Effect of Plasma Treatment (He/CH4) on the Glass Surface for the Reduction of Powder Flux Adhesion in the Spray Drying Process

Abstract

A 50Hz glow discharge He/CH 4 plasma was generated and applied for the glass surface modification to reduce the powder adhesion on wall of spray dryer. The hydrophobicity of the samples determined by the water droplet contact angle and adhesion weight on glass, dependent on the CH 4 flow rate and plasma exposure time. The presence of CH 3 groups and higher surface roughness of the plasma treated glass were the factors for its hydrophobicity development. Response surface methodology (RSM) results using central composite rotatable design (CCRD) showed that optimal responses were obtained by the combination of parameters, CH 4 gas flow rate = 3 sccm and exposure time = 10 min. In optimum conditions, the contact angle increased by 47% and the weight of the adhesion reduced by 38% (w/w). The plasma treatment could enhance the value of the contact angle and thus reduced the adhesion on the spray dryer glass surface.

Enhancing polytetrafluoroethylene (PTFE) coated film for food processing: Unveiling surface transformations through oxygenated plasma treatment and parameter optimization using response surface methodology

“…The water contact angles on the surfaces of borosilicate glass and stainless-steel substrates were determined using a goniometer (Rame-Hart, Inc., Model 200-00), following the procedure outlined by Sari [21] with minor adjustments. Contact angle values were averaged across five distinct points on the substrate surface (n = 5) [22,23]. All measurements were conducted at ambient temperature (29 ± 1˚C).…”

“…This process can adjust the surface free energy, impacting material properties like wettability and adhesion. The recovery mechanism of hydrophobicity is influenced by various material-and process-dependent factors, including precursor selection, substrate characteristics, treatment parameters, and the micro-environment during aging, all intertwined with enthalpy considerations [22]. In fact, liquid immersion notably accelerates hydrophobic recovery timescales in LDPE films compared to dry environments like vacuum or humid air [37].…”

Wettability effect of the surface morphologies of Musa acuminata leaves

“…The water droplet either sits on the peaks of the rough surface (heterogeneous) or wetting the grooves (homogeneous), depending on how it is formed. The water droplet that sits on the peaks has 'air pockets' along its contact with the surface and hydrophobicity is determined by the water contact angle (Ramlan et al 2018).…”