泡沫聚合法制备超大多孔水凝胶

采用泡沫体系分散聚合法,过硫酸铵(APS)及N,N,N′,N′-四甲基乙二胺(TMEDA)为氧化还原引发体系,N,N′-亚甲基双丙烯酰胺(MBA)为交联剂,碳酸钠为发泡剂,聚氧化乙烯-氧化丙稀(PF127)为泡沫稳定剂,用羧甲基纤维素钠(CMC)接枝丙烯酸(AA)和2-丙烯酰胺基-2-甲基丙磺酸(AMPS)合成了CMC-g-(AA-co-AMPS)超大多孔水凝胶。通过FTIR、SEM表征,表明材料是具有超大多孔结构的CMC-g-(AA-co-AMPS)水凝胶。对各影响因素的研究表明,在m(CMC)∶m(AA)∶m(AMPS)为1∶4∶1,w(APS)为0.8%[其中m(APS)∶m(TMEDA)=2∶1],w(Na2CO3)=65%,w(PF127)=0.2%,温度为65℃时,制得的凝胶吸蒸馏水倍率可达1281g/g,吸0.9%盐水倍率达143g/g,10min时已基本达到溶胀平衡。     

复合酸掺杂导电聚苯胺的合成及性能

采用复合酸掺杂微乳液法合成导电聚苯胺. 探讨了反应温度和掺杂剂质量比对聚苯胺性能的影响,并通过四探针、塔菲尔曲线、激光粒度分析、热重分析以及红外光谱测试技术,对聚苯胺进行了研究与表征. 结果表明,当聚合温度为15 ℃、磺基水杨酸和十二烷基苯磺酸钠的质量比为2.5∶1时,掺杂态聚苯胺电导率和溶解度达到最大值,同时具有良好的防腐蚀能力;其中电导率可达11 S/cm,在氮甲基吡咯烷酮(NMP)中溶解度可达85%;经电化学工作站测试的塔菲尔曲线可知,其腐蚀电位为-0.391 V. 热重分析表明,复合酸掺杂聚苯胺热分解温度约为440 ℃;粒径分析表明,约有90%的聚苯胺颗粒集中在50～100 nm之间.红外光谱表明,复合酸掺杂聚苯胺各主要吸收峰均向低频方向移动,说明掺杂的有效性.     

正交轴逆流色谱法分离标准蛋白质及实际样品

 以m(质量分数为 12 .5 %的PEG80 0 0 )∶m(质量分数为 2 5 %的磷酸氢二钾 ) =1∶1或m(质量分数为 12 .5 %的PEG80 0 0 )∶m(质量分数为 30 %的磷酸氢二钾 ) =1∶1为溶剂系统 ,用下相作流动相 ,上相作固定相 ,操作时采用5 0 0r/min的转速和 6 0mL/h的流动相流速 ,考察了正交轴逆流色谱法对标准蛋白质及羊肚菌糖蛋白和枸杞糖肽的分离情况。将结果与高效液相色谱分离结果相比较 ,前者在分离度损失不大的基础上提高了进样量 ,证明了其用于制备的有效性 ,从而为分离制备天然生物大分子提供了一个新方法。     

废旧锂离子电池基石墨烯/聚苯胺复合材料制备及其电化学性能研究

以废旧手机锂离子电池回收的负极石墨粉制备的氧化石墨烯(GO)和苯胺单体为原料,利用GO活化H_2O_2产生的·OH为氧化剂,采用原位复合法制备了不同质量比的石墨烯/聚苯胺复合材料,通过FTIR、XRD和SEM对其进行了表征,并利用循环伏安、交流阻抗、恒电流充放电等对其电化学性能进行测试。结果表明,该类石墨烯/聚苯胺复合材料具有良好的电化学性能,当电流密度为100mA/g时,质量比为1∶10制备的石墨烯/聚苯胺复合材料(rGO/PANI-10)的比电容达到481F/g,较石墨烯比容量(161F/g)提高了199%,较聚苯胺比容量(351F/g)提高了37%;在500mA/g电流密度下,rGO/PANI-10充放电循环1000圈后,电容保持率为77%,表现出较好的循环稳定性。     

磁场作用下原位聚合制备聚苯胺/纳米ZnO复合材料

首先用硅烷偶联剂(KH550)对所制备粒径在100 nm以下的纳米ZnO进行表面修饰(M-ZnO), 然后在弱磁场(0.4 T)下乙醇/水/十二烷基苯磺酸(DBSA)体系中原位聚合分别制备了重均分子量达3×10⁴的聚苯胺(PANI)及聚苯胺/纳米ZnO复合材料. 红外分析表明纳米ZnO的加入使聚苯胺的特征峰向低波数方向移动|溶解性测试表明聚苯胺及其复合材料在氯仿和N-甲基吡咯烷酮中均有较高的溶解度(高于80%)|X-射线衍射表明磁场能有效地改善聚苯胺主链的规整性, 使聚苯胺分子链有更好离域的π电子体系|M-ZnO的引入显著地提高了PANI的电导率(可达220 S/m), 同时具有较好的透光性(80%)|这表明PANI/纳米ZnO复合材料在柔性光电器件领域具有潜在的应用价值.     

染料敏化太阳能电池用聚苯胺/石墨复合对电极的制备与性能研究

引入一种具有网状结构的导电聚苯胺为催化材料,以导电石墨为填充材料,并对其共混后丝网印刷在FTO导电面上,制备了聚苯胺/石墨复合对电极.主要解决对电极催化活性和导电特性不能有效兼顾,制作工艺复杂的问题.扫描电镜(SEM)结果表示,通过二者简单的共混后,导电聚苯胺的网状结构依然存在,石墨的加入有效填充了聚苯胺之间的空隙,在不影响原来催化活性的基础上增强了对电极的导电性.利用循环伏安(CV)和电化学阻抗(EIS)对复合对电极的催化和导电特性进行研究.对该复合对电极组装成的DSSCs进行光电性能测试,结果表明,当石墨的质量分数达到10%时,基于聚苯胺/石墨复合对电极组装成DSSCs的光电转换效率达到了8.5%,为同等条件下传统Pt电极的123%.     

Fe(ClO_4)_3氧化合成聚乙撑二氧-三噻吩

分别以Fe(Cl O4)3、FeCl3、Fe2(SO4)3作为氧化剂,对3′,4′-乙撑二氧-2,2′∶5′,2″-三噻吩(TET)进行了化学氧化聚合,并研究了聚合条件对聚合物结构和电化学性能的影响。利用红外光谱、紫外光谱、X射线衍射对聚合物进行了表征,采用循环伏安、恒电流充放电等电化学方法研究了聚合物的电化学性能。结果表明:当TET与Fe(Cl O4)3的摩尔比为1∶4,反应温度为18℃,反应时间为12 h时,聚3′,4′-乙撑二氧-2,2′∶5′,2″-三噻吩(PTET)具有更好的共轭结构和电化学性能,导电率可达1.47 S/m,比电容可达133 F/g。     

APS引发制备高分子量PDMDAAC

以已知杂质种类和含量的一步法工业二甲基二烯丙基氯化铵(DMDAAC)单体水溶液为原料,用过硫酸铵(APS)为引发剂,采取低温一次性加入引发剂,分阶段升温方式进行聚合反应,通过合成工艺的优化方法,得到了最高特性黏数值为3.17 dL/g的聚二甲基二烯丙基氯化铵(PDMDAAC),单体转化率为94.8%,采用NMR、IR光谱测试技术对产物进行了结构表征。分别考察了DMDAAC质量分数为57.5%~70.0%、APS与DMDAAC质量比为0.15∶100~0.40∶100、Na4EDTA与DMDAAC质量比为0~0.014 2∶100、聚合反应引发温度T1在40~50℃、聚合反应熟化温度T3在50~90℃范围内的以上5个因素对产物特性黏数和单体转化率的影响规律。结果表明,DMDAAC质量分数为65.0%、APS与DMDAAC质量比为0.35∶100、Na4EDTA与DMDAAC质量比为0.007 1∶100、T1为46℃、T2为50℃,T3为70℃,各反应3 h为最佳工艺条件。     

APS/NaClO 复合氧化剂对乳液法合成聚苯胺的微观形貌及其电化学性能的影响

采用乳液法, 以过硫酸铵(APS)和次氯酸钠(NaClO)为复合氧化剂合成导电聚苯胺(PANI). 考察了NaClO 的加入与否对PANI 微观形貌与电化学性能(循环伏安和电导率)的影响, 以及APS、乳化剂十二烷基苯磺酸钠(SDBS)和NaClO的用量对PANI 电化学性能的影响. 结果表明: NaClO 的加入对PANI 的微观取向结构具有重要的影响. 与采用单一APS 合成的PANI 相比, 复合氧化剂合成的PANI 具有较高的循环伏安峰电流以及更加优异的电导率(约为前者的2.6倍). 当苯胺(An)与APS 的物质的量比(n_An:n_APS )为8:7, An 与SDBS 的物质的量比(n_An:n_SDBS )为10:4, NaClO 用量为5%(质量分数)时, PANI 的各项性能指标达到最好; 紫外可见光谱和红外光谱的表征结果表明, 采用复合氧化剂并未对PANI 的分子结构产生明显的影响.     

利用荧光非辐射能量转移观察磺酸基聚电解质分子链形态

2-丙烯酰胺基-2-甲基丙磺酸(AMPS)与N,N-二甲基丙烯酰胺(DMAA)共聚合成了一系列电荷密度为5%～99%的强聚电解质,并分别用萘和芘标记.随试样电荷密度升高,用分子间非辐射能量转移(NRET)测定的聚电解质接触质量浓度ρ^*从0.55减小到0.25g/L,比激基缔合物荧光测定的ρ^*约小一个数量级.在稀溶液范畴内,随试样电荷密度增加,分子链间的NRET先减弱,至AMPS质量分数达30%后又增强.该现象可用Manning的反离子凝聚与聚电解质聚集理论予以定性说明.     

聚苯胺/离子液体/蒙脱土纳米复合材料的制备及其导电性能研究

采用1-羧甲基-3-甲基咪唑氯化盐离子液体对钠化蒙脱土进行插层改性,然后用苯胺的盐酸溶液进行二次插层,以过硫酸铵为氧化剂,盐酸溶液为掺杂剂,使进入离子液体/蒙脱土(CMMIm/MMT)层间的苯胺(An)发生氧化聚合反应,制备了一种具有良好导电性的聚苯胺/离子液体/蒙脱土复合材料(PANI/CMMIm/MMT).用红外光谱、X-射线衍射,热重分析和DSC对样品进行了表征.结果表明当离子液体/蒙脱土用量为7.5%、盐酸浓度为1mol/L、过硫酸铵与苯胺的摩尔比为1∶1、0℃下反应6h时制备的PANI/CMMIm/MMT纳米复合材料电导率最高,达到了0.3S/cm,是相同条件下聚苯胺/钠化蒙脱土纳米复合材料电导率的2.5倍,聚苯胺的7.5倍.     

Poly(methacrylamide‐co‐2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid) hydrogels: Investigation of pH‐ and temperature‐dependent swelling characteristics and their characterization

Novel poly(methacrylamide‐co‐2‐acrylamido‐2‐methyl‐ 1‐propanesulfonic acid) (poly(MAAm‐co‐AMPS)) hydrogels were synthesized by free radical polymerization of methacrylamide (MAAm) and 2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid (AMPS) in deionized water at 60 °C by using ammonium peroxydisulfate (APS), N,N′‐methylenebisacrylamide (MBAAm) and N,N,N′,N′‐tetramethylethylenediamine (TEMED) as initiator, crosslinker, and activator, respectively. To investigate the effects of feed content on the pH‐ and temperature‐dependent swelling behavior of poly(MAAm‐co‐AMPS), molar ratio of MAAm to AMPS in feed was varied from 90/10 to 10/90. Structural characterization of gels was performed by Fourier transform infrared (FTIR) spectroscopy using attenuated total reflectance (ATR) technique. Thermal and morphological characterizations of gels were performed by thermogravimetric analysis (TGA) and scanning electron microscopy (SEM), respectively. Although an apparent pH‐sensitivity was not observed for the poly(MAAm‐co‐AMPS) gels during the swelling in different buffer solutions, their temperature‐sensitivity became more evident with the increase in AMPS content of copolymer. Thermal stability of poly(MAAm‐co‐AMPS) gels increased with MAAm content. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2010     

静电纺丝法制备聚丙烯腈/聚苯胺复合纳米纤维及其表征

利用静电纺丝技术,以聚丙烯腈(PAN)和苯胺(ANI)为前驱物,用过硫酸胺(APS)溶液在低温下缓慢氧化聚合,制备了PAN/PANI复合纳米纤维,直径约500 nm.通过扫描电子显微镜(SEM)、红外光谱(FTIR)、X射线衍射(XRD)和激光拉曼(RAMAN)光谱仪等测试手段对材料的形貌和结构进行了表征.探讨了材料制备过程中影响纤维形貌、尺寸、均匀度的因素和PANI含量对复合纤维导电性能的影响,结果表明,PAN浓度、ANI的加入量和电压是影响纤维特性的主要因素;PANI在PAN基体中呈纳米尺寸分布,复合纳米纤维具有良好的导电性能,导电率可达10-2S/cm.     

Micelle-assisted synthesis of PANI nanoparticles and application as particulate emulsifier

Well-defined water-dispersible polyaniline (PANI) nanoparticles were synthesized by in situ chemical oxidative polymerization of aniline in the presence of an amphiphilic P(AMPS-co-VM) copolymer micelle. P(AMPS-co-VM) copolymer was prepared by the free radical polymerization of 7-(4-vinylbenzyloxyl)-4-methyl-coumarin (VM) and 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) which can self-assemble into micelles in aqueous solution. Here, P(AMPS-co-VM) copolymer micelle is used not only as soft template but also as acid dopant in our reaction system. The structure, size, and morphology of PANI nanoparticles were characterized by various experimental techniques. It is found that the morphology and the size of the PANI nanoparticles strongly depend on the molecular characteristics of the P(AMPS-co-VM) copolymer. The synthesized PANI nanoparticles behaved as particulate emulsifier for the stabilization of oil-in-water emulsions.     

Preparation of hierarchical polyaniline nanotubes based on self‐assembly and its electrochemical capacitance

This article reports the preparation and self‐assembly of polyaniline (PANI) nanotubes, which were chemically synthesized by using in situ doping polymerization in the presence of ammonium persulfate (APS; (NH₄)S₂O₈) as the oxidant without the use of an external template. The synthesized hierarchically nanotubes with a shape of a single nanotube with a length of 0.6 to 0.8 µm and an average with of 100 nm assembled from nanoparticles. The effects of the [salicylic acid]/[aniline] ratio on the size and capacitance of PANI nanotubes were studied. The specific capacitance behavior of the PANI nanotubes was also investigated by using cyclic voltammogram and galvanostatic charge–discharge tests. A maximum discharge‐specific capacitance of 422.5 F/g could be achieved, suggesting its potential application in electrode material for electrochemical capacitors. Copyright © 2011 John Wiley & Sons, Ltd.     

Swelling Behavior of N-t-butylacrylamide Copolymer and Terpolymers

Copolymers and terpolymers of N-t-butylacrylamide (TBA) with 2-acrylamido-2-methyl propane sulfonic acid (AMPS) and N-hydroxy methyl acrylamide (NHMAAM) were prepared by solution polymerization in a 1:1 (v/v) mixture of methanol and water at 50 °C keeping the TBA content in the feed constant at 60% based on mole ratio. The contents of AMPS or NHMAAM used for the preparation of TBA-AMPS and TBA-NHMAAM copolymers were 40 mole %. Molar percentages of AMPS and NHMAAM monomers in the feed for the preparation of TBA-AMPS-NHMAAM terpolymers were varied as 10:30, 20:20, and 30:10, respectively. The effects of temperature, AMPS and crosslinker contents, and the drying of swollen gels on the swelling behavior of ionic and non-ionic TBA gels were investigated in distilled water between 10–50 °C and in buffer solutions having various pHs (1.9, 3.1, 5.6, 7.1, and 9.8) with constant ionic strength of 0.08 M at 20 °C using both the dry and the swollen forms of gels. The chemical structures and microscopic morphologies of the polymers were investigated by FTIR and SEM, respectively.     

乳液聚合中聚苯胺膜形成的动力学研究

以(NH4)2S2O8(APS)为氧化剂,十二烷基苯磺酸(DBSA)同时为乳化剂和掺杂剂,采用乳液聚合方法制备聚苯胺膜(PANIfilm),用石英晶体微天平(QCM)实时监测聚苯胺膜的形成过程,并对其动力学过程进行研究.结果表明,聚苯胺成膜反应对APS是0.5级,对苯胺是1级,聚苯胺膜增长速率随温度的升高而增加,而聚苯胺膜的最终沉积量却减小,表观活化能Ea=41.15kJ/mol,与均相溶液聚合成膜法的结果相近;随着DBSA浓度的增加,聚苯胺膜增长速率减小,而最终的沉积量增大.     

一种快速响应电场敏感多孔水凝胶的合成及其性能研究

以4-乙酰基丙烯酰乙酸乙酯(AAEA)、2-丙烯酰胺基-2-甲基-1-丙磺酸(AMPS)为单体,不同分子量的聚乙二醇(PEG)为成孔剂,通过自由基溶液聚合法,合成了新型多孔快速响应电场敏感性水凝胶.结果表明,成孔剂PEG被洗脱后在凝胶内部形成了互相贯穿的孔洞结构,孔径在30～120μm之间.以PEG6000为成孔剂致孔后的多孔凝胶溶胀速率和消溶胀速率最快,在去离子水中30s达到溶胀平衡,在0.1mol/L的NaCl溶液中40min达到消溶胀平衡;电场作用下凝胶的消溶胀速度大大加快,12min内即可达到平衡.凝胶中AMPS含量的增多会加快凝胶在电场中的响应速度;而高温下,随着AAEA含量的增加,凝胶内部疏水基团增多并收缩产生大量的疏水微区,限制了凝胶内部水分的持续排出,因此n(AAEA)∶n(AMPS)=3∶1的凝胶4min内即可排出表面水分达到消溶胀平衡,可保水率却高达75%.同时,增大电解液的pH值、浓度以及提高电解电压,均会加快凝胶的消溶胀行为.     

Adsorption of 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) and related compounds onto montmorillonite clay

Sodium montmorillonite clay (Na-MMT) was modified using 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS). The objective of this study was to determine which chemical group is the 'driving force' leading to the adsorption of AMPS inside the clay galleries. AMPS has been reported to be a good candidate as a clay modifier for the preparation of polymer-clay nanocomposites by in situ free radical polymerization in emulsion. However, the way in which AMPS interacts with the surface of MMT has not yet been studied. The type of interaction between organic modifiers and clay plays a determining role in the successful preparation of polymer-clay nanocomposite materials. The adsorption ability of three other organic compounds similar to AMPS, namely sodium 1-allyloxy-2-hydroxypropyl sulfonate (Cops), N-isopropylacrylamide (NIPA) and methacryloyloxyundecan-1-yl sulfate (MET), was also evaluated. These selected compounds also have functional groups potentially able to interact with the clay surface (i.e., a sulfonate group, an amido group, or a sulfate group, respectively). Results of FT-IR, TGA and SAXS analyses showed that AMPS, NIPA, Cops and MET all interacted with clay, but to various extents.