Optimal fabrication of carbonate free kaolin based low cost ceramic membranes using mixture model response surface methodology

Abstract

Abstract This article aims to address the relevance of D-optimal mixture model based RSM design methodology for the optimal fabrication of carbonate free low cost ceramic membranes. The RSM design methodology was validated by targeting alterations in the composition of kaolin, feldspar and saw dust precursors during low cost ceramic membrane fabrication. Experimental findings of key dependent membrane product variables namely average pore size and porosity were regarded as biases to identify optimal kaolin, feldspar and saw dust precursor compositions. Further, a comparative study was conducted to evaluate upon the sensitivity of optimal compositions while considering flexural strength as an additional response variable. The optimal precursor compositions were 48.19 mass % kaolin, 28.62 mass % feldspar and 8.19 mass % saw dust for which optimal responses of average pore size and porosity were 1.00 ± 0.05 μm and 28.47 ± 0.29%. However, while considering flexural strength as additional response variable, the optimal compositions varied marginally (48 mass % kaolin, 27.81 mass % feldspar and 8.26 mass % saw dust) for which the optimal responses of pore size, porosity and flexural strength were evaluated as 0.93 ± 0.02 μm, 29.98 ± 1.10% and 8.75 ± 0.57 MPa. Hence, the most relevant RSM model refers to the model designed without considering flexural strength as an additional variable and with reduced model complexity.