Guangxi University of Technology

About: Guangxi University of Technology is a education organization based out in Liuzhou, China. It is known for research contribution in the topics: Quantum chromodynamics & Population. The organization has 1174 authors who have published 925 publications receiving 4211 citations.

Optimization of process parameters for supercritical carbon dioxide extraction of Passiflora seed oil by response surface methodology

Abstract: Response surface methodology (RSM) was employed to optimize the process parameters of supercritical carbon dioxide extraction of the passion fruit seed oil. The effects of temperature, pressure and extraction time on the oil yield were investigated. Results showed that the data were adequately fitted into the second-order polynomial model. The linear and quadratic of independent variables, temperature, pressure and extraction time, the interactions between temperature and extraction time, pressure and extraction time had a significant effect on the oil yield. It was predicted that the optimum extraction process parameters within the experimental ranges would be the extraction temperature of 56 °C and pressure of 26 MPa and extraction time of 4 h. Under these conditions, the oil yield was 25.83%. The color of passion fruit seed oil extracted by supercritical carbon dioxide is golden orange. Its physical and chemical properties come up to the required standard for edible oil. The content of unsaturated fatty acid in passion fruit seed oil was up to 89.43% and the content of linoleic acid was over 72%.

Functionalized nanoporous TiO2 fibers on quartz crystal microbalance platform for formaldehyde sensor

Abstract: This paper describes the detection of formaldehyde through analyses of the resonance frequency signal from quartz crystal microbalance (QCM) sensors coated with a novel organic–inorganic hybrid sensing coating. Nanoporous titanium dioxide (TiO2) fibers with high Brunauer–Emmett–Teller (BET) surface area (68.72 m2/g) were fabricated by electrospinning a sol–gel titanium tetraisopropoxide (TIP)/polystyrene (PS) composite solution and following calcination process. Ethylene glycol (EG) dispersed TiO2 nanofibers were drop casted onto the electrode of QCM, followed by the functionalization of the sensing polyethyleneimine (PEI) on the fibers. The nanoporous TiO2 fibers covered with PEI layers worked as a highly sensitive sensing interface to provide output signal for weight changes during exposure to formaldehyde vapor. The developed formaldehyde-selective sensors exhibited rapid response and low detection limit (1 ppm) at room temperature. This is because the high specific surface area of the electrospun nanoporous TiO2 fibers and efficient nucleophilic addition reaction between formaldehyde molecules and primary amine groups of PEI. Our new synthetic methodology promises to be a powerful approach to fabricating hybrid organic–inorganic nanostructures on QCM for gas sensing and chemical analysis.