基于纳米纤维素的柔性导电材料研究进展

纳米纤维素是一种从纤维素中分离获得的纳米级材料,具有优异的光学性能、力学性能以及反应活性,在导电材料的制备领域具有广阔的应用前景。本文简要介绍了基于纳米纤维素的柔性导电材料的制备原理,对利用不同导电介质制备获得的柔性导电材料进行了总结,并针对纳米纤维素基柔性导电材料的后续研究做了进一步展望。     

静电纺丝和炭化法制备纳米纤维素储能材料研究进展

为促进纳米纤维素材料在储能领域的应用,综述了以其为原料,采用静电纺丝和炭化技术以及2种方法结合制备用于电池和超级电容器等电极材料和隔膜材料的工艺。通过分析发现:静电纺纳米纤维素材料具有电化学性能优异、柔性较好等优点,可用作增强材料与导电材料复合使用;炭化处理纳米纤维素材料具有独特微孔结构,比表面积大等特点,其存在的形态主要有气凝胶、纳米纤维膜及薄膜等;重点分析了2种方法叠加制备纳米纤维素材料在储能领域应用中存在的问题;提出构建环保、形态结构多样的天然基材储能器件是未来的发展方向,指出静电纺丝和炭化制备纳米纤维素材料在柔性储能器件和小巧型移动端储能设备中具有较好应用前景。     

超级电容器中纳米纤维素基水凝胶电极的研究进展

纳米纤维素表面含有大量羟基且长径比高，具有较好的润湿性和分散电活性材料的能力，是一种较好的电极材料基底，可作为超级电容器电极材料的优先选择。但是其缺点在于导电性不高，需要加入导电材料进行提升。本文归纳了纳米纤维素基水凝胶电极的分类，探讨了纳米纤维素基水凝胶电极的合成方法，对比分析了不同导电材料的纳米纤维素基水凝胶电极的电化学性能，并对其在未来应用领域的发展前景进行了展望。     

导电复合纤维基柔性应变传感器的研究进展

为促进导电复合纤维在柔性应变传感器领域的应用,从导电材料和柔性基体的结合方式出发,对传感器的制备方法进行综述分析,其制备方法主要分为3类,包括导电材料/柔性基体匀质复合纤维、导电材料包覆柔性纤维和柔性基体包覆导电纤维。在此基础上,对3类导电复合纤维传感器的性能进行比较分析,总结了各导电网络的传感性能。分析发现纤维的形变行为和导电网络的压阻效应决定了传感器的应变性能和敏感性,导电材料和柔性基体的界面作用是影响传感器稳定性和耐久性的关键因素,复合纤维及纤维集合体和多重导电的网络结构的研发有利于高性能传感器的开发。最后,介绍了导电纤维柔性应变传感器的应用情况和发展趋势,并提出了今后的研究方向。     

纤维素基柔性导电材料的研究进展

纤维素基柔性导电材料具有良好的柔韧性、对环境友好、较高的导电率等优点,因而在智能可穿戴设备中具有很大的应用潜力。文中列举了纤维素基导电材料的制备方法,详细阐述了纤维素与碳材料、导电聚合物复合得到的柔性导电材料的特点,同时诠释了在纤维素基中掺入N、P、S、B等杂原子以及金属化合物对其导电性能的影响。并提出基于纤维素基柔性导电材料存在的问题和未来发展方向。     

多功能纳米纤维素基水凝胶伤口愈合材料的研究进展

纳米纤维素具有良好的生物相容性和无毒性,基于纳米纤维素的新一代水凝胶伤口愈合材料研究逐渐成为热点,但用纳米纤维素制备水凝胶伤口愈合材料面临诸多挑战,如愈合材料的自愈合、促细胞增殖、抗菌和可注射性能的提高等。本文对纳米纤维素基水凝胶伤口愈合材料以上性能的提高研究进行了综述,重点讨论了纳米纤维素经改性、交联、复合等技术制备纳米纤维素基水凝胶的过程与方法,总结了合成机理并展望了纳米纤维素基水凝胶伤口愈合材料多功能化的发展趋势。     

纳米纤维素/MXene柔性电子器件的制备及应用研究进展

纳米纤维素/MXene复合材料兼顾MXene优异的导电性能、丰富的表面官能团和超高比表面积,以及纳米纤维素基材料优良的力学性能和机械稳定性,成为应用于柔性传感、电磁屏蔽、能源储存等领域的热门材料。本文对纳米纤维素/MXene复合材料的制备方法进行论述,重点阐述其作为柔性电子器件在压力传感器、电磁屏蔽材料、超级电容器中的性能及最新研究进展,归纳总结纳米纤维素/MXene复合材料所面临的挑战,并对其未来发展趋势进行展望。     

聚吡咯纤维素纳米晶复合导电材料的制备及其性能表征

摘要：通过硫酸水解法由棉纤维制备纤维素纳米晶,再采用原位化学氧化法,在纤维素纳米晶表面进行吡咯的原位聚合,成功制得包裹聚吡咯的纤维素纳米晶复合导电材料。产物的相貌、结构和性能的研究表明：聚吡咯－纤维素纳米晶复合导电材料表现出核壳结构,纤维素纳米晶与聚吡咯间存在着较强的相互作用有利于聚吡咯均匀地包覆纤维素纳米晶;有机掺杂剂DBSNa由于分子体积大,降低了分子间作用力,其电导率不如无机掺杂剂NaCl,但是热稳定性和比电容好于NaCl,并且显著提高了复合体系的电化学容量,做为超级电容器具有良好的应用前景。     

纤维素基水凝胶作为柔性超级电容器电解质的研究进展

传统超级电容器多使用液态电解质组装，然而其因过多外力而破损时，有毒且易挥发的液体电解质会发生泄露，进而引发安全隐患。为解决这一问题，需要开发柔性超级电容器，以抵抗外部力量的破坏。近年来，纤维素材料因绿色、经济和可再生的特点成为储能装置的理想材料，以纤维素基水凝胶组成的超级电容器表现出良好的物理、化学性能（如高柔韧性、优良的机械强度和导电能力）。纤维素基水凝胶在柔性超级电容器领域的应用已成为当前研究热点。本文综述了纤维素基水凝胶电解质的最新研究进展和成果，包括不同纤维素及其衍生物制备水凝胶电解质的性能与特点。最后，讨论了未来纤维素材料作为新能源材料的研究潜力和挑战。     

半纤维素基水凝胶制备方法研究进展

半纤维素是自然界中含量丰富的一类天然杂多糖,具有可再生、生物相容性好、可生物降解等特点,在水凝胶材料的制备领域逐渐受到关注。本文对近年来利用半纤维素制备水凝胶的化学和物理方法进行了概述,重点介绍了化学交联法中的自由基聚合成胶,在物理交联法中,对通过氢键、结晶、冻融等作用成胶进行了总结。此外,对半纤维素与无机纳米粒子混合制备有机/无机复合凝胶的研究进行了说明。最后,对半纤维素基水凝胶材料的应用前景进行了展望。     

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.     

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.     

低温带皮菜籽粕微粉的不同粒级部分的功能特性

为研究低温带皮菜籽粕微粉的不同粒级部分的功能特性,以经低温脱脂的带皮菜籽粕为原料,经微粉碎后筛分成212~425μm、150~212μm和106~150μm的3个不同粒级的微粉样品,检测这些样品的吸水性、吸油性、乳化性和乳化稳定性、蛋白质体外消化率。结果表明:1 3个不同粒级的微粉样品之间的粗纤维含量存在显著差异,表明三者的结构组成成分有一定差异。23个微粉样品的乳化活性和乳化稳定性随粒度级别的减小而显著增加(P0.01)。33个微粉样品的蛋白质体外消化率随粒度级别的减小而显著增加(P0.01)。4不同粒级带皮菜籽粕微粉样品的吸水性与吸油性受其结构组成物质不同和粒度的双重影响,与粒度的相关性不明显。     

Microbiology of food taints

Fresh and processed foods are often spoilt by the presence of undesirable flavours and odours caused by microbial action. The aim of this paper is to review the current knowledge of microbiologically induced taints that occur in a wide range of foodstuffs, including meats, poultry, fish, crustaceans, milk, dairy products, fruits, vegetables, cereals and cereal products. Examples have been chosen where the compounds responsible for the taint have been identified and sufficient data obtained to demonstrate the involvement of microorganisms. However, in some cases the full identity of the causative organism may not have been elucidated. The types of microorganisms covered by this review include bacteria, fungi, yeasts, actinomycetes and cyanobacteria. Although cyanobacteria do not in general infect foods, their presence in aqueous systems and water supplies can lead to off-flavours in aquatic organisms and processed foodstuffs. Several examples of each of these processes are discussed. Wherever possible, the likely biosynthetic pathway used by the microorganism to produce the offending compound in a foodstuff is indicated.     

Analysis for organic residues from aids to polymerization used to make plastics intended for food contact

Polymers intended for food contact use have been analysed for organic residues which could be attributed to a range of substances employed as polymerization aids (e.g. initiators and catalysts). A wide range of polymers was extracted with solvents and the extracts analysed by gas chromatography-mass spectrometry (GC-MS). The overwhelming majority of substances identified were not derived from aids to polymerization but were oligomers, additives and adventitious contaminants. However, a small number of substances were identified as initiator residues. These included tetramethylsuccinonitrile (TMSN) which was observed in two polymers and it derived from recombination of two azobisisobutyronitrile (AIBN) initiator radicals. Methyl benzoate, benzoic acid, biphenyl and phenyl benzoate were detected in one poly(methyl methacrylate) sample and in two polyvinylchlorides and they are thought to be derived from benzoyl peroxide initiator. TMSN was subsequently targeted for analysis of poly-(methyl methacrylate) plastics using proton nuclear magnetic resonance spectrometry (¹     

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

Experiments were performed to characterize the kinetics of the permeation of different medium molecular weight model permeants: bisphenol A, warfarin and anthracene, from liquid paraffin, through a surrogate potential functional barrier (25 microns-thick orientated polypropylene--OPP) into the food simulants olive oil and 3% (w/v) acetic acid. The characterization of permeation kinetics generally observed the permeation models previously reported to explain the experimental permeation results obtained for a low molecular weight group of model permeants. In general, the model permeants exhibited behaviour consistent with their relative molecular weights with respect to (a) the time taken to attain steady-state permeation into the food simulant in which they were more soluble, (b) their subsequent steady-state permeation rates, and (c) their partition between liquid paraffin and the OPP membrane.     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. I: Interlaboratory studies of methods of analysis

This paper describes the first part of a project undertaken to develop mussel reference materials for Paralytic Shellfish Poisoning (PSP) toxins. Two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin (STX) and decarbamoyl-saxitoxin (dc-STX) in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the second part of the project: the certification exercise. In the first study, 18 laboratories were asked to measure STX and dc-STX in rehydrated lyophilized mussel material and to identify as many other PSP toxins as possible with a method of their choice. In the second interlaboratory study, 15 laboratories were additionally asked to determine quantitatively STX and dc-STX in rehydrated lyophilized mussel and in a saxitoxin-enriched mussel material. The first study revealed that three out of four postcolumn derivatization methods and one pre-column derivatization method sufficed in principle to determine STX and dc-STX. Most participants (13 of 18) obtained acceptable calibration curves and recoveries. Saxitoxin was hardly detected in the rehydrated lyophilized mussels and results obtained for dc-STX yielded a CV of 58% at a mass fraction of 1.86 mg/kg. Most participants (14 out of 18) identified gonyautoxin-5 (GTX-5) in a hydrolysed extract provided. The first study led to provisional criteria for linearity, recovery and separation. The second study revealed that 6 out of 15 laboratories were able to meet these criteria. Results obtained for dc-STX yielded a CV of 19% at a mass fraction of 3.49mg/kg. Results obtained for STX in the saxitoxin-enriched material yielded a CV of 19% at a mass fraction of 0.34mg/kg. Saxitoxin could not be detected in the PSP-positive material. Hydrolysis was useful to confirm the identity of GTX5 and provided indicative information about C1 and C2 toxins in the PSP-positive material. The methods used in the second interlaboratory study showed sufficiently consistent analysis results to undertake a certification exercise to assign certified values for STX and dc-STX in lyophilized mussel.     

The Ministry of Environmental Protection Issued "Feasible Technology Guidelines for Pollution Prevention and Control in Wood Pulping Process of the Paper Industry (Trial)" and Two Other Guiding Technical Documents

On December 27t＂, 2013, the Ministry of Environmenta Protection announced that, in order to implement ＂The Environmental Protection Law of the People＇ s Republic of China＂, improve the working system in environmenta protection technologies, and promote technologica advancement in pollution prevention, the Ministry of Environmental Protection sponsored the formulation of three guiding technical documents including ＂Feasible Technology Guidelines for Pollution Prevention and Contro n Wood Pulping Process of the Paper Industry （Trial）＂     

1~(st) Intelli-Tissue~ EcoEc Tissue Machine Supplied by PMP Group Successfully Put into Operation in China

正On April 29th,2014,Intelli-Tissue EcoEc tissue machine supplied by PMP Group successfully put into operation at Hebei Xuesong Paper Co.,Ltd.,this is the first such kind of paper machine of PMP Group in China.