Abstract
In this work, polydimethylsiloxane (PDMS) polymeric membranes were fabricated by incorporating fumed silica nanoparticles which were functionalized with two silane coupling agents—NH2(CH2)3Si(OC2H5)3(APTS) and NH2(CH2)2NH(CH2)3Si(OC2H5)3(TSED)—for selective removal of ethanol from aqueous solutions via pervaporation. It was demonstrated that large agglomerates were not observed indicating the uniform distribution of modified silica throughout the PDMS matrices. It is noted that the ethanol diffusivity and the water contact angles were both increased remarkably, being beneficial to the preferential permeation of ethanol through the membranes. The pervaporation results showed that the addition of the two types of modified silica nanoparticles dramatically enhanced both the permeability and selectivity of hybrid membranes. Compared to APTS, silica modified by TSED at the concentration of 4 wt. % resulted in the optimum pervaporation membranes with the maximum separation factor of 12.09 and the corresponding permeation flux of approximately 234.0 g·m−2·h−1in a binary aqueous mixture at 40°C containing 10 wt. % ethanol. The observation will benefit the choice of coupling agents to improve the compatibility between hydrophilic fillers and hydrophobic polymers in preparing mixed matrix membranes.
Highlights
With the aggravation of environmental pollution and the rising of the oil crisis, the clean energy, such as bioethanol, produced by biomass fermentation has got more and more attention [1]
It is worth mentioning that the PDMS chains can be chemically bonded to the SiO2 nanoparticles using the coupling agent TSED, and there is no difference on the morphologies between APTS-SiO2 and TSED-SiO2 filled PDMS hybrid membranes
In order to enhance the ethanol separation performance and improve the compatibility between the PDMS matrix and nano-fumed silica particles, the fumed silica was functionalized with two silane coupling agents for comparison
Summary
With the aggravation of environmental pollution and the rising of the oil crisis, the clean energy, such as bioethanol, produced by biomass fermentation has got more and more attention [1]. Pervaporation as a membrane separation process is an attractive technique in terms of energy and cost efficiency as compared with broadly utilized separation methods (such as distillation and gas stripping) [4, 5]. This process allows desirable components to preferentially permeate through a membrane impulse driven by a difference in chemical potentials. In this work, fumed silica nanoparticles after surface treatment by silane coupling agents were dispersed into PDMS matrix to fabricate hybrid membranes layered on cellulose acetate (CA) support membranes for recovering ethanol from water by pervaporation. To illustrate the influence of coupling agents on the separation performances, 3-aminopropyltriethoxysilane (NH2(CH2)3Si(OC2H5), APTS) and N-(3-triethoxysilylpropyl)ethylenediamine (NH2(CH2)2NH(CH2)3Si(OC2H5), TSED) were employed to modify the silica, and the effects of modified silica on the properties of hybrid membranes were evaluated
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
