纤维素接枝环糊精水凝胶的制备及其性能研究

以环氧氯丙烷作为化学交联剂,在碱性均相纤维素溶液中,将β-环糊精接枝到微晶纤维素上,合成了接枝β-环糊精的功能性纤维素基水凝胶。研究了水凝胶的溶胀动力学和温敏性能,发现该水凝胶对温度敏感。考察了该水凝胶对甲基橙、亚甲基蓝的吸附性能,实验结果表明,接枝β-环糊精的纤维素基水凝胶对甲基橙和亚甲基蓝具有很好的吸附效果,其吸附容量分别达到3.48mg/g、1.42mg/g,其脱附性能也较好。并运用差热扫描(DSC)、热重(TGA)和扫描电镜(SEM)对该水凝胶进行分析。     

高吸附性PVA-co-PE纳米纤维水凝胶的制备及废水处理

以PVA-co-PE纳米纤维为基底,添加β-环糊精聚合物制备了一种高效水凝胶吸附剂。通过SEM、ATR等测试方法对其形貌和成分进行分析。同时以亚甲基蓝染料为模拟污染物,研究了不同影响因素对吸附效果的影响,并对其吸附热力学与动力学进行分析研究。结果表明,添加了β-环糊精聚合物的PVA-co-PE纳米纤维水凝胶对亚甲基蓝有着很好的吸附性,吸附过程符合Langmuir吸附模型,最大吸附量为61.596 mg/g。在亚甲基蓝初始质量浓度为200 mg/L以下时,去除率可达98%以上。该水凝胶对亚甲基蓝溶液的吸附符合二级动力学吸附模型。同时该改性水凝胶有着较好的循环吸附性能,循环吸附4次后去除率仍在50%以上。对不同染料进行吸附,吸附效果为甲基紫亚甲基蓝直接湖蓝5B活性艳蓝19。     

单宁/羧甲基纤维素水凝胶的制备及吸附性能

以单宁、羧甲基纤维素为单体,环氧氯丙烷为交联剂,制备单宁/羧甲基纤维素复合水凝胶。通过单体质量比、交联剂用量、交联时间3个因素,优化单宁/羧甲基纤维素复合水凝胶的制备工艺。以阳离子染料亚甲基蓝为有机吸附质,考察了染料初始质量浓度、pH、温度等因素对水凝胶吸附性能的影响。正交实验表明,制备单宁/羧甲基复合水凝胶的最佳条件为:单宁/羧甲基纤维素质量比1.2∶1.0,环氧氯丙烷用量0.8%,交联时间36 h。吸附实验表明,当亚甲基蓝初始质量浓度大于1 500 mg/L时,水凝胶中的空隙被填充,吸附位点趋于饱和,吸附量达到最大530.43 mg/g;pH在中性条件下有利于增加水凝胶与亚甲基蓝之间的静电吸附与络合作用,吸附率为80.2%;热力学数据表明,水凝胶对亚甲基蓝的吸附为自发放热物理吸附过程,在常温条件下更利于吸附的进行。     

棉秆皮微晶纤维素/β-环糊精气凝胶纤维的制备及吸附性能

棉秆皮微晶纤维素和β环糊精在尿素体系下低温溶解制备纺丝溶液,以湿法纺丝和冷冻干燥法制备棉秆皮微晶纤维素/β-环糊精气凝胶纤维,用以吸附染料废水中的亚甲基蓝。采用单因素方法分析确定了β-环糊精添加量,以及吸附条件对亚甲基蓝吸附量的影响。结果表明：棉秆皮微晶纤维素与β-环糊精质量比为5∶2,吸附温度20℃,吸附时间5 h, pH值=7时,制备的气凝胶纤维吸附效果好;染液质量浓度为50 mg/L时,棉秆皮微晶纤维素/β-环糊精气凝胶纤维对亚甲基蓝的吸附量最大,为56 mg/g;吸附过程符合准二级吸附动力学模型和Langmuir吸附等温线模型。扫描电镜结果说明添加β-环糊精的气凝胶纤维孔径比纯棉秆皮微晶纤维素气凝胶纤维孔径更大,形状更规则,对染料废水中亚甲基蓝的吸附效果更好。     

γ PGA水凝胶对亚甲基蓝染液的脱色处理

利用两种相对分子质量的γ 聚谷氨酸（γ PGA）制备水凝胶,将其应用于亚甲基蓝溶液脱色处理,并采用FT IR及SEM法对水凝胶的三维网络结构进行了表征。结果表明,两种凝胶对染料的吸附量均随pH值和γ PGA浓度的增加而增加,相对分子质量100万的凝胶对染料的吸附受转速影响较小,相对分子质量70万的凝胶在转速120 r/min时对染料的吸附会迅速增加。吸附动力曲线表明,相对分子质量100万的干凝胶0.2 g在1 g/L的染液中,2 h内可基本达到吸附平衡,最大吸附染料量为496 mg/g;相对分子质量70万的干凝胶0.2 g在1 g/L的染液中,4 h内可基本达到吸附平衡,最大吸附染料量为465 mg/g。     

多孔木素/醋酸纤维素基微纳米碳纤维的制备及功能化应用

采用静电纺丝的方法,通过调整木素与醋酸纤维素的质量比来制备具有多孔结构的前驱体纤维,然后经预氧化和碳化得到具有不同孔隙结构的木素/醋酸纤维素基微纳米碳纤维,并对制备所得的碳纤维进行傅里叶变换红外光谱、热重分析、场发射扫描电子显微镜、氮气吸附脱附以及亚甲基蓝吸附等表征。结果表明,木素与醋酸纤维素纺丝混合性良好,混纺之后前驱体纤维热稳定性与玻璃化转变温度均优于醋酸纤维素;当醋酸纤维素与木素质量比为8:2时,制备的多孔微纳米碳纤维直径较细,孔洞分布均匀,比表面积最大为173.42 m~2/g,水接触角最大为129.3°,亚甲基蓝吸附量最优,吸附量达到49.30 mg/g,且循环使用7次之后其亚甲基蓝吸附量仍能达到初次使用的95%以上。     

双模型介孔硅对亚甲基蓝和罗丹明B的吸附研究

采用溶胶-凝胶法制备了双模型介孔二氧化硅材料,以其为吸附剂探究用于亚甲基蓝和罗丹明B的吸附性能。通过XRD、TEM、N2吸附-脱附等对样品进行了表征。结果表明,双模型介孔二氧化硅呈现约为3 nm和31 nm两种孔径,对两种染料的吸附符合Freundlich等温吸附方程,其吸附动力学符合准二级动力学。吸附后,亚甲基蓝在p H为5、罗丹明B在p H为5～10的缓冲溶液中便于脱附,而且亚甲基蓝在无水乙醇体系中的脱附效果最优。双模型介孔二氧化硅作为吸附剂可重复再生使用。     

麦秆水凝胶的制备及其对Cu(Ⅱ)、Mn(Ⅱ)的吸附

以麦秆为原料,通过自由基接枝共聚反应制备对Cu(Ⅱ)、Mn(Ⅱ)具有高效吸附性能的麦秆水凝胶。实验中先将麦秆粉碎成粉,用氢氧化钠溶液超声纯化,然后以过硫酸铵为引发剂,以丙烯酸和丙烯酰胺为单体,以N,N-亚甲基双丙烯酰为交联剂,得到麦秆水凝胶。通过傅里叶红外光谱仪（FT-IR）、扫描电子显微镜（SEM）、热重分析仪（TGA）等对水凝胶进行表征,并研究其对Cu(Ⅱ)、Mn(Ⅱ)等重金属离子的吸附性能。结果表明,通过FT-IR和SEM分析显示麦秆水凝胶成功制备;麦秆水凝胶对Cu(Ⅱ)、Mn(Ⅱ)具有良好的吸附性能,吸附过程符合准二级动力学模型,在Cu(Ⅱ)、Mn(Ⅱ)离子浓度分别为500 mg/L和400 mg/L,振荡吸附6 h后吸附量分别达到238.1 mg/g和176.9 mg/g。     

纤维素/MXene复合气凝胶的制备及其对亚甲基蓝的吸附机制

将新型二维纳米材料掺杂进凝胶三维结构框架材料得到复合凝胶，可以增强凝胶对亚甲基蓝染料(MB)吸附能力，对于研究去除印染废水具有重要意义。以微晶纤维素为凝胶框架材料，MXene(MX)为功能掺杂剂，通过冷冻干燥法制备纤维素/MXene复合气凝胶。利用扫描电子显微镜、傅里叶红外光谱、EDS元素分析等表征其微观形貌及化学结构，并探究对亚甲基蓝的吸附作用。结果表明：制备的MXene呈现二维层状结构，掺杂后复合气凝胶呈现三维多孔结构，且MXene的加入提高了复合气凝胶的孔隙率；复合气凝胶的吸附效果远远高于纯纤维素气凝胶，对亚甲基蓝的吸附率高达80%;当温度为20℃,染料溶液初始质量浓度为50 mg/L时，复合气凝胶质量为100 mg,吸附效果最佳，通过动力学模型拟合分析，复合气凝胶吸附亚甲基蓝染料主要吸附过程为化学吸附。     

疏水纤维素柔性凝胶材料吸附苯酚性能研究

以粉末状纤维素和丙烯酰胺为单体,过硫酸钾为引发剂,N, N-亚甲基双丙烯酰胺为交联剂,制备了纤维素柔性凝胶材料（MPCs）,经疏水改性处理后得到疏水纤维素柔性凝胶材料（T-MPCs）,并用于吸附分离溶液中的苯酚。通过改变苯酚溶液pH值、初始浓度和吸附剂添加量,研究T-MPCs吸附苯酚的影响因素和吸附机理。结果表明,T-MPCs是一种表面多孔的柔性凝胶材料,在吸附温度25 ℃、溶液pH值7.0、吸附时间360 min、初始浓度200 mg/L的条件下,T-MPCs添加量为1000 mg/L时,其对苯酚的平衡吸附量为148.9 mg/g,吸附过程符合准二级动力学模型及Freundlich等温吸附模型,具有良好的再生能力,5次循环再生后,T-MPCs吸附性能下降15.2%。     

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.     

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     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press