Preparation of Polymeric Membranes and Microcapsules Using an Ionic Liquid as Morphology Control Additive. Issue 1 (November 2015)

• Record Type: Journal Article
• Authors: Lakshmi, D. Shanthana; Cundari, Teresa; Furia, Emilia; Tagarelli, Antonio; Fiorani, Giulia; Carraro, Mauro; Figoli, Alberto
• Is Part Of: Macromolecular symposia. Volume 357:Issue 1(2015)
• Page Start: 159
• Page End: 167
• Publication Date: 2015-11
• Subjects: ionic liquid -- microcapsules -- morphology -- PES -- polymeric membrane; Macromolecules -- Congresses; Polymers -- Congresses; Polymerization -- Congresses; Macromolecules -- Periodicals; Polymers -- Periodicals; Polymerization -- Periodicals; 547.705
• DOI: 10.1002/masy.201400214
• Languages: English
• ISSNs: 1022-1360

Abstract

Summary: Hydrophilic porous polyethersulfone (PES) membranes and microcapsules were prepared via Non‐Solvent Induced Phase Separation (NIPS) with the ionic liquid (IL) 1‐butyl‐3‐methylimidazolium hexafluorophosphate ([BMIM][PF6 ]) as structure control agent, added to the conventionally employed PVPK17 pore former. The introduction of [BMIM][PF6 ] affects the phase inversion mechanism, resulting in different morphologies of the materials. Optimal conditions for the preparation of membranes (ILMs) were: 10–15 wt.% PES, 0–4 wt.% PVPK17, 5–25 wt.% [BMIM][PF6 ], while slightly different conditions were applied for the preparation of microcapsules (ILMCs): 10% wt.% PES, 0–4% wt.% PVPK17, and 5–15 wt.% [BMIM][PF6 ]. Thus, the produced porous spongy microcapsules (average diameter ∼800 μm) and flat sheet ionic liquid membranes (ILMs) were characterized by electronic microscopy (SEM), FTIR and Raman spectroscopy and thermal analysis. [BMIM][PF6 ] concentration is a key factor for controlling the internal membrane morphology. Indeed, higher concentrations of [BMIM][PF6 ] additive increases the viscosity of casting solution and reduces solvent exchange speed, thereby altering the membrane morphology from a channelled structures (finger‐like) to a spongy type.