Zwitterionic sulfobetaine-grafted poly(vinylidene fluoride) membrane with highly effective blood compatibility via atmospheric plasma-induced surface copolymerization

Development of nonfouling membranes to prevent nonspecific protein adsorption and platelet adhesion is critical for many biomedical applications. It is always a challenge to control the surface graft copolymerization of a highly polar monomer from the highly hydrophobic surface of a fluoropolymer membrane. In this work, the blood compatibility of poly(vinylidene fluoride) (PVDF) membranes with surface-grafted electrically neutral zwitterionic poly(sulfobetaine methacrylate) (PSBMA), from atmospheric plasma-induced surface copolymerization, was studied. The effect of surface composition and graft morphology, electrical neutrality, hydrophilicity and hydration capability on blood compatibility of the membranes were determined. Blood compatibility of the zwitterionic PVDF membranes was systematically evaluated by plasma protein adsorption, platelet adhesion, plasma-clotting time, and blood cell hemolysis. It was found that the nonfouling nature and hydration capability of grafted PSBMA polymers can be effectively controlled by regulating the grafting coverage and charge balance of the PSBMA layer on the PVDF membrane surface. Even a slight charge bias in the grafted zwitterionic PSBMA layer can induce electrostatic interactions between proteins and the membrane surfaces, leading to surface protein adsorption, platelet activation, plasma clotting and blood cell hemolysis. Thus, the optimized PSBMA surface graft layer in overall charge neutrality has a high hydration capability and the best antifouling, anticoagulant, and antihemolytic activities when comes into contact with human blood.     

Preparation and characterization of phosphorylated Zr-doped hybrid silica/PSF composite membrane

Polysulfone (PSF) membranes are broadly applied in many fields owing to good physicochemical stability, resistance to oxidation and chlorine. But when treated with wastewater containing oil, PSF membranes are easy to be contaminated for its hydrophobicity, which can result in the declining of flux and lifespan of the membrane and limit their application in large scale. To enhance the capability of PSF membrane in the above circumstances, phosphorylated Zr-doped hybrid silica particles (SZP particles) were firstly prepared. SZP particles have various point defects inside their structure and lots of hydroxide radicals on their surface. SZP particles were added to the porous matrix of PSF to prepare a novel composite membrane (SZP/PSF) through a phase inversion process. Finally, the optimum preparation conditions of SZP/PSF composite membranes were determined. The optimum conditions are: the mass ratio of PSF, PEG400 and SZP is 12:10:10; ultrasound 10 min inside each 30 min; the pre-evaporating time is 10s. Optimized SZP/PSF composite membrane was characterized by scanning electron microscope (SEM) and ultrafiltration experiment. The results indicate that SZP particles can be uniformly dispersed in SZP/PSF composite membranes with excellent hydrophilic property, antifouling capability and tensile strength. Therefore, it can be concluded that the optimized SZP/PSF composite membrane is desirable in the treatment of wastewater containing oil and wastewater.     

Polyphenol/FeIII Complex Coated Membranes Having Multifunctional Properties Prepared by a One‐Step Fast Assembly

The membrane filtration process has received much attention as one of the most promising water purification techniques. However, it still has several disadvantages, such as organic‐, oil‐, and biofouling, membrane contamination by microorganisms, and the difficulty in rejecting heavy metal ions, which are closely related to the membrane surface properties. Various approaches have been used to prepare membranes with antifouling, antimicrobial, or heavy metal ion removal properties on their surfaces. However, membranes with all these properties have not yet been reported. It might be possible to prepare membranes with such multifunctional properties by modifying the membrane surfaces with various organic and/or inorganic functional materials using multiple chemical/physical modification procedures, though the process should be very tedious, costly, and time consuming. Here, a multifunctional filtration membrane is prepared by a rapid one‐step assembly coating of tannic acid and iron ion (Fe^III) on a commercial poly(ether sulfone) membrane. The catechol‐ and gallol‐rich surfaces combine all of the desirable properties such as antifouling against proteins, oils, and microorganisms, as well as antimicrobial and heavy metal ion removal properties. This study provides a facile approach to prepare multifunctional filtration membranes that have potential applications in practical water purification.     

高通量抗污染碳量子点/聚砜纳米复合分离膜的制备

先以4-氨基水杨酸(ASA)为原料发生水热反应合成碳量子点(CDs),随后将其共混分散在铸膜液中用非溶剂诱导相分离法制备了PSF/CDs纳米复合膜。透射电子显微镜(TEM)观测和傅里叶变换红外光谱(FTIR)证实,CDs具有小尺寸和大量亲水基团的特点。使用水接触角分析(WCA)、扫描探针显微镜(SPM)和扫描电子显微镜(SEM)对分离膜进行了表征,发现纳米复合膜具有比原始膜更好的亲水性和更多的孔洞,从而使分离膜具有更高的通量和抗污染性能。PSF/CDs膜的通量回复率(FRR)超过90%,总污染率(Rt)低于60%,且可逆型污染为主要污染源。CDs含量(质量分数)为2%的复合膜整体效果最佳。具有更强抗污染能力的纳米复合膜,其水通量甚至为纯PSF膜的3倍。     

磺化氧化石墨烯/聚砜复合膜的制备及抗污染性能

采用浸没沉淀-相转化法制备了磺化氧化石墨烯/聚砜（SGO/PSf）复合膜,对SGO/PSf复合膜的亲水性、纯水通量、孔隙率、表面Zeta电位、膜断面和表面形貌进行测定。为了分析SGO/PSf复合膜的抗污染性能,采用自制牛血清白蛋白（BSA）探针,借助原子力显微镜（AFM）测定了SGO/PSf复合膜与BSA之间的黏附力。结果表明,由于SGO与聚乙烯吡咯烷酮（PVP）的协同作用,SGO含量为0.5wt%的SGO/PSf复合膜的表面自由能最大（114.47 mJ/m2）,亲水性最好,对BSA的截留率为97.5%,污染恢复率达到80.06%。BSA与SGO含量为0.5wt%的SGO/PSf复合膜之间的黏附力最小（-0.61 mN/m）,说明SGO含量为0.5wt%的SGO/PSf复合膜的抗污染能力最强。      

Highly antifouling double network hydrogel based on poly(sulfobetaine methacrylate)and sodium alginate with great toughness

Hydrogels with good antifouling and mechanical properties as well as biocompatibility have great appli-cation potential in the field of biomedicine.In this paper,a newly double network(DN)hydrogel was prepared based on zwitterionic material sulfobetaine methacrylate(SBMA)and natural polysaccharide,sodium alginate(SA).The PSBMA network is covalently crosslinked while the SA network is ionically crosslinked by Ca2+.The hybrid crosslinked double network structure endows the DN hydrogel with excellent mechanical properties(E=0.19±0.01 MPa,σ=0.73±0.03 MPa),fast self-recovery ability as well as excellent fatigue resistance.Moreover,the results show that the PSBMA/SA-Ca2+DN hydrogel is biocompatible and resists the absorption of non-specific proteins and adhesion of microorganisms,such as cells and algae,exhibiting outstanding antifouling properties.These unique characteristics of PSBMA/SA-Ca2+DN hydrogel make it a promising candidate for biomedical application,such as artificial connective tissues,implantable devices,and underwater equipment.     

聚丙烯接枝聚丙烯酸微滤膜的pH响应性

研究了聚丙烯接枝聚丙烯酸微滤膜的pH响应性及其在牛血清蛋白溶液过滤中的抗污染性。聚丙烯酸(PAA)接枝链可提高膜亲水性,但会造成膜孔堵塞:在低接枝率(<17%)下,PAA大幅度提高膜亲水性,膜通量和pH响应性随接枝率的增加逐渐增大;接枝率过大(>17%)时,PAA对膜孔的堵塞作用占主导,膜通量和pH响应性逐渐下降。与未接枝膜相比,在碱性条件下接枝膜对牛血清蛋白(BSA)分子具有一定的抗污染性能,而酸性条件下则加剧BSA对膜的污染,但改性后接枝膜的通量大幅度增长,使这种膜在BSA类蛋白质的微滤领域仍有较好的应用前景。     

PDMS中空纤维复合膜渗透汽化分离丙酮-水溶液

采用干湿相转化法纺制了聚砜(PSF)中空纤维超滤底膜,并采用溶液浸渍法制备PDMS/PSF中空纤维复合膜.研究了PDMS膜的溶胀性能和PDMS/PSF膜渗透汽化性能,考察了PDMS/PSF膜的稳定性以及料液温度、料液丙酮浓度和渗透物侧压力等因素对膜渗透汽化性能的影响.结果表明,PDMS膜对丙酮有很强的吸附能力而对水的吸附能力则相对较弱,渗透液中丙酮浓度大于膜溶胀液中丙酮浓度,远远大于浸泡液中丙酮浓度,连续操作72 h膜的渗透汽化性能保持稳定,渗透通量随料液温度以及料液浓度的升高而增加,分离系数随料液浓度的增加而降低,基本不受温度的影响.当丙酮质量分数5%、料液温度为60℃时,渗透通量为632 g/(m2.h),分离系数为35.8,丙酮和水的表观活化能分别为45.7和49 kJ/mol.     

Antifouling coatings: recent developments in the design of surfaces that prevent fouling by proteins, bacteria, and marine organisms

The major strategies for designing surfaces that prevent fouling due to proteins, bacteria, and marine organisms are reviewed. Biofouling is of great concern in numerous applications ranging from biosensors to biomedical implants and devices, and from food packaging to industrial and marine equipment. The two major approaches to combat surface fouling are based on either preventing biofoulants from attaching or degrading them. One of the key strategies for imparting adhesion resistance involves the functionalization of surfaces with poly(ethylene glycol) (PEG) or oligo(ethylene glycol). Several alternatives to PEG-based coatings have also been designed over the past decade. While protein-resistant coatings may also resist bacterial attachment and subsequent biofilm formation, in order to overcome the fouling-mediated risk of bacterial infection it is highly desirable to design coatings that are bactericidal. Traditional techniques involve the design of coatings that release biocidal agents, including antibiotics, quaternary ammonium salts (QAS), and silver, into the surrounding aqueous environment. However, the emergence of antibiotic- and silver-resistant pathogenic strains has necessitated the development of alternative strategies. Therefore, other techniques based on the use of polycations, enzymes, nanomaterials, and photoactive agents are being investigated. With regard to marine antifouling coatings, restrictions on the use of biocide-releasing coatings have made the generation of nontoxic antifouling surfaces more important. While considerable progress has been made in the design of antifouling coatings, ongoing research in this area should result in the development of even better antifouling materials in the future.     

聚乙烯醇/磺化聚醚醚酮/对氨基二苯胺电活性复合膜的制备与性能

以聚乙烯醇(PVA)、磺化聚醚醚酮(SPEEK)和对氨基二苯胺(p-ADA)为原料,通过水溶液流延成膜法制备了PVA/SPEEK/p-ADA电活性复合膜。借助核磁共振谱(1 H-NMR)、红外光谱(FTIR)和X射线光电子能谱(XPS)分别对SPEEK和复合膜的化学结构进行了表征。采用万能材料试验机和电化学综合站分别对复合膜的力学性能和电性能进行分析测试。结果表明,当PVA含量为60%(质量分数)、SPEEK含量为35%(质量分数)、p-ADA含量为5%(质量分数)时复合膜的力学性能最佳,拉伸强度和弹性模量分别达到64 MPa和2 538 MPa,较纯PVA分别提高了52%和122%。电压窗口为-0.8~0.8 V时,PVA-60%/SPEEK-35%/p-ADA-5%复合膜具有明显的电活性,并且该电活性复合膜在外界酸碱环境发生改变时具有变色性。     

碳纤维/聚砜复合材料的性能和破坏形态的研究

本文着重研究了碳纤维/聚砜(CF/PSF)复合材料中纤维不同分布方式和不同含量对其性能(力学、耐磨、热机械行为等)和破坏形态的影响。短纤CF/PSF复合材料的冲击强度随CF含量的增加略有下降,抗拉和弯曲强度有所提高;而长纤CF/PSF复合材料的力学性能比纯PSF大大提高,其层间剪切强度为树脂基体PSF抗拉强度的80%左右。CF/PSF复合材料的破坏均呈现出纤维—树脂界面脱粘现象。CF/PSF复合材料比纯PSF具有更优异的耐磨性能和更高的热形变温度。     

聚乙二醇/磺化聚苯醚质子交换膜的制备与性能研究

采用溶液共混浇铸法制备了一系列的聚乙二醇/磺化聚苯醚(PEG/SPPO)共混膜SPPO的红外光谱图显示了磺酸基团的成功引入;X-射线衍射图表明,加入柔性的聚乙二醇,SPPO的有序程度降低;膜的离子交换容量(IEC值)、质子传导率和吸水率等理化性能结果表明:PEG/SPPO共混膜的质子传导率和离子交换容量虽然较纯SPPO膜有所下降,但是最大也分别达到了1.80mequiv.g-1和0.061S/cm(PEG/SPPO=10/90,90℃),仍然可以满足质子交换膜的使用要求,而复合膜的吸水率和溶胀率较SPPO膜大幅降低。整体来说,复合膜的各项综合性质良好,有望应用于直接甲醇燃料电池。     

Phosphonic acid-functionalized hollow silica spheres by nitroxide mediated polymerization

A new strategy to prepare phosphonic acid-functionalized hollow silica spheres is proposed via nitroxide mediated polymerization of diisopropyl p-vinylbenzyl phosphonate on the surface of hollow silica spheres (HSSs) and hydrolysis thereafter. The thickness of the organic layer of PVBPA can be controlled by the quantity of the monomers. The structure and morphology of poly(vinylbenzyl phosphonic acid) (PVBPA) grafted HSSs (HPSSs) are confirmed by FTIR and TEM. The addition of HPSS in PVBPA membranes can improve the water retentivity of the composite membranes. The composite membranes with HPSSs exhibit higher water uptake and proton conductivity than the pure PVBPA membranes.     

超滤膜材料抗污染改性方法研究进展

从改性材料和方法两方面综述近几年抗污染超滤膜材料改性的研究进展情况.亲水/疏水两性基团如含聚氧乙烯或含聚乙二醇单体、双离子两性分子和聚2-甲基丙烯酸羟乙酯及聚丙烯酰胺等是制备高性能、化学稳定超滤膜的主要改性材料.采用自由基引发聚合、取代或酯化反应、共混、表面涂层或等离子体表面处理等作为改性的主要方法.膜材料改性研究的拓展大大提高了有机超滤膜的抗污染性能,使其应用更加稳定,使用范围更加广泛.     

PSF／CaCO3复合材料的性能研究

采用双螺杆挤出机制备ＰＳＦ／ＣａＣＯ３复合材料，从而研究其复合组份与性能的关系。研究结果表明：ＰＳＥ／ＣａＣＯ３复合材料部分力学性能与热性能比ＰＳＦ树脂有所提高。     

Zwitterionic PMCP‐Modified Polycaprolactone Surface for Tissue Engineering: Antifouling,Cell Adhesion Promotion,and Osteogenic Differentiation Properties

Biodegradable polycaprolactone (PCL) has been widely applied as a scaffold material in tissue engineering. However, the PCL surface is hydrophobic and adsorbs nonspecific proteins. Some traditional antifouling modifications using hydrophilic moieties have been successful but inhibit cell adhesion, which is not ideal for tissue engineering. The PCL surface is modified with bioinspired zwitterionic poly[2‐(methacryloyloxy)ethyl choline phosphate] (PMCP) via surface‐initiated atom transfer radical polymerization to improve cell adhesion through the unique interaction between choline phosphate (CP, on PMCP) and phosphate choline (PC, on cell membranes). The hydrophilicity of the PCL surface is significantly enhanced after surface modification. The PCL‐PMCP surface reduces nonspecific protein adsorption (e.g., up to 91.7% for bovine serum albumin) due to the zwitterionic property of PMCP. The adhesion and proliferation of bone marrow mesenchymal stem cells on the modified surface is remarkably improved, and osteogenic differentiation signs are detected, even without adding any osteogenesis‐inducing supplements. Moreover, the PCL‐PMCP films are more stable at the early stage of degradation. Therefore, the PMCP‐functionalized PCL surface promotes cell adhesion and osteogenic differentiation, with an antifouling background, and exhibits great potential in tissue engineering.     

聚砜纳米纤维增韧CFRP的制备及性能

介绍了一种聚砜纳米纤维增韧碳纤维/环氧树脂复合材料的新方法。无规取向的纳米纤维通过静电纺丝直接将纳米纤维接收于碳纤维/环氧树脂预浸布上,实现增韧复合材料的目的。探讨了混合溶剂(丙酮、DMAC)配比和聚砜纺丝溶液浓度对纳米纤维直径及分布的影响,测试了不同含量的聚砜纳米纤维增韧复合材料的型层间断裂韧性（G_ⅡC）,并同相等含量的聚砜溶剂法膜增韧复合材料性能进行了比较。在聚砜质量分数分别为1%、3%、5%的情况下,纳米纤维增韧复合材料的G_ⅡC分别增加54%、130%、177%,高于溶剂法膜增韧的复合材料。微观结构照片表明,纳米纤维增韧复合材料中,相分离后的聚砜小球贯穿于整个复合材料层间,而且呈现无规取向分布的海岛结构。增韧后复合材料的层间剪切强度（ILSS）都有略微的减小,溶剂法膜增韧后ILSS减小更明显。DMTA试验表明,与溶剂法膜相比较,纳米纤维与环氧树脂基体的相容性更好。      

Modification of polysulfone with pendant carboxylic acid functionality for ultrafiltration membrane applications

p-Carboxyphenoxymethyl polysulfone (CPMPSF) was synthesized in two steps: (i) chloromethylation of polysulfone (PSF) by in situ generated chloromethyl radical in presence of stannic chloride in tetrachloroethane and (ii) reaction of chloromethylated PSF with p-hydroxybenzoic acid in presence of potassium carbonate in dimethylformamide. The structures of the modified PSFs were confirmed by elemental analysis, IR, ¹H–NMR and $^{{13}}$ C–NMR techniques. The PSF and CPMPSF based ultrafiltration membranes were prepared according to phase–inversion process using water as nonsolvent at 4° and 15 °C, employing casting dope having different amounts of polymer (PSF or CPMPSF), polyvinylpyrrolidone (PVP) and solvent, dimethylformamide (DMF). The membranes were characterized for their pore size, pure water flux and flux and rejection for the permeation of different molecular weight poly(ethylene glycol) (PEG) solutions and sodium chloride (NaCl) solution. The pore radius of the CPMPSF membrane which was prepared without PVP in the casting dope was about 222 Å, whereas, that of the membrane prepared in the presence of PVP (6 wt%) in the casting dope was about 124 Å. For the PSF membranes, pore radii were 80 Å (without PVP) and 176 Å (with PVP 6 wt%). The CPMPSF-based membranes exhibited higher flux and rejections for PEG and NaCl solutions, as compared to the PSF membranes, due to the presence of hydrophilic carboxylic acid group. The CPMPSF membrane exhibited about 48% rejection of NaCl when tested for 5000 ppm feed solution at 400 psi.     

PVDF-g-PNIPAAm温敏抗污染膜的制备及性能研究

通过自由基共聚将聚(N-异丙基丙烯酰胺)(PNIPAAm)接枝到了碱处理聚偏氟乙烯(PVDF)粉末上,合成接枝共聚物PVDF-g-PNIPAAm。以此为原材料通过相转化法制备温敏抗污染分离膜。通过调控反应时间,达到不同的PNIPAAm接枝率,研究了不同接枝率对膜结构及性能的影响。结果表明,随着反应时间的延长,PNIPAAm的接枝率逐渐增加。成膜过程中发挥致孔作用明显致使膜表面的微孔数目逐渐增加。此外,PNIPAAm的接枝率越高膜的亲水性越强,且温敏性能提高。由于室温下PNIPAAm的亲水性,膜表面易形成水化层,从而提高改性膜的抗蛋白质污染性能。     

Novel carbon fiber/epoxy composite toughened by electrospun polysulfone nanofibers

Novel carbon fiber/epoxy composite toughened by electrospun polysulfone (PSF) nanofibers was prepared to enhance fracture toughness of the composite, and compared the morphology and toughness to those of composite toughened by PSF films prepared by solvent method. Polysulfone nanofibers with the average diameter of 230 nm were directly electrospun onto carbon fiber/epoxy prepregs to toughen the composite. SEM observations of the polysulfone nanofibers toughened composite revealed that polysulfone spheres with uneven sizes presented uniform dispersion through interleaves of the composite, which was different from those of composite toughened by PSF films. Mode I fracture toughness (G_IC) of the nanofibers toughened composite was 0.869 kJ/m² for 5.0 wt.% polysulfone nanofibers content, which was 140% and 280% higher than those of PSF films toughened and untoughened composite due to the uniform distribution of polysulfone spheres.