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41.
不锈钢是高压氢系统的常用材料,在氢能储输技术中发挥重要作用,但高压氢环境引起的塑性降低、疲劳裂纹扩展速率加快等不锈钢氢脆问题,严重阻碍了氢能的产业化发展,在不锈钢材料表面制备阻氢涂层是解决不锈钢氢损伤问题的重要手段之一。本文首先综合介绍了典型涂层材料的应用特点及阻氢性能,探讨了制备工艺对涂层阻氢性能的影响、不同涂层材料的阻氢机理,并分析了涂层阻氢性能影响因素,之后总结了涂层阻氢性能评价方法及各种评价方法的优势与不足,并根据各种评价方法的技术特点,指出每种方法的适用范围。最后,基于阻氢涂层研究进展,文章提出以开发新型涂层结构为研究重点,同时加快新型涂层材料的探索,并重点关注涂层氢环境原位性能评价方法的研究。 相似文献
42.
Jixin Lin Weiwen Wang Jiaqi Cheng Zhixiang Cui Junhui Si Qianting Wang Wenzhe Chen 《应用聚合物科学杂志》2020,137(41):49252
To improve the interaction between cells and scaffolds, the appropriate surface chemical property is very important for tissue engineering scaffolds. In this work, the dopamine (DA) was first introduced into thermoplastic polyurethane (TPU) matrix to obtain TPU/DA nanofibers by electrospinning. Subsequently, the TPU@polydopamine (PDA) composite nanofibers with core/shell structure were fabricated by in situ polymerization of PDA. In comparison with TPU nanofibers, the uniformization of PDA coating layer on the surface of TPU/DA composite nanofibers significantly increased due to the addition of DA, which used as the active sites to guide the PDA particles accumulated along with the fiber direction. The hydrophilicity and water uptake ability of TPU@PDA composite nanofibers were larger than those of TPU nanofibers. The TPU@PDA composite nanofibers possess excellent comprehensive mechanical properties of high strength, stiffness, elasticity, and recoverability because of the hydrogen bonding occurrence between PDA and DA, as well as between PDA and TPU matrix. The attachment and viability of mouse embryonic osteoblasts cells (MC3T3-E1) cultured on TPU@PDA composite nanofibers were obviously enhanced compared with TPU nanofibers. Those results suggested that the modified TPU@PDA composite nanofibers have superior mechanical and biological properties, which promoting them potentially useful for tissue engineering scaffolds. 相似文献
43.
Edwin A. Murillo 《应用聚合物科学杂志》2020,137(8):48386
Waterborne star-shaped styrene-alkyd resins (SSARs) were synthesized from a branched alkyd resin (AR) and styrene (St) by miniemulsion polymerization. SSARs are an environmentally friendly material. The ratio of AR to St for obtaining SSARs was as follows: 50:50 (SSAR1), 60:40 (SSAR2), 70:30 (SSAR3), and 80:20 (SSAR4). The conversion percentage was directly proportional to St used, and was higher than 94.0 %. Infrared analysis and protonic nuclear magnetic resonance revealed the reaction between AR and St. The synthesis process also leads to the formation of polystyrene and its concentration increases with the concentration of St. The values of the reacted double-bond fractions were higher than 17.80%. The SSARs drop size was bigger than the particle size. The miniemulsion colloidal stability was good at room temperature. The SSARs zeta potential was between −55 and −90 mV. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48386. 相似文献
44.
Thien Vuong Nguyen Phi Hung Dao Tuan Anh Nguyen Viet Hung Dang Minh Nguyet Ha Thi Thuy Trang Nguyen Quoc Trung Vu Ngọc Linh Nguyen Tran Chien Dang Phuong Nguyen-Tri Dai Lam Tran Le Trong Lu 《应用聚合物科学杂志》2020,137(37):49116
This work aims to clarify the photocatalytic degradation mechanism and heat reflectance recovery performance of waterborne acrylic polymer/ZnO nanocomposite coating. To fabricate the nanocomposite coating, ZnO nanoparticles (nano-ZnO) were dispersed into acrylic polymer matrix at the various concentrations from 1 to 6% (by total weight of resin solids). The photocatalytic degradation of nanocomposite coating under ultraviolet (UV) light irradiation has been investigated by monitoring its weight loss and chemical/microstructural/morphological changes. As the topcoat layer, its heat reflectance recovery has been evaluated under UV/condensation exposure by using an artificial dirty mixture of 85 wt% nanoclay, 10 wt% silica particles (1–5 μm), 1 wt% carbon black, and 2 wt% engine oil. After 108-cycle UV/condensation exposure, infrared spectra and weight loss analysis indicated that the maximal degradation for nanocomposite coating is observed at 1 wt% nano-ZnO. On the other hand, after 96 hr of UV light exposure, the nanocomposite coating with1 wt% nano-ZnO could restore effectively the reflective index of solar-heat reflectance coating (from 58.45 to 80.78%). Finally, the photodegradation mechanism of this waterborne acrylic polymer coating has been proposed as the UV-induced formation of CC CO conjugated double bonds. As a result, its self-cleaning phenomenon can be achieved as the recovery of heat reflectance. 相似文献
45.
为抑制铝碳质长水口使用过程中石墨的氧化,其表面会涂覆含 20%~30%Al2O3的抗氧化涂层,但切割丝钢等特种钢冶炼过程必须严格控制钢液中夹杂的 Al2O3的含量,因此需要制备低氧化铝含量的抗氧化涂层。本文通过调节涂料组成、加水量和水玻璃加入量制备了低铝抗氧化涂层,并利用扫描电镜分析了抗氧化实验后试样断口的显微结构。结果表明:以粘土粉、钾长石粉和硅砂为主要原料,添加 10%硼砂的涂料可在 800 ℃形成良好的釉层,此时涂料中 A12O3的含量可降至 12%,得到了低铝涂料;当加入占涂料质量 80%的水和 40%的水玻璃时,涂层具有最佳的涂覆性能和抗氧化性能,涂层和长水口基体结合致密,保护了长水口中的石墨不被氧化。 相似文献
46.
Víctor Carnicer M José Orts Rodrigo Moreno Enrique Sánchez 《Ceramics International》2018,44(11):12014-12020
In this research, Suspension Plasma Spraying (SPS) technique was used for the thermal deposition of a multicomponent mixture made up of an Y-TZP/Al2O3 matrix with SiC particles. Two suspensions of Y-TZP and Al2O3 with different SiC particles content (6?wt% and 12?wt%) were tested as feedstocks in the SPS process. Three stand-off distances were varied in order to assess coating microstructure and evaluate the presence of SiC in the final coatings. Coatings were characterised in terms of porosity, microstructure and phase distribution. The estimate of the amount of SiC in the coating was carried out by XRD technique.Findings showed typical cauliflower-like SPS microstructure which intensifies with stand-off distance. Coatings porosity varied significantly between 8% and 25% whereas minimum porosity was found for the intermedium stand-off distance of 40?mm.Microstructure analysis also revealed the presence of SiC particles in the coatings which was confirmed by EDX analysis, overall XRD tests as well as TG analysis. Finally, evaluation of SiC content in the final coatings by means of XRD analysis showed that most of SiC particles (c.a 80%) of the feedstocks were preserved in the final coatings. 相似文献
47.
Enikö György Constantin Logofatu Ángel Pérez del Pino Angela Datcu Oana Pascu Raluca Ivan 《Ceramics International》2018,44(2):1826-1835
Light induced catalytic processes have attracted significant attention during the last years for wastewater treatment due to their efficiency in decomposition of organic contaminants. In this study we report the synthesis of graphene oxide (GO)/ZnO hybrid layers with high photocatalytic efficiency using laser radiation. The results show that the hybrid layers exhibit much improved photodecomposition efficiency as compared to pure GO or ZnO both under UV and visible-light irradiation. The enhanced photocatalytic efficiency of the hybrid as compared to the reference pure ZnO and GO layers was attributed to the contribution of GO to the separation and transport of the photogenerated charge carriers. Additionally, under visible light irradiation the organic molecules can act as first sensitizers in the degradation process. The recyclability of the layers was also investigated through repetitive photodegradation cycles under UV- or visible-light irradiation. After consecutive degradation runs, the hybrid photocatalyst layers were still stable and retained high degradation efficiency, ensuring reusability. The photocatalytic activity of the layers was correlated with the gradual change of their chemical structure during consecutive degradation cycles. Owing to the high photodegradation efficiency, reusability, and ease of recovery the synthesised hybrid layers consisting of easily available materials are suitable for environmental purification applications. 相似文献
48.
Ömer Kesmez Esin Akarsu H. Erdem Çamurlu Emre Yavuz Murat Akarsu Ertuğrul Arpaç 《Ceramics International》2018,44(3):3183-3188
Single layer and multilayer films consisting of SnO2, Ta2O5, SiO2, TiO2, indium tin oxide (ITO) and antimony tin oxide (ATO) have been prepared by sol-gel dip coating technique. All of the multilayer films contained a SiO2 top layer, which was composed of SiO2 nanoparticles. The other films had polymeric character. Obtained films were characterized by ellipsometry, XRD, AFM and SEM. Light transmittance values of the films were compared. Films other than SiO2 and Ta2O5 were found to have crystalline structure. Thickness values of the films were in the range of 30–115 nm and roughness values were in 1.2–23 nm range. Single layer porous silica provided 95% light transmittance, whereas ITO-TiO2-SiO2 multilayer film provided a light transmittance of 97.2%. 相似文献
49.
Jaqueline Oliveira de Moraes 《Drying Technology》2018,36(7):830-840
Tape casting is a suitable process for large-scale production of biodegradable films. This study presents a comparison of three drying procedures of starch–cellulose films: i) conduction drying, ii) infrared drying (42.3?W?m?2, higher infrared heating power damaged the films), and iii) conduction-infrared drying. All the drying procedures were performed at approximately 60°C. Drying times from the second and third methods were close to 1?h, half the time observed for conduction drying. Films from the second and third methods showed similar hygroscopicity (0.15?g.?g?1, RH 43%), tensile strength (31.3?MPa, RH 58%), and glass transition temperature (?12.13°C, RH 43%). 相似文献
50.
W. Fan Z.Z. Wang Y. Bai J.W. Che R.J. Wang F. Ma W.Z. Tao G.Y. Liang 《Journal of the European Ceramic Society》2018,38(13):4502-4511
Due to the limited temperature capability of current YSZ thermal barrier coating (TBC) material, considerable effort has been expended world-wide to research new candidates for TBC applications above 1200?°C. Our study suggested that Sc2O3 and Y2O3 co-doped ZrO2 (ScYSZ) had excellent t’ phase stability even after annealed at 1500?°C for 336?h. The thermal expansion coefficient of ScYSZ was comparable to the value of YSZ. The thermal conductivity of fully dense ScYSZ was in the range of 2.13–1.91?W?m?1?K?1 (25–1300?°C), approximately 25% lower than that of YSZ. Although the fracture toughness of dense ScYSZ was slightly lower than YSZ, an evident decline in elastic modulus was found. Additionally, thermal cycling lifetime of plasma sprayed ScYSZ coating (914 cycles) at 1300?°C was about 2.6 times longer than its YSZ counterpart. The superior comprehensive properties confirm that ScYSZ is a prospective candidate material for high-temperature TBC application. 相似文献