碳纳米管整理腈纶及其导电性的研究

用强酸改性多壁碳纳米管,将改性后的多壁碳纳米管用高温水浴的方法整理到腈纶上。以纤维体积比电阻为指标,通过单因素分析确定制备碳纳米管腈纶的优化工艺参数,并对其性能进行测试分析。红外光谱测试结果表明,强酸改性后的碳纳米管成功接上-COOH官能团。当溶液的pH为3,碳纳米管的质量分数为0.03%,黏合剂的用量为3 mL时,碳纳米管腈纶的体积比电阻最小。扫描电镜分析结果表明,经碳纳米管整理后的纤维表面分布有管状导电物质。机械性能测试结果表明,碳纳米管腈纶断裂强力和断裂伸长率都有所提高。TG测试结果表明,碳纳米管腈纶的热稳定性有一定的提升。     

聚对苯二甲酸丙二醇酯/聚苯胺复合导电纱的电学与力学性能

针对原位聚合的纱线连续导电处理方法存在原料利用率低的问题,通过改进了制备工艺,制备了聚对苯二甲酸丙二醇酯 / 聚苯胺（PTT/ PANI）复合导电纱线,研究了氧化剂浓度对复合导电纱线导电性能以及力学性能的影响关系。结果表明：利用该法可以连续制备高电导率的PTT/ PANI复合导电纱线,随着氧化剂浓度的提高,PTT纱线表面聚苯胺电导率先增大后降低,但纱线电导率逐渐提高趋于稳定。在大拉伸条件下,纱线电阻随拉伸的增大而增大,并成指数关系。在小应变拉伸回复循环条件下,复合导电纱线的电阻变化较为复杂。复合导电纱线的断裂强力和断裂伸长率较处理前有所下降,初始模量有所增大。     

PEDOT:PSS复合涤/棉导电非织造布的制备及其性能

为制备具有良好导电性能和使用性能的非织造布,利用原位聚合的方法在涤/棉非织造布上原位生长致密的聚(3,4-乙撑二氧噻吩):聚苯乙烯磺酸钠(PEDOT:PSS)导电聚合物,探究掺杂剂体积占比、氧化剂体积占比等工艺参数对导电非织造布性能的影响。实验结果表明：PSS∶过硫酸铵(APS)∶EDOT的比例为2∶1.5∶1、聚合时间为10 h为最佳工艺,制备的导电非织造布的电导率最高为29.044 mS/cm;最佳制备工艺下导电非织造布的断裂强力为20.18 N,伸长率为85.23%;导电织物耐洗涤性良好,透气率可达329.19 mm/s,为导电非织造布在柔性电子中的应用提供参考。     

消臭粘胶纤维的制备与性能研究

将具有消臭功能的海藻糖粉末和蛋白石微粉水化液与粘胶纺丝液共混,选取最佳添加形式与共混比例,根据粘胶纤维生产工艺制备消臭粘胶纤维,并测试其基本性能与消臭性能。结果表明,与普通粘胶纤维相比,消臭粘胶纤维断裂强度、断裂伸长率均有所下降,回潮率稍有降低,比电阻减小,消臭性能优异。     

超低比例导电涤纶与棉混纺产品的设计与开发

探讨超低比例导电涤纶与棉混纺产品的生产工艺及抗静电性能。测试分析了不同比例导电涤纶对混和纤维导电性能的影响,并进行了超低比例导电涤纶与棉混纺纱、布产品的试制与性能测试。结果表明:导电涤纶与棉混和纤维的体积比电阻随着导电涤纶含量的增加而减小,但超过1%后,体积比电阻的下降幅度趋缓;含有0.5%~1%导电涤纶纤维的纺织品可以满足一般的抗静电要求,并具有较好的抗静电耐久性;采用梳棉机后部棉卷定量混和喂入方法可以保证正确的混和比例和均匀的混和效果;导电涤纶含量是影响纺织品抗静电性能的主要因素,混纺纱线密度、织物的组织结构等对抗静电性能影响不大。     

羊毛导电混纺纱导电性能的研究

探讨影响羊毛导电混纺纱导电性能的因素。对不同类型的导电纤维进行优选,并测试分析了导电纤维的长度、含量及混纺纱线密度对羊毛导电纤维混纺纱导电性能的影响。指出:随着导电纤维长度的增长,纱线的体积比电阻呈下降趋势;导电纤维含量在1.5%～3.0%时较符合实际生产需要;随着纱线线密度的增大,纱线体积比电阻呈增大趋势。     

功能性聚砜酰胺纳米复合材料的研究现状与分析

聚砜酰胺具有良好的耐热性、热稳定性和阻燃性能,但常规聚砜酰胺纤维存在体积比电阻高和抗紫外线性能差等缺陷,导致后续加工困难,限制了其在防护类服装领域的应用.通过对功能性聚砜酰胺纤维制备及改良现状的概括与分析,重点介绍了碳纳米管基本力学和导电性能以及纳米二氧化钛紫外线吸收和屏蔽功能,阐述了碳纳米管和纳米二氧化钛对聚砜酰胺纤...     

蚕丝的苹果酸脱胶

采用苹果酸对蚕丝进行脱胶,通过单因素实验,讨论了苹果酸质量浓度、反应温度、反应时间和浴比对蚕丝脱胶效果的影响,研究了脱胶后蚕丝的性能变化,得出了苹果酸的脱胶工艺条件。结果表明:最佳工艺为苹果酸质量浓度11 g/L,反应温度100℃,反应时间30 min,浴比1︰60。此条件下脱胶处理的蚕丝断裂强力损失与断裂伸长损失均较小,生丝中的丝胶基本上脱尽。蚕丝的红外光谱图研究结果表明,最佳脱胶工艺处理后蚕丝的主体结构不受影响。     

聚苯胺及聚苯胺涤纶复合导电织物的制备

以H2SO4为掺杂酸,过硫酸铵为氧化剂,采用化学氧化聚合法制备聚苯胺,用扫描电镜和数字万用表对其形态和导电性能进行测试;以H2SO4为掺杂酸,过硫酸铵为氧化剂,采用原位聚合法制备聚苯胺涤纶复合导电织物。对聚苯胺涤纶复合导电织物的导电性能、力学性能及耐洗性进行测试。结果表明,制备聚苯胺的最佳工艺条件为：过硫酸铵与苯胺单体摩尔比为1：1,硫酸浓度为1 mol/L,反应时间为6 h,反应温度为15～25 ℃。制备聚苯胺涤纶复合导电织物的最佳工艺条件为：过硫酸铵与苯胺单体摩尔比为1：1,硫酸浓度为1 mol/L,反应时间为2 h,反应温度为15～25 ℃。     

碳黑涂覆型聚酯导电纤维的制备与性能

为克服传统涂覆型导电纤维导电耐久性较差的缺点,采用纤维表面部分溶解的技术制备具有导电耐久性的溶解涂覆型聚酯导电纤维。研究和讨论了涂覆液中碳黑和聚酯含量对纤维体积比电阻及线密度的影响,并对所得纤维力学性能、耐水洗性能及耐热性能等进行了讨论和分析。结果表明,所得碳黑涂覆型聚酯纤维体积比电阻可达9.2Ω.cm,具有较好的导电耐久性且基本保持原纤维特性。     

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.     

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.     

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.     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

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.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.