| A supercritical fluid extraction and expansion (SFEE) patent process was developed in this study, which combined the advantages of supercritical fluid extraction (SFE) and rapid expansion of supercritical solution (RESS) with on-line coupling. Stearic acid and alkyl ketene dimer (AKD) were used as a model sample for its microsizing via a SFEE patented technology. According to the analysis of experiment and data, optimizing the nozzle structure and evaluating uncertainty in measurement by monte carlo method (MCM) with MATLAB calculation.In the preparation of stearic acid products, pre-pressure rising from 15MPa to 35MPa:pre-temperature at 60℃, particle size falling from 1.45μm to 0.98μm; pre-temperature at 75℃, particle size falling from 1.71μm to 1.16μm. At 75℃, the stearic acid products cutting-edge became bent explain that the preparation of thermal sensitive material by SFEE is successful. The optimal conditions of preparation stearic acid products is 35MPa and 60℃. High temperature and low pressure are advantages to the experiment. In the preparation of AKD, pre-pressure rising from 15MPa to 30MPa:pre-temperature at 40℃, particle size falling from 2.28μm to 1.50μm; pre-temperature at 60℃, particle size falling from 2.2μm to 1.19μm. The superhydrophobic properties of different target surface were obtained by spraying AKD products. The optimal conditions of preparation stearic acid products is 30MPa and 60℃. High temperature and pressure are advantages to the experiment.Optimizing the SFEE nozzle with fluent software, the optimal conditions of the designed SFEE nozzle is:angle of incidence, α=125°, ring conic hole angle, β=80°, pre-pressure, P=17MPa, pre-temperature,T=373K, ring gap width, e=0.3mm.Evaluating uncertainty by MCM is using probability to produce input samples Xi, spreading by probability model f, estimating the distribution of output Y, and then obtaining an estimate of the output quantity y, the standard uncertainty u(y), ylow, and yhigh, the coverage interval. |
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