磺化聚醚砜超滤膜的制备研究

本文研究了磺化聚醚砜的制备和膜性能的测试 ,通过选择适当的配方研制性能稳定的较小孔径的超滤膜。该膜在 0 .2Mpa操作压力下对聚乙二醇 1 0 0 0 0的截留率大于 95 % ,水通量为 5 5L/m2 H ,通过扫描电镜观察膜的断面结构 ,结果表明 :PES膜断面形态属于典型的非对称指状孔结构 ,SPES膜断面形态是海绵层结构     

聚砜/纳米TiO2有机-无机复合超滤膜的制备与表征

用阴离子表面活性剂改性的纳米TiO2,加入到聚砜铸膜液中,采用相转化法制备了分散均匀的聚砜/ TiO2复合超滤膜.通过测定纯水通量、对牛血清蛋白的截留率、水接触角、粘度、抗污染性、机械强度等实验,研究了不同TiO2加入量对膜的超滤性能和力学性能的影响.并在扫描电镜下观察了膜的表面与断面形态,测定了膜的孔密度、孔隙率、孔径及其分布,从而考察了添加纳米TiO2对膜微观结构的影响.结果表明,当纳米TiO2的加入量为2%(wt)时,膜的孔隙率增大,平均孔径减小;同时膜的性能得到了明显的改善,纯水通量提高了69%,同时膜的抗压强度和断裂强度也分别提高了50%和26.7%,并且膜的亲水性也明显增强,水接触角由72.1度降低到41.4度,从而使膜的抗污染性明显改善.但进一步增加TiO2的浓度(3%(wt)以上),膜的机械强度、亲水性和超滤性能反而下降.因此在聚砜膜中适量地添加纳米TiO2粒子,可明显改善膜的亲水性和力学性能,提高膜的通量,增强膜的抗污染能力,从而拓宽了膜的应用领域.     

负载纳米银磺化聚醚砜超滤膜的制备及其抗菌性

为了改善聚醚砜(PES)膜的抗污染性能,将PES磺化并制成超滤膜,然后将超滤膜浸渍在硝酸银溶液中,吸附Ag~+的超滤膜在维生素C的还原作用下将Ag负载在膜表面,制备了负载纳米银磺化超滤聚醚砜膜(SPES-Ag)。通过扫描电镜(SEM)、原子力显微镜(AFM)、X射线衍射(XRD)对SPES-Ag超滤膜进行了表征,并通过细胞吸附法进行了抗菌性测试。结果表明,纳米银的平均尺寸为120 nm,它的负载提高了超滤膜的抗菌性能,对大肠杆菌、假单胞菌和金黄色葡萄球菌的抗菌率分别达到了96.7%,98.3%,87.7%。此外,水通量和截留率的测试结果表明,SPES-Ag超滤膜的水通量为438.4 L/(m~2·h),对牛血清蛋白(BSA)的截留率达到94.3%。     

纳米TiO2及掺杂TiO2的制备进展

纳米TiO2在净化污水,降解有机物以及制备太阳能电池等领域具有广阔的应用前景,已成为国内外开发热点之一。本文简介了纳米TiO2和掺杂纳米TiO2的制备方法及其研究进展。提出了目前存在的一些问题及解决途径。     

CdS/TiO2复合纳米粒子的制备及其产氢性能研究

采用化学沉淀法制备了CdS包覆TiO2（CdS/TiO2）复合纳米粒子,利用XRD、TEM、SEM、UV-vis吸收光谱等对其进行了表征分析,并以可见光分解水制氢为探针反应考察了复合纳米粒子的活性。结果表明,CdS/TiO2 复合纳米粒子的颗粒大小约为40nm,TiO2 以锐钛矿型存在,CdS以六方相存在;复合纳米粒子的吸收光谱较TiO2 发生“红移”,大幅拓宽了对可见光区的吸收范围。光解水制氢实验表明,CdS/TiO2 复合纳米粒子具有良好的可见光释氢活性和光学稳定性。     

纳米TiO2苯丙复合乳液的制备

苯丙乳液囚其良好的物理化学性能,日益受到人们的青睐。将纳米TiO2经硅烷偶联剂改性后用于苯丙乳液的聚合,可使苯丙乳液的某些性能有所提高。设计中采用预乳化的方法,在初步实验的基础上,做了单因素实验确定了反应时间和温度;通过正交实验,最终确定了苯丙乳液聚合的最佳条件及最优配方。     

铝镁双醇盐制备MgAl2O4尖晶石陶瓷超滤膜

Spinel (MgAl2O4) ultrafiltration membranes were prepared on porous α-Al2O3 plates via the sol-gel route. Mg-Al double alkoxide [MgAl2(iprO)s] was first synthesized as the precursor, then hydrolyzed and peptized in aqueous solution. The gel layer was coated from the colloidal sol on the intermediate layer (α-Al2O3), which was formerly prepared to modify the porous substrate, and then thermally treated at 900℃. The processing parameters such as pH, temperature and sol composition during the sol preparation were optimized for controlling particle size. The pore size of the 2μm thick top layer is about 13 nm as estimated by both the BSA (Bovine Serum Albumin)retention test and an empirical equation.The water permeability of the obtained spinel membrane is 55～143 kg/(min.cm2.Pa).     

原位聚合法制备纳米TiO2/硅丙复合乳液

采用硅烷偶联剂对纳米TiO2进行表面处理，使其亲水性表面改为亲油性，并在其表面接枝上可反应的有机官能团，然后通过原位聚合法与有机硅改性丙烯酸聚合物复合，制得性能稳定的纳米TiO2／硅丙复台乳液。采用透射电子显微镜表征了乳液的结构及其形态。     

PI/TiO2纳米复合材料的制备及其热稳定性

PI可与无机纳米微粒复合生成性能更加优良的复合膜材料.对以PI为基料、纳米TiO2微粒为添加物制成的PI/TiO2膜进行了研究,考察纳米粒子的用量及固化工艺对PI/TiO2膜热稳定性能的影响.实验结果表明,随着TiO2含量的增加,PAA/TiO2贮存时间变短,而固化后PI/TiO2膜的热稳定性能提高.采用阶梯升温固化,固化温度为310℃时,得到的PI/TiO2膜热稳定性能较好.     

TiO2复合氧化物的制备及其加氢脱硫应用进展

对TiO2及TiO2-Al2O3、TiO2-SiO2和TiO2-ZrO2载体的制备技术及其在加氢脱硫中的应用做了综述。众多研究者的研究表明，以TiO2调变的Al2O3、SiO2、ZrO2载体能影响MoO3与Al2O3、MoO3与SiO2及MoO3与ZrO2之间的相互作用，改善MoO3，在载体表面的分散，促进其还原，有利于提高催化剂表面活性组分的数量，提高催化剂的HDS活性。     

具有耐污染性的SiO2/聚砜共混膜的研究

我国的水资源日益短缺.为缓解供水不足的紧张局面,可进行污水的深度处理回用.膜分离是一种有效的回用方法,但膜易受污染,导致通量下降.作者采用溶胶-凝胶法制备了耐污染性强的SiO2/聚砜复合膜,并对其进行了性能表征.SEM图像显示该膜具有双皮层不对称结构,膜内均匀分散有SiO2粒子,该粒子既能增强膜的强度,又能提高膜的耐污染能力.以自来水对该膜进行了水通量测试,测试表明所制膜水通量较高,在0.10 MPa下可达250～300L/(m2·h).     

低截留分子量聚醚砜超滤膜

以聚醚砜(PES)为原料，均苯三甲酸(TMA)为添加剂，采用浸没沉淀相转化法制备聚醚砜超滤基膜，之后将聚乙烯醇(PVA)溶液涂覆在膜表面，经加热交联得到低截留分子量超滤膜。实验结果表明，随着聚乙烯醇浓度升高，截留分子量先减小再增加；随着热处理温度的升高，水通量减少，截留分子量减小。聚乙烯醇质量浓度为0.1%，80℃加热10 min，膜的截留分子量为900，纯水通量为6.10 L/(m²·h)。红外光谱分析证实PVA与TMA反应生成了交联结构。     

聚乙烯醇-醋酸纤维素共混超滤膜的制备与性能研究

用聚乙烯醇(PVA)、醋酸纤维素(CA)、冰醋酸、水为制膜原料,用相转化制备了PVA-CA共混超滤膜.在一定范围内研究了不同膜液组成对超滤膜性能的影响,得到了较佳的膜液配方.制备的PVA-CA共混超滤膜在操作压力0.30MPa下,处理质量浓度为1000mg/L的水油型模拟含油乳化液,其渗透速率约40L/(m2@h2),除油率可达90%以上,并且此超滤膜的耐水性和溶胀性均优于未改性的PVA超滤膜.     

聚砜/聚苯胺-嵌段式聚醚Pluronic F127复合超滤膜的制备及性能

选用具有不同改性机理的嵌段式聚醚Pluronic F127与聚苯胺(PANI)纳米纤维共同作为添加剂共混改性聚砜(PSf)超滤膜,利用浸没沉淀相转化法制备出PSf/PANI-F127复合超滤膜。考察、比较并分析两种改性材料同时存在对膜结构和膜性能的影响。膜结构通过傅里叶衰减全反射红外(ATR-FTIR)、X射线光电子能谱(XPS)、X射线能量色散谱(EDS)、扫描电镜(SEM)和接触角等测试表征。膜性能通过纯水通量、截留率、抗污染性能以及添加剂稳定性结果进行评价。实验结果表明,Pluronic F127的加入可以更有效地提高膜表面亲水性,而PANI纳米纤维的加入则可以使膜孔隙率增大、表面孔径尺寸降低、皮层变薄。实验进一步发现,两种添加剂在改善膜结构与性能上起协同作用。PANI-F127一方面提高了膜纯水通量与抗污染性能,另一方面克服了单独使用Pluronic F127时添加量大、截留率低、添加剂易流失的缺点。     

Preparation and properties of soluble copolysulfoneimide and performance of solvent‐resistant ultrafiltration membrane

Soluble copolysulfoneimides were synthesized by thermal two‐step method in solution of N‐methyl‐2‐pyrrolidone. The used aromatic diamines were bis[4‐(3‐aminophenoxy)phenyl]sulfone (BAPS‐m) and 3,3′‐diaminosulfone, and dianhydrides were pyromellitic dianhydride, 4,4′‐oxyphthalic anhydride, and 3,3′,4,4′‐diphenylsulfone tetracarboxylic dianhydride. The molar ratio of diamines was changed to reduce the content of BAPS‐m. The thermal and mechanical properties of polyimides were investigated. The polyimide ultrafiltration membrane with molecular weight cut‐off of 10 kDa could be successfully prepared by phase‐inversion method. Various solvent (water, alcohols, acetone, and hexane) fluxes were measured to investigate solvent‐resistance and membrane behavior during solvent permeation. The activation energy relationship between hexane flux and viscosity with temperature was also studied. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1024–1030, 2002     

自组装法制备PVDF-SiO2/PVSQ超疏水复合膜及膜蒸馏抗污染性能

采用乙烯基三甲氧基硅烷(VTMOS)对SiO₂疏水改性,通过自组装法,将改性SiO₂接枝在商业PVDF(聚偏氟乙烯)膜表面,使其表面达到超疏水。利用场发射电子显微镜、红外光谱仪、接触角测量仪及毛细流孔径分析仪等仪器对改性前后膜的表面形貌、化学组成、接触角及孔径变化等性能参数进行表征。结果表明,VTMOS不仅对SiO₂疏水改性,还通过自身的水解缩聚反应,生成了规整圆球状的聚乙烯基倍半硅氧烷(PVSQ)微粒,纳米级SiO₂分布于微米级PVSQ表面,在改性膜表面构造了多层次微/纳米粗糙表面,在低表面能疏水基团乙烯基和甲氧基的共同作用下,成功实现了超疏水改性,改性膜水接触角达到159.5°,滚动角降至8.1°。以NaCl、HA和CaCl₂混合溶液为进料液,对商业PVDF膜和改性膜进行了长期直接接触式膜蒸馏(DCMD)实验,探究其抗污染性能。结果表明,改性膜适用于长期DCMD实验,并表现出比商业PVDF膜更稳定的通量,截盐率始终大于99.99%,具有良好的稳定性和抗污染性能。     

Tannic acid coating and in situ deposition of silver nanoparticles to improve the antifouling properties of an ultrafiltration membrane

The construction of antifouling membranes has been a desirable approach for addressing membrane-fouling issues in the ultrafiltration (UF) process. Antifouling means antiadhesive and antimicrobial; however, few researchers have achieved both properties in a facile and effective manner. In this article, we report a direct tannic acid (TA) coating method combined with the in situ deposition of silver nanoparticles (Ag NPs); this was used to improve the antifouling properties of a positively charged polymeric UF membrane. The results show that the TA–Ag NP modified membranes showed improved protein resistance (flux recovery rate = 71.2% after modification vs 17.8% before modification) and less attachment of bacteria (Escherichia coli K1) on the membrane surface and reduced cell viability in the resulting bacterial suspension (reduced by ≥90%) because of the combined antimicrobial properties of both the TA and Ag NPs. This indicated that our modification method was promising for UF membrane antifouling applications. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47314.     

磺化聚醚砜(SPES)/聚砜(PSF)共混超滤膜的研制

以磺化聚醚砜(SPES)和聚砜(PSF)为膜材料,用共混法制备了SPES/PSF超滤膜。采用均匀实验设计法,研究了SPES/PSF共混超滤膜的制膜工艺,并通过回归分析得到了水通量的模型方程。根据模型方程,作者进行了单因素影响模拟计算,考察共混比、聚合物总浓度、添加剂浓度等对水通量的影响。结果表明:根据最优配方所制备的SPES/PSF膜的水通量为93.1 L/(m2.h),对聚乙烯醇的截留率达93.37%。     

多通道TiO_2超滤膜的制备及其在印染废水中的应用

以多通道α-Al2O3陶瓷微滤膜为支撑体,采用溶胶凝胶法制备完整TiO2超滤膜。通过扫描电镜(SEM)表征膜的形貌,采用错流过滤方式考察膜的纯水通量、截留相对分子质量及分离性能。结果表明:制备的多通道TiO2超滤膜,其膜层表面完整,无裂缝、针孔等缺陷且厚度均匀,纯水通量为1.08×10-3L/(m2.h.Pa),截留相对分子质量为9 000。对直接黑OB染料及退浆废水中聚乙烯醇(PVA)的截留率均达到99%以上,截留效果显著。     

Synthesis and characterization of soluble polyimides and its ultrafiltration membrane performances

Soluble polyimides were synthesized and characterized from two diamines and four dianhydrides by the two- and the one-step method. Most of the polyimides could be soluble by one-step method except α,α′-bis(4-aminophenyl)-1,4-diisopropyl benzene/3,3′,4,4′-benzophenonetetracarboxylic dianhydride system in limited organic solvents. Glass transition temperatures ranged from 186 to 233°C and crystalline melt temperatures were not observed. All the soluble polyimides showed good thermal, mechanical, and electrical properties. The polyimides did not have crystalline structure and limited solubilities. The effective solvent had a medium dispersion component associated with weak polar and hydrogen components. The polymer from one-step polymerization had a narrower molecular weight distribution than the two-step method. Polyimide synthesized with 4,4′-oxydiphthalic anhydride and bis[4-(3-aminophenoxy)phenyl]sulfone by two-step method could only be prepared by the typical phase inversion method. Other membranes except this polyimide membrane could not be prepared by the typical phase-inversion method because of poor solubility about polar solvents. The flux of this ultrafiltration membrane was very high, and this membrane could especially retain polymer having a molecular weight 20,000 to above 90%. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 907–918, 1999