排序方式: 共有4条查询结果,搜索用时 15 毫秒
1
1.
Metallic materials are the most used materials as orthopedic or dental implants due to
their excellent mechanical properties. However they are not able to create a natural bonding with
the mineralized bone and occasionally suffer localized corrosion. This work describes the
electrochemical behavior of a hybrid sol–gel thin film with the addition of green inhibitor. These
films enhance the ability of the implant to make a union with the existing bone and improve its
resistance to aggressive environment. An ethanol solution of the polymerized vinyltrimethoxysilane
(PVTMS) was mixed with an aqueous solution of henna extract (Lawsonia inermis) and refluxed to
give homogeneous sols. Nanostructure hybrid PVTMS/henna thin films were deposited on the
stainless steel 316L by spin-coating. The morphology, composition and adhesion of hybrid sol–gel
coatings have been examined by SEM, EDX and pull-off test, respectively. Addition of high
additive concentrations (0.1%) did not disorganize the sol–gel network. Direct pull-off test
recorded a mean coating-substrate bonding strength larger than 20.6 MPa for the hybrid sol–gel
coating. The effect of henna extract, with various added concentrations from 0.012% to 0.1%, on
the anticorrosion properties of sol–gel films have been characterized by electrochemical impedance
spectroscopy (EIS) and potentiodynamic polarization tests in simulated body fluid (SBF) solution
and has been compared to the bare metal. Henna extract additions (0.05%) have significantly
increased the corrosion protection of the sol–gel thin film to higher than 90%. The in vitro
bioactivity of prepared films indicates that hydroxyapatite nuclei can form and grow on the surface
of the doped sol–gel thin films. The present study shows that due to their excellent anticorrosion properties, bioactivity and bonding strength to substrate, doped sol–gel thin films are practical
hybrid films in biomedical applications. 相似文献
2.
Biodegradable starch/poly (vinyl alcohol) film reinforced with titanium dioxide nanoparticles 总被引:1,自引:0,他引:1
下载免费PDF全文
![点击此处可从《矿物冶金与材料学报》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Zahra Hejri Ali Akbar Seifkordi Ali Ahmadpour Seyed Mojtaba Zebarjad Abdolmajid Maskooki 《矿物冶金与材料学报》2013,20(10):1001-1011
Biodegradable starch/poly (vinyl alcohol)/nano-titanium dioxide (ST/PVA/nano-TiO2) nanocomposite films were prepared via a solution casting method. Their biodegradability, mechanical properties, and thermal properties were also studied in this paper. A general full factorial experimental approach was used to determine effective parameters on the mechanical properties of the prepared films. ST/PVA/TiO2 nanocomposites were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results of mechanical analysis show that ST/PVA films with higher contents of PVA have much better mechanical properties. In thermal analysis, it is found that the addition of TiO2 nanoparticles improves the thermal stability of the films. SEM micrographs, taken from the fracture surface of samples, illustrate that the addition of PVA makes the film softer and more flexible. The results of soil burial biodegradation indicate that the biodegradability of ST/PVA/TiO2 films strongly depends on the starch proportion in the film matrix. The degradation rate is increased by the addition of starch in the films. 相似文献
3.
油中水滴静电聚并微观机理研究 总被引:1,自引:0,他引:1
利用电场对多相体系进行分离处理广泛应用于石油化工等行业,电场力作用下液滴间的相互运动聚并是聚结的基础和前提条件.本文从液滴间静电力学模型出发,通过动态微观实验对液滴的聚并过程进行了完整的记录和分析,确定不同实验条件下液滴的聚并方式和角度,以及液滴从静止状态到发生相对运动时的临界条件.结果发现当两等大液滴间距与液滴半径之比大于1时,液滴间中心连线与电场力夹角θ<54.7°或θ>125.3°,两液滴间作用力表现为吸引力,当液滴间距较小时,能产生聚结的最大倾角增大为81.3°.液滴间相对距离增大时,移动临界电场强度迅速升高,较大液滴发生相对移动所需的场强低于小颗粒液滴.实验结果验证了相关理论,进一步完善了静电聚结机理. 相似文献
4.
1