Fabrication and Characterization of Carbon Nanotube Filled PDMS Hybrid Membranes for Enhanced Ethanol Recovery

Abstract

Ethanol separation via the pervaporation process has shown growing application potential in solvent recovery and the bioethanol industry. In the continuous pervaporation process, polymeric membranes such as hydrophobic polydimethylsiloxane (PDMS) have been developed to enrich/ separate ethanol from dilute aqueous solutions. However, its practical application remains largely limited due to the relatively low separation efficiency, especially in selectivity. In view of this, hydrophobic carbon nanotube (CNT) filled PDMS mixed matrix membranes (MMMs) aimed at high-efficiency ethanol recovery were fabricated in this work. The filler K-MWCNTs was prepared by functionalizing MWCNT-NH 2 with epoxycontaining silane coupling agent (KH560) to improve the affinity between fillers and PDMS matrix. With K-MWCNT loading increased from 1 wt % to 10 wt %, membranes showed higher surface roughness and water contact angle was improved from 115°to 130°. The swelling degree of K-MWCNT/ PDMS MMMs (2 wt %) in water were also reduced from 10 wt % to 2.5 wt %. Pervaporation performance for K-MWCNT/PDMS MMMs under varied feed concentrations and temperatures were evaluated. The results supported that the K-MWCNT/PDMS MMMs at 2 wt % K-MWCNT loading showed the optimum separation performance (compared with pure PDMS membranes), with the separation factor improved from 9.1 to 10.4, and the permeate flux increased by 50% (40−60 °C, at 6 wt % feed ethanol concentration). This work provides a promising method for preparing a PDMS composite with both high permeate flux and selectivity, which showed great potential for bioethanol production and alcohol separation in industry.

Sandwich-Type Self-Healing Sensor with Multilevel for Motion Detection

“…Furthermore, Figure a2–3,b2–3 illustrates that CNT-KH560 exhibited reduced agglomeration compared to CNT alone (yellow dashed lines represent CNT agglomerates). This can be attributed to the presence of KH560, which weakened the surface forces between CNT particles and promoted their separation and dispersion from the main body . Additionally, the dispersion of modified CNT in methanol was found to be greatly improved (Figure S2), providing direct evidence of KH560s ability to enhance CNT dispersion.…”

“…This can be attributed to the presence of KH560, which weakened the surface forces between CNT particles and promoted their separation and dispersion from the main body. 34 Additionally, the dispersion of modified CNT in methanol was found to be greatly improved (Figure S2), providing direct evidence of KH560s ability to enhance CNT dispersion. Figure 2c1− CNT-KH560.…”

Surface-modified silicalite-1-filled PDMS membranes for pervaporation dehydration of trichloroethylene

“…Conversely, the water permeability of the MMM decreased by 20%, leading to a furfural selectivity of 42.7%. Tian et al 14 conducted a study in which they fabricated a PDMS mixed matrix membrane (MMM) incorporating hydrophobic carbon nanotubes (CNT). The K-MWCNT/ PDMS MMM exhibited superior separation performance, particularly when the CNT loading was at 2 wt%.…”