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1.
Umi Zalilah Zaidi Kumutha Malar Vellasamy 《Journal of Adhesion Science and Technology》2013,27(22):2476-2493
Ti6Al4V (Ti64) alloys is an alpha-beta titanium alloy with good corrosion resistance, high strength-to-weight ratio, excellent physiochemical stability and good biocompatibility. However, Ti64 alloy loses its biocompatibility when it is introduced into human tissues due to possible toxic of Vanadium (V) and Aluminum (Al) ion release. Thus, modification using silver silicon nitride films onto Ti64 via magnetron sputtering technique was proposed. In this study, a set of experimental depositing AgSiN films on Ti64 alloys using different bias voltage (0, ?75, ?150 and ?200?V) were fabricated. The surface characterization and mechanical performance of the thin films with respect to bias voltage were studied using scanning electron microscope (SEM), atomic force microscope (AFM), X-ray diffraction (XRD), nanoindentation and scratch test. Meanwhile, the biological function of the films was tested through wettability and antibacterial tests. According to the results, all thin films showed similar morphology with the highest adhesion strength (596?mN) was obtained for AgSiN thin film deposited at ?75?V. The hardness (5.5?GPa) and elastic modulus (211.0?GPa) of sample deposited at ?150?V showed an improvement for about 50% compared to the Ti64 substrate (H?=?2.75, E?=?113.8). The lowest compressive residual stress 0.06?GPa was noted for samples that have highest adhesion strength and highest thickness. In terms of biological functionality, all films showed hydrophilic property with wetting angle observed were below 90°. An inhibition zone area that observed on Bulkholderia pseudomallei (B.Psudomallei) and Escherichia coli (E.coli) were 7 and 10?mm respectively, which proved the AgSiN films as a promising candidate to be used in antibacterial applications. 相似文献
2.
纳米TiO2的表面改性研究 总被引:9,自引:1,他引:8
以硅烷偶联剂为改性剂,通过平行实验和正交实验研究了纳米TiO2有机化表面改性的影响因素。结果表明,硅烷偶联剂用量为10%、pH值为6、改性时间为1.0~1.5h,改性后的纳米TiO2的亲油化度达到74.2%,并能较好地分散于二甲苯和环己烷中。 相似文献
3.
Catherine CombellasFrédéric Kanoufi Driss MazouziAndré Thiébault Patrick BertrandNicolas Médard 《Polymer》2003,44(1):19-24
Reduced PTFE can be grafted by nitro and bromo-phenyl diazonium tetrafluoroborate salts in a manner similar to that used for carbon, except that no application of a reductive potential during grafting was required. Grafting was evidenced by cyclic voltammetry, X-ray fluorescence or ToF-SIMS. Nitro- and bromo-phenyl moieties were covalently linked to the PTFE material and could be eliminated only by abrasion. 相似文献
4.
Electrodeposition methods have been used to obtain polypyrrole and polyaniline polymer layers, bilayers and blends of these polymers on carbon steel by passivation of the steel surface in the electrodeposition solution (oxalic acid and monomer) between −0.5 and 0.3 V versus Ag/AgCl and subsequent electrodeposition using different techniques (potentiodynamic, galvanostatic and potentiostatic). The results obtained indicate that prepassivation gives rise to adherent polymer layers with excellent corrosion resistance. Of all the bilayers obtained, the best results are yielded with those in which polyaniline is deposited as the base for the deposition of polypyrrole.
The electrodeposition of Zn microparticles on the previously deposited polymer layers promotes a great improvement in the corrosion current in highly aggressive solutions such as NaCl due to the effect of Zn as an anodic corrosion inhibitor. The drop in the corrosion rate depends on the amount of Zn deposited on the polymer layer, up to a certain point after which the protective effect ceases to be observed. 相似文献
5.
Spinel LiMn2O4 is a promising cathode due to its advantages of low-cost, nontoxicity and thermal stability. However, the dissolution of manganese and the phase transformation induce the rapid capacity fade. Surface coating is an effective method to improve its electrochemical performance. In this work, spinel LiMn2O4 modified with perovskite LaCoO3 was prepared using a novel molten salt method. The resulted samples were characterized by X-ray diffraction (XRD), transmission/scanning electron microscopy (TEM/SEM), Fourier transformation infrared (FT-IR), Raman, and X-ray photoelectronic spectroscopy. The content of Mn3+ increased with the LaCoO3 coating accompanied by the increased concentration of oxygen vacancy. LiMn2O4 modified with 2% LaCoO3 shows a higher capacity and cycling stability than others at 0.2 C, while the cathode with 4% LaCoO3 shows the best rate performance at a larger current at 2 and 5 C. This enhanced performance can be attributed to improved interfacial conductivity between the cathode and electrolyte and the protective effects of coating. 相似文献
6.
The aim of this work is to develop new selective cation exchange membranes (CEMs) from bivalent to monovalent selectivity by surface functional groups. So, a novel hybrid cation exchange membrane was prepared by polymerization of polyaniline on a composite membrane, made of polyvinylidene fluoride (PVDF) and sulfonated PVDF (S-PVDF). Polyaniline was doped with different doping agents and their effect on total salt extraction and selectivity of bivalent to monovalent cations was evaluated. The chemical and morphological properties of hybrid membranes were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Ion exchange capacity (IEC), transport number, ion conductivity and water uptake decreased after surface polymerization. Composite membrane has a good selectivity (∼2) for bivalent and excellent removal of both cations. The hybrid membrane, doped with pTSA has a very high selectivity for monovalent ions (∼7.1) and a high removal of monovalent ions. 相似文献
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景强 《化学工业与工程技术》2008,29(3):24-27
综述了超高分子量聚乙烯(UHMWPE)纤维复合材料界面的重要性,总结了表面改性方法对UHMWPE纤维以及UHMWPE/树脂界面的影响。 相似文献
9.
P. Sivaraman 《Electrochimica acta》2007,52(15):5046-5052
A novel method of modification of cation exchange membrane for improved permselectivity is reported in this paper. Acrylic acid grafted fluorinated ethylene propylene copolymer membrane after sulphonation (FEP-g-AA-SO3H) was used as the cation exchange membrane for modification. Polyaniline is deposited electrochemically on to the membrane. The deposition of polyaniline starts from the surface of the membrane and growth proceeds inside the membrane. The amount of polyaniline deposited depends upon the polymerization time. The presence of polyaniline is confirmed by FTIR, scanning electron microscopy, X-ray mapping, cyclic voltammetry and ion exchange capacity measurements. The electrodialysis experiments show improved permselectivity for divalent cations. 相似文献
10.
《Ceramics International》2016,42(11):12543-12555
Zirconia is gaining interest as a ceramic biomaterial for implant applications due to its biocompatibility and desirable mechanical properties. At present, zirconia-based ceramic is often seen in the applications of hip replacement and dental implants. This paper briefly reviews different surface modification techniques that have been applied to zirconia such as polishing, sandblasting, etching, biofunctionalization, coating, laser treatment, and ultraviolet light treatment. The cellular response of osteoblast-like cell, osteoblast cell, fibroblast, and epithelial cell to the modified surface is discussed in terms of their adhesion, proliferation, and metabolic activity. The potential of surface modification to make zirconia a successful implant material in the future is highly dependent on the establishment of successful in vitro and in vivo studies. Hence, further effort should be made in order to deepen the understanding of tissue response to the implant and the tissue regeneration process. The review concludes with future prospect of research and further challenges in developing better zirconia bioceramics. 相似文献
11.
Scale formation has been recognised as a widespread problem in membrane filtration and water desalination processing for water treatment. In this paper, the effect of surface energy of Ni-P-PTFE composite coatings on the microstructure and adhesion of CaSO4 deposits was investigated. The surface energies of the Ni-P-PTFE coatings were altered by changing the PTFE proportion in the coatings. Initial experimental results showed that the surface energy of the coatings had a significant influence on the microstructure and adhesion of CaSO4 deposits. The Ni-P-PTFE coatings have a potential for reducing CaSO4 scale formation on water treatment equipment. 相似文献
12.
This paper reports the synthesis of coating silica particles, in order to design hybrid materials with hydrophobic surface properties. The silica particles were prepared in basic conditions under atmosphere of carbon dioxide (CO2), using tetraethylorthosilicate (TEOS) as a precursor and octyltriethoxysilane (OTES) as a surface modifying agent. It was demonstrated that the contact angles of silica hybrid films could be changed by varying temperature and pressure of CO2. The investigation of the prepared hybrid materials by dynamic light scattering (DLS) and environmental scanning electron microscopy (ESEM), respectively, showed that they consisted mainly of particles with a diameter of 100–250 nm. Fourier transform infrared (FT-IR) spectra indicate that the interaction between the coupling reagents, at different conditions, is mainly through chemical bonding. 相似文献
13.
A new method of the surface modified starch (SM-St) by grafting reaction of the hydroxyl groups on the starch with l-lactic acid was developed. A novel biodegradable starch grafted copolymer, starch-g-poly(l-lactide) (St-g-PLLA), was synthesized in situ by the ring-opening graft polymerization of a l-lactide (LLA) monomer onto the surface of the SM-St granules in the presence of Sn(Oct)2 as a catalyst. The PLLA grafting efficiency could reach as high as 64 wt%. The structure of St-g-PLLA was characterized by IR, DSC and WAXD. The good adhesion between the two components had been evidenced by SEM observations. The medium-resistance of St-g-PLLA and the mechanical properties of the PLLA composite blending with St-g-PLLA were much better than that of the PLLA/starch blending composite. 相似文献
14.
Emine Yo?urtcuo?lu 《Powder Technology》2011,214(1):47-53
This paper investigates the surface modification of calcite from the Ni?de region of Turkey with sodium oleate (SDO) as a modification agent, which is incorporated into the calcite with wet ultra-fine grinding in a laboratory stirred ball mill. The effect of surface modification is evaluated by a floating test, which measures the active ratio (AR), fourier transform infrared spectrometry (FT/IR) and thermogravity analyses (TG-DTA). The results indicate that the hydrophilic surface of calcite becomes hydrophobic after the incorporation of SDO through wet-stirred ball milling. 相似文献
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Asymmetric membranes fabricated from poly(acrylonitrile-co-maleic acid) (PANCMA) were immobilized with heparin and/or insulin to improve their surface properties. These biomacromolecule-immobilized PANCMA membranes were prepared by the amination of the membrane surface with ethylenediamine, followed by the reaction of the amino groups with heparin and/or insulin in the presence of 1-ethyl-3-(3-dimethyl amidopropyl) carbodiimide. The surface-modified membranes were analyzed by X-ray photoelectron spectroscopy to confirm the immobilization of the biomacromolecules. Morphological changes on the membrane surface and in the cross section were characterized by scanning electron microscopy. The surface hydrophilicity and hemocompatibility of the studied membranes were evaluated on the basis of water contact angle, platelets adhesion and cell attachment measurements. It was found that, after the immobilization of the biomacromolecules, the water contact angle and the amount of adhered platelets and macrophages on the membrane decreased significantly when compared with the nascent ones, indicating the improvement of surface hydrophilicity. Furthermore, the heparin immobilized membrane showed the best hemocompatibility among the corresponding membranes studied. 相似文献
17.
Surface modification on polytetrafluoroethylene (PTFE) films was performed with sequential hydrogen plasma/ozone treatments and surface-initiated polymerization. C-H groups were introduced to the surface of PTFE films through defluorination and hydrogenation reactions under hydrogen plasma treatment. The C-H groups then served as ozone accessible sites to form peroxide groups under ozone treatment. Grafting polymerization initiating from the peroxide groups was performed on the PTFE film surface with using acrylamide, acrylic acid, glycidyl methacrylate and 2-(2-bromoisobutyryloxy)ethyl acrylate (BIEA) as monomers. With utilizing the isobutylbromide groups on the surface of PTFE-g-PBIEA film as initiators, sodium 4-styrenesulfonate (NaSS) was polymerized onto the PTFE film surface via atom transfer radical polymerization, to bring arborescent macromolecular structure to PTFE film surface. The chemical structures of the macromolecules on PTFE film surfaces were characterized with FTIR-ATR, SEM-EDX and XPS. The surface hydrophilicities of modified PTFE films were significantly enhanced with the modification. 相似文献
18.
以聚丙烯酰胺(PAM)为分散剂,制备纳米ATO(SnO2·Sb2O3)导电粉末水相悬浮液,并用硅烷偶联剂修饰,将修饰后的纳米ATO悬浮液加入到聚丙烯腈原液(NaSCN溶剂)中共混,得到蓝绿色的聚丙烯腈共混原液。采用Zeta纳米粒度与电位分析仪、热台偏光显微镜、红外光谱等仪器测试了纳米ATO微粒在聚丙烯腈原液中的分散性能;用流变仪研究了共混原液的流变性能。在中型湿法纺丝机上纺制了2h左右的腈纶纤维,不堵喷丝孔。测试了纤维的力学性能和抗静电性能,用DSC和TG研究了纤维的热性能。 相似文献
19.
The surface of as-prepared LiMn2O4 was modified with Al2O3 by a melting impregnation method. X-ray diffraction, field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) studies indicated that Al2O3 nano-particles are distributed around the spinel. X ray absorption fine structure analysis (XAFS) further demonstrated that Al atoms were also doped to the surface of LiMn2O4 particles. The nano-Al2O3 particle coating improves the capacity retention of spinel LiMn2O4 efficiently at both room temperature and 55 °C. The mechanism of improvement for surface modified LiMn2O4 can be attributed to the inhibition of a surface Jahn-Teller distortion and the decrease of manganese dissolution, leading to good electric contact among particles. 相似文献
20.
Surface modification of organic pigment particles for microencapsulated electrophoretic displays 总被引:3,自引:0,他引:3
Zi-Qiang WenYa-Qing Feng Xiang-Gao LiYu Bai Xiao-Xu LiJing An Min Lu 《Dyes and Pigments》2012,92(1):554-562
The surface modification of Pigment Yellow 13, Pigment Red 254 and Pigment Blue 15 to improve their electrophoretic properties in electrophoretic suspension were studied. The particle size distribution and the surface morphology of the modified pigments were determined, the presence of the functional groups on the surface of pigments was confirmed, and the dispersion stability and chargeability of pigments suspended in electrophoretic slurry were characterized. For the application of microencapsulated electrophoretic displays, the colored microcapsules containing the modified organic pigments were prepared and spread on an ITO coated conducting film. A working prototype of electrophoretic display was successfully fabricated in this approach. 相似文献