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1.
In this study, TiO2 nanocomposite films with 10 g/L of TiO2 and copper loaded TiO2 nanoparticles as nanofillers were deposited on the glass substrates using the sol gel dip-coating method. FE-SEM and UV-vis spectrophotometer were used to evaluate morphological and optical properties of copper loaded titania nanoparticles. In addition, XPS and water contact angle techniques were used to study the surface properties and superhydrophilicity of titania nanocomposite films, respectively. The results indicated that copper loaded TiO2 nanoparticles had a significant effect on the hydrophilicity of nanocomposite film and maintaining it in a dark place for a long time (6.2 degree for titania nanocomposite films with copper loaded nanoparticle and 23.7 degree for nanocomposite film with titania nanoparticles).  相似文献   

2.
Hybrid coatings of poly(L-lysine) and apatite were formed on the micro-arc oxidized titania through a biomimetic process. Phosphorous (P)-containing titania films were prepared by micro-arc oxidation (MAO) of titanium (Ti) substrates in an electrolyte solution containing β-glycerol phosphate disodium salt pentahydrate. The hybrid coatings were grown by immersing MAO titania in the poly(L-lysine)-containing simulated body fluid (SBF) solution. After 72 h immersion, the globular precipitates appeared on the surface of titania films and grew up to ~ 10 µm. These precipitates consisted of 100–200 nm nano-flakes with a distorted (less straight) morphology. XRD and FT-IR confirmed that these precipitates were poly(L-lysine)-containing apatite nanocomposite.  相似文献   

3.
Polymer nanocomposites with high loadings of nanoparticles (NPs) exhibit exceptional mechanical and transport properties. Separation of polymers and NPs from such nanocomposites is a critical step in enabling the recycling of these components and reducing the potential environmental hazards that can be caused by the accumulation of nanocomposite wastes in landfills. However, the separation typically requires the use of organic solvents or energy-intensive processes. Using polydimethylsiloxane (PDMS)-infiltrated SiO2 NP films, we demonstrate that the polymers can be separated from the SiO2 NP packings when these nanocomposites are exposed to high humidity and water. The findings indicate that the charge state of the NPs plays a significant role in the propensity of water to undergo capillary condensation within the PDMS-filled interstitial pores. We also show that the size of NPs has a crucial impact on the kinetics and extent of PDMS expulsion, illustrating the importance of capillary forces in inducing PDMS expulsion. We demonstrate that the separated polymer can be collected and reused to produce a new nanocomposite film. The work provides insightful guidelines on how to design and fabricate end-of-life recyclable high-performance nanocomposites.  相似文献   

4.
《Materials Letters》2007,61(14-15):2908-2910
This work reports the preparation of acetic acid-modified TiO2 nanoparticles by sol–gel synthesis method. The nanoparticles can be incorporated directly into the polymer matrix to form transparent high refractive index nanocomposite thin films. The result shows that increasing the titania content in the hybrid nanocomposite thin films can significantly increase the refractive index. Hybrid nanocomposite thin film with refractive index value of 2.38 had been prepared. All prepared films also exhibit excellent optical transparency in the visible region.  相似文献   

5.
The present paper reports on the evaluation of two silsesquioxane-based hybrid nanocomposites with methacrylate units containing titania and/or silver nanoparticles aimed as antibacterial coatings for monumental stones. Sol–gel reaction of titanium isopropoxide and/or 3-(trimethoxysilyl)propyl methacrylate, in the presence of silver nitrate and a primary amine surfactant, yielded new types of hybrid nanocomposites with high antibacterial/antifungal efficacy. Different polymer behaviours regarding a frequently used monumental stone originating from Romania were evidenced through Fourier-transform infrared (FTIR) spectroscopy and powder X-ray diffraction (PXRD) technique. Conclusions regarding the stones acid-resistant character and lower influence of salt weathering on its durability, as well as a better protective coating containing titania units were revealed.  相似文献   

6.
Inspired by the hierarchical structure of the mastoid on the micrometer and nanometer scale and the waxy crystals of the mastoid on natural lotus surfaces, a facile one‐step hydrothermal strategy is developed to coat flower‐like hierarchical TiO2 micro/nanoparticles onto cotton fabric substrates (TiO2@Cotton). Furthermore, robust superhydrophobic TiO2@Cotton surfaces are constructed by the combination of hierarchical structure creation and low surface energy material modification, which allows versatility for self‐cleaning, laundering durability, and oil/water separation. Compared with hydrophobic cotton fabric, the TiO2@Cotton exhibits a superior antiwetting and self‐cleaning property with a contact angle (CA) lager than 160° and a sliding angle lower than 5°. The superhydrophobic TiO2@Cotton shows excellent laundering durability against mechanical abrasion without an apparent reduction of the water contact angle. Moreover, the micro/nanoscale hierarchical structured cotton fabrics with special wettability are demonstrated to selectively collect oil from oil/water mixtures efficiently under various conditions (e.g., floating oil layer or underwater oil droplet or even oil/water mixtures). In addition, it is expected that this facile strategy can be widely used to construct multifunctional fabrics with excellent self‐cleaning, laundering durability, and oil/water separation. The work would also be helpful to design and develop new underwater superoleophobic/superoleophilic materials and microfluidic management devices.  相似文献   

7.
Superhydrophobic coatings are widely applicable, e.g., as self-cleaning surfaces or water–oil separation membranes, yet their wider usage is impeded due to costs of fabrication, size, or substrate limitation. Spray-coating is a versatile coating procedures and might offer a good solution for the fabrication of these superhydrophobic coatings, due to the fact that coatings can be fabricated on various materials in a simple, fast, and inexpensive manner. Most procedures rely on hybrid coatings of hydrophobized nanoparticles and a polymeric matrix, which have several drawbacks including the easy loss of nanoparticles and difficult waste handling. Here, the fabrication of the superhydrophobic material, called Fluoropor, for the first time, by spray-coating on various substrates including metals, tissues, concrete, and glass is presented. It is fabricated by spray-coating a mixture of a highly fluorinated monomer blended with porogens followed by photopolymerization. The superhydrophobicity of the material relies on the porous structure on the micro-/nanoscale across the bulk material and does not require any nanoparticles. Excellent self-cleaning ability of these coatings, resistance against thermal and abrasive impact, and their application as oil–water separation membranes are shown. This versatile applicability is highly promising for real-world application as self-cleaning coatings or oil–water separating membranes.  相似文献   

8.
Transparent substrates are widely used for optical applications from lenses for personal and sports eyewear to transparent displays and sensors. While these substrates require excellent optical properties, they often suffer from a variety of environmental challenges such as excessive fogging and surface contamination. In this work, it is demonstrated that a wet-style superhydrophobic coating, which simultaneously exhibits antifogging, antireflective, and self-cleaning properties, can be prepared by pattern transferring low-surface-energy microstructures onto a heterostructured nanoscale thin film comprising polymers and silica nanoparticles. The polymer–silica nanocomposite base layer serves as a hydrophilic reservoir, guiding the water molecules to preferentially condense into this underlying region and suppress reflection, while the low-surface-energy microstructure enables contaminants adsorbed on the surface to be easily removed by rinsing with water.  相似文献   

9.
目的 针对普通纺织品材料防水性和防污性较差的问题,制备具有自清洁功能的超疏水涂层纺织品,并研究其性能.方法 以涤纶织物为基材,通过非溶剂诱导相分离法,使用聚偏氟乙烯和疏水纳米二氧化硅复合液在纺织品表面构筑微纳粗糙结构,采用聚二甲基硅氧烷对其进行疏水化处理,获得自清洁超疏水涂层纺织品.采用扫描电子显微镜、X射线能量散射光谱和视频光学接触角测量仪等对其结构和性能进行表征,并通过机械摩擦、洗涤、酸/碱/盐溶液浸渍和紫外光照等方法对其表面超疏水稳定性进行考察.结果 当聚偏氟乙烯质量分数为2%,疏水纳米二氧化硅质量分数为0.4%,聚二甲基硅氧烷质量分数为1%时,制备的纺织品的表面接触角可达(162.2°±0.8°),滚动角达(2.0°±0.4°),具有优异的超疏水自清洁效应;经72 h酸/碱/盐溶液浸渍、196 h紫外光照、2500次摩擦和120次家庭水洗后,其表面接触角仍大于150°,表现出优异的超疏水稳定性.结论 采用简便的非溶剂相分离法制备的涂层纺织品具有优异的自清洁性能,并且其超疏水性能具有机械耐久性和化学稳定性,有望应用于纺织材料包装领域.  相似文献   

10.
Nanomaterials with high stability and efficient antibacterial activity are of considerable interest. The preparation of silver nanoparticles (AgNPs) on titania coatings and their effective antibacterial activity against Staphylococcus aureus ATCC 6538 were reported. Titanium dioxide (TiO2) coatings with AgNPs were prepared on Si wafers using the reactive magnetron sputtering method. The surface topography of AgNPs/TiO2 coatings imaged using scanning electron microscopy revealed that the size and surface density of AgNPs grown by the photoreduction of silver ions were dependent on the concentration of AgNO3 in the primary solution and the time of TiO2 exposure to UV illumination. Evaluation of the antimicrobial properties and surface analysis before and after the biological test of AgNPs/TiO2 coatings indicates their high antimicrobial stability and durability. Furthermore, the interdependence between the concentration of released silver and bacterial growth inhibition was demonstrated. In addition, direct contact killing and released silver-mediated killing have been proposed as a bactericidal mechanism of action of tested coatings with AgNPs.  相似文献   

11.
The Zirconia nanoparticles are dispersed well in the plating bath using polyelectrolyte dispersant and NiZrO2 nanocomposite coatings containing monodispersed ZrO2 nanoparticles are successfully prepared under DC electrodeposition condition. The effects of the dispersant concentration on the dispersibility of Zirconia nanoparticles in the plating bath and the hardness of nanocomposite coatings have been investigated. The results shows that the hardness of nanocomposite coatings are strongly influenced by the dispersion state of ZrO2 nanoparticles in the composite coatings and only a very low volume percent of monodispered ZrO2 nanoparticles in Ni-ZrO2 composite coatings will result in higher hardness of the coating.  相似文献   

12.
The fundamental relationship between microstructure,constituent,processing and performances of separating materials is really a vital issue.Traditional preparation methods for separation membranes are complex,time-consuming and easy to be fouled.Also,the durability of conventional coatings on membrane is poor.By combination of bioinspiration from mussel adhesive and fish scales’underwater superoleophobicity,we propose a general route to prepare organic-inorganic hybrid coatings,while no complex apparatus is needed.Specifically,based on the biomimetic adhesion of polydopamine(PDA),we used it as a binder to adhere TiO2nanoparticles and built rough microstructure on fabric.In this way,we obtained TiO2-PDA treated fabric with special wettability.These TiO2-PDA treated samples owned superamphiphilicity in air,underwater superoleophobicity(underwater oil contact angles(OCAs)>150°),underoil superhydrophobicity(underoil water contact angles(WCAs)>150°),excellent multiresistance;and can separate polar/nonpolar liquid mixture effectively.It also owned superaerophobicity underwater(underwater bubble contact angles(BCAs)>150°).The proposed TiO2-PDA coatings are highly expected to be employed for real situation of water pollution remediation,self-cleaning,oil extraction and harsh chemical engineering issues.  相似文献   

13.
A new kind of multifunctional Co0.85Se‐Fe3O4 nanocomposites is synthesized by loading Fe3O4 nanoparticles (NPs) with a size of about 5 nm on the surface of Co0.85Se nanosheets under hydrothermal conditions without using any surfactant or structure‐directing agents. The Co0.85Se‐Fe3O4 nanocomposite exhibits remarkable catalytic performance for hydrogenation of p‐nitrophenol (4‐NP) at room temperature and good adsorption behavior for methylene blue trihydrate in water. This nanocomposite also shows a high specific surface area and magnetic separation capability for recyclable utilization. The enhanced performances both in catalysis and adsorption are better than either individual component of Co0.85Se nanosheets or Fe3O4 nanoparticles, demonstrating the possibility for designing new multifunctional nanocomposites with improved performances for catalysis, adsorbents, and other applications.  相似文献   

14.
This work reports the preparation of TiO2/Epoxy nanocomposites coatings with high refractive index and optical transparency. Highly dispersed titania nanoparticles were synthesized by sol-gel method at room temperature. The TiO2 nanoparticles can be dispersed directly into the polymer without the use of organic surfactant. Nanocomposite coating with refractive index of 1.668 can be obtained by adding 30 wt% TiO2 nanoparticles into the polymer matrix. All coatings with different amount of TiO2 exhibit excellent optical transparency of more than 90%. Although higher refractive index of the nanocomposite can be obtained by increasing the content of TiO2 nanoparticles, cracks also appear in the surface of the hybrid coating.  相似文献   

15.
The promising aspects of nanocomposite coatings to mimic the nano roughened self cleaning surface of lotus leaf is explored in this paper. A detailed study on nanosilica and clay based nanocomposite coatings using dip coating and layer by layer self assembly (L–b–L) is being described where lotus leaf effect has been mimicked on the cotton fabric surface using these particles as they develop nanosized surface roughness which helps to produce a super-hydrophobic surface. Nanosilica performs better in creating nano roughness on cotton fabric wherein the contact angle is ${>}$ 150 $^{\circ}$ . The water contact angle of 2 wt% fluoro emulsion (Nuva HPU) treated cotton fabric increases from 115 $^{\circ}$ to 155 $^{\circ}$ when the fabric is pretreated with 0 ${\cdot} $ 5 wt% nanosilica emulsion. The water repellency rating of fabric treated with 0 ${\cdot }$ 16 wt% nanosilica along with 2 wt% Nuva HPU is comparable to that of 4 wt% Nuva HPU treated cotton fabric. On the other hand, 40 bilayers of nanosilica need to be applied on cotton fabric surface through L–b–L technique to create uniform nano roughening and gives a water repellency rating of 4. The air permeability of L–b–L nanocoated cotton fabric is not adversely affected by the super-hydrophobic nanostructured coating.  相似文献   

16.
等离子体喷涂氧化钛涂层的生物活性研究   总被引:1,自引:0,他引:1  
以纳米TiO2粉末为喷涂原料, 采用大气等离子体喷涂技术在医用钛合金上制备氧化钛涂层. 利用酸和碱溶液对氧化钛涂层表面进行生物活化处理, 体外模拟体液浸泡实验考察涂层的生物活性. 采用XRD、SEM、FTIR、EDS等测试技术对改性前后氧化钛涂层的生物活性进行表征. 结果表明: 氧化钛涂层和钛合金基体的结合强度较高, 其值高达40MPa, 涂层的耐模拟体液腐蚀性优于钛合金. 酸和碱溶液表面改性后的氧化钛涂层经模拟体液浸泡可在其表面生成含有碳酸根的羟基磷灰石(类骨磷灰石), 显示良好的生物活性.  相似文献   

17.
Titania coatings containing crystalline titania particles 10 to 20 and 100 to 300 nm in size or a combination of such particles have been produced by a sol–gel process on the surface of aluminum substrates. According to X-ray diffraction characterization results, the coatings consist predominantly of crystalline titania in the form of anatase. The decomposition of an organic test dye (Rhodamine B) in an aqueous solution under irradiation with UV light demonstrates that the highest photocatalytic activity is offered by the coatings containing both nanometer- and submicron-sized titania particles.  相似文献   

18.
PDMS-TiO2-SiO2 hybrid coatings have been prepared on glass substrates via sol-gel method. The structural evolution of the coatings containing different PDMS amounts was examined by TG-DTA and FTIR. It was found that the hybrid character of coatings can be reserved after heating at 200 °C. The alkali resistance of hybrid coatings in 1 N NaOH solution at 50 °C was investigated by X-ray fluorescence analysis, weight loss and scanning electron microscopy. The results showed that the coating could resist effectively the alkali attack for 24 h. Such alkali resistance depended on the added amount of PDMS and the coating with 20 wt.% PDMS showed a better alkali resistance.  相似文献   

19.
目的 基于普通织物材料防水性较差的问题,制备一种具有超疏水涂层的聚酯纤维织物,并对其性能进行研究。方法 以聚酯纤维织物为基材,基于紫外光固化技术通过浸涂法,使用商用气相纳米SiO2颗粒(S-SiO2)、端乙烯基聚二甲基硅氧烷(Vi-PDMS)在织物表面构筑微纳粗糙结构,获得超疏水的织物。采用扫描电子显微镜、水接触角测量仪对其微观结构和疏水性能进行表征,并通过机械摩擦实验对其超疏水稳定性进行考察。结果 当Vi-PDMS和S-SiO2质量比为1∶4时,选择交联剂为三羟甲基丙烷三丙烯酸酯(TMPTA)制备的聚酯纤维织物表面的水接触角可达到151°,滚动角可达9°;且经过40次循环摩擦后,其表面水接触角仍大于140°,具有一定的耐磨性。结论 基于紫外光固化技术,采用操作简便的浸涂法制备的聚酯纤维织物具有优异的超疏水性能和一定的耐磨性,为织物超疏水性能研究提供参考,有望应用于超疏水聚酯纤维织物领域。  相似文献   

20.
Collagen/hydroxyapatite (HA) nanocomposite thin films containing 10, 20, and 30 wt.% HA were prepared on commercially pure titanium substrates by the spin coating of their homogeneous sols. All of the nanocomposite coatings having a thickness of ∼7.5 μm exhibited a uniform and dense surface, without any obvious aggregation of the HA particles. A minimum contact angle of 36.5° was obtained at 20 wt.% HA, suggesting that these coatings would exhibit the best hydrophilicity. The in vitro cellular assays revealed that the coating treatment of the Ti substrates favored the adhesion of osteoblast-like cells and significantly enhanced the cell proliferation rate. The cells on the nanocomposite coatings expressed much higher alkaline phosphatase (ALP) levels than those on the uncoated Ti substrates. Increasing the amount of HA resulted in a gradual improvement in the ALP activity. The nanocomposite coatings on Ti substrates also exhibited much better cell proliferation behaviors and osteogenic potentials than the conventional composite coatings with equivalent compositions, demonstrating the greater potential of the former as implant materials for hard tissue engineering.  相似文献   

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