PPy／SiO2纳米复合材料的合成与表征

以水为反应介质,在ＳｉＯ２纳米级粒子存在下,用化学方法合成了聚吡咯／ＳｉＯ２纳米复合材料,利用元素分析,红外光谱,热失重,透射电子显微镜和四探针技术表征了这些材料的组成,结构和性能,压片成型后,材料的电导率主达４２．９ｓ／ｃｍ。     

原位聚合制备聚吡咯/石墨烯复合材料及其电化学性能研究

通过原位聚合法制备出聚吡咯/石墨烯(PPy/GE)复合材料。用红外光谱(FT-IR)、扫描电镜(SEM)、透射电镜(TEM)等分析手段对复合材料的结构和形貌进行表征,发现聚吡咯均匀地包覆在石墨烯表面。循环伏安测试表明复合材料对电极对I-/I3-电解质氧化还原体系具有较好的催化能力。电化学交流阻抗测试结果说明掺入聚吡咯后可有效降低石墨烯对电极的电荷转移阻抗。组装成染料敏化太阳能电池(DSSCs),在AM 1.5(100mW.cm-2)的模拟太阳光照射下,得到4.12%的光电转换效率。     

Electrically Conductive Polystyrene/Polypyrrole Nanocomposites Prepared via Emulsion Polymerization

Polypyrrole (PPy) nanoparticles in polystyrene (PS) matrix were synthesized by emulsion polymerization using ferric sulfate, sodium dodecyl sulfate, and n-amyl alcohol as an oxidant, emulsifier and dopant, and co-emulsifier, respectively. The content of PPy nanoparticles in the composites varied from 14.11 to 34.63 wt%, as calculated from elemental analysis. Field Emission Scanning Electron Microscopy images showed spherical nanopartciles of PPy with diameters of 30–74 nm were well dispersed in PS matrix. It was found that the thermal stability and electrical conductivity of PS/PPy composites increased with increasing content of PPy nanoparticles.     

界面聚合法制备阿维菌素微胶囊悬浮剂

为了摸索界面聚合法制备阿维菌素微胶囊悬浮剂的方法,探索了以水为反应介质的界面聚合法制备壁材为聚脲的阿维菌素微胶囊悬浮剂的实验方法,研究了乳化剂的种类、分散剂的种类、壁材的用量、搅拌速度、界面聚合时间等因素对微胶囊的粒径和包覆率的影响。结果表明,选用甲苯-2,4-二异氰酸酯和乙二胺作为壁材,聚合时间为4 h,搅拌速度为1000 r/min,乳化剂选择OP–10,以GY–DS02+GY–D05(m/m,3/2)作为分散剂,可制得平均粒径2μm、包覆率在90%以上的微胶囊。     

聚丙烯/蒙脱土纳米复合材料的结构及物理性能研究

采用化学反应法制备了Ziegler-Natta/有机改性蒙脱土复合催化剂,并通过丙烯单体原位插层聚合法制备出聚丙烯/蒙脱土(PP/MMT)纳米复合材料,研究了复合材料的微观结构、热性能以及加工稳定性等。结果表明,原位聚合法制备的复合材料为剥离型纳米复合材料,其中MMT片层以纳米尺寸均匀分散在PP基体中,MMT平均厚度小于10nm;随MMT含量的提高,复合材料的热稳定性提高;原位聚合制备的PP/MMT纳米复合材料在长时间剪切过程中部分MMT会发生自聚集,控制剪切时间可以有效防止MMT的自聚集;原位聚合制备的PP/MMT复合材料(粉料)中,PP以α晶型为主,纳米MMT的引入并不会诱导生成聚丙烯β晶型,复合材料中β晶型的出现与退火条件有关。     

界面聚合法制备聚硫脲缓释微胶囊的研究

以对苯二甲酰异硫氰酸酯与邻苯二胺为原料,通过界面聚合法合成了一种新型聚硫脲微胶囊,考察了搅拌速率、乳化剂用量、投药量等因素对微胶囊粒径及释放性能的影响。     

Syndiotactic Polystyrene/Organoclay Nanocomposites: Synthesis via In Situ Coordination‐Insertion Polymerization and Preliminary Characterization

Summary: Syndiotactic polystyrene (sPS)/organophilic clay nanocomposites were obtained by in situ coordination‐insertion polymerization of styrene. Two cationic surfactants (alkylammonium and alkylphosphonium) were used for the intercalation of montmorillonite (MMT). For each organically modified clay, three protocols were performed using an MAO‐activated hemi‐metallocene catalyst, in order to compare the influence of experimental conditions on the composite microstructure and on its thermal stability. The microstructures of nanocomposites were investigated by wide angle X‐ray scattering and DSC. Partially exfoliated or intercalated materials were obtained in all cases and a decrease of crystallinity is observed. Thermal properties were also studied by DSC and thermogravimetric analysis. The presence of clay does not have a strong influence on the sPS thermal transitions but the thermal decomposition process of the material was slowed down in the presence of few organoclay percents, particularly in the degradation beginning. The influence of these two organically modified clays on the thermal stability of the material is discussed.

Gel and suspension formed from the combination of cloisite with toluene (left) and styrene (right), respectively.     

界面聚合法制备MABR中空纤维膜

利用界面聚合法制备了用于无泡曝气膜生物反应器(MABR)废水处理的聚苯胺 聚偏氟乙烯中空纤维复合膜,考察了普通聚合、掺杂和脱掺杂3种制备条件下得到的中空纤维膜的表面性能。测定了中空纤维膜的气体通量、膜丝表面亲水性,并观察了膜丝表面粗糙度的变化。结果表明,与初始聚偏氟乙烯中空纤维膜相比,复合中空纤维膜的表面亲水性得到显著改善,特别是掺杂后膜的接触角由原先的89°下降到73°;脱掺杂后复合中空纤维膜的气体通量大于掺杂改性膜,但是小于原膜丝;脱掺杂后复合中空纤维膜的表面粗糙度较初始膜有较大提高。挂膜试验中,脱掺杂后的复合中空纤维膜表现出了优异的生物挂膜性能,是一种具有潜在应用价值的MABR中空纤维膜。     

Preparation and Properties of Fe3O4/Polypyrrole/Poly(Pyrrole-Co-Acrylamide) Nanocomposites

Polypyrrole (PPy)/poly(pyrrole-co-acrylamide) (Poly(Py-co-AAm)/nanocomposite was prepared by a simple and inexpensive in-situ co-polymerization of pyrrole and acrylamide in the presence of Fe₃O₄ nanoparticles. The nanocomposites were characterized by FTIR, SEM, XRD, TGA, and conductivity measurements. The FTIR spectra ascertain the chemical interlinking of polypyrrole and copolymer with magnetite nanoparticles. The XRD revealed that crystallinity of the copolymer was increased with weight percentage of the magnetite nanoparticles. SEM analysis showed that the nanoparticles were well shaped and uniformly dispersed in the nanocomposites. Thermal stability and the electrical conductivity of the nanocomposite were higher than that of polypyrrole and the copolymer.     

Spontaneous and Electrochemical Reduction of Silver by Polypyrrole Deposits

Abstract

Polypyrrole (ppy) coatings doped with p-toluene sulfonate sodium on stainless steel mesh (SSM) have been electrosynthesized in aqueous solution. The removal of Ag⁺ ions from acidic solutions was investigated through spontaneous reduction (SR) and electrochemical reduction (ER) procedures using reduced composite ppy-SSM. Higher removal efficiencies and current efficiencies were obtained by ER process for ppy-SSM rather than SR process for ppy-SSM and ER process for SSM under comparable conditions. Due to its high efficiency and simplicity, ER was supposed to be an alternative advantageous method for the recovery of low-level silver concentration in industrial wastewater. Cyclic voltammetry was carried out to characterize the electrochemical behavior of ppy-SSM in acid solutions containing Ag⁺. Metallic silver deposited on ppy-SSM has been evidenced by scanning electron microscopy (SEM) analysis.     

界面细乳液聚合制备有机-无机杂化纳米胶囊

将甲基丙烯酸3-三甲氧基硅丙酯(MPS)引入以小分子烃为模板的苯乙烯细乳液聚合中,制备有机-无机杂化纳米胶囊。MPS由于其水解产物的亲水性及能够水解-缩合反应的特性使得MPS能够同时起界面聚合诱导剂和自由基锚定剂的作用,制备有机-无机杂化纳米胶囊,但囊化率不高。为了强化MPS的诱导和锚定作用,向体系中进一步加入N-异丙基丙烯酰胺(NIPAM)、二乙烯基苯(DVB),可以得到囊化率更高的产品。详细讨论了NIPAM、DVB用量对有机-无机杂化纳米胶囊形态的影响。乳化剂用量以及小分子烃模板含量也是影响胶囊形态的重要因素。     

Preparation and characterization of rubber–clay nanocomposites

Rubber–clay nanocomposites were prepared by two different methods and characterized with TEM and XRD. The TEM showed clay had been dispersed to one or several layers. The XRD showed that the basal spacing in the clay was increased. It was evident that some macromolecules intercalated to the clay layer galleries. The clay layer could be uniformly dispersed in the rubber matrix on the nanometer level. The mechanical tests showed that the nanocomposites had good mechanical properties. Some properties exceeded those of rubber reinforced with carbon black, so the clay layers could be used as an important reinforcing agent as the carbon black was. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1879–1883, 2000     

界面聚合网状壳体聚氨酯相变微胶囊的制备与性能

采用界面聚合法,以异佛尔酮二异氰酸酯(IPDI)与三官能度的三乙醇胺(TEA)为反应单体,制备了具有高致密性网状交联结构的相变微胶囊。考察了不同芯/壁质量比对微胶囊表面形貌和粒径分布的影响,以及TEA用量对微胶囊表面形貌、化学结构、热稳定性和致密性的影响。结果表明,所制备微胶囊呈球形分布,表面完整致密,当芯/壁质量比≥2.73∶1.00时,微胶囊表面凹陷消失。当芯/壁质量比为2.73∶1.00,TEA用量为3.5 g时,所制备微胶囊壳体致密无破损,具有优良的热稳定性和致密性,可耐200℃以上高温,经120℃烘干6 h后,微胶囊的质量损失率为5.52%。微胶囊的熔融温度(T_m)和熔融热焓(△H_m)分别为22.5℃和86.37J/g,储热性能较好。     

界面聚合制备复合荷电镶嵌膜

以聚醚砜中空纤维膜为支撑膜,通过界面聚合方法制备了能有效传递电解质而截留低分子量有机物的复合荷电镶嵌膜。水相单体溶液含有2,5-二胺基苯磺酸、聚乙烯亚胺;有机相单体溶液含有均苯三甲酰氯和4-氯甲基苯酰氯;通过三甲胺溶液化学修饰将界面聚合复合层中的氯甲基基团转换为阳离子季胺盐基团。讨论了界面聚合条件和操作条件对荷电镶嵌膜分离性能的影响,分别采用原子力显微镜(AFM)、扫描电镜(SEM)及压汞仪等现代分析手段,对荷电镶嵌膜断面结构、表面形貌及孔径尺寸进行了系列表征。研究结果表明：界面聚合时间越长,生成的复合选择层越厚,所得膜的水通量越小,膜对无机盐的截留率也就越高;而界面聚合单体浓度增加,膜的水通量及膜对无机盐的截留率都会减小;另外,操作压力增大,膜的水通量及膜对无机盐的截留率均会增加。在操作压力为0．2MPa条件下,复合荷电镶嵌膜对无机盐的截留率均小于20％,而对二价酚橙和甲基绿的截留率均大于95％。     

Preparation and Properties of Vinylester Resin/Clay Nanocomposites

Summary: Vinylester resin matrix composites were fabricated with 1, 3, 5 and 10 wt.‐% loadings of organoclay. The composite samples were subjected to various characterization techniques like X‐ray diffraction, flexural testing, dynamic mechanical analysis, thermogravimetric analysis, and scanning electron microscopy. The clay samples as well as the clay–resin composites were investigated by X‐ray diffraction. From the shift in the peak positions and the change in d‐spacing values, it was evident that there was intercalation in the 10 wt.‐% composites, whereas exfoliation occurred in the 1, 3, and 5 wt.‐% composites. The flexural strength and the breaking energy of all the composites were decreased compared with the unfilled resin, but there was an increase in flexural modulus value by 13%. From the dynamic mechanical analysis of the 3 and the 5 wt.‐% composites, it was observed that the loss modulus value was higher in the 3 wt.‐% composites, but the glass transition temperature was slightly higher in the 5 wt.‐% composites. Thermal degradation behavior was also improved in the 5 wt.‐% composites compared with the 3 wt.‐% composites.

Fracture surface of 3 wt.‐% clay filled vinylester resin matrix composite in different magnifications.     

Preparation and Properties of High Performance Multilayered PANi/PMMA/PPG-b-PEG-b-PPG/FGHMDA Nanocomposites via in Situ Polymerization

In this attempt, novel conjugated polymer/graphite nanocomposites with exposed surface area were fabricated by in situ polymerization using polyaniline, poly(methyl methacrylate) and poly(propylene glycol)-block-poly(ethylene glycol) block- poly(propylene glycol) as matrices and functionalized graphite as a filler. Structural and morphological analysis revealed the modification of graphite as well as oxidative polymerization of numerous matrices over the surface of modified graphite ensuing multilayered nanocomposites. The increased values of T_g (59 and 103°C) obtained from thermal analysis reflect the improved thermal stability of prepared nanocomposites and exhibit better adsorption capacity (35.5cm³/g). Maximum electrical conductivity (7.4 S/cm) was also observed for multilayered nanocomposite.     

丁腈橡胶/膨胀石墨导电纳米复合材料的制备和性能

采用熔融插层法制备了丁腈橡胶/膨胀石墨纳米复合材料。扫描电镜(SEM)研究表明,超声处理后的膨胀石墨薄片厚度为纳米级。透射电镜(TEM)研究证实,膨胀石墨确以纳米级尺寸分散在橡胶基体中。力学性能研究表明,填加5份膨胀石墨时,纳米复合材料的拉伸强度最大,为28·4MPa,是不含膨胀石墨的复合材料的1·8倍。导电性能研究显示,填加10份膨胀石墨时,纳米复合材料的表面电导率和体积电导率分别为1·1×10-9S/cm和1·2×10-9S/cm,是不含膨胀石墨的复合材料的100倍和43倍。     

Nanocomposites from phenolic resin and various organo‐modified montmorillonites: Preparation and thermal stability

Phenolic resin (PF)/montmorillonite (MMT) nanocomposites have been successfully prepared using intercalative polymerization of resole‐type phenolic resins in montmorillonites modified by octadecylamine (C18), benzyldimethylhexadecylammonium chloride (B2MH), benzyltriethylammonium chloride (B3E), and benzyldimethylphenylammonium chloride (B2MP). X‐ray diffraction measurements and transmission electron microscope observations showed that clay platelets were partially exfoliated or intercalated after complete curing of the phenolic resins. The cured nanocomposites were named as modifier‐MP (MP means montmorillonite‐phenolic resin), for example, B3E‐MP. Thermogravimetric analysis showed that thermal decomposition temperatures (T_ds) of the cured nanocomposites B2MP‐MP (826 K), B3E‐MP (794 K), and B2MH‐MP (783 K) were much higher than those of C18‐MP (768 K) and cured phenolic resin (737 K). Therefore, thermal stability of the nanocomposites depends mainly on the chemical structure of the organic modifiers. B2MP‐MP possesses the highest T_d since B2MP contains both benzyl and phenyl groups, followed with B3E‐MP and B2MH‐MP whose modifiers contain only one benzyl group. This is attributable to favorable interaction between phenolic resin and organic modifiers containing benzene rings. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5336–5343, 2006     

聚吡咯/二氧化硅复合材料的制备及导电性的研究

以三氯化铁(FeCl3)为氧化剂,对甲苯磺酸钠(TSANa)为掺杂剂,在水中使吡咯(Py)单体在二氧化硅(SiO2)粒子表面发生化学氧化聚合反应,制备了具有良好导电性的聚吡咯/二氧化硅(PPy/SiO2)复合材料。结果表明:当FeCl3与Py的摩尔比为2 5,Py与SiO2的质量比为0 3,TSANa的浓度为0 020g·ml-1,在10℃下反应4h,得到的复合材料具有最高电导率12 6S·cm-1。FT-IR结果表明:在形成复合材料过程中PPy与SiO2发生了一定的物理和化学作用。     

界面聚合法制备黄色电子墨水微胶囊

通过界面聚合法,用戊二醛改性的三乙烯四胺,与2,4-甲苯二异氰酸酯反应,制备出含黄色电子墨水的聚脲微胶囊。在搅拌速度为800~1 000 r/m in、乳化剂OP-10的浓度为0.05~0.12 mol/L的条件下,制备的微胶囊干燥后不易破裂,有一定机械强度、韧性、耐水性和耐热性;微胶囊壁厚约2μm;在直流电场中有显著的电泳现象,响应时间为0.2 s。