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.     

pH响应性表面对蛋白质吸附的调控

通过表面引发原子转移自由基聚合在固定了引发剂的硅表面接枝了聚甲基丙烯酸叔丁酯(PtBMA),而后通过水解得到聚甲基丙烯酸(PMAA)聚合物刷.通过X射线光电子能谱、椭圆偏振仪和水接触角测试证明了接枝改性的成功.研究发现PMAA改性表面的浸润性和对蛋白质的吸附行为都具有一定的pH响应性.在较低pH值时改性表面相对疏水,随...     

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.     

聚丙烯表面的生物相容性修饰: 表面氨基放大还原胺化接枝磷酰胆碱

在氨气氛中对聚丙烯薄膜表面进行等离子处理, 获得了不同浓度的表面氨基. 表面氨基的数量经1,6-己二异氰酸酯键合三(2-氨乙基)胺可成倍增加. 用还原胺化法将磷酰胆碱醛共价接枝到表面氨基上获得了磷酰胆碱改性的聚丙烯薄膜. X射线光电子能谱(XPS)测定结果表明, 接枝磷酰胆碱基团的表面覆盖率可达20%～40%. 衰减全反射傅立叶变换红外(ATR-FTIR)和动态接触角测定结果也都说明磷酸胆碱基团被成功地接枝于聚丙烯表面. 还原胺化法结合等离子处理及表面氨基放大技术, 有望成为获取新型生物材料的一种有效途径.     

表面接枝含氟苯乙烯共聚物的聚酯薄膜制备与表征

利用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)薄膜表面接枝苯乙烯和4-氟苯乙烯的共聚物.研究不同反应时间和不同配比下接枝共聚物对聚酯薄膜表面组成、结构和性能的影响.通过傅利叶变换红外光谱仪(ATR/FTIR),X-射线光电子能谱仪(XPS),凝胶渗透色谱(GPC)和扫描电子显微镜(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;利用接触角测试和表面能计算对比研究接枝改性前后PET薄膜的表面性能.结果表明反应时间和单体百分含量对接枝百分率及接触角有一定的影响,随着反应时间的增长,聚酯薄膜表面接枝百分率增大,接触角增加,表面自由能下降.     

高亲水性聚四氟乙烯微粉的制备及其性能研究

通过预辐射接枝方法在聚四氟乙烯(PTFE)微粉上成功接枝丙烯酸(AAc)和2-丙烯酰胺-2-甲基丙磺酸(AMPS),制备了高亲水性的PTFE微粉.采用红外光谱(FTIR)、X射线光电子能谱(XPS)和接触角(CA)测试表征了改性PTFE微粉的化学结构和亲水性变化;采用扫描电子显微镜(SEM)观察改性PTFE微粉表面形貌;采用电泳法测试了改性PTFE微粉的zeta电位;通过热重分析(TGA)测试了辐射接枝对PTFE微粉热稳定性的影响.结果表明,改性PTFE微粉亲水性和分散稳定性随着接枝率的增加而增强;在单体浓度为20%,AAc与AMPS之比为2且反应温度为70℃时接枝率达到26.6%,此时改性样品PTFE-g-P(AAc-co-AMPS)在水溶液中的分散稳定性效果较好,并能够长期稳定存在.水接触角由改性前的148.8°下降到改性后的30.2°,对应的zeta电位从-4.3 m V降为-83.4 m V.     

聚苯乙烯细胞培养板表面的糖化温敏修饰及其对细胞行为的影响

采用紫外光固定化法, 对组织培养用聚苯乙烯板进行半乳糖糖化温敏修饰. 通过红外光谱(ATR-FTIR)和X射线光电子能谱(XPS)对改性表面的化学组成及结构进行了表征, 并采用原子力显微镜(AFM)观察了改性表面形貌, 发现改性表面比未经修饰表面粗糙度增加. 静态接触角测试结果表明, 改性表面具有良好的温度响应性. 对人肝肿瘤(HepG-2)细胞在改性表面的吸/脱附行为的研究结果表明, HepG-2细胞在半乳糖糖化温敏表面表现出比在未经修饰聚苯乙烯细胞培养板表面更好的生长趋势, 当环境温度降低时, 细胞发生自动脱附, 避免了酶解法对细胞功能造成的损伤.     

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.     

聚甲基戊烯膜式氧合器表面碳酸酐酶的固定化及性能研究

聚甲基戊烯(PMP)膜式氧合器表面先用水等离子体改性,以引入羟基官能团;再以溴化氰为偶联剂,将碳酸酐酶(CA)偶联至其表面.改性后用X射线光电子能谱(XPS)、表面接触角及酶活性测定等方法研究PMP表面性能变化.结果表明,等离子体处理后,在PMP表面引入了大量的含氧官能团,与水的表面接触角从103.37°降低至50.01°.再将CA引入PMP表面后,与水的表面接触角进一步降低至39.23°;XPS的C1谱图中出现蛋白质的特征峰;以对硝基苯酚乙酸酯为底物,测得表面接枝CA的活性达到理论单分子层接枝活性的73%.改性后PMP表面物理化学性质的变化证明本文方法确实能成功地将羟基官能团、CA引入其表面.本方法有望应用在膜式氧合器上以提高其清除血液中CO2的能力.     

玻璃表面铜-胺氧化还原引发自由基接枝聚合

将3-氨基丙基三乙氧基硅烷(KH-550)固定于玻璃片表面,利用铜-胺氧化还原反应在水溶液中引发缺电子乙烯基单体,如N,N-二甲基丙烯酰胺(DMAAm)进行自由基接枝聚合.通过衰减全反射红外分析(ATR-FTIR)、接触角、原子力显微镜(AFM)和X射线光电子能谱(XPS)等方法进行表征,证明玻璃表面已接枝上功能性聚合物链,且不会产生游离均聚物.当原料配比为m(CuSO4):m(DMAAm):m(H2O) ＝5:1000:1000,反应温度为80℃,反应时间为4h时,所得样品GlassKH-550-g-PDMAAm的接枝率与单位面积接枝量分别达到了0.342％和0.47 mg/cm2.接枝后玻璃表面化学组成和形貌都发生了显著变化.本方法操作简单、效果明显,具有一定普适性.     

Immobilization of Bovine Serum Albumin on Poly(ether ether ketone)for Surface Biocompatibility Improvement

UV-induced graft polymerization of acrylic acid(AA)on poly(ether ether ketone)(PEEK)films was carried out to introduce-COOH for the subsequent immobilization of bovine serum albumin(BSA).BSA was introd...     

Surface Heparinization of Poly(ether ether ketone)

Photo-grafting of hydrophilic monomer and space arms was used to enhance the hydrophilicity of poly(ether ether ketone)(PEEK) with the aim of extending its application to biological fields. PEEK films were surface modified by UV grafting of acrylic acid(AA) to introduce ―COOH on PEEK surface. Adipic amine was used as a space arm to introduce heparin on PEEK surface based on the condensation reaction between ―NH₂ and ―COOH. The modified PEEK(PEEK-COOH, PEEK-NH₂ and PEEK-Hep) was characterized by energy-disperse spectroscopy (EDS), X-ray photoelectron spectroscopy(XPS) and water contact angle measurements, which show that heparin was grafted on PEEK surface. The contact angles of modified PEEK films were lower than those of original films, demonstrating a significant improvement of surface hydrophilicity.     

UV-induced Self-initiated Graft Polymerization of Acrylamide onto Poly(ether ether ketone)

Photo-grafting of hydrophilic monomer was used to enhance the hydrophilicity of poly(ether ether ketone) (PEEK) with the aim of extending its applications to biological fields. PEEK sheets were surface modified by grafting of acrylamide(AAm) with ultraviolet(UV) irradiation in the presence or absence of benzophenone(BP). The effects of BP, irradiation time and monomer concentration on the surface wettability of PEEK were investigated. Characterization of modified PEEK using scanning electron microscopy(SEM), energy-disperse spectrometer(EDS) and water contact angle measurements shows that AAm was successfully grafted on PEEK surface both in presence and absence of BP. With the increase in irradiation time and monomer concentration, contact angles decrease to as low as 30°, demonstrating a significant improvement of surface hydrophilicity. In agreement with the decrease in contact angle, under identical conditions, the nitrogen concentration increases, suggesting the increase in grafting degree of the grafting polymerization. This investigation demonstrates a self-initiation of PEEK due to its BP-like structure in the backbone of the polymer. Though the graft polymerization proceeds more readily in the presence of BP, the self-initiated graft polymerization is clearly observed.     

基于多巴胺自聚合及肝素固定改善钛的血液相容性

利用多巴胺自聚合及肝素固定的方法对纯钛进行表面修饰, 以改善其血液相容性. 采用水接触角测量、 X射线光电子能谱(XPS)和甲苯胺蓝法(TBO)等方法对所修饰的材料进行了表征. 采用溶血实验检测了材料的溶血性能, 并结合活化部分凝血活酶时间(APTT)测试和血小板黏附实验对所修饰材料的血液相容性进行了评价. 结果表明, 多巴胺能够在钛表面实现自聚合, 肝素可以共价接枝在聚多巴胺层上, 经肝素修饰后的材料的表面亲水性显著提高, 而且具有较低的溶血率, APTT时间显著延长, 血小板的黏附数量和被激活程度也显著降低. 因此, 纯钛经多巴胺自聚合以及肝素接枝修饰后的血液相容性得到了显著改善, 有望成为具有抗凝血功能的新型心血管植入材料.     

Surface bio-modification of poly(hydroxybutyrate-co-hydroxyhexanoate) and its aging effect

In this work, poly(hydroxybutyrate-co-hydroxyhexanoate) (PHBHHx) film was fabricated by a solution-casting method and subsequently was modified by NaOH treatment to improve the surface hydrophilic property. Surface properties including hydrophilicity, surface appearance and functional groups were characterized by water contact angle measurement, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The results showed the hydrophilicity of PHBHHx film was obviously improved by the NaOH treatment due to the topography changes promoted by the NaOH-etching and the introduction of polar groups included hydroxyl and carboxyl on the topmost surface layers. However, the modified film exhibited an aging effect: the hydrophilicity decreases with time elapsed during storage. It was found that the aging rate was strongly dependent on the crystallinity of the film and the storage environment. The sample with high-crystallinity lost hydrophilic property slower than that with low-crystallinity. Hydrophilic and low-temperature environment also prevented the modified PHBHHx from fast losing of the hydrophilicity.     

Enhanced adhesion of copper plating to polyether ether ketone based on active oxygen species generated under ultraviolet irradiation

Polyether ether ketone (PEEK) is a substrate for metal plating to overcome insulation defects and satisfy the increased demands of mechanically robust electronic circuit boards. However, pristine PEEK is hydrophobic; hence, the adhesion between the metal film and PEEK substrate is poor. Therefore, the PEEK surface should be modified to improve hydrophobicity. We have proposed the active oxygen (AOS) treatment under ultraviolet (UV) light as an alternative to a conventional plasma treatment method. Characteristics of the PEEK surfaces obtained by these methods are compared. We explore the effects of reactive-oxygen and UV light exposure time on the PEEK surface modification. The contact angle of water drop on PEEK after the AOS treatment is lower than that of untreated PEEK. Furthermore, COO groups are observed on the PEEK surface after the treatment. Although plasma treatment has the effect of roughening the surface, it is desirable not to roughen the surface for use in electronic circuit boards. Moreover, we have reported the adhesion strength between PEEK and copper plating without surface roughening.     

Tethering hydrophilic polymer brushes onto PPESK membranes via surface-initiated atom transfer radical polymerization

Surface-initiated atom transfer radical polymerization (ATRP) was used to graft hydrophilic comb-like poly((poly(ethylene glycol) methyl ether methacrylate), or P(PEGMA), brushes from chloromethylated poly(phthalazinone ether sulfone ketone) (CMPPESK) membrane surfaces. Prior to ATRP, chloromethylation of PPESK was beforehand performed and the obtained CMPPESK was prepared into porous membranes by phase inversion process. It was demonstrated that the benzyl chloride groups on the CMPPESK membrane surface afforded effective macroinitiators to graft the well-defined polymer brushes. Attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) confirmed the grafting of P(PEGMA) chains. Water contact angle measurements indicated that the introduction of P(PEGMA) graft chains promoted remarkably the surface hydrophilicity of PPESK membranes. The effects of P(PEGMA) immobilization on membrane morphology, permeability and fouling resistance were investigated. It was found that the comb-like P(PEGMA) grafts brought smaller pore diameters and higher solute rejections to PPESK membranes. The results of dynamic anti-fouling experiments showed the anti-fouling ability of the membranes was significantly improved after the grafting of P(PEGMA) brushes.     

Surface Modification of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) Membrane by Combining Surface Aminolysis Treatment with Collagen Immobilization

Amino groups were introduced onto a poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) surface by applying 1,6-hexanediamine treatment. The effects of aminolysis time and 1,6-hexanediamine concentration on hydrophilicity of the treated PHBV were investigated using contact angle measurement. The occurrence of the aminolysis and the introduction of NH₂ groups were verified by X-ray photoelectron spectroscopy (XPS) and ninhydrin method. By use of the NH₂ groups as active sites, collagen was further immobilized on the aminolyzed PHBV (NH₂-PHBV) membrane via a cross-linking agent, glutaraldehyde. The increase of nitrogen content and further decrease of water contact angle after immobilization of collagen suggested that the surfaces became more hydrophilic. Mouse bone marrow stromal cells (BMSc) cultured on untreated PHBV and treated PHBV films were evaluated by cell attachment, cell proliferation, and morphological observation under scanning electron microscope (SEM). The order of cytocompatibility is Coll-PHBV > NH₂-PHBV > PHBV, indicating coll-PHBV was a promising material in future tissue-engineering application.     

Remarkable reduction of irreversible fouling and improvement of the permeation properties of poly(ether sulfone) ultrafiltration membranes by blending with pluronic F127

Hydrophilic modification of ultrafiltration membranes was achieved through blending of Pluronic F127 with poly(ether sulfone) (PES). The chemical composition and morphology changes of the membrane surface were confirmed by water contact angle, X-ray photoelectron spectroscopy, scanning electron microscopy, and protein adsorption measurements. The decreased static water contact angle with an increase in the Pluronic F127 content indicated an increase of surface hydrophilicity. XPS analysis revealed enrichment of PEO segments of Pluronic F127 at the membrane surface. The apparent protein adsorption amount decreased significantly from 56.2 to 0 microg/cm(2) when the Pluronic F127 content varied from 0% to 10.5%, which indicated that the blend membrane had an excellent ability to resist protein adsorption. The ultrafiltration experiments revealed that the Pluronic F127 content had little influence on the protein rejection ratio and pure water flux. Most importantly, at a high Pluronic F127 content membrane fouling, especially irreversible fouling, has been remarkably reduced. The flux recoveries of blend membranes reached as high as 90% after periodic cleaning in three cycles.     

Surface Performance and Cytocompatibility Evaluation of Acrylic Acid-Mediated Carboxymethyl Chitosan Coating on Poly(tetrafluoroethylene-co-hexafluoropropylene)

To improve the biocompatibility of poly(tetrafluoroethylene-co-hexafluoropropylene) (FEP) film, a technique based on Ar plasma pretreatment and UV-induced grafting polymerization was used to immobilize carboxymethyl chitosan (CMCS) on the FEP film surfaces. Initially Ar plasma was used to treat FEP film. Then, plasma treated FEP film was modified via UV-induced grafting polymerization with hydrophilic acrylic acid (AAc) monomer. The following immobilization of CMCS on the FEP-pAAc surface was carried out via an amidation reaction. The change of chemical composition and surface morphology of FEP film were characterized by attenuated total reflectance Fourier transform infrared (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), scanning electronic microscopy (SEM) and atomic force microscopy (AFM). Results of water contact angles measurement showed that the hydrophilicity of the surface has improved significantly after surface modification. Furthermore, methyl thiazolyl tetrazolium (MTT) assay and cell morphology analysis confirmed that mouse fibroblasts (L929 cells) attachment and proliferation were improved remarkably on the modified FEP surface. These results suggest that CMCS were successfully employed to surface engineering FEP film, and enhanced its cell biocompatibility. The approach presented here may be exploited for surface modification of biomaterials.