Microencapsulation of n-tetradecane with poly (methyl methacrylate-co-methacrylic acid) shell by seeded emulsion polymerisation and its thermal energy storage characteristics.

This study aims to enhance the latent heat storage properties of the microcapsules by altering the amount of crosslinking agent from 3 to 20%w/w, the core-to-shell ratio from 1:1 to 2:1, and the amount of initiator from 1 to 3%. The phase change material n-tetradecane (C-14) was microencapsulated by using poly (methyl methacrylate -co- methacrylic acid) as a shell material through an oil by water-seeded emulsion polymerisation technique. The structural, morphological, and thermal properties of microcapsules were evaluated by using Fourier transform infrared spectroscopy, optical microscopy, scanning electron microscopy, differential scanning calorimetry analysis, and thermogravimetric analysis. The average particle size of the microcapsules ranges from 01 to 15 µm. The results showed that the microcapsules have a higher melting enthalpy value of 127.3 ± 0.06 J/g with a microencapsulation efficiency of 66.72% when a 20% w/w crosslinker was used. The thermal stability of the phase change material (PCM) was increased by ∼30 ± 2 °C by encapsulation.

Enhancement of antroquinonol production during batch fermentation using pH control coupled with an oxygen vector.

BACKGROUND: Antroquinonol, a ubiquinone derivative that shows anticancer and anti-inflammatory activities, is produced during solid-state fermentation of Antrodia camphorata; however, it cannot be biosynthesized via conventional submerged fermentation. RESULTS: A method for enhancing the biosynthesis of antroquinonol by controlling pH and adding an oxygen vector in a 7 L bioreactor was studied. In shake-flask experiments, a maximum antroquinonol production of 31.39 ± 0.78 mg L-1 was obtained by fermentation with adding 0.2 g L-1 coenzyme Q0 (CoQ0 ), at the 96th hour. Following kinetic analysis of the fermentation process, pH control strategies were investigated. A maximum antroquinonol production of 86.47 ± 3.65 mg L-1 was achieved when the pH was maintained at 5.0, which exhibited an increase of 348.03% higher than the batch without pH regulation (19.30 ± 0.88 mg L-1 ). The conversion rate of CoQ0 improved from 1.51% to 20.20%. Further research revealed that the addition of n-tetradecane could increase the production of antroquinonol to 115.62 ± 4.87 mg L-1 by increasing the dissolved oxygen in the fermentation broth. CONCLUSION: The results demonstrated that pH played an important role in antroquinonol synthesis in the presence of the effective precursor CoQ0 . It was a very effective strategy to increase the yield of antroquinonol by controlling pH and adding oxygen vector. © 2018 Society of Chemical Industry.