Membrane Emulsification Process as a Method for Obtaining Molecularly Imprinted Polymers.

Joanna Wolska,Nasim Jalilnejad Falizi

doi:10.3390/polym13162830

Abstract

The membrane emulsification process (ME) using a metallic membrane was the first stage for preparing a spherical and monodisperse thermoresponsive molecularly imprinted polymer (TSMIP). In the second step of the preparation, after the ME process, the emulsion of monomers was then polymerized. Additionally, the synthesized TSMIP was fabricated using as a functional monomer N-isopropylacrylamide, which is thermosensitive. This special type of polymer was obtained for the recognition and determination of trace bisphenol A (BPA) in aqueous media. Two types of molecularly imprinted polymers (MIPs) were synthesized using amounts of BPA of 5 wt.% (MIP-2) and 7 wt.% (MIP-1) in the reaction mixtures. Additionally, a non-imprinted polymer (NIP) was also synthesized. Polymer MIP-2 showed thermocontrolled recognition for imprinted molecules and a higher binding capacity than its corresponding non-imprinted polymer and higher than other molecularly imprinted polymer (MIP-1). The best condition for the sorption process was at a temperature of 35 °C, that is, at a temperature close to the phase transition value for poly(N-isopropylacrylamide). Under these conditions, the highest levels of BPA removal from water were achieved and the highest adsorption capacity of MIP-2 was about 0.5 mmol g−1 (about 114.1 mg g−1) and was approximately 20% higher than for MIP-1 and NIP. It was also observed that during the kinetic studies, under these temperature conditions, MIP-2 sorbed BPA faster and with greater efficiency than its non-imprinted analogue.

Highlights

Membranes are an integral part of our everyday life and are used in many areas of industry
The membrane emulsification process was used, during which a mixture of NIPAM, methyl methacrylate (MMA), EGDMA, AIBN, toluene, and bisphenol A (BPA) was passed through the metallic membrane and taken to the aqueous phase composed of 1 wt.% poly(vinyl alcohol) (MW 130 kDa) with 2 wt.% NaCl
The thermoresponsive molecularly imprinted polymer (TSMIP) was prepared by the non-covalent technique of molecular imprinting

Summary

Introduction

Membranes are an integral part of our everyday life and are used in many areas of industry (e.g., chemical, petrochemical, pharmaceutical, and food industries). New possibilities for using these materials in other areas are still being sought. One of them is a process using membranes to obtain single oil-in-water (o/w) or water-in-oil (w/o) emulsion systems as well as multiple emulsion systems, w/o/w, as well as o/w/o. This process is called membrane emulsification (ME). This technique has received increasing interest over the last 30 years as an alternative method to produce emulsions and particles and is a promising technique that allows the production of droplets of emulsion under controlled conditions with very low polydispersity [1,2]. The process requires a much lower energy input compared to traditional emulsification methods such as, e.g., rotating stirrer methods or homo-mixers [3,4]

Methods

Results

Conclusion