磺化酚酞型聚醚砜/改性蒙脱土纳米复合膜的研究

用季胺盐改性蒙脱土和磺化酚酞型聚醚砜首次制得了磺化酚酞型聚醚砜/改性蒙脱土纳米复合质子交换膜,并用1H NMR、SEM、FT-IR等分析手段对其进行了表征,测定了复合膜的质子导电率.研究结果表明:改性蒙脱土以纳米颗粒形式分散于磺化酚酞型聚醚砜聚合物基体中;在相同测试温度下,磺化酚酞型聚醚砜/改性蒙脱土纳米复合质子交换膜的质子电导率随着改性蒙脱土含量增加而增加,添加10%(wt)改性蒙脱土的复合质子交换膜,在80℃下的质子电导率为8.53×10-4S/cm.     

硅烷偶联剂改性钛酸钡对SPEEK质子交换膜性能的影响

为提高无机填料在聚合物中的分散性,利用硅烷偶联剂KH570对钛酸钡(BT)表面改性.采用溶液浇铸法制备磺化聚醚醚酮(SPEEK)/改性BT(KH570-BT)复合质子交换膜.利用透射电镜观察了改性前后BT在SPEEK基体中的分散情况并系统研究了KH570-BT掺杂量对复合质子交换膜性能的影响.结果显示,与BT相比,KH570-BT的分散性得到明显改善.将KH570-BT掺杂进SPEEK后,复合膜的质子电导率、甲醇渗透率、热稳定性及选择性均出现明显提升.室温下,SPEEK/KH570-BT-1.0复合膜的质子电导率达到63.7 mS/cm,高于同配比的SPEEK/BT-1.0(σ=57.7 mS/cm)和SPEEK(σ=58.6 mS/cm);SPEEK/KH570-BT-1.0的选择性达到20.9×10~4 S·s/cm~3,与SPEEK/BT-1.0(17.2×10~4 S·s/cm~3)和SPEEK(17.7×10~4 S·s/cm~3)相比,分别提升了21.5%和18.1%.     

低温燃料电池用聚(2,5-苯并咪唑)/磺化海泡石复合质子交换膜的制备与性能EI北大核心CSCD

采用原位法制备了一种适用于低温燃料电池的新型聚(2,5-苯并咪唑)/磺化海泡石(ABPBI/S-Sep)复合质子交换膜。对海泡石酸活化和磺化改性前后的化学结构、亲水性和分散性以及复合膜的形貌、吸水率、磷酸掺杂水平与质子传导率等性能进行了表征和测试。结果显示,所制备的S-Sep粒子在ABPBI聚合物基体中分散均匀,并能促进聚合物分子链的规整排布;与纯ABPBI膜相比,S-Sep粒子的添加显著增强了复合膜对水和磷酸的吸收和保留能力,且在相同或相近磷酸掺杂水平下,ABPBI/S-Sep复合膜的质子传导率显著提高。在40～90℃温度范围内,饱和湿度98%RH时复合膜的质子传导率与Nafion 212相当;在低湿度60%RH时,高磷酸掺杂水平的ABPBI/S-Sep复合膜质子传导率略低于98%RH的结果,但显著优于Nafion 212的质子传导性能。不同温湿度环境下的质子传导率结果表明S-Sep改性ABPBI复合膜具备低温环境使用的特点,可替代Nafion类全氟磺酸膜应用于低温质子交换膜燃料电池。     

SPPEK/PWA质子导电复合膜的制备与性能

以磺化杂萘联苯聚醚酮(SPPEK)为基体,采用共混法制备了SPPEK/PWA复合质子交换膜。采用红外光谱、热分析与交流阻抗等方法对复合膜的结构和性能进行了研究,并与Nafion117膜进行了比较。结果表明,磷钨酸(PWA)的掺杂使得复合膜的吸水率和溶胀度增大,同时热稳定性能得到提高。复合膜在20℃时的质子电导率为0.67×10-2S/cm,接近Nafion117膜的质子电导率(1.08×10-2S/cm)。且随着温度的升高,电导率逐渐增大,最高可达1.18×10-2S/cm。此外,对复合膜不同方向上的电导率进行了测试,表明膜平面方向上的电导率(8.10×10-2S/cm)高于厚度方向上电导率(7.50×10-3S/cm)约一个数量级。     

基于巯基改性磺化海泡石与聚(2,5-苯并咪唑)原位复合的宽温域用质子交换膜

天然海泡石经微波辅助酸活化和巯基偶联剂改性得到磺化海泡石,然后原位合成制备燃料电池宽温域用聚(2,5-苯并咪唑)/磺化海泡石(ABPBI/S-Sep)复合质子交换膜。研究了海泡石改性前后结构变化,以及S-Sep粒子的加入对复合膜的微观形貌、结构、力学性能、吸水固酸能力以及高、低温下质子传导性能的影响。研究发现,海泡石粒子经微波辅助酸活化处理后产生了解纤维化,磺化改性提高了其与聚合物相容性;S-Sep纤维状粒子均匀分散在ABPBI基体中可诱导聚合物分子链取向排列,从而提高复合膜的力学性能,其特有的纳米通道结构及高比表面积显著提高了复合膜的吸水率和固酸能力。在相似磷酸(PA)掺杂水平下,复合膜在40~180℃宽温域下的质子传导率和峰值功率密度均高于ABPBI膜,并且磷酸掺杂水平为1.85的复合膜在90℃以下,60%和98%RH时质子传导性能以及80℃、0%RH时单电池性能均与Nafion 212相当,表明低磷酸掺杂水平下的S-Sep改性ABPBI复合膜具备从低温到高温且不控制湿度的宽温域使用优势,可拓展基于PA掺杂聚苯并咪唑类膜材料的使用温度范围。     

SiO_2/SPFEK质子交换膜的化学稳定性及导电性能研究

为提高磺化聚醚醚酮(SPFEK)质子交换膜的化学稳定性及质子传导率等性能,采用溶胶-凝胶法制备了SiO_2/SPFEK复合质子交换膜,利用扫描电子显微镜(SEM)对复合膜的微观形态进行了表征,并考察了不同SiO_2掺杂量对质子交换膜性能的影响.结果表明,纳米SiO_2能提高膜的质子传导率和氧化稳定性.当SiO_2掺杂质量分数为8%时,复合膜的质子传导率在80℃时为5.59×10~(-2) S/cm,且表现出良好的氧化稳定性等.     

原位合成法二氧化硅/硅钨酸改性聚乙烯醇质子交换膜的研制

以聚乙烯醇(PVA)为基体,利用原位合成法制备了二氧化硅(SiO2)和硅钨酸(SiWA)微粒在PVA基质中均匀分布的二氧化硅/硅钨酸改性聚乙烯醇(SiO2/SiWA-m-PVA)质子交换膜,利用扫描电镜(SEM)和热重分析仪(TG)分别对膜的形貌及热稳定性进行了表征,四氯化硅与钨酸钠摩尔比对SiO2/SiWA-m-PVA质子交换膜的质子导电性能、阻醇性能的影响.结果表明,四氯化硅与钨酸钠摩尔比为1∶1时,原位合成的二氧化硅和硅钨酸在质子交换膜中分散均匀,在温度低于100℃时SiO2/SiWA-m-PVA膜保水性能好;室温质子电导率为1.48×10-2 S/cm,甲醇渗透率为1.37×10-7 cm2/s,比相同条件下Nafion117膜甲醇渗透率低一个数量级,应用于直接甲醇燃料电池单电池能量密度可达11.82 mW/cm2.     

磷钨酸/磺化聚芳醚酮砜复合型高温燃料电池用质子交换膜

为了满足高温质子交换膜燃料电池使用要求,采用溶液铺膜法制备了磺化聚芳醚酮砜(SPAEEKS)与磷钨酸(HPA)复合型质子交换膜。红外光谱证明磷钨酸中的桥氧原子和端氧原子与磺酸基团形成了强烈的相互作用。扫描电镜照片显示磷钨酸粒子能够均匀地分散在聚合物的基体中。磷钨酸的引入提高了复合膜的热稳定性 ,含有 30wt%HPA、SPAEEKS磺化度为0.8的复合膜(HPA30/SPAEEKS-0.8)的玻璃化转变温度达到236℃,质量损失5%时的热分解温度达到了299℃。在相同测试条件下,HPA30/ SPAEEKS-1. 0在80℃时质子传导率高于Nafion 117,而且在120℃ 达到了0.098S/cm。结果表明,HPA30/SPAEEKS-1. 0 有望在高温质子交换膜燃料电池中得到应用。     

磷钨酸表面处理对燃料电池质子交换膜热稳定性的影响

研究了磷钨酸掺杂改性后质子交换膜的热稳定性及热降解动力学,利用热重分析在氮气气氛下和升温速率分别为5℃、20℃和30℃时,采用Kissinger、Flynn-Wall-Ozawa、Friedman和Starink方法对磷钨酸改性后的非等温动力学数据进行了分析。热失重曲线显示磷钨酸改性后质子交换膜分解率达到5%和10%时,最低热降解温度分别为173.6℃和284.8℃。采用不同方法的计算结果显示,改性后膜分解反应受D2机理控制,表观活化能约为163.74 kJ/mol。改性前后膜的电导率(σ)分别为8.34×10-7S/cm及2.57×10-5S/cm。     

聚偏氟乙烯-磺化聚苯乙烯质子交换膜的制备与表征

采用热诱导溶液聚合和相转移技术,制备了新型聚偏氟乙烯-磺化聚苯乙烯(PVDF-SPS)质子交换膜。采用X射线衍射光电子能谱(XPS)、环境扫描电镜(ESEM)和红外光谱(FT-IR)对PVDF-SPS质子交换膜进行了表征,研究了质子膜的吸水率、质子传导率和甲醇渗透系数。结果表明,PVDF-SPS质子膜具有优良的亲水性能,较高的质子传导率和较低的甲醇渗透系数。PVDF-SPS质子交换膜在25℃的质子传导率和甲醇渗透系数分别为2.93×10-2S/cm和8.61×10-8cm2/s,其质子传导率与甲醇渗透系数比值为3.40×105S.s/cm3,超过Nafion-117膜的20倍。     

Nylon 610/functionalized multiwalled carbon nanotubes composites by in situ interfacial polymerization

Nylon 610 (poly(hexamethylenesebacamide)) nanocomposites containing well dispersed multiwalled carbon nanotubes (MWCNT) were prepared using an in situ interfacial polymerization. Scanning electron microscopy showed that the MWCNT were well embedded and adhered to the nylon 610 matrix. The interfacial interaction of nylon 610/MWCNT on the grafted nylon 610 chains on the MWCNT was enhanced by improving the compatibility with nylon 610. This allowed a homogeneous dispersion of MWCNT in the nylon 610 matrix. Furthermore, the mechanical properties of nylon 610 were greatly improved by incorporating a small amount of MWCNT (0.1 wt.%). Because MWCNT are electrically conducting, the resulting electrical properties of the composites were approximately 5 orders of magnitude higher than pure nylon 610 matrix (from 10^− 17 S/cm to 10^− 12 S/cm). Overall, the results suggest that in situ polymerization is an ideal technique for producing a perfect dispersion of MWCNT in polymeric matrices.     

A simple and effective method to form metallic nanoparticles onto composites made up of organic polymers and layered inorganic ion exchangers as fillers

A new easy method for the preparation of polymeric nanocomposites supporting metal nanoparticles is presented. The method concerns the use of a layered inorganic ion exchanger converted in the proper metallic form and exfoliated to act as filler of organic polymers with twofold aim of obtaining a composite (or nanocomposite) and to have metal ions that can be suitably reduced with a proper reducing agent to form metal nanoparticles. This strategy has been applied to the system polyvinylidene fluoride (PVDF) filled with layered a-zirconium phosphate in copper form. Several physical techniques (X-ray powder diffraction, atomic force microscopy, high resolution transmission electron microscopy) have been used to characterize the Cu-nanoparticles, whose dimensions range from 5 to 200 nm for those placed inside or on the surface of the polymeric matrix respectively, depending on the dispersion degree of the inorganic filler. The method is simple and can be used for different polymeric matrices and/or metal ions in order to produce metal/polymer systems with promising technological application.     

纳米SiO2/SPFEK复合质子交换膜的制备及性能

以自制的磺化聚芴醚酮和正硅酸乙酯为原料,采用溶胶凝胶(Sol-gel)法合成了掺杂纳米SiO2的复合质子交换膜,利用能量分散谱(EDS)线扫描、热失重分析法、扫描电镜对膜的结构、热稳定性、微观形态进行了表征。并考察了质子交换膜的各种性能。结果表明,纳米SiO2能提高膜的质子传导率和氧化稳定性能。当SiO2掺杂质量分数为9%时,复合膜的质子传导率在80℃时为5.96×10-2(S/cm),在80℃的Fenton’s试剂(3%的过氧化氢和2 mg/L的FeSO4)中进行氧化稳定性测试,膜在117 min时才开始碎裂,表现出良好的氧化稳定性。     

石墨烯/聚苯胺复合材料的电磁屏蔽性能

采用直流电弧放电法制备高结晶性石墨烯, 利用乙醇助溶分散法得到石墨烯/聚苯胺电磁屏蔽复合材料, 研究不同掺杂比例的石墨烯/聚苯胺复合材料的电磁屏蔽性能。拉曼光谱分析表明: 由于石墨烯与聚苯胺之间的相互作用, 复合材料中聚苯胺特征峰比纯聚苯胺特征峰稍弱或向低频方向移动。复合物的电导率随石墨烯掺杂量的增加而增大, 当掺杂质量分数为25%时, 其电导率达到19.4 S/cm, 接近纯石墨烯电导率(20.1 S/cm)。频率为2~18 GHz时, 复合材料的电磁屏蔽效能随着石墨烯掺杂量和频率的增大而增强; 当石墨烯掺杂质量分数为25%时, 总屏蔽效能在2~18 GHz范围内由19.8 dB增至34.2 dB, 增加了约42%, 其中吸收部分占总屏蔽效能的比例为66%~81%, 这表明石墨烯/聚苯胺复合材料的电磁屏蔽性质是以电磁波吸收为主; 同时也说明了拥有特殊结构与特性的石墨烯是一种较好的聚苯胺填料, 在微波屏蔽与微波吸收领域将会有广阔的应用前景。     

Reactive fillers based on SWCNTs functionalized with matrix-based moieties for the production of epoxy composites with superior and tunable properties

Composite materials based on epoxy matrix and single-walled carbon nanotubes (SWCNTs) are able to exhibit outstanding improvements in physical properties when using a tailored covalent functionalization with matrix-based moieties containing terminal amines or epoxide rings. The proper choice of grafted moiety and integration protocol makes it feasible to tune the composite physical properties. At 0.5 wt% SWCNT loading, these composites exhibit up to 65% improvement in storage modulus, 91% improvement in tensile strength, and 65% improvement in toughness. A 15?°C increase in the glass transition temperature relative to the parent matrix was also achieved. This suggests that a highly improved interfacial bonding between matrix and filler, coupled to improved dispersion, are achieved. The degradation temperatures show an upshift in the range of 40-60?°C, which indicates superior thermal performance. Electrical conductivity ranges from ~10(-13) to ~10(-3) S cm(-1), which also shows the possibility of tuning the insulating or conductive behaviour of the composites. The chemical affinity of the functionalization moieties with the matrix and the unchanged molecular structure at the SWCNT/matrix interface are responsible for such improvements.     

Preparation and properties of composites with staggered alignment of carbon nanotubes induced by electric field

In this paper, bulk polymeric composites with staggered orientation of carbon nanotubes (CNTs) in polymer matrix were prepared by means of a macro layer-by-layer (MLBL) method, while an alternating current (AC) electric field was applied for inducing alignment of the CNTs. Test results verified that there existed a relationship between conductive capacity of the composites and orientation of the CNTs in matrix. Conductivity of the composites containing aligned CNTs represented a dependency on time and testing history on the composite specimens. Among the composites with different orientation types of CNTs in the matrices, the composite specimens including staggered orientation of CNTs in polymer matrix demonstrated the most outstanding electric conductivity and showed similar conductive properties in the two directions of the CNT alignment.     

磷掺杂石墨相氮化碳的制备及其在锂硫电池中的应用

通过热缩聚合成法,采用尿素为原料,制备石墨相氮化碳(g-C₃N₄),以磷酸氢二胺作为磷源,制备不同磷含量的磷掺杂g-C₃N₄ (xP-CN),研究磷掺杂对xP-CN的微观结构、形貌及xP-CN/S复合材料作为锂硫电池正极材料电化学性能的影响。研究表明,磷掺杂后xP-CN的层间距增大,导电性提高,比表面积变大,10% P-CN的比表面积最大达到101.741 m2·g?1。10% P-CN/S复合材料在0.05 C (1 C=1675 mA·h·g?1)下首次放电比容量达到1383.8 mA·h·g?1,在0.2 C下循环100次后可逆比容量为860.0 mA·h·g?1,而g-C₃N₄/S复合材料比容量仅为178.3 mA·h·g?1;10% P-CN/S复合材料经过倍率测试后比容量可以回复到0.2 C时的93.6%,表现出良好的循环性能和倍率性能。      

质子交换膜掺杂固体无机质子导体材料的研究进展

主要介绍了目前掺杂质子交换膜用的几种无机质子导体磷酸锆、杂多酸、硫酸氢盐等,并进一步介绍了将这些无机质子导体引入到聚合物中的3种掺杂方法:混合浇铸法、离子-沉淀法和溶胶-凝胶法.重点介绍了国内外掺杂无机固体质子导体的燃料电池用质子交换膜的研究进展.     

Mechanical,electrical and thermal properties of aligned carbon nanotube/polyimide composites

Carbon nanotubes (CNTs) have high strength and modulus, large aspect ratio, and good electrical and thermal conductivities, which make them attractive for fabricating composite. The poly(biphenyl dianhydride-p-phenylenediamine) (BPDA/PDA) polyimide has good mechanical and thermal performances and is herein used as matrix in unidirectional carbon nanotube composites for the first time. The strength and modulus of the composite increase by 2.73 and 12 times over pure BPDA–PDA polyimide, while its electrical conductivity reaches to 183 S/cm, which is 10¹⁸ times over pure polyimide. The composite has excellent high temperature resistance, and its thermal conductivity is beyond what has been achieved in previous studies. The improved properties of the composites are due to the long CNT length, high level of CNT alignment, high CNT volume fraction and good CNT dispersion in polyimide matrix. The composite is promising for applications that require high strength, lightweight, or high electrical and thermal conductivities.