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171.
Chunxia Wu Junhong Jia Hongwei Che Jingbo Mu Shufeng Zhao Xiaoliang Zhang 《Surface and interface analysis : SIA》2016,48(10):1056-1061
Nanodot‐textured surface, nanorod‐textured surface and nanocomposite‐textured surface were prepared by the hydrothermal technique and successive ion layer absorption and reaction technique. The adhesion and friction properties of the three kinds of nanotextured surfaces were investigated using an atomic force microscope colloidal probe. Experimental results revealed that the nanorod‐textured surface and nanocomposite‐textured surface can significantly reduce adhesive and friction forces compared with a nanodot‐textured surface. The main reason for this phenomenon was that the nanorod and nanocomposite textures can reduce contact area between the sample surface and the colloidal probe. The effects of surface root mean square roughness, applied load and sliding velocity on the adhesion and friction behaviors of the nanotextured surfaces were investigated. The adhesive and friction forces of the nanotextured surfaces decreased with the increasing surface root mean square roughness. Compared with the nanocomposite‐textured surface, the nanorod‐textured surface has better adhesion and frictional performance. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
172.
Chao Cai Zhen Chen Yujie Chen Hua Li Zhi Yang Hezhou Liu 《Journal of polymer science. Part A, Polymer chemistry》2021,59(23):2911-2945
In nature, many organisms can effectively fix to contact substrates and move and prey in complex living environments, such as underwater, seawater, and tidal environments, owing to special secreted chemical components and/or special micro/nanostructures on the adhesive surface of these organisms. Inspired by the adhesive performance of organisms, extensive research related to adhesive components and adhesive surfaces has been conducted recently. To better understand the underlying adhesive mechanisms and facilitate further continuous inspiration, a brief overview of recent wet/underwater adhesive materials is provided herein. First, the adhesive processes and underlying mechanisms of commonly researched organisms, such as mussels, octopuses, clingfish, and tree frogs, are discussed, and the corresponding bioinspired artificial adhesives are presented. Then, the applications of these bioinspired adhesives, such as intelligent robots (signal monitoring and sensing devices), wearable devices (including wet climbing and electronic skin), biomedicines (including wound dressings, bone adhesion, and rapid hemostasis), are presented and summarized. Finally, we offer our perspective on the future challenges and development of bioinspired artificial adhesives. 相似文献
173.
Turkan Gencoglu Fatma Demir Duman Keziban Olcay Havva Yagci Acar Duygu Avci 《Journal of polymer science. Part A, Polymer chemistry》2018,56(24):2739-2751
The first monomers containing both phosphonate and bisphosphonate (M1) or phosphonic and bisphosphonic acid (M2) functionalities are synthesized, aiming to improve binding abilities of self-etching adhesive systems and composites: An amine having both phosphonate and bisphosphonate functionalities is prepared via Michael addition reaction between diethyl (6-aminohexyl)phosphonate and tetraethyl vinylidene bisphosphonate, its reaction with 2-isocyanatoethyl methacrylate gives M1 which is converted to M2 by selective dealkylation of the phosphonate/bisphosphonate ester groups. Their copolymerization with commercial dental monomers (bisphenol A glycidyl methacrylate, triethylene glycol dimethacrylate, and 2-hydroxyethyl methacrylate) investigated by photo-differential scanning calorimetry shows adequate photopolymerization rate and conversion. X-ray diffraction, Fourier transform infrared, and X-ray photoelectron spectroscopy analyses of M2-treated hydroxyapatite particles show formation of stable M2-calcium salts. These monomers are assessed to be not toxic according to MTT standards by in vitro cytotoxicity studies with NIH 3T3, U2OS, and Saos-2 cells. All these properties make these monomers potential candidates as biocompatible components for dental adhesives and composites. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 2739–2751 相似文献
174.
175.
水性聚氨酯胶粘剂结构与性能的研究 总被引:31,自引:0,他引:31
以聚醚烽异氟尔酮二异氰酸酯为主要原料,以二羟甲基酸为亲水单体制备了一组不同配方组成的聚氨酯乳胶粘剂。通过粘度测定、粒度分析、力度性能的测试以及DSC分析,研究了新水剂含量、软链段的类型和加料方法对乳液及其胶膜性能的影响。结果表明:二羟甲基丙酸含量在3%-8%之间可获得比较稳定的乳液,并且两步法较一步法制得的乳液分散性好,但胶膜力学性能方面,一步法较好。 相似文献
176.
以无机稀土氧化物为原料、2-甲氧基乙醇为溶剂、PVP为胶粘剂、PEG200为有机分散剂,采用溶胶-凝胶工艺成功制备出Gd2O3∶Eu3+透明闪烁薄膜。通过2次涂复,薄膜厚度达到了1.5μm,膜层均匀、无散射颗粒、无裂纹,可见光区的透射率约为80%。研究表明PVP在厚膜烧结过程中可以松弛膜的结构、减小应力的出现,避免厚膜开裂,同时还可以提高溶胶的粘度,在厚膜制备中起到了关键作用。此外,我们还研究了Gd2O3∶Eu3+闪烁薄膜的激发、发射和发光衰减时间谱,结果表明,该薄膜发光性能优良,可初步满足X射线成像用闪烁薄膜的要求。 相似文献
177.
Yusuke Uchida Kengo Fukuda Yoshihiko Murakami 《Journal of Polymer Science.Polymer Physics》2013,51(2):124-131
We have developed a novel hydrogel that is formed from a crosslinkable trilayered polymeric micelle and a polyamine for the sustained release of hydrophilic compounds. This hydrogel is quite unique because the vesicle‐like structure of the trilayered polymeric micelle acts as not only a crosslinker of the hydrogel but also a container of hydrophilic compounds. The hydrogel is rapidly formed by mixing both the trilayered polymeric micelle solution and the polyamine solution. The gelation property of the hydrogel, such as the storage modulus, can be changed by tuning the molecular weights, concentrations, and pH of the dissolving solvent of the hydrogel's constituent components. Furthermore, it is clarified that the structural difference among the micelles acting as crosslinkers affects the gelation property of the hydrogel. Amazingly, the hydrogel that is formed from the trilayered polymeric micelles possessing a vesicle‐like flexible structure exhibits a higher storage modulus than the hydrogel that is formed from the bilayered polymeric micelles possessing a highly packed, hard structure. Our results demonstrates that a microscopic structural difference of crosslinkers can induce a macroscopic (and, in some cases, an interesting and unexpected) change in the properties of the resulting hydrogels. For medical applications, the hydrogel proposed in the present article can encapsulate the hydrophilic compounds so that the hydrogel can be available as the material for their sustained release. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2013 相似文献
178.
179.
本文应用大规模分子动力学方法, 模拟了两种具有不同粗糙形貌的、刚性球形探头与弹性平面基体之间的纳米尺度接触, 计算了探头与基体之间的拉离力和黏着功, 研究了接触过程中界面黏着力随载荷的变化规律, 分析了接触界面原子的法向应力分布. 研究发现, 原子级光滑接触的黏着力随着载荷的增大而线性增大, 而原子级粗糙接触的黏着力-载荷曲线分为以不同斜率增长的两个阶段. 相比于原子级光滑探头, 原子级粗糙探头与基体之间具有较小的拉离力和黏着功, 却在接触过程中形成了较大的黏着力. 因此, 拉离力和黏着功不能表征出纳米接触过程中原子吸引作用对界面法向力的贡献大小. 相似文献
180.
Sevgi Haman Bayar Christoph Krafft Semra de Jürgen Popp Gunseli Guven Zafer C. Cehreli Elif Hilal Soylu 《Journal of Raman spectroscopy : JRS》2012,43(1):6-15
Human dentin specimens were treated with two different etch‐and‐rinse adhesives, Single Bond 2 (SB2) and Prime & Bond NT (PBNT), and two composite resins, TPH and P60. Cross‐sectional samples, approximately 1 mm thick, were analyzed with Raman line mapping and imaging across the dentin–adhesive–composite interface. The integrated intensities of selected bands associated with adhesive, organic material, composite and hydroxyapatite of dentin were calculated to determine the distribution of adhesive infiltration into demineralized dentin. The results were compared with the enamel‐adhesive composite interface. The demineralized zone was smaller in the enamel‐adhesive interface than in the dentin–adhesive interface. The region of collagen‐adhesive crosslinking was wider in the PBNT adhesive than in the SB2 adhesive. However, a gap at the dentin–PBNT composite interface, which was not observed at the dentin–SB2 composite interface, might compromise the dentin–restoration bond. K‐means cluster analysis of the Raman images confirmed the findings. The ultrastructure of the dentin–resin interface was studied using scanning electron microscopy. Small‐angle X‐ray scattering was also applied to reveal and quantify fine‐scale structural features. SB2 adhesive was found to diffuse more into demineralized dentin along with greater nanosized aggregations in the hybrid layer. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献