconnecting macroporosity, the CAP foam materials could be ideal biomaterials for bone repair and as scaffolds for tissue engineering.

  4. Dentine sealing provided by smear layer/smear plugs vs. adhesive resins/resin tags.

    Science.gov (United States)

    Carrilho, Marcela R; Tay, Franklin R; Sword, Jeremy; Donnelly, Adam M; Agee, Kelli A; Nishitani, Yoshihiro; Sadek, Fernanda T; Carvalho, Ricardo M; Pashley, David H

    2007-08-01

    The aim of this study was to evaluate the ability of five experimental resins, which ranged from hydrophobic to hydrophilic blends, to seal acid-etched dentine saturated with water or ethanol. The experimental resins (R1, R2, R3, R4, and R5) were evaluated as neat bonding agents (100% resin) or as solutions solvated with absolute ethanol (70% resin/30% ethanol). Fluid conductance was measured at 20 cm H(2)O hydrostatic pressure after sound dentine surfaces were: (i) covered with a smear layer; (ii) acid-etched; or (iii) bonded with neat or solvated resins, which were applied to acid-etched dentine saturated with water or ethanol. In general, the fluid conductance of resin-bonded dentine was significantly higher than that of smear layer-covered dentine. However, when the most hydrophobic neat resins (R1 and R2) were applied to acid-etched dentine saturated with ethanol, the fluid conductance was as low as that produced by smear layers. The fluid conductance of resin-bonded dentine saturated with ethanol was significantly lower than for resin bonded to water-saturated dentine, except for resin R4. Application of more hydrophobic resins may provide better sealing of acid-etched dentine if the substrate is saturated with ethanol instead of with water.

  5. Resin Viscosity Influence on Fiber Compaction in Tapered Resin Injection Pultrusion Manufacturing

    Science.gov (United States)

    Masuram, N. B.; Roux, J. A.; Jeswani, A. L.

    2017-08-01

    Viscosity of the liquid resin effects the chemical and mechanical properties of the pultruded composite. In resin injection pultrusion manufacturing the liquid resin is injected into a specially designed tapered injection chamber through the injection slots present on top and bottom of the chamber. The resin is injected at a pressure so as to completely wetout the fiber reinforcements inside the tapered injection chamber. As the resin penetrates through the fibers, the resin also pushes the fibers away from the wall towards the center of chamber causing compaction of the fiber reinforcements. The fibers are squeezed together due to compaction, making resin penetration more difficult; thus higher resin injection pressures are required to efficaciously penetrate through the compacted fibers and achieve complete wetout. The impact of resin viscosity on resin flow, fiber compaction, wetout and on the final product is further discussed. Injection chamber design predominantly effects the resin flow inside the chamber and the minimum injection pressure required to completely wet the fibers. Therefore, a desirable injection chamber design is such that wetout occurs at lower injection pressures and at low internal pressures inside the injection chamber.

  6. Comparison of Cashew Nut Shell Liquid (CNS Resin with Polyester Resin in Composite Development

    Directory of Open Access Journals (Sweden)

    C. C. Ugoamadi

    2013-12-01

    Full Text Available Natural resins can compete effectively with the synthetic ones in composite development. In this research, cashew nuts were picked and processed for the extraction of the resin content. The resin (natural resin so obtained was mixed with cobalt amine (accelerator, methyl ethyl ketone peroxide (catalyst to develop two sets of composite specimens – specimens without fibres and specimens reinforced with glass fibres. This method of sample specimen development was repeated with polyester (synthetic resin. Compressive and tensile strength tests conducted proved that composites developed with cashew nut shell liquid (CNSL resin were comparable to those developed with polyester resin. In the results, CNSL has an ultimate compressive strength of 55MPa compared to that of polyester resin with an ultimate strength of 68MPa. The result of tensile strength proved cashew nut shell liquid resin (with ultimate strength of 44MPa to be better than polyester resin with 39MPa as ultimate tensile strength. This means that natural resins could be a better substitute for the synthetic ones when the required quantities of fibers (reinforcements and fillers are used in the fibre-reinforced plastic composite developments.

  7. Macroporous biohybrid cryogels for co-housing pancreatic islets with mesenchymal stromal cells.

    Science.gov (United States)

    Borg, Danielle J; Welzel, Petra B; Grimmer, Milauscha; Friedrichs, Jens; Weigelt, Marc; Wilhelm, Carmen; Prewitz, Marina; Stißel, Aline; Hommel, Angela; Kurth, Thomas; Freudenberg, Uwe; Bonifacio, Ezio; Werner, Carsten

    2016-10-15

    Intrahepatic transplantation of allogeneic pancreatic islets offers a promising therapy for type 1 diabetes. However, long-term insulin independency is often not achieved due to severe islet loss shortly after transplantation. To improve islet survival and function, extrahepatic biomaterial-assisted transplantation of pancreatic islets to alternative sites has been suggested. Herein, we present macroporous, star-shaped poly(ethylene glycol) (starPEG)-heparin cryogel scaffolds, covalently modified with adhesion peptides, for the housing of pancreatic islets in three-dimensional (3D) co-culture with adherent mesenchymal stromal cells (MSC) as accessory cells. The implantable biohybrid scaffolds provide efficient transport properties, mechanical protection, and a supportive extracellular environment as a desirable niche for the islets. MSC colonized the cryogel scaffolds and produced extracellular matrix proteins that are important components of the natural islet microenvironment known to facilitate matrix-cell interactions and to prevent cellular stress. Islets survived the seeding procedure into the cryogel scaffolds and secreted insulin after glucose stimulation in vitro. In a rodent model, intact islets and MSC could be visualized within the scaffolds seven days after subcutaneous transplantation. Overall, this demonstrates the potential of customized macroporous starPEG-heparin cryogel scaffolds in combination with MSC to serve as a multifunctional islet supportive carrier for transplantation applications. Diabetes results in the insufficient production of insulin by the pancreatic β-cells in the islets of Langerhans. Transplantation of pancreatic islets offers valuable options for treating the disease; however, many transplanted islets often do not survive the transplantation or die shortly thereafter. Co-transplanted, supporting cells and biomaterials can be instrumental for improving islet survival, function and protection from the immune system. In the

  8. Application of BIB-SEM technology to characterize meso- and macropore morphology in coal

    Science.gov (United States)

    Giffin, Susan; Littke, Ralf; Klaver, Jop; Urai, Janos

    2013-04-01

    Coalbeds are very heterogenous in composition, which in turn affects the connectivity and transport of fluids within the coal. The composition of a coalbed influences the pore structure. Pore structure as well as pore size distribution are two important parameters used in estimating reservoir properties. This study examines the morphology and distribution of macro- and mesopores in coal samples, using broad ion beam (BIB) milling to prepare relief- and damage-free polished surfaces of coal samples for high-resolution SEM imaging. The BIB-sections of a few square millimeters are not large enough to be statistically representative so that the results cannot be easily interpreted from a coal seam standpoint. Therefore, porosity was investigated as a function of maceral type to characterize pore morphologies. Macerals were selected from the vitrinite group, e.g. telocollinite, and from the inertinite group, e.g. fusinite and macrinite. The selected macerals were BIB-milled parallel to bedding and subsequently milled perpendicular to bedding. Pore morphology and pore size distribution was examined in each of the milled sections. For a vitrinite maceral type, we found no visible macroporosity within the resolution limits of the SE detector. Pore morphology in an inertinite maceral is dependent on the original maceral. Fusinite yields large, elongated pores (often filled with mineralization), while macrinite shows comparatively smaller, rounder pores. The BIB-milled sections perpendicular to bedding often showed an alternating sequence of bedding, with bed thicknesses varying between a few micrometers to greater than half a millimeter. The distribution of pores is also reflected by bed thickness in the sections perpendicular to bedding, with many pores being concentrated in association with the beds. The distribution of pore sizes follows a similar power law at different magnifications of the same BIB-milled surface. Our results show that micropores and macropores in coal

  9. MODIFICATION OF X-5 RESIN AND ADSORPTION PROPERTY OF THE MODIFIED RESINS

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Three polymeric adsorbents with hydrogen bonding acceptors, methylamine,N-methyl-acetamide and aminotri(hydroxymethyl)methane modified resins are synthesized fromchloromethylated X-5 resin. Adsorption isotherms of phenol and theophylline onto the three modifiedresins and the original X-5 resin from aqueous solution are measured. The results show thatadsorption of compounds with hydrogen bonding donor onto methylamine and N-methylacetamidemodified resins is enhanced as compared with that onto X-5 resin, and adsorption mechanismbetween the adsorbents and the adsorbates is mainly based on hydrogen bonding and hydrophobicinteraction. While adsorption of compounds with hydrogen bonding donor ontoaminotri(hydroxymethyl)methane modified resin is lowered as compared with that onto X-5 resin, andadsorption mechanism between the adsorbent and the adsorbates is mainly based on hydrophobicinteraction.

  10. TMI-2 purification demineralizer resin study

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, J D; Osterhoudt, T R

    1984-05-01

    Study of the Makeup and Purification System demineralizers at TMI-2 has established that fuel quantities in the vessels are low, precluding criticality, that the high radioactive cesium concentration on the demineralizer resins can be chemically removed, and that the demineralizer resins can probably be removed from the vessels by sluicing through existing plant piping. Radiation measurements from outside the demineralizers establishing that there is between 1.5 and 5.1 (probably 3.3) lb of fuel in the A vessel and less than that amount in the B vessel. Dose rates up to 2780 R per hour were measured on contact with the A demineralizer. Remote visual observation of the A demineralizer showed a crystalline crust overlaying amber-colored resins. The cesium activity in solid resin samples ranged from 220 to 16,900 ..mu..Ci/g. Based on this information, researchers concluded that the resins cannot be removed through the normal pathway in their present condition. Studies do show that the resins will withstand chemical processing designed to rinse and elute cesium from the resins. The process developed should work on the TMI-2 resins.

  11. [Delayed asthma bronchiale due to epoxy resin].

    Science.gov (United States)

    Authried, Georg; Al-Asadi, Haifaa; Møller, Ulla; Sherson, David Lee

    2013-10-28

    Epoxy resin is a low molecular weight agent, which can cause both acute and delayed allergic reactions. However, it is known causing skin reactions with direct or airborne contact. Rarely it can cause airway reactions like asthma bronchiale. We describe a case of a windmill worker who developed delayed asthma bronchiale due to airborne contact with epoxy resin.

  12. Dental resin cure monitoring by inherent fluorescence

    Science.gov (United States)

    Li, Qun; Zhou, Jack X.; Li, Qingxiong; Wang, Sean X.

    2008-02-01

    It is demonstrated that the inherent fluorescence of a dental composite resin can be utilized to monitor the curing status, i.e. degree of conversion of the resin. The method does not require any sample preparation and is potentially very fast for real time cure monitoring. The method is verified by Raman spectroscopy analysis.

  13. Novel silica-based ion exchange resin

    Energy Technology Data Exchange (ETDEWEB)

    Gula, M.; Harvey, J.

    1996-12-31

    Shortcomings of chelating resins have been addressed by a new class of ion exchange resins called dual mechanism bifunctional polymers (DMBPs). DMBPs use hydrophilic cation exchange ligands with rapid uptake kinetics and use chelating ligands for selectivity for one or more metals; result is a resin that quickly recognizes and removes targeted metals from waste, remediation, and process streams. Eichrom`s Diphonix {reg_sign} resin is the first DMBP to be widely released as a commercial product; it is polystyrene based. Objective of this work is to synthesize commercial quantities of a silica-based ion exchange resin with the same or better metal ion selectivity, metal uptake kinetics, and acid stability as Diphonix. Feasibility was determined, however the process needs to be optimized. Studies at Eichrom and ANL of the performance of Diphonix resin over a broad range of HNO3 and HCl conditions and inorganic salt loadings are discussed together with the proposed method of incorporating similar characteristics into a silica-based resin. The new, silica-based resin functionalized with diphosphonic acid ligands can be used in environmental restoration and waste management situations involving processing of low-level, transuranic, and high-level radioactive wastes; it can also be used for processing liquid mixed waste including wastes contaminated with organic compounds.

  14. Shear bond strength between alumina substrate and prosthodontic resin composites with various adhesive resin systems.

    Science.gov (United States)

    AlJehani, Yousef A; Baskaradoss, Jagan K; Geevarghese, Amrita; AlShehry, Marey A; Vallittu, Pekka K

    2015-05-02

    With the increase in demand for cosmetics and esthetics, resin composite restorations and all-ceramic restorations have become an important treatment alternative. Taking into consideration the large number of prosthodontic and adhesive resins currently available, the strength and durability of these materials needs to be evaluated. This laboratory study presents the shear bond strengths of a range of veneering resin composites bonded to all-ceramic core material using different adhesive resins. Alumina ceramic specimens (Techceram Ltd, Shipley, UK) were assigned to three groups. Three types of commercially available prosthodontic resin composites [BelleGlass®, (BG, Kerr, CA, USA), Sinfony® (SF, 3 M ESPE, Dental Products, Germany), and GC Gradia® (GCG, GC Corp, Tokyo, Japan)] were bonded to the alumina substrate using four different adhesive resins. Half the specimens per group (N = 40) were stored dry for 24 hours, the remaining were stored for 30 days in water. The bonding strength, so-called shear bond strengths between composite resin and alumina substrate were measured. Data were analysed statistically and variations in bond strength within each group were additionally evaluated by calculating the Weibull modulus. Bond strengths were influenced by the brand of prosthodontic resin composites. Shear bond strengths of material combinations varied from 24.17 ± 3.72-10.15 ± 3.69 MPa and 21.20 ± 4.64-7.50 ± 4.22 at 24 h and 30 days, respectively. BG resin composite compared with the other resin composites provided the strongest bond with alumina substrate (p resin composite was found to have a lower bond strength than the other composites. The Weibull moduli were highest for BG, which was bonded by using Optibond Solo Plus adhesive resin at 24 h and 30 days. There was no effect of storage time and adhesive brand on bond strength. Within the limitations of this study, the shear bond strengths of composite resins to alumina substrate are related to the composite

  15. Ethylated Urea - Ether - Modified Urea - Formaldehyde Resins,

    Directory of Open Access Journals (Sweden)

    Mathew Obichukwu EDOGA

    2006-07-01

    Full Text Available First, phenol - formaldehyde (PF and urea - formaldehyde (UFII resins were separately conventionally prepared in our laboratory. Also, UF resin synthesized from the acid modified synthesis procedure was synthesized in a purely acid medium of pH 1.0, FU molar ratio of 1.0 and at 50oC (one-stage acid modified-synthesis procedure. Subsequently, the UF resin II was modified during synthesis by incorporating ethylated urea-ether (EUER (i.e. UFIII and glycerol (GLYC (i.e. UFV cured with and without acid curing agent. The structural and physicochemical analyses of the various resin samples were carried out.The results showed that the unmodified UF resin (UF II synthesized in acid medium of pH 1.0, F/U molar ratio 1.0, and at 50oC, cured in absence of acid curing catalyst, showed features in their spectra which are consistent with a tri-, and/or tetra-substituted urea in the reaction to give a 3 - dimensional network cured UF resin. Modification of the UF resin(UF II with ethylated urea-ether and glycerol to produce UF resins III and respectively V prominently increased the absorbance of methylene and ether groups in the spectra which are consistent with increased hydrophobicity and improved hydrolytic stability. For the conventional UF resin (UF I, the only clear distinction between spectra for the UF resin II and UF resins (III/V is the presence of diminished peaks for methylene groups at 2.2 ppm. The relationship between the logarithmic viscosity of cured PF resin with time showed continuos dependence of viscosity with time during cure up to 70 minutes. Similar trends were shown by UF resins (III/V, cured in absence of acid catalyst. In contrast, the conventional UF resins I and UF IV (i.e. UF II cured with NH4CL showed abrupt discontinuity in viscosity with time just after about 20 minutes of cure.

  16. EPOXY RESINS TOUGHENED WITH CARBOXYL TERMINATED POLYETHERS

    Institute of Scientific and Technical Information of China (English)

    YU Yunchao; LI Yiming

    1983-01-01

    Carboxyl terminated polyethers, the adducts of hydroxyl terminated polytetrahydrofuran and maleic anhydride, were used as toughener for epoxy resins. The morphology of the toughened resins was investigated by means of turbidity measurement, dynamic mechanical testing and scanning electron microscope observation. It turned out that the molecular weight and the carboxyl content of the polyether and the cure conditions are important factors, which affect the particle size of the polyether-rich domains and, in turn, the mechanical properties of the cured resin. Carboxyl terminated polytetrahydrofurans have a low glass transition temperature, and in appropriate amount they do not affect the thermal resistance of the resin. These advantages make them preferable as toughener for epoxy resins.

  17. Release and toxicity of dental resin composite.

    Science.gov (United States)

    Gupta, Saurabh K; Saxena, Payal; Pant, Vandana A; Pant, Aditya B

    2012-09-01

    Dental resin composite that are tooth-colored materials have been considered as possible substitutes to mercury-containing silver amalgam filling. Despite the fact that dental resin composites have improved their physico-chemical properties, the concern for its intrinsic toxicity remains high. Some components of restorative composite resins are released in the oral environment initially during polymerization reaction and later due to degradation of the material. In vitro and in vivo studies have clearly identified that these components of restorative composite resins are toxic. But there is a large gap between the results published by research laboratories and clinical reports. The objective of this manuscript was to review the literature on release phenomenon as well as in vitro and in vivo toxicity of dental resin composite. Interpretation made from the recent data was also outlined.

  18. Posterior adhesive composite resin: a historic review.

    Science.gov (United States)

    Fusayama, T

    1990-11-01

    Since development of the BIS-GMA composite resin, there have been many innovations to improve the physical properties for posterior use. Subsequent development of a caries detector and chemically adhesive composite resin has further revolutionally raised the value of composite resin restoration, replacing the traditional restorative system of mechanical approach by the new system of biological approach. In this system only the infected irreversibly deteriorated insensitive tissue, stainable with the caries detector, is removed painlessly. The cavity is immediately filled with the composite resin with no further tissue reduction for retention or resistance form or extension for prevention. Both enamel and dentin walls are etched by a single etchant without lining. The chemical adhesion to the cavity margin and wall minimizes the marginal failure in size and prevalence and prevents secondary caries penetration along the wall. The chemically adhesive composite resin is thus a useful restorative material much kinder to teeth than amalgam.

  19. 大孔树脂纯化酸石榴汁中花青素的研究%Purification of anthocyanins from pomegranate juice using macroporous resin

    Institute of Scientific and Technical Information of China (English)

    赵贝塔; 赵巍; 刘邻渭; 谢乐

    2014-01-01

    [目的]筛选分离纯化酸石榴汁花青素的最佳树脂,优化酸石榴汁纯化的工艺条件,为石榴汁花青素的工业化生产提供参考.[方法]从AB-8、X-5、D101、D101A和NKA-9等5种大孔树脂中,通过静态吸附-解吸试验,筛选适合酸石榴汁花青素纯化的大孔树脂,分析花青素质量浓度、温度、pH及解吸液乙醇体积分数和pH对树脂静态吸附-解吸的影响,并在静态试验的基础上,通过动态吸附-解吸试验,确定最佳的吸附流速和解吸流速.[结果]AB-8树脂是纯化酸石榴汁花青素的最佳树脂,其对酸石榴汁花青素静态吸附-解吸的最优工艺条件为:室温25℃、pH2.5、花青素质量浓度0.131 2 mg/mL,解吸液采用体积分数70%酸化乙醇(pH 2.0);动态吸附-解吸的最适工艺条件为:吸附流速1.5 mL/min,解吸流速2.0 mL/min.[结论]AB-8大孔树脂对酸石榴汁花青素的纯化效果最佳,适用于酸石榴汁中花青素类物质的纯化.

  20. 神秘果种子多酚大孔树脂纯化工艺研究%Purification of polyphenols from Synsepalum dulcificum seed with macroporous resins

    Institute of Scientific and Technical Information of China (English)

    马艺丹; 刘红; 马思聪; 闫瑞昕; 廖小伟

    2016-01-01

    分别采用6种大孔树脂(AB-8、D101、HPD-500、S-8、DM130、X-5)纯化神秘果种子多酚,以吸附量、吸附率、解吸量、解吸率为评定参数,优选出X-5为最佳树脂.研究其吸附等温线,发现其与Langmuir等温线拟合良好.静态吸附与解吸结果表明:最佳pH 5.8,最佳解吸液为70%乙醇.动态吸附与解吸结果表明:最优样品液浓度为1.2 mg/mL,吸附液体积为100 mL,解吸液体积为50 mL,吸附流速为1.0 mg/mL,解吸流速为1.5 mg/mL.研究结果表明:经X-5纯化后的神秘果种子多酚含量提高了2倍,T-AOC测定总抗氧化能力提高了2.5倍.说明该工艺适用于神秘果种子多酚的纯化.