High-Security Plastic with Integrated Holographic and Phosphorescent Images.

Organic room temperature phosphorescence (ORTP) polymer materials have sparked considerable research interests in recent years, but their optical function is still limited for multi-mode optical imaging. Herein, a feasible and universal approach is proposed to endow ORTP polymer materials with periodic refractive index modulation functions by holographic patterning. The key to this approach is to design a two-stage stepwise crosslinking.

Supramolecular H-Aggregates of Squaraines with Enhanced Type I Photosensitization for Combined Photodynamic and Photothermal Therapy.

Combined photodynamic and photothermal therapy (PDT and PTT) can achieve more superior therapeutic effects than the sole mode by maximizing the photon utilization, but there remains a significant challenge in the development of related single-molecule photosensitizers (PSs), particularly those with type I photosensitization. In this study, self-assembly of squaraine dyes (SQs) is shown to be a promising strategy for designing PSs for combined type I PDT and PTT, and a supramolecular PS (TPE-SQ7) has been successfully developed through subtle molecular design of an indolenine SQ, which can self-assemble into highly ordered H-aggregates in aqueous solution as well as nanoparticles (NPs). In contrast to the typical quenching effect of H-aggregates on reactive oxygen species (ROS) generation, our results encouragingly manifest that H-aggregates can enhance type I ROS (OH) generation by facilitating the intersystem crossing process while maintaining a high PTT performance.

Research on Cement Slurry Using Silica Fume Instead of Fly Ash.

Ordinary cement is not environmentally friendly, has high cost and lacks superior performance. Many scholars use various admixtures to adjust the properties of cement slurry, but admixtures are usually not environmentally friendly, and it is difficult to ensure that the properties after deployment meet engineering requirements. In this study, a variety of admixtures were obtained using the environmental protection method, and the optimal mixing ratio was analyzed by combining the entropy weight method and the Taguchi grey relational analysis method.

Deep-Red Emissive Squaraine-AIEgen in Elastomer Enabling High Contrast and Fast Thermoresponse for Anti-Counterfeiting and Temperature Sensing.

Two challenges remain for organic thermoresponsive materials; one is to develop high-performance red-emissive thermoresponsive materials, while another is to simultaneously achieve high contrast ratio (CR), fast and reversible thermoresponse in a single element. Herein, we not only develop a new deep-red emissive squaraine-based AIEgen (TPE-SQ12) based on a pyrylium end group, which is suitable for fabricating high-performance thermoresponsive materials, but also show an effective approach to improve both CR (∼ten times increase) and response time (less than 3 seconds), that is, molecularly dispersing AIEgen into an elastomer, attributed to the significantly expanded free volume of elastomer upon increasing the temperature that can activate the AIEgen intramolecular movements more pronouncedly. Double encryption and temperature mapping systems have been separately established by using our designed elastomer/TPE-SQ12 film, showing the great potential for anti-counterfeiting and temperature sensing.

Multi-Response Optimization of Ultrafine Cement-Based Slurry Using the Taguchi-Grey Relational Analysis Method.

The grouting technique is an important method in underground engineering that prevents water seepage and reinforces fractured rock mass. In this research, ultrafine cement-based grouting material, including ultrafine cement (UC), ultrafine fly ash (UFA), polycarboxylate superplasticizer (SP), colloidal nanosilica (CNS), sodium sulfate solution (SS) and water, was developed. The flow time, viscosity, bleeding, setting time and uniaxial compressive strength of the UC-based slurry were measured by orthogonal experiments, and the optimal mix proportion of the UC-based slurry was obtained based on the Taguchi-Grey relational analysis method.

Experimental study on seepage characteristics of microfracture with different aperture.

Exploring the flow mechanism of fluid in rock mass is important in solving the water inrush problems during tunnel excavation. However, it is difficult to obtain an undisturbed rock mass from the actual site conditions and study the flow mechanism of fluid through a fracture network composed of multiple single fractures. Therefore, a solution to simulate rock seepage using rock-like samples with single microfracture was presented in this paper.

Evidence for Aggregation-Induced Emission from Free Rotation Restriction of Double Bond at Excited State.

This paper reports that cis-TPE dicycles emit strong fluorescence, while the gem dicycles show almost no emission in solution, demonstrating that the free rotation restriction of the double bond at the excited state is the key factor for AIE effects.