聚乙二醇/膨胀石墨/聚丙烯复合相变材料的制备及表征

以膨胀石墨（EG）为基体,聚乙二醇（PEG）为相变储热介质,利用EG对PEG良好的吸附性能,制备出了PEG/EG/聚丙烯（PP）复合相变材料。采用傅立叶变换红外光谱（FT-IR）、扫描电镜（SEM）、差示扫描量热分析（DSC）等方法对复合相变材料的结构、形貌和热性能进行了表征。结果表明：EG吸附PEG后仍然保持原有疏松多孔的形态,PEG被EG均匀吸附。由于毛细管作用力和表面的物理化学吸附作用,PEG在固-液相变时,很难从微孔中渗透出来。复合相变材料的流变,形态和热性能较好时PEG/EG/PP的比例为73.2/1.8/25。     

超分子聚乙醇类“固-固相变材料”的研究

根据固-固相变材料的性质与结构特点。通过分子设计合成出了一种新型的化合物“4,4-二苯基甲烷二异氰酸甘油酯”（简称为“MTE”）,同时以MDI-MTE为硬段,以聚乙二醇（PEG）为相变单元和软段,通过原位聚合法制备出了一种聚乙醇类超分子固-固相变材料（H-PCM）。利用FT-IR、H^1-NMR、DSC和DMA测试技术。研究了相变材料的结构、相变行为及热稳定性。表明了制备出的是一种新型的、性能优异的相变材料。     

同轴静电纺多级微纳米纤维膜的制备及其相变调温性能

为开发适宜人体温度的相变调温纺织品,采用同轴静电纺丝的方法将聚乙二醇(PEG)作为芯层封装在氮化硼(BN)增强的聚丙烯腈(PAN)壳层中,制备出氮化硼/聚丙烯腈/聚乙二醇(BN/PAN/PEG)复合相变纤维.研究了相变材料配比及BN浓度对纺丝膜形貌、热性能的影响,并对纤维膜进行热成像分析、热重分析表.结果 表明:PEG...     

拉伸细化羊驼毛纤维热定形效果研究

文章选择我国培育的羊驼毛为原料,以羊毛拉伸细化技术为基础,采用单纤维拉伸的方式,通过水浴定形和化学定形2种方法,并以定形效率为指标讨论定形温度、定形时间和试剂浓度对定形效果的影响,结果表明:2种定形方法对拉伸羊驼毛的定形效果在66%～87%之间。水浴定形因定形时间长,定形温度高而定形效果较好。高锰酸钾因氧化性很强,工艺不易控制,定形时间短而定形效果较差。过硫酸钾和过硼酸钠作用缓和,定形时间长,定形效果较好。     

聚乙二醇在相变纺织材料上的应用

在对聚乙二醇(PEG)进行冷热循环处理时,其超分子结构会发生某种相的转变,从而改变宏观性质而具有特殊的蓄热调温性能.PEG的相变温度随聚合度变化而变化,在服装方面一般采用30～35℃,接近于体温.以PEG作为相变材料用不同方式添加到纺织材料上,可以使织物具有双向调温的特殊功能.     

二元复合相变储能材料制备及调温性能

为达到控制调节储能材料相变温度之目的,依据施罗德理论对二元相变储能材料进行共混,并采用溶胶-凝胶法复合二元相变储能材料,以解决储能材料在"固-液"相变过程中的液态渗漏问题。试验表明,两种相变储能材料的适宜摩尔分数比为5∶5;通过DSC分析可知,复合工艺未对相变材料的热性能产生影响,二元复合相变储能材料整理到织物上后可达到良好的调温储能效果。     

环境友好聚己内酯基复合相变纤维膜的制备及其性能

为实现聚已内酯(PCL)环境友好高分子材料在相变储能领域的应用,以PCL为壳层支撑材料,聚乙二醇(PEG)为核层相变材料,羟基化多壁碳纳米管(MWCNTs-OH)作为导热增强材料分散至核层溶液中,采用同轴静电纺丝法制备了PCL/PEG/MWCNTs-OH复合相变纤维膜,并对其结构和性能进行分析。结果表明：复合相变纤维表面光滑,具有较为完善的核-壳结构;复合相变纤维膜呈现较高的断裂应力和断裂应变,添加质量分数为4%的MWCNTs-OH时复合相变纤维膜的断裂应力为7.43 MPa,断裂应变为132.2%;核层中MWCNTs-OH的加入,提高了复合相变纤维膜的导热性能和热稳定性,而其相变温度和焓值则无明显变化,相变温度在38.85～39.35℃之间,略高于人体的正常温度,在储能调温生物医用材料领域具有潜在的应用价值。     

制备参数对温控复合织物性能的影响

为开发一种三明治结构的温控复合织物,使用静电纺丝法制备的相变纳米纤维膜作为织物的中间层,使用黏胶织物及羊毛织物分别作为织物的内外层。利用扫描电镜(SEM)和差式扫描量热仪(DSC)分别表征相变纳米纤维膜的形貌和热性能,考察相变材料的含量及相变纳米纤维膜的厚度对温控复合织物保温性和透气透湿性的影响。结果表明:相变纳米纤维膜中纳米纤维呈圆柱形,纤维表面不光滑并有折皱,其熔融相变温度为28.02℃;相变材料的含量越多、相变纳米纤维膜的厚度越大,则温控复合织物的保温性能越好,但其透气透湿性能有所下降。     

聚酰胺6/聚乙二醇相变调温纳米纤维的结构与性能

将相变材料PEG掺杂到高聚物PA6中去,通过静电纺丝制备相变调温纳米纤维。通过扫描电镜、红外光谱、热分析仪以及织物强力仪等测试方法对相变纳米纤维的结构与性能进行表征。结果表明：PEG的共混改善了纺丝液黏度,随着PEG共混比例的提高,纳米纤维的直径提高;PA6与PEG有氢键结合,随着PEG共混比例的提高,相变纳米纤维的熔融温度和熔融焓值逐渐增大,相变纳米纤维具有良好的蓄热调温性能;随着相变材料PEG共混比例的提高,相变纳米纤维的强力有一定下降。结论：该纳米纤维是一种良好的调温储能材料。     

热敏纳米纤维的制备及性能研究

相变材料是利用相变过程中的吸、放热,达到对热能进行储存和控制的一种材料。文中以聚乙二醇（PEG）为相变材料,聚乙烯醇（PVA）为封装材料,氧化石墨烯（GO）为导热材料,采用静电纺丝法制备了PVA-PEG-GO相变纳米纤维,并对其热行为进行分析。结果表明：纤维中PVA与PEG含量比为7∶3时纤维具有较好的形貌,以及较好的储能能力和较为合适的相变温度。红外热成像分析和香精释放研究表明：加入GO有效提高了相变纳米纤维的热传递效率。     

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