报告题目：Multi-color photochromic color switching of redox dyes for use in functional optical devices
报 告 人：Andrew T. Smith
Abstract: Light as a stimulus offers great promise for the development of smart materials due to the high degree of control over the incident light. By taking advantage of the different properties of light: wavelength, intensity, time of exposure, etc, many different stimuli responsive materials can be fabricated for use as sensors, rewritable paper, encryption devices, etc. Presently light responsive materials suffer from two critical problems: (1) the kinetic response of photochromic systems are too slow to realize functional devices for practical use, and (2) most systems either exhibit a single-color changing response or rely on sacrificial chromophores to achieve multi-color functionality. In order to overcome these challenges, herein, I will discuss how combining semiconductor photocatalyst with layered 2d materials can lead to highly active photocatalyst. By coupling the semiconductor composite with color changing redox dyes, a reversible photochromic system is developed that exhibits greatly improved color switching performance and high cyclability. In addition, the development of four photochromic devices are realized by manipulating the color changing kinetics of select redox dyes. In short the four devices can be described as follows: (1) wavelength selective photochromism that take advantage of different wavelengths of light to print highly legible multicolor prints that exhibits an orthogonal design, to allow for four colors to be generated from the mixture of two chromophores; (2) intensity dependent photochromism that can show distinct color changes by differentiating between intensities of light; (3) time dependent photochromism that shows progressive color changes, that span the visible spectrum, as the system is illuminated; and (4) dual response hydro/photochromism that can exhibit different colors depending upon dark/light and dry/humid conditions.
Andrew T. Smith（美国）：2016年，在美国康涅狄格大学获化学与分子生物学学士学位；2016年至今，在美国康涅狄格大学攻读化学与分子生物学博士学位，主要从事光刺激响应材料及器件的开发与研究。发展了多种具有不同光致变色行为的器件，发表高水平SCI期刊论文10余篇。