PP/碳纳米管复合材料的结构与性能

采用原子转移自由基(ATRP)活性聚合方法在多壁碳纳米管(MWNT)表面接枝丙烯酸丁酯聚合物(PBA),并以此对聚丙烯(PP)进行改性。红外光谱(FT-IR)及透射电子显微镜(TEM)测试结果表明,采用ATRP法成功地将PBA接枝到多壁碳纳米管(MWNT)表面。采用熔融共混法制备了PP/MWNT复合材料,对其力学性能和耐热性能进行了研究,结果表明,接枝聚合物的碳纳米管提高了复合材料的拉伸强度和冲击强度,提高了PP的耐热性。MWNT-PBA和MWNT-COOH加入PP都能提高材料的性能,而MWNT-PBA比MWNT-COOH的作用更加明显。     

碳纳米管担载纳米银及其电催化甲醇氧化的研究

以水溶性离聚物聚（苯乙烯磺酸钠-co-丙烯酸）（PSA）接枝多壁碳纳米管为模板,制备了碳纳米管担载纳米银（AgNP@MWNT）,研究了在碱性条件下对甲醇氧化的电催化作用。结果表明接枝在MWNT表面的离聚物PSA有效地控制了AgNP在MWNT表面以2～4nm的尺寸均匀担载,促进了AgNP与MWNT之间的界面相互作用。制备的Ag@MWNT在水中能够稳定地均匀分散,在碱性条件下可有效地电催化甲醇氧化,抗甲醇中毒性能良好。     

不同碳纳米管对壳聚糖膜性能的影响研究

目的研究普通碳纳米管(MWNT)与羧基化碳纳米管(MWNT-COOH)对壳聚糖复合膜性能的影响。方法将质量分数不同的MWNT与MWNT-COOH分别添加到壳聚糖基材中,采用溶液共混法制得纳米复合膜,并对复合膜的溶胀性能、透湿性能、力学性能、表面形貌和抑菌性能等进行表征。结果当MWNT和MWNT-COOH的质量分数均为1%时,2种复合膜的阻湿性能和拉伸性能相对于纯壳聚糖膜有明显改善,尤其是MWNT-COOH,2种碳纳米管的加入均可增强复合膜对大肠杆菌的抑制效果。结论浓度相同时,与MWNT相比,MWNT-COOH与壳聚糖间具有更强的结合力,它的加入能更有效地改善壳聚糖膜的性能。     

纳米纤维素/氧化石墨烯/碳纳米管复合薄膜的制备及表征

以纳米纤维素(CNF)为分散介质,氧化石墨烯(GO)为增强介质,多壁碳纳米管(MWNT)为导电介质,机械搅拌后真空抽滤制备CNF/GO/MWNT复合薄膜,研究GO/MWNT含量对复合薄膜性能的影响,采用红外、Raman光谱、扫描电镜、透射电镜对薄膜的结构和形貌进行表征,采用动态力学分析、热重分析和电导率测试研究薄膜的力学性能、热性能和电性能。结果表明,薄膜的拉伸强度随GO含量的增加先增加后减小,薄膜电导率和耐热性随MWNT用量增加而增加,当CNF/GO/MWNT质量比为20/10/70时,复合薄膜性能最佳,薄膜的电导率达到236.07 S/m,拉伸强度为25.13 MPa,180~300℃区间材料的热失重为9.45%,最大热分解速率对应温度达到322.69℃。扫描电镜、透射电镜结果表明,GO在材料内部呈现规整结构,CNF能有效分散GO/MWNT,形成均匀分散液。     

茯苓–聚乙烯醇抑菌膜的制备及生物可降解动力学评价

目的 以可降解材料聚乙烯醇为基材,通过添加茯苓溶液,制备出复合抑菌薄膜,研究不同浓度茯苓对共混膜理化性能和功能性能的影响。方法 采用溶剂浇铸法制备茯苓/PVA共混膜。对共混膜的物理力学性能,以及溶解度、透光率、抑菌性、可降解性进行检测。利用红外光谱、扫描电镜对其结构进行分析表征。结果 茯苓的添加削弱了PVA分子间作用力,显著提高了断裂伸长率,由202.77%增加到398.82%,降低了拉伸强度,并且茯苓与PVA之间形成氢键,减少了水分对薄膜的溶解,薄膜溶解度由100%降到38.21%。随着茯苓质量分数的增加,薄膜的透光率下降,抑菌性得到增强。土壤降解实验表明茯苓/PVA共混膜具有良好的生物降解性。结论 制备的茯苓/PVA共混膜的力学性能和耐水性均得到提高,并且复合膜具有一定的抑菌性和可降解性。文中制备的复合膜为食品包装提供了理想选择。     

磺化聚醚醚酮/多壁碳纳米管复合质子交换膜的制备与性能

合成了表面接枝磺酸基团的改性多壁碳纳米管(S-MWNTs),通过溶液共混法制备了用于直接甲醇燃料电池的磺化聚醚醚酮(SPEEK)/S-MWNTs复合膜.扫描电镜显示,SMWNTs在掺杂量比较少时,能够在SPEEK基体中均匀分散;热重分析证明,复合膜具有优异的热稳定性.当掺杂量为1%时,复合膜的机械性能,尺寸稳定性及电导率均提高,这有效解决了纯SPEEK膜中质子电导率与机械性能、尺寸稳定性等相矛盾的问题.     

明胶/聚乙烯醇共混复合膜的相容性

以明胶(Gel)和聚乙烯醇(PVA)为基体,通过溶液共混、浇铸成膜的方法制备了一系列明胶/聚乙烯醇共混复合膜。采用分光光度法、红外光谱(IR)、扫描电镜(SEM)、热重(TG)和差示扫描量热法(DSC)初步表征了复合膜的结构,研究了两组分间的相容性。结果表明,在Gel和PVA质量比为1∶5时,Gel/PVA复合膜的透光性最好;SEM结果显示,复合膜中明胶与聚乙烯醇之间没有发生相分离;DSC测试显示,复合膜的玻璃化转变温度(Tg)并不明显;TG测试结果显示,在失重20%、40%、50%时,Gel/PVA复合膜比纯PVA膜的热失重温度提高了很多。     

共混比对电中性QSS/PVA粘合及其共混薄膜力学性能的影响

采用三步法合成了电中性季铵阳离子醚化/磺基丁二酸酯化淀粉(电中性QSS),并与聚乙烯醇(PVA)共混,研究了电中性QSS/PVA共混比对共混薄膜力学性能的影响,考察了共混比对其与棉和涤纶纤维间粘合强度的影响。结果表明:随着PVA共混比例的增加,共混物与棉和涤纶纤维间的粘合强度分别由159.3、294.3N/10~3tex逐渐增大到196.5、366.4N/10~3tex,共混薄膜的脆性降低,韧性提高,共混薄膜的断裂伸长率和耐屈曲次数分别由PVA共混比例为0%的3.88%和2345次增大到共混比例为50%的44.8%和8234次,断裂强度由26.7MPa逐渐降低到17.2MPa。     

聚苯胺/聚乙烯醇复合膜的性能研究

采用聚乙烯醇为基质材料制备了聚苯胺/聚乙烯醇(PANI/PVA)复合膜,讨论了PANI与PVA质量比、膜干燥温度对复合膜性能的影响,并对PVA膜、HCl掺杂PANI膜以及PANI/PVA复合膜的拉伸断裂强度、断裂伸长率、电导率以及热稳定性作了比较。结果表明:PVA膜的拉伸断裂强度、断裂伸长率最强,但是电导率最小;PANI/PVA复合膜电导率最大,其拉伸断裂强度、断裂伸长率比未加PVA的HCl掺杂PANI膜都得到了大大提高。在180℃之前,PVA膜最稳定,HCl掺杂PANI膜稳定性最差;在260℃之后,HCl掺杂PANI膜最稳定,PVA膜稳定性最差。     

PP/碳纳米管复合材料的制备及电性能

采用原子转移自由基(ATRP)活性聚合方法在多壁碳纳米管(MWNT)表面接枝丙烯酸丁酯聚合物(PBA),并以此对聚丙烯(PP)进行改性。红外光谱(FT-IR)及透射电子显微镜(TEM)测试结果表明,采用ATRP法成功地将PBA接枝到多壁碳纳米管(MWNT)表面。对PP/MWNT复合材料电性能研究表明,MWNT-PBA的添加比MWNT-COOH更能降低复合材料的电阻率。MWNT-PBA的加入可使PP从绝缘材料转变为抗静电材料。MWNT-PBA和MWNT-COOH加入PP都能提高材料的电性能,而MWNT-PBA比MWNT-COOH的作用更加明显。     

Electromechanical properties of nanotube-PVA composite actuator bimorphs

Oxidized multiwalled carbon nanotube (oxidized-MWNT)/polyvinyl alcohol (PVA) composite sheets have been prepared for electromechanical actuator applications. MWNT have been oxidized by nitric acid treatments. They were then dispersed in water and mixed with various amounts of PVA of high molecular weight (198?000?g?mol(-1)). The composite sheets were then obtained through a membrane filtration process. The composition of the systems has been optimized to combine suitable mechanical and electrical properties. Thermogravimetric analysis, mechanical tensile tests and conductivity measurements show that the best compromise of mechanical and electrical properties was obtained for a PVA weight fraction of about 30?wt%. In addition, one face of the sheets was coated with gold to increase the conductivity of the sheets and promote uniform actuation. Pseudo-bimorph devices have been realized by subsequently coating the composite sheets with an inert layer of PVA. The devices have been tested electromechanically in a liquid electrolyte (tetrabutylammonium/tetrafluoroborate (TBA/TFB) in acetonitrile) at constant frequency and different applied voltages, from 2 to 10?V. Measurements of the bimorph deflections were used to determine the stress generated by the nanotube-PVA sheets. The results show that the stress generated increases with increasing amplitude of the applied voltage and can reach 1.8?MPa. This value compares well with and even exceeds the stress generated by recently obtained bimorphs made of gold nanoparticles.     

聚乳酸/聚乙烯醇共混膜的制备

基于流延法和溶剂蒸发技术,以聚乳酸(PLA)和聚乙烯醇(PVA)为原料,制备可降解PLA/PVA共混膜。通过考察不同的共溶剂对共混膜成膜性能的影响,确定二甲基亚砜(DM SO)是制备PLA/PVA共混膜优良的共溶剂。研究PLA与PVA配比对PLA/PVA共混膜性能的影响,探索PLA与PVA分子链在共混膜中的结合状况。结果表明,当PLA的含量低于20%时,可以得到均质的PLA/PVA共混膜,且PLA与PVA分子链间以氢键结合。此外,在共混过程中,PLA与PVA的结晶均受到一定的破坏,结晶度比纯PLA与PVA下降。     

静电纺定向纳米纤维素-碳纳米管/聚乙烯醇复合纤维导电膜及性能

利用纤维素纳米晶须（CNCs）搭载碳纳米管（CNTs）在水相中形成均一稳定的纳米CNCs-CNTs导电复合物,并将其均匀分散于聚乙烯醇（PVA）基体中制得纺丝液,采用静电纺丝技术制备纤维定向排列的CNCs-CNTs/PVA复合导电膜。结果表明：CNCs-CNTs增强了纤维膜热力学性能,并赋予其导电功能;纤维的定向排列显著提高了膜的力学性能;随CNTs含量增加,纺丝液电导率和黏度提高,纤维直径减小;当CNCs和CNTs与PVA的质量比分别为8.0%和1.0%时,CNCs-CNTs/PVA的纤维直径、拉伸强度和电导率分别可达182 nm±35 nm、15.99 MPa±1.25 MPa和0.12 S/m±0.01 S/m;当电流密度为0.2 A/g时,其比电容可达127.1 F/g,且经过1 500次充放电循环后电容量仍保持在83.14%。基于导电膜优良的力学性能、热稳定性和导电性,CNCs-CNTs/PVA导电膜有望应用于可折叠超级电容器、柔性传感器和柔性电极材料等领域。     

Reinforcement on properties of poly(vinyl alcohol) films by embedding functionalized carbon micro coils

Carbon micro coils (CMCs) were hybridized with poly(vinyl alcohol) (PVA) through esterification reaction. The mixing of as-prepared CMC hybrid with polymer (PVA) matrix was effective to prepare PVA film where the functionalized CMC was homogeneously dispersed and embedded. The presence of CMCs in PVA film heightened the glass transition temperature of PVA. Results of tensile stress and electrical conductivity indicated that overall mechanical and electrical properties of PVA film were enforced by embedding CMC, depending on increase of the CMC concentration. These properties were further reinforced by prefunctionalization of CMC by PVA, because CMC can have an affinity to PVA in matrix through PVA immobilized on CMCs. However, mechanical and electrical properties for both nonfunctionalized and functionalized composites were depressed above a certain CMC concentration, indicating the self-orientation of CMC in the matrix, different from the behavior of carbon black.     

表面官能团化多壁碳纳米管/环氧树脂复合材料的制备及性能

本文首先将多壁碳纳米管(MWNT)进行表面化学修饰,接入羧基、胺基等官能团,采用红外光谱进行了表征.以纯化后的MWNT和表面化学修饰的MWNT作为填料,制备了MWNT /环氧树脂复合材料,研究了MWNT的加入对环氧树脂的力学性能、电学性能、热稳定性和玻璃化转变温度等的影响,并利用场发射电镜观察了胺基化MWNT在环氧树脂基体中的分散情况.     

聚乙烯醇-聚丙烯酸共混膜的阻醇及质子导电性能研究

针对目前直接甲醇燃料电池 (DMFC)中普遍使用的Nafion系列全氟磺酸膜存在的甲醇穿透问题 ,制备了在渗透蒸发醇 -水分离领域有良好分离效果的聚乙烯醇 (PVA)和聚乙烯醇 -聚丙烯酸 (PVA -PAA)共混膜并研究了其阻醇和质子导电性能 .与Nafion1 1 7膜相比 ,PVA膜和PVA -PAA共混膜的阻醇性能有明显提高 ,其导电能力虽很大程度上依赖于外加电解质溶液 ,但PAA的混入使PVA膜材料的导电性能有了很大改善     

Electroactive shape memory polymer based on optimized multi-walled carbon nanotubes/polyvinyl alcohol nanocomposites

The development of shape memory polymers (SMPs) has gained remarkable attention due to their wide range of applications, from biomedical to electromechanical. In this work, we have developed and optimized an electroactive SMP based on polyvinyl alcohol/multi-walled carbon nanotubes (PVA/MWNTs) composites. When a constant voltage of 60 V was applied to the optimized sample, the polymer shape could be recovered to the original form within 35 s. Different weight fractions of MWNT/PVA composites were prepared by using a simple solution blending and transitional solution casting method, and their microstructures, electrical conductivities, thermal conductivities, and electroactive shape memory properties were investigated. According to our systematic analysis, the enhanced performance can be attributed to the reinforcement of MWNTs that led to the improved electrical and thermal conductivities of the PVA matrix.     

磺化聚芳醚酮砜/PVA复合质子交换膜的制备与性能

为了进一步提高质子交换膜在中高温时的质子导电率,文中以高磺化度的磺化聚芳醚酮砜(SPAEKS)和聚乙烯醇(PVA)为原料,通过溶液共混法制备了PVA不同含量的磺化聚芳醚酮砜/PVA复合膜。通过对复合膜的性能测试发现,PVA的引入提高了膜的热稳定性、吸水率和保水能力。而且SPAEKS/PVA复合膜的质子传导率高于SPAEKS膜,在80℃时,复合膜的质子传导率都在0.07 S/cm以上,能够满足中高温质子交换膜燃料电池的使用要求。     

Electrical and dielectric properties of polypropylene nanocomposites based on carbon nanotubes and barium titanate nanoparticles

Functional polypropylene (PP) nanocomposites were prepared by melt compounding with multiwalled carbon nanotubes (MWNT) as the electrically conductive component and barium titanate (BT) spherical nanoparticles as the ferroelectric component. To make PP electrically conductive, more than 3 wt.% MWNT is required. Surface modification of either MWNT or BT with titanate coupling agent further improves the electrical conductivity of the PP/MWNT/BT ternary nanocomposites. Interestingly, by modifying both MWNT and BT, 2 wt.% MWNT are sufficient to make the ternary nanocomposite electrically conductive. In addition, the incorporation of MWNT greatly increases the dielectric permittivity of PP/BT nanocomposites. However, to retain a low dielectric loss, the MWNT loading should be slightly less than the percolation threshold of the nanocomposites. The improved electrical conductivity and dielectric properties make the ternary nanocomposites attractive in practical applications.