Thermoresponsive poly(oligo ethylene glycol acrylates)

Thermoresponsive polymers have been the subject of numerous publications and research topics in the last few decades mostly driven by their easily controllable temperature stimulus and high potential for in vitro and in vivo applications. P(NIPAAm) is the most studied amongst these polymers, but recently other types of polymers are increasingly being investigated for their thermoresponsive behavior. In particular, polymers bearing a short oligo ethylene glycol (OEG) side chain have been shown to combine the biocompatibility of polyethylene glycol (PEG) with a versatile and controllable LCST behavior. These polymers can be synthesized via controlled radical polymerization techniques from various monomers consisting of an OEG chain and a polymerizable group like a (meth)acrylate, styrene or acrylamide. OEG acrylates offer significant advantages over, e.g., OEG methacrylates as the lower hydrophilicity of the backbone facilitates thermoresponsive behavior with smaller, more defined side chains. Furthermore, PEG acrylates can be polymerized using all major controlled radical polymerization techniques, unlike OEG methacrylates. This review will focus on OEG acrylate based (co)polymers and will provide a comprehensive overview of their reported thermoresponsive properties. The combination and comparison of this data will not only highlight the potential of these monomers, but will also serve as a starting point for future studies.     

SANS studies on catalyst ink of fuel cell

The structure of solid polymer electrode and catalyst ink of fuel cell has been investigated by focusing‐ (FSANS) and contrast‐variation small‐angle neutron scattering (CV‐SANS). The solid polymer electrode, consisting of carbon (C), platinum, and ionomer (polymer, P), exhibited a power‐law function with two asymptotes, i.e., from I(q) ～ q^?1 to I(q) ～ q^?4 with a crossover around q ≈ 0.005 Å^?1. The scattering functions of the catalyst ink, i.e., the polymer electrodes dispersed in water, were successfully decomposed to the corresponding partial structure factors, S_CC(q), S_PP(q), S_CP(q), exclusively representing C‐C, P‐P, and C‐P correlations. S_CC(q) was a monotonic decreasing function of q, dominating in the scattering from carbon clusters. On the other hand, S_PP(q) exhibited a scattering maximum characteristic of polyelectrolyte solutions. This suggests that ionic clusters in polyelectrolyte solutions are formed in catalyst ink. The cross term, S_CP(q), indicated that the carbon scattering is dominant and significant amount of ionomer is adsorbed on the carbon agglomerates. It is concluded that the catalyst ink consists of carbon agglomerates surrounded by ionomers and the presence of ionic‐cluster path plays a key role in the performance of the solid polymer electrodes in polymer electrolyte fuel cells. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39842.     

荧光灯和护眼台灯的电磁波辐射及其屏蔽技术研究

通过对学生目前使用的荧光台灯和护眼台灯的电磁波辐射测试发现,二者均不同程度地存在电磁波辐射问题,研究还发现,越靠近荧光台灯和护眼台灯部位,电磁波辐射越强,在离约35厘米之外,电磁波辐射强度可符合有关规定要求;经过进一步研究,制备了一种既透明又导电的塑料薄膜——透明导电高分子薄膜,该透明导电薄膜经过与荧光台灯灯罩前部连接并固定接地后,测试结果表明,透明导电高分子薄膜既阻挡了电磁波对使用者的辐射,同时又不影响照明使用。研究结果可用于屏蔽学生使用荧光台灯和护眼台灯时产生的电磁波辐射,从而最大限度地保障学生的身体健康。     

荧光涂层的设计、制备与应用研究进展

荧光材料能够在紫外或可见光的作用下产生荧光,并已广泛应用于日常生活中.然而,由于荧光材料通常为小分子,在使用过程中存在易流失、效率低、功能单一等问题.针对这些问题,近年来研究人员将荧光物质与树脂等基质结合制备荧光涂层.综述了荧光涂层的设计、制备与应用的研究进展,重点介绍了荧光物质与涂层的结合方式以及基于不同种类荧光基团的荧光涂层设计与构建.结合方式分为物理掺杂和化学键合.荧光材料分为四大类,有荧光蛋白、有机荧光基团、稀土配合物和发光纳米粒子,不同的结合方式、不同种类的荧光材料各有优缺点,选择恰当的结合方式和荧光材料对发挥荧光材料的功能至关重要.荧光涂层在特定条件下可以发射出荧光,在外部刺激(如离子、作用力、pH变化等)作用下发射的荧光会产生变化,基于此可应用于如腐蚀预警、离子检测、防伪加密等.对荧光涂层在生物医药、金属防腐预警、防伪加密等方面的应用等进行了详细阐述,同时对荧光涂层未来发展做了展望.     

凝胶剂用量对胶印油墨性能的影响

采用有机铝型凝胶剂制备凝胶型连接料和胶印油墨,并研究了不同凝胶剂用量对连接料和胶印油墨的流变性能、印刷适性和乳化率的影响。试验结果表明:随着凝胶剂用量的增加,连接料和油墨的流动性能、黏弹性和触变性提高,并可有效减少飞墨,提高抗乳化能力,改善水墨平衡性能,使胶印油墨的流变性能更加适应高速印刷的要求。     

树枝状大分子PAMAM-DSD的合成及其在造纸中的应用

在低代端酯基PAMAM树形分子(G0.5-COOCH3)末端引入4,4′-二氨基二苯乙烯-2,2′-二磺酸,在常温常压下合成一种高分子荧光增白剂(PAMAM-DSD)。实验显示,在纸张涂布中使用PAMAM-DSD,纸张的白度以及耐光性均得到明显改善。确定了PAMAM-DSD在涂布颜料中的适宜用量。     

含吡嗪、喹啉荧光探针的合成及其对金属离子的识别研究

设计合成了3个含有吡嗪基团的荧光探针分子和喹啉基团的荧光探针分子,其结构通过红外(FT-IR)、质谱(MS)、核磁共振氢谱(1HNMR)进行表征,通过吸收光谱和荧光光谱研究了不同金属离子对目标探针分子的影响。结果表明:Cd2+使401 nm处荧光蓝移了20 nm;Co2+、Hg2+、Pb2+、Zn2+使357 nm处荧光分别红移了20、50、1401、40 nm;Cd2+、Hg2+使349 nm处荧光分别红移了707、5 nm。     

微波辐射合成荧光增白剂PEB

利用微波技术,采用正交实验方法,以2-羟基-1-萘甲醛和丙二酸二乙酯为原料,乙酸酐为催化剂,合成了5,6-苯并香豆素-3-甲酸乙酯(荧光增白剂PEB)。考察了四个因素(微波作用时间,微波辐射功率,原料投料比,催化剂用量)等因素对产物产率的影响。实验证明:以微波功率195W,2-羟基-1-萘甲醛(A)、丙二酸二乙酯(B)、催化剂(C)的投料摩尔比为1.5∶1∶2,加热时间30 min,产物收率可达89%。较之传统加热方法(反应时间6 h,收率80%)反应时间大大缩短,反应收率也有所提高。     

Templated Chemistry for Sequence‐Specific Fluorogenic Detection of Duplex DNA

We describe the development of templated fluorogenic chemistry for detection of specific sequences of duplex DNA in solution. In this approach, two modified homopyrimidine oligodeoxynucleotide probes are designed to bind by triple‐helix formation at adjacent positions on a specific purine‐rich target sequence of duplex DNA. One fluorescein‐labeled probe contains an α‐azidoether linker to a fluorescence quencher; the second (trigger) probe carries a triarylphosphine group that is designed to reduce the azide and cleave the linker. The data showed that at pH 5.6 these probes yielded a strong fluorescence signal within minutes on addition to a complementary homopurine duplex DNA target. The signal increased by a factor of about 60, and was completely dependent on the presence of the target DNA. Replacement of cytosine in the probes with pseudoisocytosine allowed the templated chemistry to proceed readily at pH 7. Single nucleotide mismatches in the target oligonucleotide slowed the templated reaction considerably; this demonstrated high sequence selectivity. The use of templated fluorogenic chemistry for detection of duplex DNAs has not been previously reported and could allow detection of double‐stranded DNA, at least for homopurine–homopyrimidine target sites, under native and nondenaturing conditions.     

基于高频电感耦合的等离子体无极光源技术

在简述无极光源发明史的基础上,介绍了等离子体无极光源的分类和特点,重点讨论"高频电感耦合等离子体无极光源"的结构特性和应用发展。