材料表面润湿性的控制与制备技术

润湿性是材料表面的重要特征之一.影响材料表面润湿性的主要因素有:材料表面能、表面粗糙度以及表面微纳结构,其中低表面能材料是制备超疏水性的基本条件,表面粗糙度和表面微细结构是决定性因素.理论研究和实验证明,接触角随着表面能的降低而增加,随着表面粗糙度的增加而增大,而表面微/纳结构对润湿性具有重要的影响.常用的低表面能材料是有机硅和氟树脂以及其相应的改性树脂,如硅氧烷等.常用的表面粗糙化和微/纳结构的制备方法有模板法、化学气相沉积、溶胶-凝胶法、微细加工、粒子填充等方法.此外,材料表面润湿性的调控和疏水亲水性的可逆转变也取得了进展.     

低浸润性表面的制备及其功能化研究进展

固体表面呈现低浸润状态的材料称为低浸润性表面材料。根据浸润性的不同,在日常生活和工业生产中发挥巨大的作用。这类材料的制备思路是构建表面的粗糙化和降低表面能。目前其发展趋势是保留结构材料固有属性,获得低浸润性表面,同时赋予某些特殊功能以拓宽其应用范围。综述了国内外基于无机、有机材料基体的低浸润表面材料的制备、性能和应用的研究进展,进一步概括了对温度、光、磁、酸碱性、介质、多重响应等刺激响应性低浸润表面材料的研究现状和应用前景,讨论了低浸润表面材料发展的局限性和问题,展望了功能响应性低浸润材料的发展前景。     

X射线粉末衍射的发展与应用——纪念X射线粉末衍射发现一百年(续前)

正3.2表面与薄膜的结构分析用其他材料在基底材料的表面涂膜或对基底材料进行某种表面处理(如氧化、渗氮、喷丸等)来改变材料表面的化学组成、结构和性能,以适应对材料性能的要求,是当前材料工业中常用的方法。研究和测定改性后表面材料的组成、结构和性质很重要,X射线衍射是一种重要和常用的方法。但是,这些表面薄膜或多层膜的厚度都很小,为纳米量级。在通     

低温等离子体对材料表面改性的研究现状

低温等离子体作为一种新型分子活化手段,存在着大量的、种类繁多的活性粒子,易于和材料表面发生反应,适用于材料表面的改性处理。综述了适用于材料表面改性的低温等离子体主要放电方式,每种放电方式产生低温等离子体的原理,应用范围;归纳了以低温等离子体对材料表面实施改性后对材料表面微观结构和性能的影响,包括材料的表面化学元素、润湿性、表面微观结构等;最后指出了低温等离子体用于材料表面改性存在的问题以及未来的发展方向。     

肝素和Ⅳ胶原在Ti表面组装及不同组装层数对内皮祖细胞的影响

利用层层自组装技术将带有相反电荷的肝素和Ⅳ型胶原交替组装到材料表面,研究了组装前后及不同组装层数对内皮祖细胞的影响。Ti通过碱活化处理后,表面带上羟基,与多聚赖氨酸中的羧基结合,使材料形成带正电荷的氨基表面,接着将带有异种电荷的肝素和Ⅳ型胶原交替滴加到材料表面形成多层自组装层。通过傅立叶红外掠射检测各步处理后材料表面基团的变化,通过甲苯胺蓝定量表征材料表面肝素组装量,通过原子力显微镜观察组装前后材料表面形貌变化,通过水接触角的测定跟踪组装过程中材料表面亲疏水性能变化。结果显示肝素和Ⅳ型胶原成功地组装到材料表面,修饰后的表面较Ti表面内皮祖细胞的粘附数量多,随着组装层数的增加,细胞在材料表面粘附数量也逐渐增加,且其生长与增殖逐步加快。     

与血液接触材料表面活化的研究进展

与血液接触材料的表面活化是对材料表面进行改性处理,并粘附生长有利于抗凝血性的蛋白和细胞等,进而发展具有表面生物活性的材料,通过生物识别途径,更好地提高其抗凝血性.从表面结构、抗凝活化层表面、表面内皮细胞化、表面磷脂化等方面概述了与血液接触材料表面活化的近期研究进展.     

空间材料表面充放电性能试验评估方法研究

空间材料的表面充放电可导致材料表面污染加速、热控性能和其他物理性能改变并产生电磁干拢 ,通过材料选择可以减少表面带电及其产生的危害 ,其中对材料进行充放电特性测试与评价是材料选择的重要依据。介绍了用于空间材料表面充放电特性试验评价的主要设备及其工作原理 ,重点介绍了试验的方法。试验结果及数据应用表明 ,利用该设备和试验方法可以较好地评价空间材料表面充放电特性     

基于纳米二氧化硅和碳纳米管耦合的水泥基材料性能研究

通过在水泥基材料中加入纳米二氧化硅和碳纳米管,设计了一种基于纳米改性的水泥基表面强化材料,研究了该水泥基表面强化材料的力学性能和抗裂性能。结果表明:随着纳米二氧化硅颗粒掺量的增加,表面强化材料的抗压强度先增大后减小,碳纳米管的加入能够显著提高表面强化材料的抗裂性能。2%纳米二氧化硅、0.1%碳纳米管掺量的表面强化材料性能最优。     

氨气低温等离子体技术对聚碳酸酯聚氨酯表面改性

利用氨气低温等离子体对聚碳酸酯聚氨酯材料进行表面修饰改性研究,讨论了改性条件对材料表面亲水性和表面形态的影响.蛄果表明,修饰材料表面的亲水性得到改善,随着表面氨基浓度增大,接触角降低;表面形态由高度平整光滑变为粗糙结构,而且粗糙程度因修饰条件不同而异;材料表面N/C比值从原始材料的2.44%上升到3.98%.时效性考察...     

润湿性梯度材料研究进展

润湿性是固体表面的重要性质之一,其由表面化学组成和表面粗糙度共同决定。随着人们对润湿性研究的深入,实际应用领域对表面润湿性的要求也不再仅限于传统的亲/疏水性。由于润湿性梯度材料具有不同于单一润湿性材料的性能,近些年来受到越来越多的关注和研究。目前,大量的科学研究集中于探索利用表面化学梯度修饰或构筑表面结构梯度等方法获得具有润湿性梯度的表面材料,进一步研究表面能和结构梯度对材料性能的影响。介绍了润湿性梯度材料的研究现状、制备方法、研究进展及其在多领域中的应用。     

Blood interactions with plasticised poly (vinyl chloride): influence of surface modification

Surface modification of plasticised poly (vinyl chloride) (PVC), with di-(2-ethylhexyl) phthalate (DEHP) as plasticiser, for the improvement of blood compatibility in potential clinical use such as cardiopulmonary bypass was achieved by heparinisation. The influence of surface modification on blood compatibility was assessed in terms of the influence on fibrinogen and factor XII adsorption in vitro, and the generation of thrombin-antithrombin III complex (TAT) and the complement component C3a, in vitro and ex vivo. Electron spectroscopy for chemical analysis (ESCA) was used to characterise the heparinised surface in order to correlate the surface properties with the blood response. Results indicate that at the plasticised PVC surface there is a higher content of heparin than that of the PVC and the DEHP content is lower than that present at the surface of standard plasticised PVC. The blood compatibility assessment confirms the importance of surface modification for the improvement of blood compatibility.     

氧化钛薄膜的血液相容性研究

本文研究了离子束增强沉积技术制备的氧化钛薄膜的血液相容性与薄膜的结构，成分，表面能，以及蛋白质在薄膜表面的吸附之间的关系。实验表明，血液相容性是表面能和功函数共同作用的结果。表面能决定蛋白质的吸附量，功函数决定蛋白质的变性。     

Effect of nitrogen on blood compatibility of nickel-free high nitrogen stainless steel for biomaterial

The aim of this paper was to study the effect of nitrogen content on blood compatibility including platelet adhesion and kinetic clotting time of nickel-free high nitrogen stainless steel (HNS), also in comparison with a conventional austenitic stainless steel AISI 317L. X-ray photoelectron spectroscopy (XPS) was used to analyze the surface chemical composition. The surface wettability and surface free energy (SFE) of these materials were characterized by water contact angle (WCA) measurement to analysis the relationship between surface properties and blood compatibility. Kinetic clotting time was used to evaluate the blood coagulation for these materials and platelet adhesion was assessed by scanning electron microscopy (SEM). The results showed that more platelets adhered on the surface of 317L stainless steel than that on HNS, and with the increase of nitrogen content, the amount of adherent platelets was further decreased on the surface of HNS. Kinetic clotting time results also showed the increased nitrogen content extended the initial clotting time of HNS. The results of surface properties also explained the effect of nitrogen on blood compatibility by traditional theory of SFE and interfacial energy.     

Ultralow fouling and functionalizable surface chemistry based on a zwitterionic polymer enabling sensitive and specific protein detection in undiluted blood plasma

A crucial step in the development of implanted medical devices, in vivo diagnostics, and microarrays is the effective prevention of nonspecific protein adsorption from real-world complex media such as blood plasma or serum. In this work, a zwitterionic poly(carboxybetaine acrylamide) (polyCBAA) biomimetic material was employed to create a unique biorecognition coating with an ultralow fouling background, enabling the sensitive and specific detection of proteins in blood plasma. Conditions for surface activation, protein immobilization, and surface deactivation of the carboxylate groups in the polyCBAA coating were determined. An antibody-functionalized polyCBAA surface platform was used to detect a target protein in blood plasma using a sensitive surface plasmon resonance (SPR) sensor. A selective protein was directly detected from 100% human blood plasma with extraordinary specificity and sensitivity. The total nonspecific protein adsorption on the functionalized polyCBAA surface was very low (<3 ng/cm (2) for undiluted blood plasma). Because of the significant reduction of nonspecific protein adsorption, it was possible to monitor the kinetics of antigen-antibody interactions in undiluted blood plasma. The functionalization effectiveness and detection characteristics using a cancer protein marker candidate of polyCBAA were compared with those of the conventional nonfouling oligo(ethylene glycol)-based surface chemistry.     

316L不锈钢和NiTi合金微磁场表面粗糙度对血液相容性的影响

在316L不锈钢、NiTi合金的含SrFe12O19磁性粉末的TiO2薄膜表面用溶胶-凝胶法再涂覆不同层数的TiO2薄膜,以降低材料微磁场表面的微粗糙度,并用扫描电镜、粗糙度仪分析薄膜的表面粗糙度.测试了不同粗糙度的微磁场表面的动态凝血时间和溶血率,研究了微磁场表面的粗糙度对材料血液相容性的影响.结果表明,粗糙度小的微磁场表面的血液相容性比粗糙度大的微磁场表面的血液相容性好.即对于平整光滑的微磁场表面,可以利用微磁场提高材料血液相容性的同时,进一步改善材料的血液相容性.     

Permanent Anticoagulation Blood-Vessel by Mezzo-Sized Double Re-Entrant Structure

Having a permanent omniphobicity on the inner surface of the tube can bring enormous advantages, such as reducing resistance and avoiding precipitation during mass transfer. For example, such a tube can prevent blood clotting when delivering blood composed of complex hydrophilic and lipophilic compounds. However, it is very challenging to fabricate micro and nanostructures inside a tube. To overcome these, a wearability and deformation-free structural omniphobic surface is fabricated. The omniphobic surface can repel liquids by its “air-spring” under the structure, regardless of surface tension. Furthermore, it is not lost an omniphobicity under physical deformation like curved or twisted. By using these properties, omniphobic structures on the inner wall of the tube by the “roll-up” method are fabricated. Fabricated omniphobic tubes still repels liquids, even complex liquids like blood. According to the ex vivo blood tests for medical usage, the tube can reduce thrombus formation by 99%, like the heparin-coated tube. So, the surface will soon replace typical coating-based medical surfaces or anticoagulation blood vessels.     

钛材料表面固定多聚赖氨酸-肝素纳米颗粒以改善血液相容性的研究

通过将多聚赖氨酸(PLL)-肝素纳米颗粒固定在多巴胺涂覆的钛表面,以改善其血液相容性。利用zeta电位仪及甲苯胺蓝法检测纳米颗粒的粒径及成分,通过傅立叶变换红外光谱(FT-IR)、X射线光电子能谱(XPS)及水接触角等对颗粒固定前后表面理化性质的变化进行表征。通过体外血小板粘附实验、肝素释放及活化部分凝血活酶时间(APTT)检测对改性样品的血液相容性进行评价。结果表明,PLL-肝素纳米颗粒成功固定在多巴胺沉积的钛表面,纳米颗粒的固定有效降低钛材料表面血小板的粘附行为,大大提高了血液相容性。     

Bio artificial surfaces - Blood surface interaction

Contact between blood and an artificial surface is a well known problem in medicine.Endothelial cells cover the whole circulatory system in a single layer. They are, besides many other systemic hemodynamic functions, responsible for keeping the balance between blood coagulation and blood flow. In case of trauma, the deficit of endothelial cells and the loss of endothelial cell function, in combination with other factors, are responsible for the activation of the coagulation cascade. This also happens in disease of arteriosclerosis, when plugs cover the inner surface of blood vessels, disrupting the continuous layer of endothelial cells.So far, it was not possible to create an artificial surface covering all these functions. The requirements we have to artificial surfaces is that they should be as inert as possible, i.e. not activate the platelets and the coagulation cascade on the one hand and allow a turbulence free blood flow on the other hand.What are the problems resulting from the contact between artificial surface and human blood?The first problem is thrombosis. The activation of the platelets and the coagulation cascade result in small blood clots. Adhering to the surface, these clots will occlude artificial vessels. In case of embolism, the consequence is very often a cerebral insult.The second is infection: in the case of systemic infection, bacteria can be detected in blood culture. Some of them have a high affection to artificial surfaces. Attached to the surface, even systemic antibiotic therapy becomes inadequate. Thrombus and pannus formation are the consequences and the replacement of the vascular prostheses or the artificial heart valve is the only therapy possible.In modern medical practice, blood can be in contact with synthetic materials and metal for a short time, such as only some hours, or for some months or even permanently, i.e. for the rest of the patient's life.     

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.