Impregnation of viscose substrate with nicotinamide in supercritical carbon dioxide

Abstract

An investigation of green and sustainable impregnation of viscose substrate was performed for the first time by employing nicotinamide as a drug model for manufacturing drug-loaded cosmetic textiles in supercritical carbon dioxide fluid. The effects of impregnation time, operating temperature, pressure, and cosolvent on the drug loading capacity (DLC) of nicotinamide into viscose fabric were explored. The results show that the DLC increased gradually with impregnation time up to an equilibrium value at 60 min. The DLC significantly increased with temperature from 40 to 80℃ at a system pressure higher than 12 MPa, accompanied by a decrease at a higher temperature. However, a smaller effect of the system temperature on the DLC was also observed at a system pressure lower than 12 MPa. DLC was much higher at 40℃ when the operating pressure was 10 or 12 MPa. Different improvements for the DLC were also achieved with different system pressures at various system temperatures, especially at operating pressures higher than 12 MPa. While DLC initially increased with pressure, it decreased afterwards when the operating temperature was 40℃. Moreover, the results from different cosolvents show that the DLC was evidently enhanced with the dosage of acetone as well as methanol in supercritical carbon dioxide fluid, whereas an overall tendency to decrease was also encountered for the utilization of ethanol. Furthermore, impregnation was characterized and validated by scanning electron microscopy, Fourier transform infrared, X-ray diffraction and elemental analysis.