Interfacial Polymerization at the Alkane/Ionic Liquid Interface

Abstract

Polymerization at the liquid–liquid interface has attracted much attention for synthesizing ultrathin polymer films for molecular sieving. However, it remains a major challenge to conduct this process outside the alkane–water interface since it not only suffers water‐caused side reactions but also is limited to water‐soluble monomers. Here, we report the interfacial polymerization at the alkane/ionic liquid interface (IP@AILI) where the ionic liquid acts as the universal solvent for diversified amines to synthesize task‐specific polyamide nanofilms. We propose that IP@AILI occurs when acyl chloride diffuses from the alkane into the ionic liquid instead of being triggered by the diffusion of amines as in the conventional alkane–water system, which is demonstrated by thermodynamic partitioning and kinetic monitoring. The prepared polyamide nanofilms with precisely adjustable pore sizes display unprecedented permeability and selectivity in various separation processes.

Cyclomatrix polyphosphazene organic solvent nanofiltration membranes

“…Compared to these other IP NF membranes, aluminasupported TPE-HCCP membranes reveal acceptable permeance with good rejection (above 92%) for a small dye such as MB (with a molecular weight of 319.9 Da) in acetone and ethanol. Notably, the prepared membrane has a comparable permeance and a slightly lower rejection than polyester (4) and a polyamide (5) TFC membranes [13,31].…”

“…The PAN supports were soaked in water overnight while the ceramic supports were kept dry before IP. The observed defects could be due to the [10,13,31,32,[34][35][36]38]. The legend for each membrane shows polymer type/support type (Solvent for permeance measurement, Mw of solute-solvent used to measure the rejection of solute).…”

“…To this aim, the membrane should have small and precise well-distributed pores, which often leads to a relatively low solvent flux as a consequence of the often encountered trade-off between selectivity and permeance [1]. To the best of our knowledge, limited studies, such as [10,13,[28][29][30][31][32][33][34][35][36][37][38], succeeded in developing membranes with a rejection above 90% for dyes with M w of 314 g mol − 1 to 328 g mol − 1 and acceptable ethanol permeances of more than 1 L m − 2 h − 1 bar − 1 .…”

“…6. Comparison of the prepared alumina-supported TPE-HCCP membrane performance for small solutes (314 Da < Mw < 327.3 Da) from this work with other IP NF membranes reported in open literature[10,13,31,32,[34][35][36]38]. The legend for each membrane shows polymer type/support type (Solvent for permeance measurement, Mw of solute-solvent used to measure the rejection of solute).…”

AIE-Enabled In Situ and Real-Time Visualization of Polymer Growth during Interfacial Polymerization

“…The polymerization is carried out in the recently proposed alkane−ionic liquid (IL) interfacial polymerization system, which has excellent solubility to a wide range of water-insoluble monomers, including TAPE. 35 Due to the moderate reactivity of isocyanate and the loose polymer structure, the polymerization rate is relatively slow and the resulting polymer is thick enough to be observed by CLSM. This approach enables in situ and real-time monitoring of polymer growth during interfacial polymerization (Figure 1).…”