基于桉木预水解液的多形态碳微球的制备研究

以桉木溶解浆生产过程中的副产物预水解液为原料,采用水热碳化工艺对预水解液进行处理,以制备碳微球。探讨了水热碳化过程中聚（4-苯乙烯磺酸-马来酸共聚物）钠盐（PSSMA）用量对碳微球形貌及得率的影响,并探究了不同结构碳微球的成形机理。结果表明,预水解液是制备碳微球的理想碳源,PSSMA可通过在碳微球表面提供静电斥力以调控碳微球形貌,使碳微球由交联的球簇结构转变为单分散微球结构和微球超结构。随着PSSMA用量增加和碳化时间的延长,碳微球及其超结构的粒径均呈先下降再趋于平缓的趋势;但PSSMA对碳微球得率的影响较小。     

活性染料/聚苯乙烯复合胶体微球的制备及其在桑蚕丝织物上的结构生色

为提高纺织品结构生色光子晶体的色彩饱和度,通过静电吸附将黑色活性染料引入带正电聚苯乙烯(PSt)胶体微球表面,制备了一种外表面吸附染料型PSt结构基元(活性染料/PSt微球),采用数码喷印方式在桑蚕丝织物上构建结构生色光子晶体。研究了染料在PSt胶体微球表面的吸附条件和吸附模型,对活性染料/PSt微球的结构形貌及所得光子晶体的排列和结构生色效果进行表征。结果表明:PSt微球表面染料的吸附量随时间、温度和染料用量的增大而增大;该吸附模型符合Langmuir型;活性染料/PSt微球具有典型的核壳结构,微球粒径较吸附前略有增大;白色蚕丝织物表面所构建的活性染料/PSt光子晶体生色结构,微球排列规整有序,呈现鲜艳明亮的结构色。     

微球的制备技术及其在制革工业中的应用

微球是一种具有聚合物壁的微型密封容器,其制备是通过微胶囊化过程实现的。本文综述了微球的结构,并介绍了几种常见的微球制备方法及其特点。微球作为一种新型的功能材料,应用广泛,文中着重介绍了微球在皮革涂饰剂、皮革消光补伤剂、皮革鞣剂等领域的应用。     

淀粉接枝共聚物微球的合成与降解研究

在反相悬浮体系中以K2S2O8-NaHSO3引发N,N'-亚甲基双丙烯酰胺与淀粉的接枝共聚,制备了淀粉接枝典聚物微球.用人工肠液对所得淀粉微球进行体外降解,运用FT-IR、SEM、粒度分析仪对微球及其降解产物进行了表征分析,用正交实验分析了合成因素对微球粒径的影响.结果表明:共聚物微球形态圆整,平均粒径50.2μm,微球中存在酰氨基结构.正交实验表明:N,N'-亚甲基双丙烯酰胺和油水比对微球的平均粒径影响较大;体外降解表明:微球在3～4 h内基本维持稳定聚合结构,之后降解迅速.     

氨基化聚苯乙烯微球的制备及在克伦特罗抗体纯化中的应用

进行氨基聚苯乙烯微球制备方法及其应用于克伦特罗抗体纯化的研究。通过分散聚合法制备聚苯乙烯微球,硝基反应成硝基化聚苯乙烯微球,再还原成氨基化微球。并利用电子显微镜及红外光谱仪对微球形态及结构进行表征。成功制备氨基聚苯乙烯微球后,将微球与盐酸克伦特罗分子发生重氮化反应,得到连接克伦特罗分子的微球。将这种微球免疫亲和吸附分离盐酸克伦特罗的抗体。最后将纯化后的抗体通过紫外检测,电泳检测等方法证明所制备的微球用于抗体的纯化可行。     

果胶酶固定化的载体——磁性壳聚糖复合微球的制备与性能表征

通过化学共沉淀法合成纳米Fe_3O_4粒子,再以Fe_3O_4为磁核采用乳化交联法制备可固定果胶酶的载体——磁性壳聚糖复合微球。通过TEM、SEM、FT-IR等对微球的粒径、形貌、结构、粒径分布和磁响应性进行了表征。结果表明:制得的磁性壳聚糖微球的粒径在50nm左右,分布较窄,且呈规则的球形,红外光谱测定微球的特征官能团结构,表明已包覆了Fe_3O_4粒子;分光光度法表明磁性微球具有很强的磁响应性。     

功能性高分子微球在质子交换膜中的应用性能研究进展

通过分析高分子微球的发展现状和质子交换膜燃料电池的应用现状与前景,探讨了功能性高分子微球的不同化学结构与物理化学性质,以及功能性高分子微球在质子交换膜中的应用性能,介绍了制作聚合物质交换复合膜的4种方法。     

磁性高分子微球及其在食品工业中的应用

磁性高分子微球作为一种高分子材料,已在生物学、细胞学、生物医学、药学和环境保护等领域得到了广泛应用。通过介绍磁性高分子微球的结构类型、特点、制备及在食品工业中的应用,使读者对磁性高分子微球作用有进一步的了解。     

淀粉接枝共聚微球对Cd2+的吸附性能研究

在反相悬浮体系中以K2S2O8-NaHSO3 引发N,N'- 亚甲基双丙烯酰胺与淀粉的接枝共聚,制备淀粉接枝共聚物微球,研究微球对Cd2+ 的吸附行为,利用红外、SEM、X 射线衍射仪和综合热分析仪对微球及其吸附产物进行表征,研究吸附机理。结果表明：微球对Cd2+ 吸附行为符合Langmiur 方程和Freundlich 方程;吸附Cd2+ 使微球的结晶结构被进一步破坏,结晶度下降,同时促进了微球中主链断裂。     

药物载体淀粉微球的可控降解及释药行为研究

模拟人体胃肠环境,对淀粉微球的降解性能进行了研究,使其在人体中的可控降解成为可能;借助FT-IR对微球降解后的结构进行了表征,粒度分析仪跟踪微球降解过程中的粒度变化;以亚甲基蓝为药物模型,考察了淀粉微球的载药及释药行为。结果表明：可以控制微球在3h内基本不降解,12h内缓慢降解;微球载药率约20％,包封率可达90％;微球在0-2.5h释药迅速,释药量31％,2.5-12h均匀释放,释药量40％,12-24h平衡缓释,释药量10％。     

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.     

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.     

Influence des ions sur le pouvoir hydratant de l'ure e: e tude sur peau de porc ex vivo

This study deals with the influence of ions (NaCl and MgSO4) in a W/O emulsion containing 10% urea. Moisturization kinetics are assessed by corneometry on pig skin ex vivo. The formula's influence on urea penetration is measured by infrared spectrometry with an ATR device and the stripping method. Corneometry and spectroscopy were chosen to record simultaneously the hydratation levels and urea localization into superficial cell layers. Urea crystallization after evaporation of emulsions and aqueous solutions is described. Results show that urea does not hydrate nor penetrate when applied to the skin through an aqueous gel. In a W/O emulsion, sodium chloride increases the ability of urea to moisturize without improving penetration. In vitro urea crystallization is disturbed by sodium chloride or magnesium sulphate for solutions and emulsions. This stabilization by ions is correlated with good moisturization values. The stabilization of urea in the solute state provided by ions increases its water epidermal binding capacity without enhancing penetration.