Interfacial AIE for Orthogonal Integration of Holographic and Fluorescent Dual-Thermosensitive Images.

Orthogonal integration of thermosensitive images is of vital significance for advanced anticounterfeiting, which however remains formidably challenging due to the trade-off that facile thermoresponse needs easy molecular motion while robust imaging requires molecular restriction. Herein, a viable approach is demonstrated to tackle the challenge by in situ fixing a predesigned aggregation induced emission luminogen (AIEgen) at the polymer/liquid crystal (LC) interface via precisely controlled interfacial engineering, in which the AIEgen is enriched in LC phases during polymerization induced phase separation and subsequently driven to the interface by the interfacial thiol-ene click reaction. Crosstalk-free integration of holographic and fluorescent dual-thermosensitive images with high sensitivity, high contrast ratio, and robust performance is successfully realized in a single unit, attributed to the simultaneously LC-facilitated AIEgen molecular motion and polymer-restricted AIEgen diffusion at the interface. The exciting characteristics of these orthogonally integrated dual images will enable them to prevent illegal replication and thus are expected to be promising for high-security-level anticounterfeiting applications.

Hypercrosslinking porous polymer layers on TiO2-graphene photocatalyst: Enhanced adsorption of water pollutants for efficient degradation.

Solar-driven photocatalysis offers an environmentally friendly and sustainable approach for the degradation of organic pollutants in water without chemical additives, but the low specific surface area and adsorption capacity of common photocatalysts restricts the surface reactions with the contaminants. Herein, we hypercrosslinked polymer layers on TiO2-graphene surface to enlarge the specific surface area from 136 to 988 m2/g, leading to a high adsorption capacity of sulfadiazine as 54.3 mg/g, which is 15.5 times that of TiO2-graphene (3.5 mg/g). The adsorption kinetics reveals the combination of physical and chemical adsorption by porous benzene-based polymer for sulfadiazine enrichment. Besides, the polymer layers with broad light absorption enable the composite to function efficiently as visible-light-driven photocatalysts. Thus, the as-designed composite exhibits excellent performance for sulfadiazine removal by integrating the adsorptive and photocatalytic processes, especially for the diluted sulfadiazine solution. More importantly, the porous polymer layer can function as a filter for weakening the interference of TiO2 surface with the natural matters from complex water matrices. Based on the identification of dominant reactive species, the possible attacking pathway and the sulfadiazine subsequent degradation are presented. Further, the enhanced adsorption and photodegradation efficiency can also be achieved for the removal of other typical pollutants such as 4-chlorophenol and methylene blue. This study highlights an adsorption-enhanced-degradation mechanism for water pollutants that can direct the design of high-performance photocatalysts under visible light.

High-optical-quality blends of anionic polymethine salts and polycarbonate with enhanced third-order non-linearities for silicon-organic hybrid devices.

A series of anionic polymethine dyes with different aromatic counterions are prepared to improve their compatibility as guests in an amorphous polycarbonate host. When they are used as the cladding material for silicon hybrid slot waveguides, four-wave mixing wavelength conversion and two-photon absorption-based optical-power modulation are observed. Such guest-host materials may be attractive candidates for all-optical signal-processing applications.

A new approach to fluorescence "turn-on" sensing of alpha-amino acids.

For the first time, a conjugated fluorescent polymer was utilized to probe alpha-amino acids, sensitively and selectively, through a new approach. First the strong fluorescence of the prepared polyfluorene (P1) was quenched by trace copper ions, and then the quenched fluorescence was recovered upon the addition of alpha-amino acids, making P1 a new and sensitive biosensor toward alpha-amino acids. The experimental results demonstrated that the alpha-amino acid selective nature of P1 over other analytes was relatively good. Thus, the work reported here might open up a new avenue for developing new biosensors.

"H"-shape second order NLO polymers: synthesis and characterization.

In this work, two "H"-shape and one "AB"-type second order nonlinear optical (NLO) polymers were prepared for the first time. The linkage positions of chromophores in the "H"-shape polymers were shoulder-to-shoulder, in which the chromophore moieties were part of the polymeric backbone. The subtle structure could be easily modified by the introduction of different isolation groups, to adjust the property of the resultant polymers. All the polymers exhibited good film-forming ability and thermal stability. The second harmonic generation (SHG) experiments demonstrated that the two "H"-shape polymers (P1 and P2) exhibited large SHG coefficients of d(33) values (up to 90 pm V(-1)), and P2 even demonstrated relatively good long-term temporal stability.