氧化微纤化纤维素/海藻酸钠/胶原复合水凝胶的研究

以胶原、海藻酸钠和氧化微纤化纤维素为原料制备了氧化微纤化纤维素/海藻酸钠/胶原(OMFC/SA/Col)复合水凝胶。用红外光谱、扫描电镜分析了复合水凝胶的结构和形貌,通过接触角和压缩试验研究了其亲水性和力学性能。结果表明:OMFC和胶原间发生了席夫碱反应;复合水凝胶在20%应变时的压缩应力可达0.45MPa,可满足软骨浅表层的要求;其应变可达90%以上,韧性好;其亲水性好,OMFC含量对其亲水性影响不大。     

新型复合水凝胶AM/HAK的制备及其对烟草生长发育的影响

[目的]制备新型复合水凝胶,为烟草抗旱栽培开发新型保水材料.[方法]以丙烯酰胺(AM)为单体,分别以羧甲基纤维素钠(CMC)和腐植酸钾(HAK)为交联介质,N,N'-亚甲基双丙烯酰胺为交联剂,过硫酸铵(APS)为引发剂,制备了聚丙烯酰胺/羧甲基纤维素和聚丙烯酰胺/腐植酸钾复合水凝胶.采用红外光谱(FT-IR)对其结构进...     

聚丙烯酰胺复合TEMPO氧化纳米纤维素的黏性水凝胶

本研究将TEMPO氧化纳米纤维素（TONC）加入丙烯酰胺（AM）单体中,通过自由基聚合制备了具有高强胶黏性能的聚丙烯酰胺（TONC/PAM）复合水凝胶。采用傅里叶变换红外光谱和X射线光电子能谱表征了TONC/PAM复合水凝胶的结构,探讨了TONC/PAM复合水凝胶的形貌、流变和溶胀行为,研究了不同TONC含量的TONC/PAM复合水凝胶对不同基材的拉伸剪切强度。结果表明,随着TONC含量增加,复合水凝胶孔径和溶胀率逐渐变大。当TONC含量为0.4%时,复合水凝胶孔径为（600±50） μm,溶胀率达1700%。当固化时间为48 h时,不含TONC的水凝胶在木材上的最大拉伸剪切强度为5.0 MPa;而TONC含量为0.2%的复合水凝胶的最大拉伸剪切强度可达8.0 MPa。该复合黏性水凝胶在木材和建筑中具有很大的应用潜力。     

海藻酸钠-聚丙烯酰胺/凹凸棒土复合水凝胶的吸附性能研究

以海藻酸钠、丙烯酰胺和凹凸棒土为主要原料,采用溶液聚合方式制备了海藻酸钠-聚丙烯酰胺/凹凸棒土复合水凝胶。研究了引发剂用量、交联剂用量、海藻酸钠用量、凹凸棒土用量对染料吸附性能的影响。最佳条件下,海藻酸钠-聚丙烯酰胺/凹凸棒土复合水凝胶对亚甲基蓝的去除率可达98%。     

木质纤维素各组分在其复合水凝胶制备及功能化中的关键作用

近年来,木质纤维素复合水凝胶的制备及功能化等研究备受关注,特别是木质纤维素多组分或全组分复合水凝胶的研究取得了一系列重要的进展。本文综述了木质纤维素复合水凝胶制备中纤维素、半纤维素、木质素等各组分的关键作用及其在生物医药、污水处理、催化吸附、紫外阻隔等功能化应用方面的研究进展。     

双醛改性纤维素纳米纤丝增强木质素水凝胶及其耐温耐盐性能研究

将双醛纤维素纳米纤丝（DA-CNF）应用到木质素水凝胶的制备中,利用DA-CNF在水凝胶中的互穿网络作用以及醛基与碱木质素酚羟基发生缩合反应,从而达到增强木质素水凝胶强度的目的。傅里叶变换红外光谱（FT-IR）分析结果表明,聚乙二醇二缩水甘油醚（PEGDGE-500）以及DA-CNF与木质素发生了反应;扫描电子显微镜（SEM）分析结果表明,添加DA-CNF后,木质素水凝胶的结构呈多孔性;添加DA-CNF能够显著改善木质素水凝胶的物理强度、热稳定性和耐温耐盐性能,当DA-CNF添加量为2.0%时,木质素水凝胶拉伸应力由69 kPa提高至175 kPa,压缩应力由0.18 MPa提高至1.5 MPa,初始降解温度由209℃提高到248℃。DA-CNF增强的木质素水凝胶具有较高的耐温耐盐特性,在150℃、pH值=9的20万矿化度的盐水中老化20天后,其质量保留率仍可达86.4%,且具有较好的pH适应性。综上所述,DA-CNF增强的木质素水凝胶具有潜在的油田封堵应用潜力。     

氯离子响应性纳米纤维素荧光水凝胶的构筑

为解决传统PVA复合水凝胶制备过程中使用有毒试剂或需要反复多次冻融能耗高、过程繁琐的问题,以植酸(PA)作为交联剂将荧光纳米纤维素(F-CNCs)与聚乙烯醇(PVA)有机结合,基于多重氢键作用,构建了力学性能好、Cl^-响应灵敏的PVA/F-CNCs/PA纳米纤维素荧光水凝胶。基于F-CNCs优异的力学性能、荧光性能、良好的生物相容性及纳米效应,分析了PVA水凝胶良好的荧光性能及Cl^-响应性。结果表明:当F-CNCs的含量为0.6 g 时,PVA/F-CNCs/PA复合水凝胶的压缩强度提高了150%,且结晶度以及热稳定性均有所提高。PVA/F-CNCs/PA复合水凝胶在低的pH值下对Cl^-敏感,荧光淬灭效率在Cl^-浓度为0~0.2 mol/L范围内呈线性响应,表明制备得到的纳米纤维素荧光水凝胶在Cl^-浓度分析检测、疾病诊断、生物和化学传感器等方面具有潜在应用价值。     

基于pH调节的CMCS-PMMS/PAAm复合水凝胶的构筑与性能研究

以聚甲基丙烯酸甲酯-甲基丙烯酸/二氧化硅(Poly(MMA/MAA)/SiO2,PMMS)、羧甲基壳聚糖(CMCS)、丙烯酰胺(AAm)为原料,EDC/NHS为催化剂,通过调节体系pH值和自由基聚合反应制备了系列CMCS-PMMS/PAAm复合水凝胶,并对其流变性能、力学性能、溶胀性能、导电性能及生物相容性进行研究.结...     

PVA/BC/LiCl复合水凝胶的制备及性能

为了探讨聚乙烯醇(PVA)/细菌纤维素(BC)/氯化锂(LiCl)复合水凝胶的制备及性能，以PVA作为水凝胶基质材料，BC作为增强材料，LiCl为导电物质，甘油-水混合物为溶剂，采用溶胶-凝胶法制备了PVA/BC/LiCl复合水凝胶材料，并对水凝胶材料的形貌结构、力学性能和电导率进行测试。结果表明：加入BC可以有效提高水凝胶的力学性能，加入LiCl可以明显提高水凝胶的电导率；PVA/BC/LiCl复合水凝胶具有良好的导电性能和力学性能。     

蚕丝蛋白/明胶复合水凝胶的结构与生物相容性

针对蚕丝蛋白水凝胶不易快速凝胶成型的问题,将明胶蛋白水溶液与蚕丝蛋白以一定质量比复合,通过挤出式3D打印设备制备得到蚕丝蛋白/明胶复合水凝胶,并对复合水凝胶的流变性能、微观结构和生物相容性进行分析。结果表明:明胶的添加提高了复合水凝胶的黏度和储能模量,有利于3D打印过程中蚕丝蛋白的快速凝胶成型;明胶的添加未对蚕丝蛋白的二级结构产生影响,通过3D打印法可制备具有微周期格栅状蚕丝蛋白/明胶复合水凝胶支架,该支架具有三维多孔结构;当蚕丝蛋白与明胶质量比为50∶50时,复合水凝胶支架的断裂强度达3.43 MPa,是纯蚕丝蛋白的3.9倍;培养7 d后,MC3T3-E1细胞可在复合水凝胶支架上生长、增殖和分化。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the