Self-aggregating behavior of poly(4-vinyl pyridine)and the potential in mitigating sand production based onπ-πstacking interaction

Unconsolidated sandstone reservoirs are most susceptible to sand production that leads to a dramatic oil production decline.In this study,the poly(4-vinyl pyridine)(P_(4)VP)incorporated with self-aggregating behavior was proposed for sand migration control.The P_(4)VP could aggregate sand grains spontaneously throughπ-πstacking interactions to withstand the drag forces sufficiently.The influential factors on the self-aggregating behavior of the P_(4)VP were evaluated by adhesion force test.The adsorption as well as desorption behavior of P_(4)VP on sand grains was characterized by scanning electron microscopy and adhesion force test at different pH conditions.The result indicated that the pH altered the forms of surface silanol groups on sand grains,which in turn affected the adsorption process of P_(4)VP.The spontaneous dimerization of P_(4)VP molecules resulting from theπ-πstacking interaction was demonstrated by reduced density gradient analysis,which contributed to the self-aggregating behavior and the thermally reversible characteristic of the P_(4)VP.Dynamic sand stabilization test revealed that the P_(4)VP showed wide pH and temperature ranges of application.The production of sands can be mitigated effectively at 20-130℃ within the pH range of 4-8.

The Amperometric Glucose Enzyme Electrode by Immobilized Glucose Oxidase in Glucose Oxidase/N-ethyl-Poly (4-vinyl)pyridine Multilayer

Multilayers of glucose oxidase(GOD)/N-ethyl-poly (4-vinyl) pyridine (EPVP) have been assembled on thiol self-assembled monolayers on gold electrode.This electrode can be used as an amperometric enzyme elcctrode for glucose. Fe (CN)63-/4- incorporated in EPVP layer acts as the electron mediator, the linear range was 0.1 to 6 mmol/L when the number of GOD layers was 5.

Kinetic hydrate inhibitor performance of new copolymer poly(N-vinyl-2-pyrrolidone-co-2-vinyl pyridine)s with TBAB

In oil and gas field, the application of kinetic hydrate inhibitors （KHIs） independently has remained problematic in high subcooling and high water-cut situation. One feasible method to resolve this problem is the combined use of KHIs and some synergists, which would enhance KHIs’ inhibitory effect on both hydrate nucleation and hydrate crystal growth. In this study, a novel kind of KHI copolymer poly（N-vinyl-2-pyrrolidone-co-2-vinyl pyridine）s （HGs） is used in conjunction with TBAB to show its high performance on hydrate inhibition. The performance of HGs with different monomer ratios in structure II tetrahydrofuran （THF） hydrate is investigated using kinetic hydrate inhibitor evaluation apparatus by step-cooling method and isothermal cooling method. With the combined gas hydrate inhibitor at the concentration of 1.0 wt%, the induction time of 19 wt% THF solution could be prolonged to 8.5 h at a high subcooling of 6℃. Finally, the mechanism of HGs inhibiting the formation of gas hydrate is proposed.

CONDUCTING BLENDS OF POLY (2-VINYL PYRIDINE) AND POLYETHYLENE OXIDE WITH HIGH MOLECULAR WEIGHT

Ionic, electronic and mixed (ionic-electronic) conductivities of blends of poly(2-vinyl pyridine) (P2VP) and poly(ethylene oxide) (PEO) with high molecular weight after doped with LiClO4, TCNQ or LiClO4 and TCNQ were investigated. Effects of LiClO4 and TCNQ concentrations on the conductivity of PEO/P2VP/LiClO4 or TCNQ blend were studied. The ionic conductivity of PEO/P2VP/LiClO4 blend increases with increasing PEO content. At a Li/ethylene bride molar ratio of 0.10 and a TCNQ/2-vinyl pyridine molar ratio of 0.5, the mixed conductivity of PEO/P2VP/LiClO4/TCNQ is higher than the total of ionic conductivity of PEO/P2VP/LiClO4 and electronic conductivity of PEO/P2VP/TCNQ when the weight ratio of PEO and P2VP is 6/4 or 5/5. Scanning electron microscopy (SEM) on the broken cross-section of the PEO/P2VP/LiClO4 blend and differential scanning calorimetry (DSC) results show that LiClO4 could act as a compatibilizer in the blend.

Crystal Structure of Poly[(2,6-di(2’,4’-dicarboxylphenyl)pyridine-κ4 O:O′:O″:O′′′)-(μ2-1,4-bis(1-imidazolyl)benzene-κ2N:N’)cobalt(II)],C_(39)H_(24)Co_(2)N_(7)O_(8)

[Objective]The paper was to synthesize a new structure of metal organic framework,and to provide new materials for plant pathogens testing.[Method]A mixture of 2,6-di(2’,4’-di-carboxylphenyl)pyridine,1,4-bis(1-imidazolyl)benzene,Co(NO_(3))2·6H_(2)O were added to the solution of DMF:H2O=3:3 and heated at 433K for 4 d.[Result]Red crystals of the title compound were obtained(yield 76.3%,based on Co).[Conclusion]The crystal data were obtained as follows:C_(39)H_(24)Co_(2)N_(7)O_(8),monoclinic,P21/c,a=16.222(7)A,b=12.653(5)A,c=17.456(7)A,β=102.386(6)°,V=3500(2)A_(3),Z=4,Rgt(F)=0.0550,wRref(F2)=0.1509,T=293(2)K.

Study the Influence of UV-Irradiation on the Photo Stability of Pure and Plasticized Poly (4-Vinyl Biphenyl) in Solid Films

The effect of UV irradiation and blending with phthalate and terephthalate plasticizers on the photo-stability of Poly (4-vinyl biphenyl) was studied at different intervals of irradiation time and in presence of air. The increase in irradiation time on the photodegradation of polymer thin films caused a change in the intensity and shape of the fluorescence band. It has been found that the stability of the polymer decreases with the increase of irradiation time, and to increases with the increase of the amount of added phthalate and terephthalate plasticizers, which is evidence of polymer photodegradation. The FT-IR spectra of irradiated pure and blended polymer with phthalate and terephthalate plasticizers showed a decrease in some absorption bands and increase in the other bands, this is also another factor for the occurrence of photo degradation of the irradiated polymer. The increase in the intensity of absorption of carbonyl and hydroxyl region, indicates a possible photogegradation of polymeric chains and the formation of alcohols, aliphatic ketones and to the increase in the number of (C=C) that resulted from hydrogen abstraction during chains-scission.

Copper iodide nanoparticles on poly(4-vinyl pyridine) as new and green catalyst for multicomponent click synthesis of 1,4-disubstituted-l,2,3-triazoles in water

Poly（4-vinyl pyridine） supported nanoparticle of copper（Ⅰ） iodide is reported as a green and recyclable catalyst for the regioselective synthesis of 1,4-disubstituted-1H-1,2,3-triazoles from benzyl halides,sodium azide and terminal alkynes in water. This catalyst can be recovered by simple filtration and recycled up to 8 consecutive runs without any loss of its efficiency.

P(4VP-co-St)/SiO_2固载的取代钴卟啉对乙苯的催化氧化性能

通过轴向配位法将不同结构的钴卟啉(CoTXPP(X=H,Cl,NO2))分别固载到接枝微粒聚(4-乙烯基吡啶-co-苯乙烯)/SiO2(P(4VP-co-St)/SiO2)上,室温下分别制备了P(4VP-co-St)/SiO2固载的金属卟啉催化剂CoTPP-P(4VP-co-St)/SiO2,CoTClPP-P(4VP-co-St)/SiO2和CoTNPP-P(4VP-co-St)/SiO2,利用傅立叶变换红外(FTIR)光谱和电子吸收光谱对其结构及轴配过程进行了表征.在无溶剂、无助催化剂和还原剂的体系中,研究对比了其催化分子氧氧化乙苯为苯乙酮的性能,考察了不同反应条件对苯乙酮产率的影响.研究发现,其催化活性随着环外取代基吸电子能力的增强而提高.CoTNPP-P(4VP-co-St)/SiO2的催化活性和选择性最好,在120℃常压下其催化乙苯反应12h,苯乙酮收率达到25.53%,产物α-甲基苄醇的含量则极少.与普通的催化剂不同,在催化氧化体系中,CoTNPP-P(4VP-co-St)/SiO2存在最适宜用量,过量的CoTNPP-P(4VP-co-St)/SiO2反而会使其催化活性降低;P(4VP-co-St)/SiO2表面CoTXPP的固载密度存在一最佳值.此外,固载化以后,催化剂具有较好的重复使用性.结果表明,接枝微粒P(4VP-co-St)/SiO2对金属卟啉不仅有明显的保护作用,而且能提高其稳定性.

4-乙烯基吡啶 - 苯乙烯共聚物正离子与十二基烷基硫酸钠相互作用研究

４乙烯基吡啶苯乙烯共聚物正离子与十二基烷基硫酸钠相互作用研究郑晓亮曹维孝（北京大学化学与分子工程学院北京１００８７１）关键词４乙烯基吡啶苯乙烯共聚物正离子，十二烷基硫酸钠，疏水相互作用，胶束交联水溶性聚合体尤其是聚电解质与表面活性剂相互...

用化学交联法制备聚(4-乙烯基吡啶)纳米凝胶微球

在1,1,2-三氯乙烷/甲醇混合溶剂中用碘代甲烷使聚(4-乙烯基吡啶)(P4VP)线性高分子部分季铵化后,在水中制成微乳液,并用1,4-二碘丁烷交联剂对P4VP微乳液内部进行化学交联,得到固化凝胶微球. 考察了部分季铵化比率、交联温度以及聚合物浓度对微球直径和直径分布的影响,发现微球直径随季铵化比率的增加、交联温度的增加及聚合物浓度的减少而减小. 当季铵化比率为75%(摩尔比)、交联温度为60oC、聚合物浓度为1.0%(w)时,得到了直径为20 nm、粒径分布为15%的凝胶微球. 本研究的重要特征是不加入任何乳化剂也能得到很小的纳米凝胶微球.

聚4-乙烯吡啶季铵盐的合成及绿色棉织物的抗菌整理

为了研究聚4-乙烯吡啶季铵盐对棉织物的抗茵性．以4乙烯吡啶为单体，以无水甲醇为溶剂，以偶氮二异丁腈（AIBN）为引发剂，用溶液聚合的方法合成聚4-乙烯吡啶，用溴代正丁烷将其季铵化，制成季铵盐型抗菌剂，与不同浓度的交联剂配制成季铵盐抗菌整理剂对棉织物进行抗菌整理，以大肠杆菌为致病菌体，采用抑茵圈法测试其抗茵性能．实验结果表明：添加了不同浓度交联剂的抗茵效果不同，当交联剂的浓度为1～2g／L时棉织物的抗菌性能最好．

接枝于硅胶表面的P4VP-Cu(Ⅱ)催化剂的制备与表征

先用偶联剂γ-（甲基丙烯酰氧）丙基三甲氧基硅对硅胶进行了表面化学改性,然后进行了4-乙烯基吡啶（4VP）的接枝聚合,制备了接枝微粒P4VP/SiO2,接着使接枝微粒表面的聚4-乙烯基吡啶与Cu（Ⅱ）离子进行配合作用,最终制备了接枝于硅胶表面的配合物催化剂P4VP-Cu（Ⅱ）/SiO2.用红外光谱与热分析法对产物的化学结构及热稳定性进行了表征,采用扫描电镜观察了微粒的形貌,并重点考察了各种反应条件对制备配合物催化剂关键步骤——接枝聚合的影响规律.接枝聚合适宜的反应条件为：乙醇为溶剂,4VP浓度为15～20 wt%,引发剂为单体质量的2 wt%,反应时间7 h,反应温度80℃,在此条件下接枝微粒的接枝度可达25 g/100 g.热失重（TG）测试结果表明：与未接枝的配合物P4VP-Cu（Ⅱ）相比,接枝在SiO2表面的配合物P4VP-Cu（Ⅱ）,热稳定性得到了显著的提高.

聚4-乙烯基吡啶功能微粒的制备及其对白坚木皮醇的吸附

采用表面接枝聚合法将聚4-乙烯基吡啶(P4VP)接枝于微米级硅胶微粒表面,制得了P4VP/Si O2微粒,并以该微粒为固体吸附剂,对水介质中的白坚木皮醇进行静态吸附实验,考察了温度和白坚木皮醇水溶液p H对吸附容量的影响,研究了P4VP/Si O2微粒对白坚木皮醇的吸附机理。实验结果表明,通过氢键作用力,P4VP/Si O2微粒对白坚木皮醇具有较强的吸附作用,在p H=7、30℃下的饱和吸附量可达152 mg/g,且等温吸附满足Langmuir方程。p H对P4VP/Si O2微粒的吸附性能有较大的影响,随p H的增大,吸附能力先增强后减弱,在p H=7时,平衡吸附量最大;随温度的升高,P4VP/Si O2微粒对白坚木皮醇的平衡吸附量减小。

Grafting of 4-Vinyl Pyridine onto Nylon-6 Initiated by Redox System

The graft copolymerization of 4-vinyl pyridine （4VP） onto nylon-6 （PA6） was studied by using potassium diperiodatonickelate（IV） （DPN）-PA6 redox system in alkaline medium. The structures of graft copolymers were confirmed by Fourier transfer infrared spectroscopy （FTIR） and X-ray diffraction. The properties of graft copolymers were investigated by thermogravimetric analysis （TGA）. A mechanism was proposed to explain the generation of radicals and the initiation. The effects of reaction variables, such as the initiator concentration, the ratio of 4VP to PA6, pH as well as reaction temperature and time were investigated. Graft copolymers with high grafting efficiency （〉95%） were obtained, which indicated that DPN-PA6 redox system is an efficient initiator for this graft copolymerization. The quaternized PA6-g-P4VP （QPAVP） was proved to be an excellent adsorbent to heavy metal ions.

聚苯乙烯-聚4-乙烯吡啶两亲性嵌段共聚物与新型荧光分子的自组装

合成了新型温敏荧光小分子,并利用活性/可控自由基聚合中的可逆加成-断裂链转移聚合反应(RAFT)合成了聚苯乙烯-聚4-乙烯吡啶两亲性嵌段共聚物(PS-b-P4VP);采用傅立叶变换红外光谱仪和凝胶渗透色谱仪分别测定了其结构和相对分子质量.将荧光小分子和PS-b-P4VP一同在甲苯或CO2气体膨胀甲苯环境中进行自组装,采用透射电子显微镜观察了其胶束形态.结果表明,CO2气体膨胀甲苯的引入对胶束的形态无明显影响.

聚(4-乙烯基吡啶硝酸盐)、硅硫酸和溴化铵催化氧化硫化物生成亚砜(英文)

A new catalytic procedure for the chemoselective oxidation of sulfides to sulfoxides was studied.A variety of aliphatic and aromatic sulfides were subjected to sulfoxidation by combining poly(4-vinyl pyridinium nitrate),silica sulfuric acid(SiO2-OSO3H),and catalytic amounts of ammonium bromide in CH2Cl2 in the presence of a few drops of water at room temperature.Excellent yields were obtained.

吡啶基聚合离子液体的制备及其对油中噻吩硫的吸附性能

以4-乙烯基吡啶(VP)和1,4-对二氯苄(PXDC)为原料,通过自由基聚合和季铵化交联反应,制得了一种高度交联的离子液体聚合物——PVP-PXDC。采用凝胶渗透色谱法、元素分析法、红外光谱分析法、扫描电镜、热重分析及比表面积分析等分析方法对离子聚合物的组成、结构、形貌、热稳定性及比表面积、孔结构参数等进行了表征,并考察了吸附剂的脱硫性能。结果表明,先通过聚合得到重均分子量16万以上的PVP线性聚合物,再在DMF溶剂中按VP与PXDC摩尔比2:1加入交联剂,可得到平均孔径为17.8 nm聚合离子液体介孔材料,其热分解温度在250℃以上,比表面积为56.9 m2·g-1。在油/剂质量比50:1和30℃条件下,其对1000 mg·kg-1模型油中二苯并噻吩(DBT)、苯并噻吩(BT)和噻吩(T)的吸附量分别为5.65、5.48和4.53 mg S·g-1,远高于常规吡啶基离子液体,吸附等温线符合Freundlich方程。

铜－吡啶类络合物模拟漆酶催化漆酚氧化聚合成膜的红外光谱分析

用红外光谱研究了Ｃｕ－ｐｙ、Ｃｕ－ＰＶＰｙ和Ｃｕ－ＱＰＶＰｙ催化漆酚氧化聚合交联过程。漆酚氧化聚合阶段的共同特征是：１．漆酚酿吸收峰１６５２ｃｒｎ￣－１先涨后落；２．共轭双烯吸收峰９８２和９４５ｃｍ￣－１逐渐减弱，而共轭三烯吸收峰９９２ｃｍ￣－１和芳醚吸收峰１２１５ｃｍ￣－１却逐步增强；３．苯环三取代吸收峰８３０、７６５ｃｍ￣－１都有所减弱，苯环四取代吸收峰８７５和８０５ｃｍ￣－１出现；４．苯环骨架吸收峰１６２０、１５９２ｃｍ￣－１之间的界限缩小甚至消失。到了漆膜的实于阶段，漆酚酿吸收峰１６５２ｃｍ￣－１再度兴起，但９９２ｃｍ￣－１吸收峰却由涨转落，其他吸收峰也有变化。以上光谱变化表明这３种催化剂都模拟了漆酶的催化作用。在Ｃｕ－ＰＶＰｙ催化漆酚氧化聚合阶段，发现孤立双键吸收峰３００８ｃｍ￣－１比共轭双烯吸收峰９８２和９４５ｃｍ￣－１消失得更早；并且从反应一开始就出现了１７１５ｃｍ｀－１羰基吸收峰。还比较了Ｃｕ－ＰＶＰｙ与Ｃｕ－ＱＰＶＰｙ催化的异同。

一种含氟和吡啶结构的双酚及其可溶性聚醚醚酮的合成与表征

以4-三氟甲基苯甲醛、4'-羟基苯乙酮为主要原料,通过改进的Chichibabin反应合成了一种新型的双酚单体——4-(4-三氟甲基苯基)-2,6-二(4-羟基苯基)吡啶,继而将其与4,4'-二氟二苯酮进行缩聚反应,合成了一种主链含氟和2,6-二苯基吡啶结构的聚醚醚酮,并以FTIR、DSC、WAXD等对其结构和性能进行了表征.研究结果表明:聚合物的对数比浓黏度为0.65 dL·g-1,耐热性优异,所得聚醚醚酮玻璃化转变温度(T g)为178℃,在空气中,5%的热失重温度为556℃,拉伸强度为99.5 MPa,杨氏膜量为3.01 GPa,断裂伸长率为14%.同时,该聚合物为无定形结构,在常温下可溶于N-甲基吡咯烷酮、N,N-二甲基乙酰胺、四氢呋喃和氯仿等有机溶剂中,介电常数为2.62(1 MHz),吸水率为0.46%.

基于季铵化聚乙烯吡啶和纳米铂固定血红蛋白的过氧化氢生物传感器的研究

将血红蛋白和季铵化聚乙烯吡啶按一定比例混合，滴涂在表面修饰了纳米铂的玻碳电极上，成功制备了性能良好的过氧化氢传感器．通过采用循环伏安法（CV）和计时电流法考察了该传感器的电化学性质．最佳实验条件下．其峰电流值与H2O2浓度在3．5×10^-6～3．15×10^-3mol／L成良好的线性关系，检测下限为1．5×10^-6mol／L（S／N=3），相关系数为0．9992．实验证明该电极对过氧化氢具有响应快，灵敏度高、线性范围宽和稳定性好的性能．