Surface Characterization of Polytetrafluoroethylene (PTFE) Substrate after Oxygenated Plasma Treatment towards Potential Food Processing Application

Abstract

The spray drying process causes the buildup of an unspecified and unique pattern of wall deposits on the wall. The powder recovery of fruit juice by spray dryer is associated with stickiness problems because of the nature of food which contains low molecular weight sugars and organic acids, which have a low glass transition temperature (Tg). The surface properties of oxygen plasma treated-PTFE substrate were evaluated by using the different parameters of Plasma Enhanced Chemical Vapour Deposition (PECVD) prior to spray drying analysis. In this study, the fabrication method of nearly perfect superhydrophobic surfaces through plasma treatment with oxygen gas was generated and utilized. The plasma-treated PTFE were deposited from a fixed flow rate of oxygen gas with 30 cm3/min by varying the deposition time from 1 to 15 minutes to induce the hydrophobic surface of the PTFE substrate. The characterization techniques used to determine the morphology and chemical bonding of the substrate are field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FTIR), respectively. The hydrophobicity of the glass samples was determined by the water droplet contact angle. Sample prepared at radio frequency (RF) power of 90W for 15 minutes duration of treatment time showed porous and spongy like microstructure which correlates with the best performance of a good contact angle which creates the superhydrophobicity regime (171o). Surface morphology analysis using scanning electron microscopy (SEM) showed changes in its roughness in the surface-treated glass substrate. The success of this method produced a huge potential for solving most of the food processing issues which relate to biofouling (e.g., powder stickiness) that would otherwise struggle to improve high productivity and recovery.