阳离子型木质素基絮凝剂的半干法合成及在造纸废水处理中的应用

在以预水解木质素（PHL）为原料、甲基丙烯酰氧乙基三甲基氯化铵（METAC）为单体、K2S2O8为引发剂条件下,通过自由基聚合反应,半干法合成了阳离子型木质素接枝聚合物（PHLM）。采用元素分析仪、电荷滴定仪、傅里叶红外光谱仪（FT-IR）、核磁共振氢谱分析仪（1H-NMR）对制备的PHLM的结构与性能进行表征。以PHLM的溶解度、接枝率和电荷密度作为考核指标,对反应条件进行了优化;并探索了PHLM在造纸废水处理中作为阳离子型絮凝剂的应用效果。结果表明,制备PHLM的最佳条件为：反应浓度60%、METAC/PHL单体摩尔比2∶1、引发剂用量3.0%、pH值4.0、温度80℃,此条件下制备的PHLM溶解度为9.65 g/L,电荷密度为3.88 mmol/g,接枝率为214.93%。当PHLM用量为25 mg/L、pH值为5.0时,PHLM对造纸废水的处理效果最优,浊度和COD_Cr去除率分别达93.3%和65.6%。     

过硫酸钾-连二亚硫酸钠氧化还原体系在蚕丝接枝增重上的应用

针对甲基丙烯酰胺(MAA)接枝增重真丝纱线中采用过硫酸钾(KPS)为引发剂而出现的增重丝泛黄的问题,提出用过硫酸钾(KPS)-连二亚硫酸钠(SH)氧化还原体系引发真丝纱线接枝增重以提高增重丝白度,研究了各种工艺参数对接枝增重率的影响。结果表明：KPS-SH氧化还原体系引发MAA接枝增重真丝纱线较过硫酸钾引发增重丝白度高;当MAA的浓度为0.4mol/L时,引发剂KPS-SH和单体MAA的质量比为5:100,其中KPS与SH的摩尔比为10:3,在pH值为3,70℃接枝反应70min的工艺条件下,真丝纱线接枝增重率较KPS引发增重丝基本不变,白度较KPS引发增重丝提高19左右。     

接枝共聚制备阳离子硫酸盐浆

以丙烯酰胺和甲基丙烯酰氧基乙基三甲基氯化铵与纸浆纤维接枝共聚制备了阳离子硫酸盐浆。实验结果表明,当引发剂硝酸铈铵的用量(对绝干浆)从2%提高到8%时,纸浆的接枝率和阳离子表面电荷密度稳步提高;进一步提高引发剂的用量,纸浆的接枝率和阳离子表面电荷密度变化平坦。随着反应温度的升高,纸浆的接枝率和阳离子表面电荷密度先升后降,当温度为50℃时接枝率和阳离子表面电荷密度最高。在浆浓较低时,随着浆浓的提高,接枝率和阳离子表面电荷密度提高,当浆浓超过11%时,接枝率和阳离子表面电荷密度下降。当甲基丙烯酰氧基乙基三甲基氯化铵在总单体中摩尔比例为40%～50%时表面电荷密度最高。通过红外光谱分析发现,丙烯酰胺和甲基丙烯酰氧基乙基三甲基氯化铵已成功地接枝到硫酸盐浆上。     

阳离子松香/AKD中性施胶剂的制备及应用

以N甲-基吡咯烷酮（NMP）为助溶剂,丙烯酰胺（AM）、甲基丙烯酰氧乙基三甲基氯化铵（DMC）、丙烯酸十八酯（ODA）、苯乙烯（St）为单体,通过无皂乳液共聚反应合成了阳离子高分子乳化剂,并制备了阳离子松香/AKD乳液。研究了高分子乳化剂合成中AM、DMC用量对乳液稳定性的影响,乳液中松香、AKD、高分子乳化剂质量比对乳液稳定性及施胶性能的影响,以及纸浆pH值、乳液用量对施胶效果的影响。结果表明：AM用量为35%,DMC用量为15%,松香、AKD和高分子乳化剂的质量比为11∶4∶3时乳液稳定性较好。适宜的施胶条件为：采用逆向施胶工艺,松香、AKD和高分子乳化剂的质量比为11∶4∶3,纸浆pH值为6,乳液用量为1%。     

糖苷化对芸豆分离蛋白功能性质的影响

本研究通过干热接枝反应制备糖苷化芸豆蛋白,探讨了不同的蛋白与糖摩尔比对糖基化反应和芸豆蛋白物化性质及功能特性的影响.研究结果表明:适度的蛋白与糖摩尔比有利于糖苷化反应,蛋白与乳糖摩尔比为1:30时,糖苷化度是48%,而蛋白与乳糖摩尔比是1:100时,糖苷化度仅为14%.干热处理诱导芸豆蛋白质的变性和聚集,这一点在蛋白的溶解度和排阻色谱分析中得到证实,表现为降低蛋白质溶解度(pH 2～10)和排阻色谱峰的总积分面积(pn 7.0).糖基化反应可以抑制干热过程中蛋白质的变性和聚集行为,在中性偏碱性以及极端酸性(pH 2～3)条件下,糖苷化蛋白具有较高的蛋白溶解度(相对于干热处理的芸豆蛋白).在较高糖苷化程度条件下(蛋白质与乳糖摩尔比为1:30),糖苷化显著改善芸豆蛋白质的溶解度(pH 4～6).此外,乳糖与蛋白质共价连结,这一点在排阻色谱分析中的得到证实.     

两性聚合物的制备及其应用研究

为制备一种对染色废水有显著脱色效果的絮凝剂,采用溶液聚合法,将两种阳离子单体二甲基二烯丙基氯化铵（DMDAAC）和丙烯酰氧乙基三甲基氯化铵（DAC）分别与丙烯酰胺（AM）,丙烯酸（AA）共聚,合成了两性聚合物。研究了阳离子单体种类和引发体系对两性聚合物合成的影响,单体配比对合成产物特性黏数[η]的影响,确定了合适的制备条件：以AM、AA和DAC为单体,过硫酸铵为引发剂,单体的质量比为AM：AA：DAC=6：2：4、体系pH为6．5。探讨了聚合物的用量、阴阳离子比例以及染色废水的温度、pH对脱色效果的影响。结果表明,所制备的两性聚合物,对皮革染色废水的脱色率达92％以上。常温（25℃）条件下,合成产物对皮革染色废水脱色的较佳pH值为3～4。     

氰乙基球形木质素吸附剂对亚甲基蓝的吸附行为研究

利用反相悬浮聚合技术,采取两步升温法制备球形木质素珠体（SLB）;以Fe2+/H2O2为引发体系,在SLB上成功接枝丙烯腈单体,制得氰乙基球形木质素吸附剂（SLBA）。实验探索该吸附剂对亚甲基蓝的吸附行为,考察了SLBA投加量、吸附时间和pH值等因素对吸附的影响,并依据动力学和热力学模型进行分析。结果表明,SLBA对亚甲基蓝的吸附过程符合二级动力学模型;在308 K、pH值为7的溶液中,SLBA吸附约1 h达到平衡,亚甲基蓝去除率达到98%左右,SLBA的饱和吸附容量为87.0 mg/g;吸附过程同时符合Langmuir和Freundlich方程,整个过程是自发的吸热反应过程,并以物理吸附为主。     

OS-PVA/P(DMC-AM)双网络水凝胶的制备及其吸附性能研究

本研究在氧化淀粉（OS）和聚乙烯醇（PVA）的存在下,通过甲基丙烯酰氧基乙基三甲基氯化铵（DMC）和丙烯酰胺（AM）间简单的自由基聚合,制备了力学性能良好、可重复循环使用的双网络水凝胶。当OS溶液质量分数9%时,制备的水凝胶性能最佳,其压缩模量可达2.01 MPa,润胀度仅11.16 g/g,在25℃下对pH值8,浓度200 mg/L的亚甲基蓝溶液吸附480 min时吸附量最高,达602.6 mg/g。经过5次吸附-脱附过程后,双网络水凝胶对亚甲基蓝的去除率仍高达94.8%,脱附率74.2%。     

交联型两性聚丙烯酸酯的制备及对纸张性能的影响

以聚乙烯醇（PVA）为高分子胶体稳定剂,甲基丙烯酸缩水甘油酯（GMA）为交联剂,丙烯酰胺（AM）、丙烯酸（AA）、丙烯腈（AN）、甲基丙烯酰氧乙基三甲基氯化铵（DMC）为共聚单体,通过无皂乳液共聚制备了交联型两性聚丙烯酸酯表面施胶剂。对阳离子基单体和交联性单体的用量、合成工艺条件等对纸张增强效果的影响进行了探讨。确定了较佳的合成条件：种子聚合法,w（PVA）=3%-4%,w（DMC）=2%-2.5%,w（GMA）=0.7%,反应温度85℃,反应时间5 h。通过差示扫描量热仪（DSC）、扫描电子显微镜（SEM）和粒度分布分析仪对乳液和纸张性能进行了检测与表征。实验证明,在pH值78条件下,以2%的聚合物乳液进行表面施胶时,可使环压指数、耐破度、抗张指数分别达到16.6 N·m/g、440 kPa、40.6 N·m/g,耐折度10次,与空白样相比均可提高30%以上。     

阳离子胶原蛋白絮凝剂的制备及表征

以皮革废弃物提取的明胶为原料,丙烯酰胺(AM)和丙烯酰氧乙基三甲基氯化铵(DAC)为单体(AM∶DAC摩尔比为4∶1),叔丁基过氧化氢和焦亚硫酸钠为引发剂,接枝共聚合成了阳离子胶原蛋白絮凝剂P(C-AM-DAC)。以絮凝剂对油田模拟废水的浊度去除率为指标,通过响应面法优化了P(C-AM-DAC)接枝共聚条件:m(明胶)∶m(单体)为1∶1.92、引发剂用量0.03mol/L、接枝温度44.2℃、接枝时间3.0h。在此条件下制备的新型絮凝剂表现出优异的絮凝效果,对油田模拟废水中污染物去除率可达91.3%。同时利用傅立叶变换红外光谱(FT-IR)和热重分析(TGA)对其进行表征。     

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