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Eutectogels have attracted increasing attention from researchers due to their broad application potential, good environmental stability, biocompatibility, and low cost. Currently reported eutectogels generally show large residue strain and hysteresis, which will cause output signal inconsistency between the loading and unloading processes and is not conducive to accurate strain monitoring. Besides, the low adhesiveness of available eutectogels brings about difficulties in the installation of the sensors and dynamic interfacial stability between the sensors and human skin. Herein, a dual ion regulation strategy is proposed to obtain eutectogels with high resilience, high adhesiveness, ultralow residue strain, wide temperature adaptability (−20–60 °C) and good environmental stability. Strain sensors based on gradient eutectogels exhibit high sensitivity, a wide linear response range, and good cycling stability. The response curve shows negligible electrical hysteresis, providing consistent output signals at the fixed strain regardless of stretch or release. Accurate micrometry with a step as minute as 50 µm is realized. Moreover, the sensors demonstrate higher signal intensity and stability in human physiological signals and motion detection due to the strong interfacial bonding. [ABSTRACT FROM AUTHOR]

Diethyl oxalate (DEO) is widely used in fine chemical industry. In comparison with traditional esterification process, carbon monoxide coupling process is a novel routine for DEO production. This environmentally friendly process provides better selectivity and yield. Its unique feature is that a closed regeneration-coupling circulation is formed. Toxic byproduct-nitric oxide (NO) from coupling reaction is recycled to re-produce ethyl nitrite through regeneration reaction. This avoids significant amount of NO x emission. However, due to a few NO x emission, a contaminant handling system is applied for environmental protection. A systematical environmental analysis is also carried out to assess this process. Regeneration-coupling circulation brings interaction behaviors and some trade-offs including reactor size and recycle flowrate, regeneration and coupling reaction, loss of reactants and NO emission. Thus, a rigorous steady simulation is established to investigate these trade-offs. Then DEO process is optimized to obtain the optimal design. Finally a more economic flowsheet to produce DEO is proposed. [ABSTRACT FROM AUTHOR]

Traditional safe-productive criteria for isoperibolic homogeneous semi-batch processes fail to consider the thermal stability of reacting system in case of cooling failure. In this paper, a new variable, normalized objective sensitivity S ( θ MTSR ) Φ , is defined. The variation of the dimensionless MTSR 0 and S θ MTSR τ j is studied based on multiple operational parameters. A new generalized criterion is proposed, which could predict when the course of reaction enters the QFS region and simultaneously does not enter the region where the reacting system is thermally unstable. The lowest threshold corresponds to the condition where S ( θ MTSR ) Φ exhibits a sharp maximum value, and the highest threshold corresponds to the condition where MTSR is equivalent to MAT. This new safe-productive region is defined as a modified QFS region. Comparison between this new generalized criterion and other criteria is carried out and a good agreement is found. Based on the new generalized criterion, a general optimization algorithm for determining the modified QFS region, especially the optimized dosing time and jacket temperature in this region, is developed and used with limited kinetic information. [ABSTRACT FROM AUTHOR]

Hydrogen peroxide (H 2 O 2 ) is an important raw material widely used in many fields. In this work a mathematical model of heat conduction with a moving boundary was proposed to study the melt crystallization process of hydrogen peroxide which was carried out outside a cylindrical crystallizer. Considering the effects of the temperature of the cooling fluid on the thermal conductivity of crude crystal, the model is an improvement of Guardani's research and can be solved by analytic iteration method. An experiment was designed to measure the thickness of crystal layer with time under different conditions. A series of analysis, including the effects of different refrigerant temperature on crystal growth rate, the effects of different cooling rates on crystal layer growth rate, the effects of crystallization temperature on heat transfer and the model's application scope were conducted based on the comparison between experimental results and simulation results of the model. [ABSTRACT FROM AUTHOR]

• A novel thermal behavior identification criterion for isoperibolic liquid-liquid semibatch reactors is proposed. • It is confirmed that the established boundary diagrams are considerably practicable. • The adiabatic temperature diagrams directly indicating the maximum MTSR value are introduced. • A practical procedure to determine thermally safe operating conditions is developed. To obtain thermally safe operating conditions for kinetically controlled liquid-liquid reactions occurring in isoperibolic semibatch reactors (SBRs), an extreme scenario in which the product (UA) of the overall heat transfer coefficient (U) and the area (A) is equal to its initial value, (UA) 0 , was studied and combined with the ideal scenario where the UA is proportional to the liquid volume. Under both scenarios, the jacket temperature evolution of the maximum temperature of synthesis reactions (MSTR) after cooling failure and the corresponding time (θ MTSR) for isoperibolic liquid-liquid SBRs was thoroughly investigated, and it was found that four types of thermal behaviors, namely IS (inherently safe), NI (non-ignition), TR (thermal runaway) and QFS (quick onset, fair conversion and smooth temperature condition) can be effectively identified by the variations of θ MTSR. Then, a thermal behavior identification criterion was proposed. Subsequently, a series of boundary diagrams based on the proposed criterion were developed along with the corresponding novel adiabatic temperature diagrams to directly provide information about the maximum value of MTSR in the case of cooling failure for any operating points in the boundary diagrams. Further, synthesizing the information from the boundary diagrams and the adiabatic temperature diagrams allows for convenient attainment of generalized thermally safe operating conditions with considerable practicability and sufficient thermal safety even in adiabatic situations. [ABSTRACT FROM AUTHOR]