聚乳酸材料的仿生修饰研究进展

聚乳酸是生物可降解、生物相容性材料,但由于存在亲水性差、缺乏细胞识别位点等缺陷,限制了其在生物医学工程中的应用.模拟细胞与基质相互作用的特点以及细胞外基质的特性,通过表面修饰、本体改性和复合加工的方法在聚乳酸中引入蛋白胶原、活性肽、多糖以及羟基磷灰石等生物活性分子,实现聚乳酸的仿生修饰,能够有效提高聚乳酸材料的生物学功能.综述了利用这些生物活性分子对聚乳酸进行仿生修饰的研究进展.     

生物高分子材料聚乳酸的改性研究进展

在对生物医用高分子材料聚乳酸的生物性能、物理力学性能进行概述的基础上，介绍了对聚乳酸进行增塑、共聚、共混、复合等改性的方法及作用。经改性后聚乳酸的力学性能、亲水性能或反应功能可以得到某些改善，且其降解性能不受影响，从而更好地满足了在生物医用及环保中的应用需要．     

MGF-Ct24E功能化聚乳酸仿生骨基质材料的制备与表征

以羟基磷灰石(HAP)表面羟基为引发基团,通过开环聚合法将丙交酯以共价化学键的方式接枝到HAP表面,得到PLA-g-HAP;再引入具有良好细胞相容性的马来酸酐和具有良好骨诱导性的力生长因子(MGF-Ct24E),得到MGF-Ct24E-MPLA-g-HAP。借助红外光谱分析、氨基酸分析、热性能分析、力学性能分析和电镜分析,对上述材料的结构及性能进行了表征。结果表明,最终产物中MGF-Ct24E的接枝率为22.63%,玻璃化转变温度为58.62℃,力学性能有明显增强,并具备了三维互通孔状结构和骨诱导生物活性。该材料有望作为新型仿生骨基质材料得到应用。     

聚乳酸接枝共聚物的研究进展

接枝共聚改性是提高聚乳酸性能的一种常用方法,能够扩展其使用范围。从共聚材料种类及性能的角度,分类介绍了近年来利用纤维素、淀粉、壳聚糖、葡聚糖等天然材料和亲水性、温敏性、聚氨基酸类聚合物等合成材料接枝改性聚乳酸的研究进展,分析了各类接枝改性聚乳酸材料的优缺点和应用,展望了该领域未来的发展方向和产业化应用中应该注意的问题,指出在今后聚乳酸基接枝共聚物材料的推广应用中应该关注产品的成本问题。     

生物降解材料聚乳酸的共聚改性研究进展

概述了生物降解材料聚乳酸的物理机械性能和生物性能,指出对聚乳酸进行改性的必要性及常用方法,其中共聚改性方法是最有效的途径之一.综述了聚乳酸与聚乙醇酸、聚己内酯、聚乙二醇、聚氨基酸等的共聚方法、共聚物的性能及其应用.经共聚改性后聚乳酸的力学性能、亲水性能或反应功能性能可以得到改善,降解周期可实现调控,从而满足在生物医学及环保方面的应用需求.     

淀粉/聚乳酸共混可降解材料研究进展

介绍了淀粉在可降解塑料中应用的发展历史和现状,阐述了近几年国内外淀粉/聚乳酸共混体系的研究进展.以期在该领域里能更好、更快的开发出可替代传统塑料的可降解材料,以解决目前人类面临地并日益突出地环境问题和能源危机.     

生物质材料增强聚乳酸基复合材料的研究进展

当前,以聚乳酸和生物质材料进行复合制备新材料是领域内的研究热点。本文综述了以聚乳酸和生物质材料为主体开展材料制备和改性的研究现状,重点阐述了聚乳酸、生物质秸秆、复合材料制备及性能优化方面的研究进展。本文对复合材料改性的研究现状进行了分析,对环保新材料领域的未来发展进行了展望,可为领域内的后续研究提供参考。     

结构仿生材料的研究进展

自然界中生物体的优异结构和特性给人类研究材料带来了灵感和启发.借鉴这些生物体的优秀结构特征是结构仿生材料的主要设计思想和方法.重点阐述了仿生增韧陶瓷材料、仿生粘附材料、仿生减阻材料、仿生减振材料和仿生系统应用在设计和制备方面的研究进展,并展望了结构仿生材料的发展前景,强调了多学科协作的重要性.     

仿生防污材料的研究进展

船舶表面的生物污损会带来极大的危害,如何防除生物污损已成为一个世界难题。尽管氧化亚铜等有毒防污剂可以有效防止海生物的附着污损,但这类防污剂对非目标生物也具有负面作用,可能带来严重的生态问题。随着国际社会对有毒防污剂和海洋环境的日益关注,发展环境友好型防污材料已势在必行。人们经常观察到自然界许多生物并没有被其它生物种类寄生聚居,这是因为在自然界中生物自身存在着各不相同但极为有效的防污机制,包括化学性质、物理性质、机械清理、生活习性,以及各种防污机制的组合等,这为研制环境友好型仿生防污材料提供了依据。综述海洋环境中仿生防污材料的研究进展,重点介绍了基于生物防污剂、表面微结构、水凝胶、抗蛋白吸附等特性进行防污的仿生材料研究,并阐述了我国在该领域已经取得的重要技术突破和主要技术成果,展望了仿生防污技术的发展趋势。     

仿生材料的研究现状

简要地介绍了贝壳珍珠层天然生物材料的结构特征，进而综述了仿生材料的研究现状。     

仿生超疏水表面的发展及其应用研究进展

受自然界荷叶 “出淤泥而不染”的启发, 超疏水现象引起了研究者广泛的关注, 并成功制备了人工超疏水表面。本文对典型的仿生超疏水材料进行梳理, 并针对近期研究成果进行了综述, 对超疏水涂层的诸多制备方法作了优缺点总结和评述, 概述了超疏水涂层在自清洁、防覆冰、耐腐蚀和油水分离领域的应用研究现状, 尤其对超疏水防覆冰的机理及实现方式作了总结分析, 剖析了现阶段超疏水研究过程中面临的挑战, 展望了未来的发展趋势, 希望为超疏水涂层在工程领域的应用研究提供参考。     

Bioinspired Materials with Self-Adaptable Mechanical Properties

Natural structural materials, such as bone, can autonomously modulate their mechanical properties in response to external loading to prevent failure. These material systems smartly control the addition/removal of material in locations of high/low mechanical stress by utilizing local resources guided by biological signals. On the contrary, synthetic structural materials have unchanging mechanical properties limiting their mechanical performance and service life. Inspired by the mineralization process of bone, a material system that adapts its mechanical properties in response to external mechanical loading is reported. It is found that charges from piezoelectric scaffolds can induce mineralization from surrounding media. It is shown that the material system can adapt to external mechanical loading by inducing mineral deposition in proportion to the magnitude of the stress and the resulting piezoelectric charges. Moreover, the mineralization mechanism allows a simple one-step route for fabricating functionally graded materials by controlling the stress distribution along the scaffold. The findings can pave the way for a new class of self-regenerating materials that reinforce regions of high stress or induce deposition of minerals on the damaged areas from the increase in mechanical stress to prevent/mitigate failure. It is envisioned that the findings can contribute to addressing the current challenges of synthetic materials for load-bearing applications from self-adaptive capabilities.     

Multiscale Toughening Mechanisms in Biological Materials and Bioinspired Designs

Biological materials found in Nature such as nacre and bone are well recognized as light‐weight, strong, and tough structural materials. The remarkable toughness and damage tolerance of such biological materials are conferred through hierarchical assembly of their multiscale (i.e., atomic‐ to macroscale) architectures and components. Herein, the toughening mechanisms of different organisms at multilength scales are identified and summarized: macromolecular deformation, chemical bond breakage, and biomineral crystal imperfections at the atomic scale; biopolymer fibril reconfiguration/deformation and biomineral nanoparticle/nanoplatelet/nanorod translation, and crack reorientation at the nanoscale; crack deflection and twisting by characteristic features such as tubules and lamellae at the microscale; and structure and morphology optimization at the macroscale. In addition, the actual loading conditions of the natural organisms are different, leading to energy dissipation occurring at different time scales. These toughening mechanisms are further illustrated by comparing the experimental results with computational modeling. Modeling methods at different length and time scales are reviewed. Examples of biomimetic designs that realize the multiscale toughening mechanisms in engineering materials are introduced. Indeed, there is still plenty of room mimicking the strong and tough biological designs at the multilength and time scale in Nature.     

聚乳酸/柠檬酸三丁酯固-液共混材料的制备与性能研究

采用双螺杆挤出机液体进料工艺,制备了聚乳酸/柠檬酸三丁酯(PLA/TBC)固-液共混材料,表征了其性能。结果表明:双螺杆挤出机液体进料工艺能够精确控制TBC在PLA中的质量分数;傅里叶红外光谱仪微观结构表征了2877cm-1特征峰的出现、羟基伸缩振动峰红移,证明TBC对PLA起到了增塑作用;当TBC含量为16%(质量分数)时共混材料从脆性材料转变为韧性材料;降解实验显示,这种共混薄膜在6个月内性能基本消失,轻微受力时薄膜粉碎。     

聚乳酸的改性以及活性聚合方法

对聚乳酸这种具有生物降解性和生物相容性的高分子材料的化学改性和活性聚合近年来的研究工作进行了综述，化学改性主要涉及丙交酯和水溶性聚合物的共聚，而许多物质可以引发丙交酯的活性聚合，特别是带官能团的烷氧基类化合物更具有实际的应用价值。     

Bioinspired Synthesis of Monolithic and Layered Aerogels

Aerogels are the least dense and most porous materials known to man, with potential applications from lightweight superinsulators to smart energy materials. To date their use has been seriously hampered by their synthesis methods, which are laborious and expensive. Taking inspiration from the life cycle of the damselfly, a novel ambient pressure‐drying approach is demonstrated in which instead of employing low‐surface‐tension organic solvents to prevent pore collapse during drying, sodium bicarbonate solution is used to generate pore‐supporting carbon dioxide in situ, significantly reducing energy, time, and cost in aerogel production. The generic applicability of this readily scalable new approach is demonstrated through the production of granules, monoliths, and layered solids with a number of precursor materials.     

Flourishing Bioinspired Antifogging Materials with Superwettability: Progresses and Challenges

Antifogging (AF) structure materials found in nature have great potential for enabling novel and emerging products and technologies to facilitate the daily life of human societies, attracting enormous research interests owing to their potential applications in display devices, traffics, agricultural greenhouse, food packaging, solar products, and other fields. The outstanding performance of biological AF surfaces encourages the rapid development and wide application of new AF materials. In fact, AF properties are inextricably associated with their surface superwettability. Generally, the superwettability of AF materials depends on a combination of their surface geometrical structures and surface chemical compositions. To explore their general design principles, recent progresses in the investigation of bioinspired AF materials are summarized herein. Recent developments of the mechanism, fabrication, and applications of bioinspired AF materials with superwettability are also a focus. This includes information on constructing superwetting AF materials based on designing the topographical structure and regulating the surface chemical composition. Finally, the remaining challenges and promising breakthroughs in this field are also briefly discussed.