聚合物基力致变色材料的研究进展

近期,通过光学性质的变化来检测机械应力的力致变色材料引起了人们广泛的研究兴趣。这种材料可以利用机械能促使高分子链内部的化学或物理结构发生转变,因此在力学传感、自愈合材料等领域具有巨大的应用价值。总结了有关力致变色聚合物材料的发展现状,详细讨论了两种力致变色聚合物材料的制备方法。第一种方法中,染料分子是通过物理共混的方法分散于高分子基体中,高分子基体受力变形时,微观聚集的染料分子会分散开来,使材料表现出不同于之前的光学性质。第二种方法则是通过化学键将力致变色基团共价连接至高分子主链或侧链上,机械刺激会诱使力致变色基团发生原子尺度的选择性化学转变并进而导致材料光学性质的变化。最后,评述了目前这类功能高分子材料所面临的问题并对其未来的发展趋势做出了展望。     

自适应伪装材料在军用服饰产品的设计应用研究

目的 总结和展望可见光波段自适应伪装材料和红外波段自适应伪装材料的发展趋势及应用现状,为进一步研究和应用提供参考.方法 基于军用服饰对抗的不同波段,总结归纳了光致变色材料、电致变色材料、热致变色材料、相变材料、电致变发射率材料、电致变温材料和光子晶体材料的发展现状.结果 自适应伪装材料在军用服饰上的应用形式多,且相关产品在不断更新换代.结论 光学自适应伪装材料可适应不同场景不同要求下的变色需求,电致变发射率材料等红外自适应伪装材料可以用于军用红外伪装中,进一步完善可实现自适应红外隐身,人工光子晶体材料作为自适应伪装材料也可用于军用产品,目前已从多角度进行研发、实验,具有很大的应用前景及发展潜力.     

SiO2胶体晶体的自组装结构及其带隙特征

光子晶体是一种具有光子带隙的新型功能材料.利用垂直沉积自组装法制成SiO2胶体晶体,并利用扫描电子显微镜和紫外分光度计对胶体晶体的显微形貌和光学特征进行了研究.结果表明,利用垂直沉积法自组装得到的SiO2胶体晶体具有面心立方结构;在可见光波段,胶体晶体在＜111＞面方向存在光子带隙.     

基于金属有机框架的光子晶体制备与应用研究进展

近年来,基于光子晶体优异的光学性能和金属有机框架(MOFs)特殊的多孔结构,使基于MOFs的光子晶体研究备受研究者们的关注。本文综述了近年来MOFs材料及其在光子晶体中的应用研究进展。首先简单介绍了MOFs和光子晶体的基本概况及MOFs与光子晶体相结合的优势,然后阐述了基于MOFs的光子晶体的制备方法,进一步概括了其应用现状,并总结了当前基于MOFs的光子晶体研究所存在的困境,最后展望了其未来的发展方向。这些工作为MOFs材料在光子晶体中的实际应用提供了策略支撑。      

多彩结构色‒柔性光子晶体材料与应用

目的 对柔性光子晶体的性质进行介绍,并对其主流的制备方法进行阐述,总结近几年来柔性光子晶体材料在包装印刷领域的应用。方法 介绍柔性光子晶体材料的主流制备方法,包括胶体粒子自组装法以及纳米压印光刻法;其次根据光子晶体材料的结构色可调性,介绍柔性光子晶体材料在包装印刷领域主要应用和研究价值。结论 目前柔性光子晶体在包装印刷方面的应用主要在于纺织、防伪、体育与健康等方面。柔性光子晶体在绿色印刷和包装领域具有重大潜力,可进一步深度研究拓宽其日常生活领域化应用,进一步推动包装印刷行业的绿色发展。     

三维光子晶体及其制备技术研究进展

光子晶体是一种新概念人工结构功能材料,通过设计可以人为调控经典波的传榆.而三维光子晶体能产生全方向的完全禁带,具有更普遍的实用性.从结构、材料及应用探索3方面介绍了近几年来光学波段三维光子晶体的最新发展动向:以器件化为指导,逐步由简单媒质简单周期向复杂媒质复合周期结构方向发展,由胶体模板自组装等纯化学制备手段向物理化学方法相融合的多元技术扩展,其应用领域也由光电子器件、集成光路进一步拓展到光电对抗、光学探测、传感等.     

多重力致变色聚合物的研究进展

力致变色聚合物(MCPs)是一类在受到机械刺激后能发生颜色或荧光变化的聚合物，在应力检测和损伤传感等方面具有广泛的应用前景。目前报道的力致变色聚合物在机械力刺激下通常只显示一种颜色或荧光的变化，这限制了它们在复杂工况及多模态分析中的应用。因此，在不同强度或不同类型力下能够产生不同颜色转变的多重力致变色聚合物成为了研究的热点。介绍了多重力致变色聚合物的研究现状，综述了其设计策略和响应机制。     

Se-SiO2三维光子晶体的制备

报道了一种新的调节二氧化硅光子晶体带隙的方法;通过化学镀向SiO2胶体晶体中填充半导体材料Se,获得了Se-SiO2两种介质复合的三维光子晶体;采用扫描电子显微镜(SEM)、X射线衍射和紫外-可见光谱仪(UV-VIS)等对Se-SiO2三维光子晶体的形貌、结构和光学性能进行了观察测试.研究结果表明,Se以纳米晶粒的形式均匀地包覆在SiO2微球表面,形成了Se壳层,与相同晶格周期的SiO2光子晶体相比,Se-SiO2光子晶体的带隙发生了明显的红移.     

垂直沉积自组装法与复杂结构光子晶体的研究进展

作为一种折光指数呈周期性分布的材料,光子晶体在功能器件、光学纤维和光学伪装材料等方面有潜在重要的应用。总结了以垂直沉积自组装法为基础,通过不同方法来制备光子晶体的研究进展,以及利用这些方法进一步制备各种具有不同复杂结构光子晶体的进展,总结了这些方法制备光子晶体的优缺点,并展望了垂直沉积自组装法制备光子晶体的发展趋势。     

复合结构光子晶体的制备及应用

复合结构纳米粒子具有许多不同于单组分胶体粒子的独特的光、电、磁、催化等物理与化学性质,是构筑光子晶体材料的重要组元.从材料复合的不同形式阐述了复合结构光子晶体的制备方法;列举了光子晶体器件的典型应用.综述了光子晶体的主要用途;并展望了复合结构光子晶体的发展方向.     

非晶光子晶体结构显色的研究进展

目的 综述国内外非晶光子晶体结构呈色的研究进展,为进一步研究非晶光子晶体在印刷颜料、光学防伪、功能性包装材料以及彩色显示器、传感器等领域的应用提供理论依据。方法 概括非晶光子晶体的概念、材料的选取与制备方法以及国内外的研究进展,分析该类材料在应用过程中存在的问题,并总结目前非晶光子晶体研究所面临的挑战和未来的发展方向。结论 非晶光子晶体具有非虹彩效应、各向同性、光局域化等特点,为包装印刷等相关领域的研究及应用提供了新思路、新方法,有望早日将这一绿色环保、经济高效型的材料实现规模化应用。     

Facile Synthesis of Monodispersed Polysulfide Spheres for Building Structural Colors with High Color Visibility and Broad Viewing Angle

The synthesis and assembly of monodispersed colloidal spheres are currently the subject of extensive investigation to fabricate artificial structural color materials. However, artificial structural colors from general colloidal crystals still suffer from the low color visibility and strong viewing angle dependence which seriously hinder their practical application in paints, colorimetric sensors, and color displays. Herein, monodispersed polysulfide (PSF) spheres with intrinsic high refractive index (as high as 1.858) and light‐absorbing characteristics are designed, synthesized through a facile polycondensation and crosslinking process between sodium disulfide and 1,2,3‐trichloropropane. Owing to their high monodispersity, sufficient surface charge, and good dispersion stability, the PSF spheres can be assembled into large‐scale and high‐quality 3D photonic crystals. More importantly, high structural color visibility and broad viewing angle are easily achieved because the unique features of PSF can remarkably enhance the relative reflectivity and eliminate the disturbance of scattering and background light. The results of this study provide a simple and efficient strategy to create structural colors with high color visibility, which is very important for their practical application.     

CdS、Ag^+掺杂改性纳米TiO_2光催化降解有机物研究

在理论分析的基础上对纳米Ti02分别进行掺CdS和掺银改性实验研究。采用XRD和粒度分析技术对改性后的样品进行表征,并以掺杂CdS、Ag^＋纳米Ti02进行光催化降解甲基橙模拟实验。结果表明,掺杂CdS、Ag^＋纳米Ti02在可见光范围内降解有机物的效率有较大提高。     

Instantaneous,Simple, and Reversible Revealing of Invisible Patterns Encrypted in Robust Hollow Sphere Colloidal Photonic Crystals

The colors of photonic crystals are based on their periodic crystalline structure. They show clear advantages over conventional chromophores for many applications, mainly due to their anti‐photobleaching and responsiveness to stimuli. More specifically, combining colloidal photonic crystals and invisible patterns is important in steganography and watermarking for anticounterfeiting applications. Here a convenient way to imprint robust invisible patterns in colloidal crystals of hollow silica spheres is presented. While these patterns remain invisible under static environmental humidity, even up to near 100% relative humidity, they are unveiled immediately (≈100 ms) and fully reversibly by dynamic humid flow, e.g., human breath. They reveal themselves due to the extreme wettability of the patterned (etched) regions, as confirmed by contact angle measurements. The liquid surface tension threshold to induce wetting (revealing the imprinted invisible images) is evaluated by thermodynamic predictions and subsequently verified by exposure to various vapors with different surface tension. The color of the patterned regions is furthermore independently tuned by vapors with different refractive indices. Such a system can play a key role in applications such as anticounterfeiting, identification, and vapor sensing.     

Optical properties caused by periodical array structure with colloidal particles and their applications

High quality opal films have been attracting much attention due to their novel properties and applications, such as smart materials with structural color, novel photonic/optical devices and three-dimensional photonic crystals. In this article, the author reported a colloidal crystal consisting of cubic closely packed (ccp) polystyrene particles and filled with polydimethylsiloxane (PDMS) elastomer. The array of ccp (111) planes diffracts light of selective wavelengths according to Bragg’s law. The PS-PDMS hybrid opal films exhibit dynamic tuning structural colors. The lattice distance of ccp (111) planes is variable by swelling PDMS elastomer with hydrophobic liquid or by applying mechanical deformation. The hybrid opal films have potential applications in wide fields, for example, in smart sensing materials, color imaging without pigments and strain mapping of plastic deformation.     

非晶无序光子晶体结构色机理及其应用

结构色是一种由光学尺度的微纳结构与光相互作用形成干涉、衍射或散射而产生颜色的物理生色效应。与化学生色不同,结构色由于没有色素或者染料的参与,因此没有颜色褪色的现象,同时能够避免使用染料和色素带来的环境污染。目前结构色材料受到研究者和应用开发人员的广泛关注,大量的研究发现结构色可以来源于光子晶体与非晶光子晶体两种结构。光子晶体由规整的周期性结构组成,产生的颜色鲜艳却具有明显的角度依赖性。而非晶光子晶体,其"自身缺陷"导致的短程有序结构具备了各向同性的光子带隙、非虹彩效应、光局域化等特点,赋予了材料柔和亮丽不随角度变化的显色效果,可控的激光效应以及优良的发光效率,从而更能满足材料领域对光散射和光传输等方面的特殊需求。对非晶光子晶体的概念和结构,与可见光作用产生颜色的原理,以及制备非晶光子晶体的不同方法(平板刻蚀法、胶体颗粒自组装法、模板法、相分离法)做了详细的讨论,并对非晶光子晶体产生的结构色效应在光电器件、功能涂料和纺织材料等多个领域中的应用进行了展望。     

Thermal Responsive Photonic Crystal Achieved through the Control of Light Path Guided by Phase Transition

Responsive photonic crystal is widely considered in the field of anti‐counterfeiting and information encryption because of their structural color changes caused by external stimulation. However, the response signal is usually achieved by adjusting the periodic lattice constant based on Bragg's law with volume changes. Thus, it is a great challenge to achieve the response of photonic crystals by non‐array parameter control. Herein, novel thermal responsive photonic crystal (TRPC) with low angle dependent structural color is fabricated by introducing poly(ethylene glycol) into the structure of low angle dependent SnO₂ inverse opal. The response is achieved through the control of light path guided by phase transition and the significant volume change caused by the change of traditional array parameters can be effectively avoided. Meanwhile, the low angle dependent structural color of TRPC can effectively reduce the interference of observation angle change to response signal caused by external thermal stimulation. Patterned responsive photonic crystals with temperature gradient response are easily obtained by combining confinement self‐assembly and direct template method, and the patterns can be presented and hidden by the control of light path, showing great potential in anti‐counterfeiting and information encryption fields.     

Tunable structural color in organisms and photonic materials for design of bioinspired materials

In this paper, the key topics of tunable structural color in biology and material science are overviewed. Color in biology is considered for selected groups of tropical fish, octopus, squid and beetle. It is caused by nanoplates in iridophores and varies with their spacing, tilting angle and refractive index. These examples may provide valuable hints for the bioinspired design of photonic materials. 1D multilayer films and 3D colloidal crystals with tunable structural color are overviewed from the viewpoint of advanced materials. The tunability of structural color by swelling and strain is demonstrated on an example of opal composites.     

Structural Coloration with Nonclose‐Packed Array of Bidisperse Colloidal Particles

Colloidal crystals and glasses have their own photonic effects. Colloidal crystals show high reflectivity at narrowband, whereas colloidal glasses show low reflectivity at broadband. To compromise the opposite optical properties, a simple means is suggested to control the colloidal arrangement between crystal and glass by employing two different sizes of silica particles with repulsive interparticle potential. Monodisperse silica particles with repulsive potential spontaneously form crystalline structure at volume fraction far below 0.74. When two different sizes of silica particles coexist, the arrangement of silica particles is significantly influenced by two parameters: size contrast and mixing ratio. When the size contrast is small, a long‐range order is partially conserved in the entire mixing ratio, resulting in a pronounced reflectance peak and brilliant structural color. When the size contrast is large, the long‐range order is rapidly reduced along with mixing ratio. Nevertheless, a short‐range order survives, which causes low reflectivity at a broad wavelength, developing faint structural colors. These findings offer an insight into controlling the colloidal arrangements and provide a simple way to tune the optical property of colloidal arrays for structural coloration.