A novel method for synthesis of polypyrrole grafted chitin

In this paper we report the grafting of polypyrrole (PPy) on to a biopolymer, chitin. Polypyrrole is chemically grafted onto chitin by using ammonium peroxydisulphate (APS) initiator, in the presence of 1 M HCl. The effects of concentration of polypyrrole on graft copolymer are studied by determining the grafting percentage. Grafting of polymer is further verified by dissolution studies. Grafted polymer samples are characterized by Fourier transform infrared spectroscopy (FTIR), UV-Vis absorption spectrum, X-ray diffraction (XRD), Differential scanning calorimetry (DSC), Thermogravimetric analysis (TGA) and conductivity studies. Mechanism of grafting has been proposed on the basis of experimental results.     

Glycine hydrochloride ionic liquid/aqueous solution system as a platform for the utilization of chitosan

Glycine hydrochloride ([Gly]Cl), a room‐temperature ionic liquid (IL), is proposed as a new, good solvent for chitosan with different deacetylation degrees and molecular weights. However, considered from the viscosity of a solution of chitosan and [Gly]Cl, a 2% [Gly]Cl IL aqueous solution was selected as an optimum solvent system for dissolving chitosan. X‐ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy were used to visualize the modifications of the native structures of chitosan during the dissolution and the regeneration processes, morphological features, and properties of the reconstituted chitosan membranes. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

N-Alkylation of chitin and some characteristics of the novel derivatives

Summary Introduction of simple alkyl groups at the C-2 nitrogen of chitin and some properties of the resulting N-alkyl-chitins have been examined. Chitosan was fully deacetylated and treated with three kinds of aldehydes, formaldehyde, acetaldehyde, and pentanal. The Schiff bases of chitosan, whose extents of substitution were dependent on the amount of aldehydes, were reduced with sodium cyanoborohydride to N-alkylated chitosans. The N-alkyl-chitosans were then transformed into the corresponding N-alkyl-chitins by acetylation with acetic anhydride followed by transesterification to remove partly formed O-acetyl groups. The resulting N-methyl-, ethyl-, and pentyl-chitins were amorphous and showed improved affinity for organic solvents. Received: 13 December 2001/Revised version: 11 January 2002/Accepted: 17 January 2002     

Entanglement network of chitin and chitosan in ionic liquid solutions

Concentrated solutions of a chitin from squid pens and of two commercial samples of chitosan were successfully prepared by using an ionic liquid 1‐butyl‐3‐methylimidazolium acetate as a solvent. The dynamic viscoelasticity data for the solutions exhibited rubbery plateaus, indicating the existence of entanglement network of chitin and chitosan in the solutions. To characterize the network, the values of the molecular weight between entanglements (M_e) for chitin and chitosan in the solutions were determined from the plateau moduli. Then the values of M_e in the molten state (M_e,melt), a material constant reflecting the inherent nature of polymer species, for chitin and chitosan were estimated to be 1.7 × 10³ and 3.0 × 10³, respectively. It was found that there was a significant difference in M_e,melt between chitin and chitosan. Compared with other polysaccharides such as cellulose and agarose in terms of the number of monosaccharide units between entanglements (N_unit), chitin had significantly smaller N_unit of 8, while chitosan had equivalent N_unit of 19. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2439–2443, 2013     

A novel side chain liquid crystalline polyester for nonlinear optics

A nematic liquid crystalline polymalonate has been synthesized by melt polycondensation of a nonlinear optical (NLO) monomer and a liquid crystalline (LC) monomer. The polymer was characterized by VPO, FTIR, DSC, WAXD, UV-visible spectroscopy and polarized optical microscopy. The LC temperature interval was found between 398 K and 420 K by DSC. Some interactions originated from the attachment of the side groups to the polymer backbone were detected by UV-vis spectroscopy. Received: 2 May 1997/Revised 24 June 1997/Accepted: 27 June 1997     

综合利用聚酯废液的新方法

从涤纶厂生产聚酯切片的废液中蒸馏回收甲醇与乙二醇,余下的固体废渣经水洗、过滤、干燥和粉碎后可代替价格昂贵的酚醛树脂或虫胶漆片作为烟花产品的原料,既降低了烟花产品成本,又获得了较大的经济效益,为综合治理聚酯废液开辟了新途径。     

Inorganic nanotubes: a novel platform for nanofluidics

Templating approaches are being developed for the synthesis of inorganic nanotubes, a novel platform for nanofluidics. Single crystalline semiconductor GaN nanotubes have been synthesized using an epitaxial casting method. The partial thermal oxidation of silicon nanowires leads to the synthesis of silica nanotubes. The dimension of these nanotubes can be precisely controlled during the templating process. These inorganic nanotubes can be integrated into metal-oxide solution field effect transistors (MOSolFETs), which exhibit rapid field effect modulation of ionic conductance. These nanofluidic devices have been further demonstrated to be useful for single-molecule sensing, as single DNA molecules can be readily detected either by charge effect or by geometry effect. These inorganic nanotubes will have great implications in subfemtoliter analytical technology and large-scale nanofluidic integration.     

A novel side chain liquid crystalline polyurethane

Summary Side chain liquid crystalline polyurethanes (SCLP) without flexible spacer were synthesized by a two step block copolymerization reaction. The polyurethanes were based on azobenzene-type mesogenic diol chain extender (DR-19), a poly(tetramethylene oxide) (PTMO) soft segment, and different diisocyanates, including 4,4-diphenylmethane diisocyanate (MDI) and hexamethylene diisocyanate (HDI). The polyurethane samples obtained from DR-19 or DR-19 and PTMO with HDI had mesomorphic phases as determined by DSC and polarizing microscopy. Received: 19 March 1998/Revised version: 27 May 1998/Accepted: 17 June 1998     

垂直管外降膜的切向旋转沟槽型液体分布器特性研究

考察了布液器尺寸、操作温度以及流动工质质量分数、流率等的影响。利用实验数据回归了流体在切向旋转沟槽内流率系数和雷诺数的关系式,可用于工程设计。同时提出了管外切向旋转沟槽液体分布器的设计计算方法,由此方法设计加工的液体分布器已成功地用于工业余热回收的第二类吸收式热泵装置。     

Tethered bimolecular lipid membranes—A novel model membrane platform

This contribution summarizes some of our efforts in designing, synthesizing, assembling, and characterizing functional tethered bimolecular lipid membranes (tBLMs) as a novel platform for biophysical studies of and with artificial membranes or for sensor development employing, e.g., membrane integral receptor proteins. Chemical coupling schemes based on thiol groups for Au substrates or silanes used in the case of oxide surfaces allow for the covalent and, hence, chemically and mechanically robust attachment of anchor lipids to the solid support, stabilizing the proximal layer of a tethered membrane on the transducer surface. Surface plasmon optics, the quartz crystal microbalance, fluorescence- and IR spectroscopies, and electrochemical techniques are used to characterize the build-up of these complex supramolecular interfacial architectures. We demonstrate, in particular, that bilayers with a specific electrical resistance of better than 10 MΩ cm² can be achieved routinely with this approach.The functionalization of the lipid membranes by the incorporation of peptides is demonstrated for the carrier valinomycin which shows in our tBLMs the expected discrimination by four orders of magnitude between the translocation of K⁺- and Na⁺-ions across the hydrophobic barrier. For the synthetic channel-forming peptide M2 the high electrical resistance of the bilayer with the correspondingly low background current allows for the recording of even single channel current fluctuations.From the many membrane proteins that we reconstituted so far we describe results obtained with the redox-protein cytochrome c oxidase. Here, we also use a genetically modified mutant with a His-tag at either the C- or the N-terminus for the oriented attachment of the protein via the NTA/Ni²⁺ approach. With this strategy, we not only can control the density of the immobilized functional units, we introduce a completely new and alternative concept for the stabilization of lipid bilayers, i.e., the protein-tethered membrane.Our efforts in experimentally characterizing the resulting membrane functions and correlating the data with the structural details of the bilayer architectures are complemented by theoretical studies modeling the electrical and electrochemical response of functional tethered lipid bilayer membranes by extended SPICE simulations.     

A novel sensor platform based on aptamer-conjugated polypyrrole nanotubes for label-free electrochemical protein detection

We first present a simple yet versatile strategy for the functionalization of polymer nanotubes in a controlled fashion. Carboxylic-acid-functionalized polypyrrole (CPPy) nanotubes were fabricated by using cylindrical micelle templates in a water-in-oil emulsion system, and the functional carboxyl groups were effectively incorporated into the polymer backbone during the polymerization by using pyrrole-3-carboxylic acid (P3CA) as a co-monomer without a sophisticated functionalization process. It was noteworthy that the chemical functionality of CPPy nanotubes was readily controlled in both qualitative and quantitative aspects. On the basis of the controlled functionality of CPPy nanotubes, a field-effect transistor (FET) sensor platform was constructed to detect specific biological entities by using a buffer solution as a liquid-ion gate. The CPPy nanotubes were covalently immobilized onto the microelectrode substrate to make a good electrical contact with the metal electrodes, and thrombin aptamers were bonded to the nanotube surface via covalent linkages as the molecular recognition element. The selective recognition ability of thrombin aptamers combined with the charge transport property of CPPy nanotubes enabled the direct and label-free electrical detection of thrombin proteins. Upon exposure to thrombin, the CPPy nanotube FET sensors showed a decrease in current flow, which was probably attributed to the dipole-dipole or dipole-charge interaction between thrombin proteins and the aptamer-conjugated polymer chains. Importantly, the sensor response was tuned by adjusting the chemical functionality of CPPy nanotubes. The efficacy of CPPy nanotube FET sensors was also demonstrated in human blood serum; this suggests that they may be used for practical diagnosis applications after further optimization.     

A green procedure for the protection of carbonyls catalyzed by novel task-specific room-temperature ionic liquid

A cheap and recyclable task-specific ionic liquid N,N,N-trimethyl-N-propanesulfonic acid ammonium hydrogen sulfate [TMPSA]HSO₄ was synthesized as dual solvent–catalyst for the protection of carbonyls via formation of acetals or ketals. The satisfactory results were obtained for the protection of carbonyls as cycloacetals or ketals with diols under the mild conditions. The products could be separated from the catalyst simply by decantation and the catalyst could be recycled and reused for several times without noticeably decreasing the catalytic activity after removal of the water.     

母液水的处理和利用

介绍了悬浮法PVC生产过程中离心母液水的产生和控制,产生的离心母液水中含有大量PVA和部分残留引发剂,COD含量超标.母液水经过陕西金泰氯碱化工有限公司处理后,COD被净化到小于10 mg/L,电导率小于10 μS,pH值在6.5～8.0之间,完全符合聚合用水的标准.以10万t/a悬浮法PVC计,每年可以减少近10万m3的废水排放,纯水价格按4元/m3计算,可节约资金30万～40万元/a.     

A novel reactive liquid rubber with maleimide end groups for the toughening of unsaturated polyester resins

An amino-terminated butadiene–acrylonitrile copolymer was chemically modified into a maleim-ido-terminated rubber and was used as a toughening agent for an unsaturated polyester resin. The reactive rubber was characterized by Fourier transform infrared spectroscopy. The mechanical and fracture properties of the blends containing the unmodified and the modified rubbers were investigated. Furthermore, a morphological analysis was carried out by scanning and transmission electron microscopy. A substantial enhancement of toughness was found when the modified rubber was used in place of the plain copolymer. © 1996 John Wiley & Sons, Inc.     

聚氯乙烯专用树脂母液水处理新工艺

阐述了聚氯乙烯专用树脂离心母液水的水质特点,研究了该离心母液水经处理后可回用于聚合循环水的新工艺。新工艺处理效率高、占地面积小、运行稳定、操作简单,实现了离心母液水的再次回收利用,节约了水资源,杜绝环境污染,为企业和社会增加了效益。     

利用壳聚糖的生产废弃液制备双乙酸钠

工业上用甲壳素生产壳聚糖会产生高浓度强碱性废液,传统工业方法是将其处理后排放,这样既浪费资源又污染环境。本文利用该废液制备防腐剂——双乙酸钠（SDA）,从废液脱色、浓缩、投入乙酸的量、反应温度、反应时间、干燥温度与时间等制备条件进行了研究,确定了最佳制备工艺。所得产品中含40.38%乙酸和58.42%乙酸钠,水含量小于2%,质量符合FAO/WHO标准。     

VCM聚合母液的综合利用

介绍了采用生化法与臭氧处理相结合的方法回收利用VCM聚合母液的工艺流程,采用该工艺处理聚合母液的运行费用为1．7元／m3,母液循环回用率为77％。     

生化法处理并回用PVC离心母液技术

介绍了PVC母液的特征和生化法处理母液的工艺,阐述了山东阳煤恒通化工股份有限公司采用"厌氧反应+两级好氧+一级BYS降解+臭氧深度处理+二级BYS降解"生化工艺处理PVC离心母液。结果表明:处理后的PVC离心母液COD≤20mg/L,浊度≤5NTU,pH值7～9,达到了回用水质标准。