Determining the critical buckling load of locally stiffened U-shaped steel sheet pile using dynamic correlation coefficient method.

U-Shaped Steel Sheet Piles (USSSP) have buckling and bending problems during construction. In this research, the structural measure of stiffened plates applied along the longitudinal direction of USSSP is analyzed and proposed. A theoretical calculation method of stiffening effect is proposed based on the dynamic correlation coefficient method and the formula for the critical buckling load of locally stiffened USSSP is derived. A parametric analysis of the number, width, and arrangement scheme of the stiffened plates on the USSSP with different lengths is examined. The empirical formula derived for the total stiffening area and the critical load of the axial compression members of the USSSP is compared with practical results from an engineering case study. The results show a quadratic function under the condition of arranging the different number of stiffened plates at equal intervals, which is accurate in deriving the critical load values USSSP after local stiffening, and provide a theoretical basis for the optimization design of local reinforcement of USSSP axial compression members in engineering projects.

A mechanically robust hydrogel with thermally induced plasticity and a shape memory effect.

A new class of smart structural hydrogels is prepared by introducing dual cross-linkers into a single-network system. The present hydrogel, on the one hand, exhibits excellent mechanical properties; on the other hand, it exhibits thermally induced plasticity and a shape memory effect without any overlap.

Injectable self-healing hydrogels formed via thiol/disulfide exchange of thiol functionalized F127 and dithiolane modified PEG.

Injectable self-healing hydrogels have found broad applications in drug delivery, tissue engineering and controlled 3D cell culture. Recently, cyclic disulfides were found to be useful in cross-linking and stabilizing liposomes by disulfide exchange polymerization, benefiting from the enhanced reactivity of the disulfide bonds. Herein, we report an injectable self-healing hydrogel constructed from cross-linked F127 with thermo and pH dual responsivity. The rapid sol-gel transition ability at body temperature allows it to be used as an injectable hydrogel. And the increased reactivity of the disulfides of cyclic dithiolane due to the ring tension makes the hydrogel self-heal under not only alkaline conditions but also neutral or even mildly acidic conditions.

An Injectable Self-Healing Hydrogel Based on Chain-Extended PEO-PPO-PEO Multiblock Copolymer.

Injectable hydrogels have been commonly used as drug-delivery vehicles and tried in tissue engineering. Injectable self-healing hydrogels have great advantage over traditional injectable hydrogels because they can be injected as a liquid and then rapidly form bulk gels in situ at the target site under physiological conditions. This study develops an injectable thermosensitive self-healing hydrogel based on chain-extended F127 (PEO90 -PPO65 -PEO90 ) multi-block copolymer (m-F127). The rapid sol-gel transition ability under body temperature allows it to be used as injectable hydrogel and the self-healing property allows it to withstand repeated deformation and quickly recover its mechanical properties and structure through the dynamic covalent bonds. It is hoped that the novel strategy and the fascinating properties of the hydrogel as presented here will provide new opportunities with regard to the design and practical application of injectable self-healing hydrogels.

Amphiphilic star copolymer-based bimodal fluorogenic/magnetic resonance probes for concomitant bacteria detection and inhibition.

Four-arm star-shaped copolymers, TPE-star-P(DMA-co-BMA-co-Gd), containing TPE cores with an aggregation-induced emission (AIE) feature, a T 1 -type magnetic resonance (MR) contrast agent, and amphiphilic cationic arms, are synthesized. By taking advantage of non-covalent interactions between star copolymers and bacteria surfaces, bimodal fluorometric/MR detection and concomitant inhibition of both Gram-positive and Gram-negative bacteria strains in aqueous media are explored.

Use of alcohols as reducing agents for synthesis of well-defined polymers by AGET-ATRP.

Alcohols have been demonstrated to be efficient reducing agents for AGET-ATRP for the first time. Well-controlled polymerizations have been successfully achieved with the typical characteristics of "living"/controlled radical polymerization.