Application of Acrylate Latex Emulsion as the Binder for Coating Aluminum Substrate by Silica-Gel Powder

摘要

The adsorbent coated exchangers are the main part of adsorption refrigeration systems. Although coated exchangers are commercially available, the coating technique and the binder used are seldom revealed and left as a challenge for researchers. Dip-coating is the most commonly used coating technique. However, the variety of binders used indicates that choosing the appropriate binder is still a matter of trial-and-error. A series of experiments were performed to introduce acrylic latex emulsion (ALE) and bitumen emulsion as the new binder for coating silica-gel powder on aluminum. The results indicate coats created by both emulsion binders are stable but the bitumen emulsion keeps its stability for about 10 min after mixing with water and silica-gel powder. The effect of ALE binder and water concentrations on water vapor equilibrium and desorption kinetics was investigated. The outcomes indicated that the sample containing 0.8 g water/g silica-gel, 0.08 g ALE binder/g silica-gel shows the fastest desorption kinetic and the minimum capacity loss. The mechanical stability of this sample was evaluated by the shear test and the pull-off test. The measured values show that the prepared laminate withstands up to 27N/cm~2 shear stress and 18N/cm~2 tensile stress.