Facile Preparation of the Porous PDMS Oil‐Absorbent for Oil/Water Separation

Abstract

Nowadays, oily wastewater and spilled oil have caused great threats on both ecosystem and human life. To address these severe problems, considerable efforts have been possessed on developing novel oil/water separation materials. The porous oil‐absorbent materials, especially the porous polydimethylsiloxane (PDMS) with excellent properties of easy fabrication and inherent hydrophobicity, have attracted tremendous attentions from worldwide. The conventional methods using salt or sugar as sacrificial template and water as solvent have been widely adopted to fabricate the porous PDMS sponge. Due to the inherent hydrophobicity of PDMS, the solvent of water hardly penetrates into the inside of PDMS, which results in the difficult and incomplete remove of the hard template. In this contribution, the 3D interconnected porous PDMS sponge is facilely prepared by utilizing a modified technique with the citric acid monohydrate as hard template and ethanol as solvent. The proposed approach is capable of removing the hard template efficiently and thoroughly, which demonstrates promising utilizations in practical applications.

Table Salt as a Template to Prepare Reusable Porous PVDF–MWCNT Foam for Separation of Immiscible Oils/Organic Solvents and Corrosive Aqueous Solutions

“…It can be seen that the adsorption capacities of the foam for the various tested oils/organic solvents are in the range of ≈300% to ≈1200%. Generally, the adsorption capacity of adsorbents was affected by the density and viscosity of oils/organic solvents . For oils/organic solvents with low viscosity, including ethanol, petroleum ether, methanol, ethyl acetate, isopropyl alcohol, chloroform, toluene, dichloromethane and acetone, the adsorption capacities were basically proportionate to their densities (Table S1, Supporting Information).…”

Lightweight, Superelastic Boron Nitride/Polydimethylsiloxane Foam as Air Dielectric Substitute for Multifunctional Capacitive Sensor Applications

“…To date, several strategies have been utilized to accomplish this purpose. For instance, microstructured or porous PDMS can be fabricated by casting onto prepatterned molds,7a,8b,9,14 using sacrificial hard templates (e.g., sugar cubes, salt crystals, citric acid monohydrate, polystyrene beads,13a and metal foams), gas foaming,13b,19 and emulsion templating . Among them, PDMS foams prepared by choosing highly porous Ni foams as templates were demonstrated to exhibit the lowest density of ≈0.1 g cm −3 (≈10 times lighter than solid PDMS) because of the relatively large pore size (few hundreds of microns) and interconnected structure of Ni foams which allow coating of diluted PDMS 18a,c,21.…”

An innovative, fast and facile soft-template approach for the fabrication of porous PDMS for oil–water separation

“…Also in this case, the large-scale production of the material was prevented by the required use of centrifuges and long procedure. To speed up the synthetic procedure more recently Yu et al 26 tried to substitute sugar particles with citric acid monohydrate (CAM) as hard template and dissolved them in ethanol. Taking advantage of the superwettability of ethanol to the porous PDMS, CAM could be easily removed from the porous PDMS in shorter time compared to previous approaches.…”