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Gel spinning of UHMWPE fibers using low molecular weight polybutene (PB) as a new spin solvent was investigated. A 98/2 wt% PB/UHMWPE gel exhibits a melting temperature around 1158C and shows large-scale phase separation upon cooling the solution to room temperature. The resulting precursor fiber from this gel was hotdrawn to a ratio of 120, yielding a fiber with tensile strength of 4 GPa and Young's modulus of over 150 GPa. Wide-angle X-ray diffraction indicates good molecular orientation along the fiber axis. The results also demonstrate the potential to further improve the mechanical properties. With respect to the gel spinning industry, this new solvent has a number of advantages over paraffin oil and decahydronaphthalene, and holds a promise of greatly improving the process efficiency. POLYM. ENG. SCI., 56:697-706,

Composite polystyrene foam with a honeycomb‐like barrier structure was processed from an expandable aqueous suspension. Optical observations confirmed the formation of such a unique structure that encapsulates each expanded polystyrene microsphere in the resulting foam. The suspension viscosity was found to highly influence the foam morphology. Results from mechanical tests showed that the existence of the barrier structure can considerably improve the mechanical performance of the composite foam. Fire retardation tests demonstrated that the barrier structure can effectively stop the fire path into the foam, suppress toxic smoke generation, and maintain structural integrity, leading to improved fire resistance in comparison with the neat polystyrene foam. POLYM. ENG. SCI., 55:1494–1503, 2015. © 2015 Society of Plastics Engineers

The coupling of CH 3 Cl CO … …over H-zeolites is an efficient reaction strategy for the transformation of methane into aromatics,w hich ensures the sustainable development of natural gas in an environmental pathway.Intheir Research Article (e202114953), Hongchao Liu, Wenliang Zhu, Zhongmin Liu, and co-workers report that high aromatics and BTX (benzene,toluene, and xylene) selectivity can be achieved with complete conversion of CH 3 Cl over HZSM-5, following anew aromatization mechanism.

Flexible strain sensors are promising candidates for intelligent wearable devices. Among previous studies, although crack-based sensors have attracted a lot of attention due to their ultrahigh sensitivity, large strain usually causes fractures in the conductive paths. Because of the unstable crack structure, the tradeoff between sensitivity and workable strain range is still a challenge. As carbon nanotubes (CNTs) and silver nanowires (AgNWs) can form a strong interface with the thermoplastic substrate and strengthen the conductive network by capillary force during water evaporation, CNTs and AgNWs were deposited on electrospun TPU fiber mats via vacuum-assisted filtration in this work. The prestretching treatment constructed a microcrack structure that endowed the sensor with the combined characteristics of a wide working range (0~171% strain), ultrahigh sensitivity (a gauge factor of 691 within 0~102% strain, ~2 × 104 within 102~135% strain, and >11 × 104 within 135~171% strain), a fast response time (~65 ms), small hysteresis, and superior durability (>2000 cycles). Subsequently, the sensing mechanism of the sensor was studied. Distributed microcrack propagation based on the “island-bridge” structure was explained in detail, and its influence on the strain-sensing behavior of the sensor was analyzed. Finally, the sensor was assembled to monitor various vibration signals and human motions, demonstrating its potential applications in the fields of electronic skin and human health monitoring.

Spin coating is one of the dominant processes for producing photoresistant thin films in integrated circuit manufacturing. The application of this process mainly focuses on flat surfaces. With the development of science and technology, the spin coating process is no longer restricted to flattened geometry. The demand for uniform thin films on curved surfaces urgently needs to be met, such as for the fabrication of anti-electromagnetic metal shielding grids on the window of fairings and grating on spherical lens. This is a challenging problem, and a fundamental mechanism is indispensable to provide guidance. However, few models have been reported about spinning a coating on curved geometry with a large central angle. To provide support for solving the problem of spin coating on a spherical surface with a large central angle, this paper presents a formulation for modeling the spin coating process on a spherical surface with a central angle close to 90 degrees and experiments that were completed to validate it. The film thickness evolution and uniformity of film thickness on a spherical surface are studied using this model and are compared with the existing literature to determine the potential advantages of the new model. Simulation results show that the uniformity of final film thickness is not ideal for uniform initial film thickness distribution. One dimensionless parameter is defined as the dominating factor to control film thickness and uniformity, which is related to the processing parameters. As demonstrated by the experimental results, this model can be adopted to predict film the thickness profile on spherical surfaces with large central angles.

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This paper describes an ultra-high pressure sensor which is in urgent need and widely used in defense industry and petroleum industry. It is designed on the combination of micro Silicon on Insulator (SOI) solid piezoresistive chip based on Micro Electro Mechanical Systems (MEMS) technique and cylindrical elastic body that could successfully convert dynamic ultra-high pressure measurement in explosion to strain measurement. Performances of the sensor including size, sensitivity, and linearity are investigated with experiment data. It's proved that the dynamic ultra-high sensor in the range of 2GPa in this paper is successful in pressure measurement in explosion. The research of ultra-high pressure sensor in this paper could not only provide a reference for the improvement of explosive property, but also lay a foundation for research of pressure sensor in the range of 10GPa of the next step.