胶体自组装法形成光子带隙材料

光子带隙晶体使人们可以有效地控制和操纵光子,但是构建光子晶体,尤其是近红外及可见光区域的光子晶体是一个困难的工作,它对材料提出了很高的要求.本文从化学的角度,利用自组装方法,对胶体晶体和反蛋白石等类光子带隙材料包括半导体、金属、金属氧化物、聚合物、染料等进行较全面的介绍,同时介绍了如何从这些材料获得光子带隙.     

三维自组装蓝相液晶光子晶体

蓝相液晶由于其独特的三维自组装结构、可见光波段的选择性光反射性能和软物质特性,被认为是最具发展潜力的可调三维光子晶体材料之一,在下一代超快响应显示、反射型显示、可调激光器和光通信等领域具有广阔的应用前景。本文综述了近年来蓝相液晶自组装结构的研究进展,包括蓝相的多级自组装三维微纳结构及子相相变行为的最新研究,通过基板表面取向处理或纳米图案化诱导、电场诱导、热处理诱导等方法控制蓝相自组装行为和三维周期性晶体结构的研究现状,以及蓝相光子晶体材料在可调谐激光器、可调光栅等光学器件领域的应用研究,最后对该领域的目前存在的挑战和未来发展方向进行了展望。     

智能响应蓝相液晶光子晶体

具有刺激响应性的智能驱动材料已成为材料科学领域的研究热点之一。液晶的超分子自组装结构与其刺激响应特性使其在新型智能功能材料的开发应用上具有天然优势。蓝相液晶由于其独特的三维超分子自组装结构、软物质特性以及可见光波段的选择性光反射,被认为是最具潜力的智能光子晶体材料之一。在温度、光照、电场、湿度等外场刺激作用下,蓝相超分子自组装结构的晶体学参数或相态非常容易发生变化,造成光子带隙的改变进而呈现出反射颜色的变化。因此,蓝相的外场响应性能及在智能材料上的应用引起了研究者的广泛关注。本文综述了智能响应蓝相液晶光子晶体外场响应性能方面的前沿动态,对蓝相液晶光子晶体的光、磁、电、力、湿度响应等方面取得的系列重要的研究成果进行了总结,并对该领域目前存在的挑战以及未来发展趋势做出展望。     

垂直排列法组装胶体晶体的最新进展

光子晶体是一种具有光子带隙的新型功能材料.利用胶体粒子自组装三维光子晶体由于其制备过程比较经济、简单,从而为很多人所关注.目前报道的方法已有多种.其中垂直排列法的简便易行使得其受到了广泛的研究,但另一方面这种方法本身的缺点也限制了它的使用范围.针对这种情况,很多研究机构提出了他们的改进方法.本文简要概述了在这一方面的最新进展,并且在本实验室已能够制备任意单分散、均一尺寸二氧化硅粒子的基础上,采用恒温快速蒸发自组装法得到了高质量的胶体晶体排列.     

化学响应性光子晶体

光子晶体是一种具有光子带隙结构的周期性电介质材料,如果将响应性材料组装到光子晶体结构中,所形成的光子晶体的带隙结构则对外界环境的变化具有响应性,而被称为响应性光子晶体。响应性光子晶体作为光子晶体的一个新领域,由于其在传感器,生物医学,临床检测等方面的潜在应用,近几年受到广泛关注。根据外界环境的不同,响应性光子晶体可简单分为化学响应性光子晶体、物理响应性光子晶体和生物响应性光子晶体等。本文将对化学响应性光子晶体的国内外研究动态做一简要介绍,重点介绍以下五种化学响应性光子晶体:金属离子响应光子晶体、pH响应光子晶体、氧化还原响应光子晶体、葡萄糖响应光子晶体和光化学响应光子晶体。     

光子晶体结构色材料的自组装制备与应用

光子晶体是由不同折射率材料周期性排列而成的结构,由于其独特的光学性质及优异的色彩饱和度,已经成为结构色材料中最重要的类型.过去几十年来,纳米粒子自组装制备光子晶体具有精准、成本低以及易大面积等优势,已经得到了广泛的研究和关注.综述了近期光子晶体结构色材料的研究进展,包括其基本的生色机制,制备方法以及在显示、色度传感和信息防伪加密等方面的实际应用.其中重点讨论了“自下而上”自组装的制备方式,并且强调了图案化和大面积结构色材料的制备方法.最后,对目前自组装制备光子晶体结构色材料所面临的挑战以及未来发展的方向进行了展望.     

胶体晶体

简要综述胶体晶体的研究进展情况,主要介绍胶体粒子的简单自组装、模板引导下的自组装和二元胶体晶体组装等几类主要的胶体晶体制备技术,并概述胶体晶体在光子晶体、传感器、光子纸张、三维有序大孔材料、二维纳米结构阵列等方面的应用。     

胶体光子晶体的平面介电常数缺陷

为引入特殊的光学性质,通常需要在三维光子晶体中人为可控地引入缺陷.通过改变局部结构单元的尺寸或介电常数,相应地引入给体或受体掺杂,带来不同的缺陷态.以前文献报道的向胶体光子晶体中引入缺陷,常会因为同时引入尺寸和介电常数掺杂,给掺杂性质的界定带来困难.本文中,我们结合对流自组装法和L-B膜法,在实心二氧化硅微球组成的三维光子晶体内引入尺寸相同的二氧化硅空心球(与实心球相比具有不同折光率)组成的单层平面缺陷,或者在空心球晶体内引入实心球缺陷层,构成实心-空心-实心或空心-实心-空心的三明治结构,在不破坏整体晶格的同时,在三维胶体光子晶体中引入单一的平面介电常数缺陷.     

三维光子晶体的制备

三维光子晶体作为一种光子带隙材料在光学器件、化学生物传感以及信息传输和存储等方面具有广泛的潜在应用价值。自1987年三维光子晶体的概念被提出以来,科学家们一直致力于在实验室用不同的手段合成不同材料和不同结构的光子晶体。本文综述了近年来出现的一些三维光子晶体制备方法,大致分为3类：“自上而下法”（top-down method）、“自下而上法”（bottom-up method）和模板辅助法（template-assisted method）,并详细阐述了每种方法的代表性工作、适用范围以及各自的优缺点。     

凝胶光子晶体*

光子晶体是一种介电常数（或折射率）可以周期性调制的结构,其自激辐射抑制和光子局域化性质使其可以简便而有力的限制、控制和调控光子。近年来,利用胶体晶体自组装性质与水凝胶的传统应用相结合制成的凝胶光子晶体在药物释放、光学开关、金属探针、生物传感器等的新应用方面的研究蓬勃发展,在新材料开发及临床应用等方面取得巨大进展。本文概述了胶体晶体自组装并对该类凝胶光子晶体进行了分类介绍并对其发展趋势进行了评述和展望。     

仿生制备功能性聚合物光子晶体

简述了自然界生物光子晶体经过不断的进化与演变而具有的一些特殊的性能,如亮丽的结构色彩、特殊的浸润性及高强度.受自然界生物光子晶体的这些特殊性能启发,通过对聚合物乳胶粒硬核软壳结构、表面功能基团及表面形貌的设计和调控等方法仿生制备了具有特殊浸润性的光子晶体;并在胶体晶体的聚合物乳胶粒间引入光交联聚合物,制备得到高强度的光子晶体;通过对蘑菇头形状乳胶粒两端的浸润性差异的设计制备,组装得到新型的各向异性结构的光子晶体.进一步发展了这些功能性光子晶体在湿度检测、油传感、自振荡体系等方面的应用.发展了通过喷涂、打印方法实现大面积、图案化聚合物光子晶体的简单制备.     

Fabrication of 3D polymeric photonic arrays and related applications

This review article describes the state-of-art methodologies, mainly self-assembly routes, which are in practice to fabricate photonic crystals (PCs) for advanced applications. The self-assembly of colloidal building blocks is an effective, affordable, and tunable approach to fabricate varieties of photonic materials of desired shapes and surface areas. Because of easy fabrication and controlled performance factors, PCs emerged as a potential platform for designing and developing optical devices with desired features such as photonic bandgap, high reflectance/transmittance, low loss, and lasing in the visible range of wavelengths. To develop next-generation optoelectronics and optical system, significant efforts are being made to explore novel and cost-effective fabrication methods to design and develop 3D-PCs platform, which is covered in this mini-review. The challenges, potential alternatives, and prospects of self-assembled 3D PCs are also discussed in this review.     

化学生物学中识别与组装的若干问题

化学与生物学的交叉与融合产生了新学科——化学生物学，开拓了化学和生物学研究的新领域，使人类得以从分子水平来阐释生命过程，揭示生命的奥秘。分子识别和组装是体系的构筑与功能集成的基础，也是自然界生物进行信息存贮、复制和传递的基础，以此来研究构筑具有特定生物学功能的超分子体系，对揭示生命现象和过程具有重要意义。本文结合我们的研究工作从（1）谷胱甘肽过氧化物酶(GPX)模拟与底物识别；（2）医用再生材料与活性支架；（3）类病毒颗粒的组装与解组装3个方面讨论了化学生物学中的识别与组装的意义。     

Directed self-assembly of two kinds of nanoparticles utilizing monolayer films of diblock copolymer micelles

We demonstrated a self-assembly of two different kinds of nanoparticles simultaneously directed on a monolayer film of diblock copolymer micelles via physical and chemical arrangements. We first incorporated gold nanoparticles physically around the micelles of a monolayer film of PS-PVP micelles having a short-range hexagonal order. Iron oxide nanoparticles were then synthesized chemically in the PVP core area of the ordered micelles, resulting in a mosaic nanopattern of magnetic iron oxide nanoparticles surrounded by metallic gold nanoparticles. Thus, we were able to direct two kinds of nanoparticles to self-assemble in the specific positions as an example of controlled fabrication of nanometer-sized building blocks.     

两亲性Janus粒子的合成及其在Pickering乳液中的应用

Janus粒子由于在光、电、力、磁及表面亲/疏水性等方面表现出各向异性,因此在稳定乳液、生物医药及功能涂层等方面展现出广阔的应用价值.两亲性Janus粒子是指一侧具有亲水性、另一侧具有疏水性的不对称材料,由于同时具有表面活性剂的性质和固体颗粒的效应,在稳定Pickenng乳液方面极具优势.基于此,本文对两亲性Janus...     

Glaser Coupling of Substituted Anthracene Diynes on a Non-metallic Surface at the Vapor-Solid Interface

The direct polymerization via irreversible C-C coupling on inert substrates will give access to new low-dimensional advanced functional materials and simplify their industrial fabrication. In this work, we present our initial results in the application of Glaser coupling to the direct on-surface polymerization of a model diacetylene compound at the solid-vapor interface. The self-assembly of the monomer and polymerization products was characterized using scanning tunneling microscopy (STM). In addition, selected optical properties and the electronic structure of all compounds were investigated.     

Noncovalent self-assembly in aqueous medium: Mechanistic insights from time-resolved cryogenic electron microscopy

Supramolecular systems based on noncovalent bonds are adaptive due to the reversible nature of the noncovalent interactions, enabling stimuli responsiveness, self-healing, facile fabrication, and recyclability. There is much effort devoted to developing new synthetic tools in supramolecular chemistry. Progress in mechanistic understanding is of crucial importance for rational design targeting functional noncovalent nanoscale assemblies. So far, insufficient insight into evolution of noncovalent assemblies hindered our ability to make progress in the field.The typical paradigm in the case of non-covalent self-assembling systems involves the concept of rapid equilibration at ambient conditions. However, when strong noncovalent interactions are involved, kinetic control may dominate the outcome of the self-assembly processes. The ability of water to impose very strong hydrophobic interactions leads to slow transformations between different structural motifs, amenable to structural mechanistic studies. Cryo-TEM emerges as a method that enables direct structural analysis via imaging of “frozen” evolving assemblies. In this review we focus on cryo-TEM imaging of intermediate structures that evolve along a supramolecular transformation pathway. The structures investigated were trapped and directly visualized, in some cases with subnanometer resolution. Direct structural information obtained by time-resolved cryo-TEM proves to be critical for mechanistic understanding of complex multistep self-assembly processes. Such knowledge is necessary to address the challenge related to rational design of novel functional self-assembled materials.     

Self-assembly on natural cellulose: Towards high-efficient catalysts

Nanoarchitectures based on the layer-by-layer self-assembly technique hold great potential for the availability and applicability of bio-inspired functional materials. The introduction of various specific functional building blocks onto the nanofibers of natural cellulose substances (e.g., commercial filter paper, cotton, etc.) through the self-assembly approach provides a facile strategy for the fabrication of artificial nanomaterials. This review summarizes a series of cellulose-based catalytic materials fabricated by utilizing the natural cellulose substance as the structural scaffolds or templates through the LbL self-assembly process. The unique three-dimensional network porous structures and high surface areas of the cellulose substances were maintained by the resultant cellulose-derived catalysts, while the excellent mechanical strength of the cellulose-based membrane catalysts was inherited from the initial cellulose substrates. When employed for the photodegradation of organic dyes, the photocatalytic hydrogen production from water splitting, and the antibiosis, these cellulose-based catalysts exhibited high activities and excellent cycling stabilities.     

二维DNA晶体的程序化设计与自组装的研究进展

按照Watson-Crick的碱基配对原则，在理论上能够人工设计与合成DNA碱基序列并自组装成任何一维和二维结构的DNA晶体。DNA分子这种底端向上(bottom-up)的自组装模式为我们提供了一种精确合成纳米材料的方法。本文将从程序化设计、合成刚性的DNA分子瓦(DNA tile)、分子瓦自组装成二维DNA晶体以及二维DNA晶体作为模板在纳米技术中的应用等方面展开，简述这一新奇的并且有着潜在应用前景的研究领域的最新进展。