PAN/TiO2-GO杂化纤维膜的电纺制备与分析

通过静电纺丝技术制备聚丙烯腈（PAN）/二氧化钛（TiO2）-氧化石墨烯（GO）杂化纤维膜,经煅烧处理后,通过扫描电子显微镜（SEM）、X射线衍射仪（XRD）、热重仪（TG）和分光光度计等仪器,分别对杂化纤维的形貌特征、结晶性能、热性能和光催化降解能力进行分析。结果表明,钛酸四丁酯（TBOT）水解产物经煅烧处理后,转变为锐钛矿型TiO2;随着TBOT添加量的增多,纤维直径逐渐减小,最小可达25 nm;TBOT的加入可以改善纤维的热稳定性;降解次甲基蓝实验可知,随着TBOT加入量的增大,样品的光催化性能有所提高;TiO2-GO/PAN杂化纤维膜经煅烧后可作为一种光催化剂。     

TiO_2光催化膜反应器处理有机废水的研究

针对TiO2光催化剂难以回收的难题,自制了聚偏氟乙烯(PVDF)中空纤维膜,并用于反应器中TiO2的回收。把PVDF膜组件和TiO2光催化器集成得到膜组件外置的光催化膜反应器,考察这种反应器对有机物废水的处理效果。研究了光源辐射照度、光催化剂含量、目标降解物类型及初始含量对降解效率的影响。结果表明,PVDF膜对TiO2纳米颗粒的截留效果可达100%,膜的水通量可达87.55 L/(m2·h)。最大吸收波长在光谱范围内,有机物的降解率随辐射照度的增大而增加;增加光催化剂含量,光催化降解率将会提高;目标降解物初始含量升高,降解率随之下降。     

TiO_2溶胶改性PVDF超滤膜的制备与性能研究

利用溶胶-凝胶法制备二氧化钛(TiO2)溶胶并添加到铸膜液中,应用非溶剂致相法制备聚偏氟乙烯(PVDF)成品膜。系统研究了溶胶态TiO2、无机态Ti O2以及无机态TiO2/分散剂体系对TiO2/PVDF杂化膜的表面形貌、热稳定性、纯水接触角的影响。结果表明,溶胶态TiO2在铸膜液中分散良好,制取所得成品膜具有优良的综合性能,溶胶态TiO2的加入使得膜的接触角明显降低,孔隙率和平均孔径增大。     

Ag/TiO2/PVDF复合纤维膜的制备及光催化性能研究

采用静电纺丝结合溶胶法制备了一系列不同Ag/TiO₂含量的Ag/TiO₂/PVDF复合纤维膜，并利用傅里叶红外光谱(FT-IR)、扫描电镜(SEM)、干湿重法、过滤测试法、微电脑抗张强度测定仪等对复合纤维膜的微观形貌、力学性能等进行表征和研究，结果表明添加适当的Ag/TiO₂时，所制备的Ag/TiO₂/PVDF复合纤维膜纤维表面比较平滑，具有较大的平均孔径和较高的孔隙率，且抗拉强度和伸长率均有所提高，但如过量添加Ag/TiO₂，则会导致膜性能受到影响。对Ag/TiO₂/PVDF复合纤维膜光催化降解溶液中亚甲基蓝(MB)的性能进行研究，结果表明，相较于PVDF原膜，Ag/TiO₂/PVDF复合纤维膜对于MB的光催化降解性能有显著提升，且其光催化降解过程符合准一级动力学模型。循环利用性能测试结果表明，Ag/TiO₂/PVDF复合纤维膜重复利用性较好，具有实际应用前景。     

离子液体接枝型纳米二氧化硅对聚偏氟乙烯膜的亲水化改性研究

采用溶液接枝法合成了离子液体接枝型纳米二氧化硅(IL-Si O2),并利用浸没沉淀相转化法制备了聚偏氟乙烯/离子液体接枝型纳米二氧化硅(PVDF/IL-Si O2)杂化膜,考察了IL-Si O2含量对杂化膜性能的影响。采用流动电位、接触角和水通量等手段分析研究了杂化膜的性能。研究结果表明,PVDF/IL-Si O2杂化膜表面带有正电荷;IL-Si O2的加入显著提高了杂化膜的亲水性、拉伸强度和断裂伸长率;杂化膜纯水通量显著增加的同时,对蛋白质的吸附量和截留率均有一定程度上的提高。     

TiO_2光催化有机-无机杂化超滤膜去除水中天然有机物研究

采用相转化法将聚偏氟乙烯(PVDF)、二氧化钛(TiO2)和聚乙二醇(PEG)共混制得TiO2光催化有机-无机杂化超滤膜。利用实验室自制有机-无机杂化超滤膜在有无紫外光照条件下,对腐殖酸(HA)和水库源水样中天然有机物(NOM)的去除率和膜污染情况进行研究和分析,并比较了不同溶液环境(pH和离子强度)和有无紫外光照条件下对腐殖酸水样超滤过程的影响。结果表明,pH较低、离子强度较高的溶液环境有助于提高PVDF-PEG-TiO2膜对HA的去除率;光催化作用可以显著减少膜通量衰减,减少膜污染。     

PVDF/SiO_2杂化内支撑型中空纤维膜的制备及性能研究

利用涤纶纤维丝(PET)编织管作为内支撑层,将纳米SiO_2添加到聚偏氟乙烯(PVDF)铸膜液中,通过涂覆-浸没沉淀相转化法制得PVDF/SiO_2杂化内支撑型中空纤维膜,考察了铸膜液中不同SiO_2含量对膜性能的影响。结果表明,PET编织管的加入,使中空纤维膜的拉伸强度超过50 MPa。随着纳米SiO_2含量增加,膜的接触角从78.5°降至60.6°,杂化膜的纯水通量增大、孔隙率提高。X射线衍射仪图谱表明,SiO_2的加入未改变PVDF的主要晶型构成。当SiO_2的质量分数为1.5%时,杂化膜的纯水通量达到192.6 L/(m~2·h),孔隙率为68%,拥有了优异的过滤性能。     

活性炭填充PEG/PVDF杂化膜的脱硫性能

制备了不同活性炭（AC）填充量的AC-PEG/PVDF杂化膜,并对其形貌与结构进行了相应的表征。以噻吩/正庚烷混合物作为模拟汽油体系,研究了所制备AC-PEG杂化膜的渗透汽化脱硫性能。研究表明,填充活性炭后,膜的脱硫性能明显提高。当活性炭填充量为5%,温度为85℃时,与未填充的PEG膜相比,AC-PEG/PVDF杂化膜的渗透通量由0.43 kg·（m²·h）^-1提高至1.14 kg·（m²·h）^-1,富硫因子由7.29提高至9.47。     

聚多巴胺改性粘土掺杂聚偏氟乙烯中空纤维杂化超滤膜的制备及性能研究

利用聚多巴胺对粘土进行改性制得PDA-Clay,显著提升粘土在有机溶剂中的分散性;将改性粘土与聚偏氟乙烯(PVDF)共混,通过相转化的方法制备PVDF中空纤维杂化膜。实验结果表明:PDA-Clay纳米颗粒的含量对PVDF中空纤维膜的结构具有明显的影响;与PVDF膜相比,杂化膜的亲水性和机械强度均有明显的提高;当PDA-Clay添加量为2.0%(质量分数)时,杂化膜的机械强度由2.0MPa提高至2.9 MPa,内外表面的接触角分别由73.7°、72.6°下降至55.4°、56.8°。因此,通过聚多巴胺亲水改性粘土,并与聚偏氟乙烯掺杂共混,可成功制备亲水性好和机械强度高的PVDF中空纤维杂化膜。     

基于硅烷偶联剂表面改性制备Al_2O_3/PVDF杂化膜

采用硅烷偶联剂(2-氰乙基)三乙氧基硅烷对纳米Al_2O_3粒子进行表面改性,利用热致相变法制备了改性Al_2O_3/PVDF有机无机杂化膜,研究了改性Al_2O_3的添加量对杂化膜性能的影响。经(2-氰乙基)三乙氧基硅烷改性后,纳米Al_2O_3粒子的团聚减少,改性后纳米Al_2O_3的平均最小粒径为52.23nm。与纯PVDF膜比较,改性纳米Al_2O_3的添加改善了PVDF膜的形貌结构,改性Al_2O_3/PVDF杂化膜形成的球晶明显增加,球晶的密度尺寸缩小,杂化膜中形成了大量连通的界面孔,膜的孔隙率升高,改善了PVDF膜的力学性能和亲水性,提高了截留率。当纳米粒子添加量达到5%时,膜的截留率提高了7.2%,膜的纯水通量达到了593.95L/(m~2·h),膜强度达到5.0MPa。     

聚丙烯酸酯/TiO2-SiO2纳米杂化材料性能的研究

采用具有核-壳结构的纳米TiO2-SjO2与热固性聚丙烯酸酯原位复合，通过溶胶-凝胶法制得了有机-无机纳米杂化材料，并对材料的结构和性能进行了表征。结果表明：聚丙烯酸酯基纳米SiO2包覆TiO2的有机-无机纳米杂化材料在无机组分质量分数低于8％时是透明的；随着TiO2-SiO2用量的增加，纳米杂化材料的附着力是先增后降，而热稳定性则是逐渐增加；拉伸强度和冲击强度随TiO2-SiO2用量的增加都是先增后降，当TiO2-SiO2质量分数为5．10％时，拉伸强度达到最大值，提高了25％；当TiO2-SiO2质量分数为3．45％时，无缺口冲击强度达到最大值，提高了27％。     

PA6/TiO2-GO复合材料的制备及其性能研究

近年来,环境污染问题越来越严重,光催化技术在处理污水和净化空气等方面发挥着重要的作用。本文通过差示扫描量热仪、电子万能拉伸试验机、可见分光光度计等仪器,主要研究不同纳米TiO2用量对PA6/TiO2-GO复合材料的热学性能、力学性能、光催化性能等的影响。通过研究发现：随纳米TiO2含量的增加,PA6/TiO2-GO复合材料的熔点逐渐降低,结晶度先增大后减小(复合材料的结晶度均大于纯PA6的结晶度);断裂强度逐渐减小,断裂伸长率逐渐增大;纳米TiO2对亚甲基蓝溶液的光催化降解能力越来越强。在相同纳米TiO2含量下,加入GO后能有效提高TiO2的光催化降解能力,光催化降解能力能提高10%左右。     

碳玻混编单向复合材料的性能分析

采用碳纤维质量含量分别为7.4%、10.7%、13.8%的三种碳玻层间混编单向织物制备了纤维增强环氧树脂复合材料,分析了该类材料的力学性能与工艺性能。结果表明:碳玻层间混编复合材料的0°拉伸模量和0°压缩模量均随碳纤维含量的提高而升高,掺入碳纤维后碳玻混杂复合材料的0°拉伸强度比纯玻纤复合材料的有所降低,但随碳纤维含量的增加而升高,碳玻层间混编复合材料的0°压缩强度则没有明显的变化规律;掺入碳纤维后,碳玻层间混编复合材料的90°拉伸强度和模量均有所下降;低碳纤维含量的碳玻层间混编单向织物具有良好的Z向渗透性能。该类新材料未来有望在风电叶片结构减重和成本优化上发挥重要作用。     

Preparation and performance of braid‐reinforced poly(vinyl chloride) hollow fiber membranes

A novel braid‐reinforced (BR) poly(vinyl chloride) (PVC) hollow fiber membrane was fabricated via dry‐wet spinning process. The mixtures of PVC polymer solutions were uniformly coated on the tubular braid which contained polyester (PET) and polyacrylonitrile (PAN) fibers. The influences of braid composition on structure and performance of BR PVC hollow fiber membranes were investigated. The results showed that the prepared BR PVC hollow fiber membranes were composed of two layers which contained separation layer and tubular braid supported layer when the PET and PET/PAN hybrid tubular braids were used as the reinforcement. But the sandwich structure appeared when the PAN tubular braid was used as the reinforcement, which revealed outer separation layer, tubular braid supported layer and the inner polymer layer. The BR PVC hollow fiber membranes that prepared by PET/PAN hybrid tubular braid had favorable interfacial bonding state compared with the membrane prepared by pure PET or PAN tubular braid. The pure water flux of the BR PVC hollow fiber membranes that prepared by the PET/PAN hybrid tubular braid were lower than that prepared by pure PET or PAN tubular braid, but the rejection of Bovine serum albumin was opposite. The tensile strength of prepared BR PVC hollow fiber membrane was higher than 50 MPa. Both of the tensile strength and elongation at break decreased with the increase of the PAN filaments in the PET/PAN hybrid tubular braid. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45068.     

金红石型TiO2对聚丙烯纤维紫外光降解的影响

分析了聚丙烯(PP)／金红石型二氧化钛(TiO2)共混纤维在人工加速紫外光降解中断裂伸长率、断裂强度、质量损失和表面形态的变化,与PP纤维进行对比,研究了纳米级和微米级金红石型TiO2对共混纤维光降解的影响。结果表明,在紫外光照射下,共混纤维中金红石型TiO2的含量越高,PP纤维断裂伸长率、断裂强度的降低和质量损失速率就越快;同时由扫描电镜照片发现,经紫外光照射120 h后,纤维表面损伤程度也随着TiO2添加量的增多而加深。纳米级和微米级金红石型TiO2都对PP的光氧化降解具有一定的催化作用,而且其含量越高,催化作用越强,但纳米级TiO2的催化作用比微米级TiO2大。     

混杂比对交织芳纶碳纤维复合材料力学性能的影响

为了分析混杂比对层内混杂复合材料力学性能的影响,利用交织方式制备芳纶碳纤维混杂增强体织物,并通过交织物纬纱系统中芳纶与碳纤维的纱线配置比例调整碳纤维在增强体结构中的混杂比。采用真空辅助成型技术制备层内混杂结构的芳纶碳纤维混杂（ACFH）复合材料,并对复合材料的拉伸性能、弯曲性能和冲击性能进行测试。结果表明,增强体纬向系统中芳纶与碳纤维的不均质性对ACFC复合材料经方向上的拉伸强度起消极作用;混杂比的增加对ACFC复合材料的纬向拉伸破坏和弯曲损伤具有抑制作用;纬向上,ACFC复合材料的拉伸强度最高提高了近6倍,弯曲强度最小增加了4.04倍;芳纶与碳纤维混杂协同作用有利于ACFC复合材料的抗冲击性能改善,且混杂比存在最佳值。     

Experimental analysis and theoretical modeling of the mechanical behavior of short glass fiber and short carbon fiber reinforced polycarbonate hybrid composites

In this research, polycarbonate (PC) composites with short glass fiber (SGF) and short carbon fiber (SCF) hybrid fiber reinforcements were compounded by single screw extruder and specimens were prepared by injection molding machine. This article aims to investigate the mechanical properties of PC hybrid composites, by means of the experimental and the theoretical methods. The composites were subjected to tensile test. Experimental results showed the improvements in tensile strength and modulus by increasing the SCF content of the hybrid composite. The theoretical tensile strength was predicted based on Kelly–Tyson model and rule of hybrid mixture. Kelly–Tyson model showed to be a good approximation to predict the tensile strength of composite. When the SCF was replaced by milled carbon fiber (MCF) to form a PC/SGF/MCF hybrid system, poorer mechanical properties are reported due to the weaker interfacial adhesion between MCF and PC, as proven by the scanning electron microscopy. POLYM. COMPOS., 37:1238–1248, 2016. © 2014 Society of Plastics Engineers     

Fabrication and characterization of functionally graded nanoclay/glass fiber/epoxy hybrid nanocomposite laminates

In this work, hardness, tensile, impact, bearing strength and water absorption tests were performed to study the mechanical properties of stepwise graded and non-graded hybrid nanocomposites. Three different stepwise graded nanocomposites and one non-graded (homogeneous) nanocomposite with the same geometry and total nanoclay content of 10 wt% were designed and prepared. Moreover, one neat glass fiber laminate was manufactured. The results of the tests indicated that addition of the graded and non-graded nanoclay improves hardness over neat glass fiber reinforcement. The maximum increase in hardness of about 53% over neat specimen is obtained for specimens that have the highest weight percentage (2 wt%) of the clay nanoparticles on its surface (S-specimen and the side of F-specimen that reinforced with 2 wt% nanoclay). The gradation process results in an increase in hardness of about 11% compared with non-graded (homogeneous) specimen. In addition, an improvement of 11.9% in strain-to-failure is achieved with specimen having greatest amount of nanoclay in the middle over neat glass fiber/epoxy composite. The other nanoclay-filled glass fiber composites have strain-to-failure close to neat glass fiber/epoxy. The addition of nanoclay reinforcement has insignificant effect on ultimate tensile strength, tensile modulus, water absorption, bearing strength and impact strength compared with neat glass fiber/epoxy.     

玄武岩-粗聚丙烯纤维干硬性混凝土拉压性能试验研究

混杂纤维增强干硬性混凝土在国内外已有广泛的应用,纤维配比是影响其拉压性能的主要因素之一。为研究玄武岩纤维与粗聚丙烯纤维配比对干硬性混凝土拉压性能的影响,将玄武岩纤维与粗聚丙烯纤维单掺或按不同比例混合掺入干硬性混凝土中,开展不同养护龄期下纤维混凝土的抗压、劈裂抗拉试验,分析纤维混杂增强效应,并基于成熟度理论修正养护龄期,优化玄武岩-粗聚丙烯纤维干硬性混凝土的劈裂抗拉强度预测模型。结果表明:玄武岩纤维与粗聚丙烯纤维的掺入不仅提升了干硬性混凝土抗压、劈裂抗拉性能,而且纤维的桥接作用能明显改善混凝土的脆性破坏特征,其中玄武岩纤维与粗聚丙烯纤维混掺配比为1 ∶2(质量比)时最为明显,表现出了最优的纤维混杂正效应。根据等效龄期-抗压强度关系式计算得到的混凝土抗压强度与劈裂抗拉强度具有更好的幂函数关系,该模型便于计算及预测不同养护温度条件下玄武岩-粗聚丙烯纤维干硬性混凝土的拉压性能。