Optimization of the PDMS/biochar nanocomposite membranes using the response surface methodology

To improve the separation performance of the polydimethylsiloxane (PDMS)/bark biochar (BB) nano-composite membranes used for alcohol/water separation, the preparation conditions of these composite membranes were analyzed and optimized. In this study, we investigated the following preparation parameters: the BB pyrolysis temperature, the weight ratio of the silane coupling agent (KH-550) to bark biochar (BB), and the BB loading amount. The regression equations were established between these three preparation parameters and the final pervaporation (PV) performance characteristics of the composite membranes. The membranes performed the best under the following optimal preparation conditions: a BB pyrolysis temperature of 407 degrees C; a silane coupling reagent/BB weight ratio of 0.86, and a BB loading amount of 3.36 wt%. According to the results of the regression analysis, a maximum permeation flux of 221.2 g.m(-2).h(-1) and a maximum selective factor of 21.3 was obtained when the feed temperature for the 5 wt% alcohol solution was set at 40 degrees C.