壳聚糖/植酸钠/纳米TiO_2-ZnO在木材表面的自组装及抗紫外性能探究

采用层层自组装方法在木材表面负载了壳聚糖/植酸钠/纳米TiO_2-ZnO二元复合膜(CH/SP/纳米TiO_2-ZnO),并设置了以组装方式、聚阴离子和纳米粒子溶液浓度及比例、浸泡时间、负载层数为变量的多组试验,探讨了二元复合膜在木材表面的抗紫外机理。通过配备有能谱仪(EDS)的扫描电子显微镜检测(SEM)和人工加速紫外老化测试,处理后的样品比未处理素材具有更好的抗紫外效果。结果显示,二元复合膜具有协同作用,较一元薄膜能进一步提高功能膜的性能效果,且充分的处理时间可以显著优化膜的性能,此外,负载层数与浓度不一定越大越好,本试验中的改良效果最佳参数为处理时间90 min,组装层数5层,二元TiO_2-ZnO共混,聚阴离子与纳米粒子浓度比例为2:1。     

壳聚糖季铵盐/硅杂化膜对棉纤维的表面修饰

为增强棉纤维的表面性能,制备了2,3-环氧丙基十二烷基二甲基壳聚糖氯化铵衍生物,利用所制备的壳聚糖季铵盐为阳离子化试剂,通过溶胶-凝胶法,硅偶联剂环氧丙基三甲氧基硅氧烷的水解缩合,在棉纤维表面上原位自发构筑壳聚糖季铵盐/硅杂化膜。SEM,EDS 结果证实了壳聚糖季铵盐/硅杂化膜存在于纤维表面上。经壳聚糖季铵盐/硅杂化膜修饰后的棉纤维表面润湿性能、吸附性能均发生了显著的变化。随着沉积时间延长,纤维表面的疏水性能以及抗紫外性能增强。     

基于纳米CuS/RGO制备超疏水多功能棉织物

褶皱状纳米CuS/RGO结合低表面能物质的聚二甲基硅氧烷(PDMS),通过浸轧法制备超疏水多功能棉织物。采用红外光谱仪(FTIR)、X射线衍射仪(XRD)、场发射扫描电子显微镜(SEM)、接触角测量仪和织物抗紫外性测试仪对样品形貌、结构及性能进行分析。结果表明,利用PDMS的交联黏结作用成功将CuS/RGO负载于棉纤维上,PDMS膜包裹在棉纤维和CuS/RGO表面,整理棉织物表面具有微观粗糙结构,具有较好的超疏水性能和抗紫外性能,接触角达到了158.4°,紫外线防护系数(UPF)为851.2,并且自清洁性能优良。     

PBA/TiO2接枝复合整理剂及其整理棉织物的抗紫外线性能

 通过原位乳液聚合制备了TiO2粒子表面接枝率为13.5%的PBA/TiO2接枝复合胶乳,以其为整理剂,通过浸轧对棉织物进行抗紫外线整理。研究表明：经PBA/TiO2接枝复合整理剂整理的棉织物具有优异的抗紫外性能和耐洗性能。扫描电镜观察发现,经PBA/TiO2整理的棉纤维表面TiO2粒子附着量大,分散更均匀。认为是纳米TiO2粒子表面存在的PBA接枝聚合物抑制了TiO2在棉纤维表面的团聚倾向,提高了TiO2与纤维聚合物的相容性和结合牢度,因而经接枝整理剂整理的棉织物具有良好的抗紫外性能。     

含纳米级凹土胶体粒子的PTT/桑皮/棉混纺纱开发

为纺制具有防紫外和抗菌性能的复合功能纱线,将纳米级凹土胶体粒子均匀分散于熔融的PTT切片中制备纺丝液进行纺丝,在一定的工艺条件下将长丝切断制备具有持久防紫外和抗菌性能的PTT短纤,探讨了将含纳米级凹土胶体粒子的PTT短纤与桑皮纤维和棉纤维混纺的混纺工艺,通过合理控制各道工序的工艺参数,成功地开发了混纺纱,经测试并与普通PTT混纺纱进行性能对比分析得出:纱线的各项性能均符合质量要求,能够用来制备复合功能户外休闲服装面料。     

Zn~(2+)离子印迹Fe_3O_4-壳聚糖纳米粒子的制备及对Zn~(2+)吸附性能的研究

采用一步共沉淀法,以Zn2+为模板,戊二醛为交联剂制备了磁性Fe3O4-壳聚糖纳米印迹粒子,分别用X-射线衍射、傅里叶红外光谱、热重分析等手段对该纳米印迹粒子进行结构和性能表征,利用原子吸收光谱研究pH,Zn2+初始浓度,温度等对其吸附性能的影响,并探讨了其对不同重金属离子的吸附选择性.实验结果表明:壳聚糖很好地包覆在纳米粒子表面,且未改变Fe3O4的尖晶石结构;纳米粒子中壳聚糖的含量约为10.2%;pH=6为较理想的吸附条件,当Zn2+初始浓度为200 mg/L时,单位吸附量最大,约为28.9 mg/g;降低温度有利于吸附的进行.印迹粒子能够较好地选择性吸附锌离子.     

壳聚糖等离子体处理对棉纤维性能的影响

研究棉纤维在低温等离子体的作用下,经壳聚糖改性处理后的性能变化情况.应用扫描探针显微镜、红外光谱等测试了改性前后棉纤维表面和化学结构的变化,并对比了改性前后棉纤维吸湿性能、强力和抗菌性能,结果表明,改性后的棉纤维强力有一定的下降.但具有了一定的抗茵性能,并且吸湿性也有所改善.     

PVA/PEI超细纤维负载纳米钯杂化材料的制备

通过静电纺丝技术制得了聚乙烯醇(PVA)/聚乙烯亚胺(PEI)超细纤维膜,使用戊二醛蒸汽交联使其具有水稳定性,进而将交联后的PEI/PVA超细纤维膜浸入PdCl2溶液中至吸附平衡,以硼氢化钠(NaBH4)为还原剂,于超细纤维膜表面原位合成Pd纳米粒子.用场发射扫描电子显微镜(FE-SEM)、傅里叶变换红外(FTIR)、紫外可见分光光度计(UV)等技术表征了PVA/PEI超细纤维,交联后的PEI/PVA超细纤维膜及负载有Pd纳米粒子的PEI/PVA超细纤维膜.研究表明:交联后的PVA/PEI超细纤维膜具有良好的水相稳定性,Pd纳米粒子在PVA/PEI超细纤维膜表面均匀分布,负载有Pd纳米粒子的PEI/PVA超细纤维膜对Cr(Ⅵ)的还原反应具有良好的催化性能.     

羟基磷灰石抗菌复合材料在纺织品功能整理中的应用

介绍了羟基磷灰石抗菌复合材料的制备方法[载银羟基磷灰石(共沉淀法和表面改性法,从经济角度考虑,倾向于使用表面改性法)、纳米TiO2/羟基磷灰石(在纳米TiO2表面包裹羟基磷灰石粒子、制得负载型光催化剂、微弧氧化、溶胶-凝胶、电沉积等)]、抗菌、光催化机理以及在纺织品功能整理中的应用(载银羟基磷灰石在织物抗菌整理中的应用、纳米TiO2/HAP复合材料在织物抗菌、防紫外整理中的应用).     

皮革用有机/无机纳米杂化抗菌剂的制备和性能

以制备皮革抗菌剂为目标,利用原子转移自由基聚合法在TiO2纳米粒子表面接枝丙烯酸酯类聚合物,并进行季铵化处理得到聚合物季铵盐,然后将改性后的纳米粒子负载在皮革表面。结合傅里叶变换红外光谱（FT—IR）、光电子能谱（XPS）、热重分析（TGA）、扫描电子显微镜（SEM）、抗菌性能评价等测试手段,系统研究了改性前后纳米TiO2粒子对皮革抗菌性能的影响。结果表明：丙烯酸酯类聚合物通过共价键被引入到TiO2纳米粒子表面,季铵化聚合物的接枝率达到48％。负载后,改性纳米粒子均匀分布在皮革纤维表面。负载改性TiO2纳米粒子的皮革具有优异的抗细菌性能。培养6h后,对于金黄色葡萄球菌的抑制率达到99．99％。     

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.     

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.     

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.     

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.