聚酯薄膜表面接枝含硅氧烷共聚物及微生物黏附性研究

通过表面引发原子转移自由基聚合(SI-ATRP)在聚对苯二甲酸乙二醇酯(PET)薄膜表面接枝聚苯乙烯-聚二甲基硅氧烷嵌段共聚物(PET-g-PS-b-PDMS),制备具有强疏水性表面的聚酯薄膜.利用X-射线光电子能谱仪(XPS),傅里叶变换红外光谱仪(FTIR/ATR),场发射扫描电镜(FESEM)对改性前后聚酯薄膜的表面组成、结构和形貌进行分析与表征;利用接触角测试仪和微生物黏附实验对比研究接枝改性前后PET薄膜的润湿性和对微生物黏附性的影响.结果表明,随反应时间延长,聚酯薄膜表面接枝量增加,水接触角增大.当接枝聚合反应时间为12 h,接枝密度可达0.72 mg/cm2,接触角达到126°,薄膜表面细菌黏附量也随之降到最低.     

表面温度敏感性聚酯薄膜的制备

通过在聚酯(PET)薄膜表面固定原子转移自由基聚合(ATRP)的引发基团,继而引发接枝聚N-异丙基丙烯酰胺(NIPAM),制备表面具有温度敏感性的聚酯薄膜.利用X射线光电子能谱仪(XPS),衰减全反射傅立叶变换红外光谱仪(FTIR/ATR),扫描电子显微镜(SEM)对接枝改性前后PET薄膜的表面组成,结构和形貌进行分析与表征;利用接触角测试仪对比研究接枝改性前后PET薄膜的表面性能;研究数据表明,随着反应时间的延长,接枝到PET薄膜表面PNIPAM的量在增加.当接枝聚合反应时间为16 h,接枝量达到0.239mg/cm2.表明SI-ATRP具有一定的"活性"特征;接枝PNIPAM改性后的PET薄膜表现出对温度的刺激响应性.     

SMA高级醇酯的合成及其对HDPE表面的改性

以苯乙烯-马来酸酐共聚物(SMA)为骨架,通过酯化反应,在SMA上接枝不同链长的高级脂肪醇侧链,制备了一系列大分子表面改性剂。将SMA及其高级醇酯化物与高密度聚乙烯(HDPE)进行共混,利用全反射红外光谱(FT-IR-ATR)及水接触角对共混体系的表面特性进行了研究。结果表明:在较低添加量范围内(w≤0.04),SMA的高级醇酯化物可以在HDPE薄膜的表面择优富集,可明显降低薄膜的水接触角,提高薄膜的表面能。     

两亲接枝共聚物PS-g-N-PEO的合成及表面性能研究——铸膜溶剂及浓度的影响

采用大分子单体法合成了一系列聚苯乙烯接枝壬基酚聚氧乙烯 (PS g NPEO)两亲共聚物 ,采用溶液铸膜法将其在PET表面制膜 ,并利用扫描电子显微镜 (SEM) ,X射线光电子能谱 (XPS) ,衰减全反射红外光谱(ATR)和水接触角 (CA)等手段研究了共聚物组成、铸膜溶剂及浓度对共聚物膜表面形貌、组成及水浸润性能的影响 .结果表明 ,两亲接枝共聚物在不同条件下可形成规则的表面微孔 ,共聚物中NPEO含量越高 ,共聚物膜表面微孔孔径越大 ,对应的水接触角越小 .以THF为铸膜溶剂时 ,制膜浓度越大 ,共聚物膜表面微孔孔径越大 ,对应的水接触角越小 ;而以甲苯为溶剂时 ,制膜浓度对共聚物膜表面形貌影响不大 ,但水接触角要较THF体系显著降低 ,水接触角与浓度关系与THF体系相反 ,制膜浓度越大 ,对应的水接触角越大 .制膜浓度相同时 ,THF作溶剂 ,共聚物膜微孔较大 ,表面亲水组分含量较低 ;以甲苯为溶剂 ,微孔较密 ,表面亲水组分较高 .     

电火花引发丙烯酰胺接枝BOPP薄膜的研究

采用FT-IR,ESCA,试样与水接触角和接枝率的测定探索了电火花用于引发丙烯酰胺(AAM)在BOPP薄膜表面接枝聚合反应的方法,研究了接枝BOPP薄膜的表面结构和亲水性能。结果表明,电火花能有效地引发AAM在BOPP薄膜表面的接枝聚合反应,随着电火花处理时间和接枝反应时间的延长,AAM在BOPP薄膜表面的接枝率增大。电火花处理10min,BOPP薄膜在70℃,20%(质量分数)的AAM水溶液中反应1h,接枝率高达2.06%。接枝后BOPP薄膜与水的接触角显著下降,亲水性能得到明显改善。     

利用等离子体技术研究聚苯乙烯表面的接枝聚合反应

用O₂等离子体对聚苯乙烯(PS)进行预处理, 再用Ar等离子体引发N-乙烯基吡咯烷酮(NVP)在其表面接枝聚合. 通过接触角(CA)及表面自由能(SE)分析, 探讨了O₂等离子体预处理条件对PS表面自由能的影响, 确定了预处理的最佳条件. 通过衰减全反射红外光谱(ATR-FTIR)、X射线光电子能谱(XPS)和动态接触角(DCA)分析, 比较了O₂等离子体预处理前后和接枝聚合前后PS的表面组成及表面性能, 实验结果表明, 利用等离子体技术能成功地将NVP接枝聚合于PS表面, 接枝聚合后的PS表面由于极性高分子链和粗糙度的增加, 亲水性增强, 水滴易在其表面铺展. 由于接枝聚合后PS表面的高分子链在水中发生重构, 使后退角降低幅度较大, 接触角滞后现象明显.     

两种不同取代结构C_(60)-苯乙烯共聚物薄膜微摩擦性能的研究

用自由基聚合法合成星状C6 0 苯乙烯共聚物和用原子转移自由基聚合法 (ATRP)合成单取代C6 0 苯乙烯共聚物 ,利用LB技术考察了它们的成膜性能并制备了多层薄膜 ,运用原子力显微镜 摩擦力显微镜(AFM FFM)初步研究比较这两种不同取代结构C6 0 苯乙烯共聚物薄膜的表面形貌和在极轻载荷下的微摩擦性能 .研究结果显示了星状C6 0 苯乙烯共聚物相对具有较好的润滑性能     

新型聚乙烯接枝共聚物的制备与表征

以聚氧乙烯和全氟辛基聚氧乙烯醚(FPEOE)为起始原料, 合成了一系列的特种氟表面活性剂及其丙烯酸酯, 用FTIR和1H NMR对其结构进行了表征, 用最大气泡法测定了其表面张力. 以其作为接枝单体, 利用反应挤出接枝的方法制备了系列功能化聚乙烯, 用FTIR确定了接枝共聚物的结构和接枝率; 用DSC、接触角测量仪和XPS对接枝共聚物的热性能、结晶行为和表面性能进行了测试分析. 结果表明, 随着聚氧乙烯分子量的增加, 氟表面活性剂的表面活性降低; 聚乙烯接枝共聚物的结晶温度高于线形低密度聚乙烯, 且具有较好的亲水性.     

聚苯乙烯-g-聚乙二醇的制备及其表面改性作用

通过沉淀聚合方法,利用自由基共聚制备了苯乙烯-顺丁烯二酸酐共聚物(SMA),利用SOCl2的酰氯反应,在SMA大分子链上接枝聚乙二醇侧链,制备了聚苯乙烯-g-聚乙二醇(PEG-g-PS)的大分子表面改性剂。利用大分子表面改性剂在聚苯乙烯基体中具有选择性迁移扩散的特性,实现了对聚苯乙烯薄膜表面极性的改善作用。采用衰减全反射傅立叶变换红外光谱仪和表面静态接触角法检测了聚苯乙烯的表面极性。结果发现,PEG-g-PS上的聚醚链段可以有效的富集在聚合物表面,明显改善PS的表面极性和亲水性,表面极性可提高3倍,达到11.6mN/m。同时,大分子表面改性剂和聚苯乙烯基体间有一定的相容性,有效地克服了小分子表面改性剂容易流失,改性寿命较短的重要缺陷,使表面改性的持久性充分增加,实现对聚合物表面改性效果终生化的目的。而且大分子表面改性剂在极性溶剂的诱导作用下,可以实现进一步的迁移扩散,充分提高了聚苯乙烯的表面极性。     

超亲水聚偏氟乙烯中空纤维膜的制备及性能

采用超声辅助接枝聚合技术, 将甲基丙烯酸缩水甘油酯(GMA)接枝到聚偏氟乙烯(PVDF)膜表面, 制备PVDF-g-GMA膜; 再利用氨基诱导环氧基团发生开环反应, 将苏氨酸(Thr)接枝到PVDF-g-GMA膜表面, 制备了具有两性离子结构表面的PVDF-g-GMA-Thr膜. 通过衰减全反射傅里叶变换红外光谱(ATR-FTIR)、 X射线光电子能谱(XPS)、 接触角测试仪、 场发射扫描电子显微镜(FESEM)和牛血清白蛋白(BSA)过滤实验等系统研究了改性前后PVDF膜表面的化学组成、 润湿性能、 表面形貌和抗污染性能. 研究结果表明, 随着PVDF-g-GMA接枝Thr反应时间的增加, PVDF-g-GMA-Thr膜的亲水性能明显提高, 接触角从90°降为0°, 呈现出超亲水性能. 同时PVDF-g-GMA-Thr膜的水通量明显提高, 当Thr诱导开环反应时间为12 h时, PVDF-g-GMA-Thr膜的水通量高达686 L/(m ²·h), 与PVDF原膜相比, 水通量提高了204.5%. 在BSA的过滤测试中, 与PVDF膜相比, PVDF-g-GMA-Thr膜呈现出良好的截留性能和抗污染性能, BSA截留率从42%提高到84%,水通量恢复率从53%提高到87%, 不可逆污染率从47%降到12%, 表明通过接枝Thr构筑两性离子结构表面可以有效减小膜污染.     

Preparation and characterization of nonfouling polymer brushes on poly(ethylene terephthalate) film surfaces

In this study, a surface grafting of nonfouling poly(ethylene glycol) methyl ether acrylate (PEGMA) on poly(ethylene terephthalate) (PET) was carried out via surface-initiated atom-transfer radical polymerization (SI-ATRP) to improve hemocompatibility of polymer based biomaterials. To do this, the coupling agent with hydroxyl groups for the ATRP initiator was first anchored on the surface of PET films using photochemical method, and then these hydroxyl groups were esterified by bromoisobutyryl bromide, from which PET with various main chain lengths of PEGMA was prepared. The structures and properties of modified PET surfaces were investigated using water contact angle (WAC), ATR-FTIR, X-ray photoelectron spectroscopy (XPS) and Atomic force microscopy (AFM). The molecular weights of the free polymer from solution were determined by gel permeation chromatography (GPC). These results indicated that grafting of PEGMA on PET film is a simple way to change its surface properties. The protein adsorption resistance on the surfaces of PET was primarily evaluated by an enzyme-linked immunosorbent assay (ELISA). The result demonstrated that the protein adsorption could be well suppressed by poly(PEGMA) brush structure on the surface of PET. This work provides a new approach for polymers to enhance their biocompatibility.     

聚对苯二甲酸乙二酯膜的表面碳氟等离子体改性及XPS取样深度与接触角间的关系

高聚物界面的能量、结构等性质，对理论研究和实际应用都是极为重要的．因为许多聚合物材料都具有一个或多个界面的多相结构，这些界面的结构和强度等，显著地影响着这些多相材料的物理、力学性能等，而它们之间的关系，是一个极为复杂的问题，只有综合界面科学、流变学、...     

一种利用梯度光掩模制备梯度表面的简便方法

以自制杂化双向拉伸聚丙烯/氧化硅(BOPP/SiOx)有机/无机杂化膜为基材,由喷墨打印机直接在杂化膜表面打印色阶图案,制备出对紫外光强度呈梯度透过的梯度光掩模;通过此掩模控制,在双向拉伸聚丙烯(BOPP)和聚对苯二甲酸乙二醇酯(PET)表面实施受限光催化氧化(CPO)光感应羟基化反应、受限光接枝丙烯酸(AA)以及表面...     

不饱和糖功能单体接枝聚氨酯膜的制备及其血液相容性

通过葡萄糖、丙烯酸羟乙酯和丁二胺反应,制备了含不饱和双键的糖基功能单体。 采用傅里叶红外光谱和核磁共振氢谱对合成的产物进行结构表征确定。 采用紫外光引发接枝聚合技术,将制备的不饱和糖单体接枝聚合到聚氨酯膜的表面,以衰减全反射模式下傅里叶红外光谱对表面接枝反应进行了确认。 通过静态水接触角实验和血小板黏附实验,分别对改性聚氨酯膜表面的亲水性和血液相容性进行了研究,结果表明,改性聚氨酯膜表面的接触角从86°降低到45°,血小板的粘附量由14.36×10³ cells/mm²减少到2.57×10³ cells/mm²,亲水性明显增强,血液相容性显著改善。     

Surface modification of non-woven fabric by DC pulsed plasma treatment and graft polymerization with acrylic acid

Direct-current pulsed plasma treatment (DPPT) followed by thermal-induced graft polymerization with acrylic acid (AA) was used to modify poly(ethylene terephthalate)/polyethylene (PET/PE) non-woven fabric (NWF) in this study. The water contact angle of plasma modified NWF decreased sharply with DPPT time in 4 s. The water content of the NWF increased with DPPT time and levelled off after 30 s. Chemical analysis by X-ray photoelectron spectroscopy (XPS) indicated that the surface property of modified NWF could be maintained for more than 8 months under ambient conditions and could be further improved by grafting with acrylic acid. The concentration of AA in PET/PE-g-AA NWF increased both with the monomer concentration and the plasma treatment time. The maximum grafting density was 1.17 μmol/cm² with 40 s DPPT and 20% (w/w) AA. Improved biocompatibility of the modified NWF was confirmed with 3T3 fibroblast cells where cell viability was analyzed by MTT assays. More cells were found to attach to the modified NWF with higher growth rates, indicating that an improvement in surface properties by DPPT followed by graft polymerization of AA is beneficial for cell attachment and growth. A much more uniform cell distribution was found within the modified NWF from confocal laser scanning microscope observations.     

193 nm激光引发PET表面的化学接枝

将聚对苯二甲酸乙二醇酯[Poly(ethylene terephthalate), PET]材料置于氨气气氛中, 利用激光光子同时激发材料表面及氨气形成自由基, 用激光引发反应并促进氨基在材料表面的接枝. 改性后的测试结果表明, 材料表面粗糙度没有显著变化, 但水接触角的减小表明表面化学结构发生了某种变化. 傅里叶变换红外光谱(FTIR/ATR)图谱在3352和1613 cm-1处出现了新的氨基吸收峰, 证实了表面接枝了氨基. 同时X射线光电子能谱(XPS)也证明了材料表面C—N键的存在, 其C1s结合能为285.5 eV, N1s为398.9 eV. 飞行时间二次离子质谱(Tof-SIMS)也检测到含氨基的分子碎片, 其碎片成像图显示接枝仅发生在激光辐照部位. 实验结果表明, 激光能在生物材料表面进行局部区域的选择性接枝.     

Superhydrophobic surface by immobilization of polystyrene on vinyl-modified titania nanoparticles

Abstract  

The organic–inorganic nanocomposite films were fabricated by grafting polystyrene (PS) onto the vinyltriethoxysilane (VTEOS) modified titanium dioxide nanopowders using free radical polymerization. The composition of the surfaces and the structure for the PS grafted titania (PS-g-TiO₂) were examined by infrared spectroscopy, X-ray photoelectron spectroscopy and thermogravimetric analysis, and the rough surface was confirmed by the evaluation of the morphological characteristics of the coating using hybrid particles. The wetting properties of the VTEOS modified titania and PS-g-TiO₂ films were investigated, which show the maximum static water contact angles of 160° and 154°, and minimum sliding angles of 3° and 4°, respectively.     

Surface modification of an ethylene-acrylic acid copolymer film: grafting amine-terminated linear and branched architectures

Polymer films can be tailored for a specific application by modifying their surface properties. In this study, linear and branched architectures were grafted to ethylene-acrylic acid (EAA) copolymer films using the so-called grafting from approach. Dicyclohexylcarbodiimide was used to activate the carboxylic acid functionality on the surface of the EAA copolymer film before reacting it with selected di- and tri-amine compounds. The carboxylic acid functionality was subsequently regenerated by reacting the amine-grafted film with succinic anhydride. These reaction steps were then repeated to create the linear and branched architectures on the EAA film surface. The film surface resulting from each reaction step was analyzed using attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy and contact angle measurements. A systematic analysis of the ATR-FTIR results was performed to estimate the average conversion of the reaction schemes and to explain the observed contact angle results. A significant reduction in water contact angle for the EAA film grafted with a branched architecture was observed. The EAA film grafted with a linear architecture showed a marginal reduction in water contact angle when ethanol was used as a solvent for ethylenediamine. When the solvent for ethylenediamine was changed to water, the contact angle decreased noticeably. However, analysis of control films showed that the reduction in the contact angles was due to the solvent treatment. In the case of branched architectures, such reduction in contact angle due to the solvent treatment was not observed. Several control experiments were performed to ensure that the reduction in the contact angles was in fact due to the grafted species and not due to exposure to various solvents used in the reaction scheme.     

Surface modification of poly(ethylene terephthalate) via hydrolysis and layer-by-layer assembly of chitosan and chondroitin sulfate to construct cytocompatible layer for human endothelial cells

Surface modification of poly(ethylene terephthalate) (PET) film was performed by surface hydrolysis and layer-by-layer (LBL) assembly followed a mechanism of electrostatic adsorption of oppositely charged polymers, exemplified with chitosan and chondroitin sulfate (CS). Hydrolysis of PET in concentrated alkaline solution produced a carboxyl-enriched surface. The changes of weight loss and surface chemistry, morphology and wettability were monitored and verified by UV-vis spectroscopy, atomic force microscopy (AFM) and water contact angle. Assembly of positively charged chitosan and negatively charged CS was then conducted in a LBL manner to create multilayers on the hydrolyzed PET film. The process of layer growth and oscillation of surface wettability were monitored by UV-vis spectroscopy and water contact angle measurement, respectively. In vitro cell culture revealed that the adherence of endothelial cells was significantly enhanced on the biomacromolecules-modified PET film with preserved endothelial cell function, in particular on those assembled with larger number of chitosan/CS layers. However, with regard to cell proliferation and viability properties after cultured for 4 days, minor difference was determined between the modified and the unmodified PET films.