Complexation-Tailored Morphology of Asymmetric Block Copolymer Membranes

• Published in: ACS applied materials & interfaces Vol. 5; no. 15; pp. 7152 - 7159
• Main Authors: Madhavan, Poornima, Peinemann, Klaus-Viktor, Nunes, Suzana P
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 14.08.2013
• Subjects: additives; Alcohols - chemistry; Anthracenes - chemistry; atomic force microscopy; Chemistry, Organic - methods; composite polymers; Hydrogen Bonding; Light; light scattering; Membranes, Artificial; Micelles; Microscopy, Atomic Force - methods; Microscopy, Electron, Scanning - methods; nanopores; Phthalic Acids - chemistry; Polymers - chemistry; Porosity; Rheology; rutin; Rutin - chemistry; scanning electron microscopy; Scattering, Radiation; Spectrophotometry, Infrared - methods; Spectroscopy, Fourier Transform Infrared - methods; Surface Properties; membranes; self-assembly; block copolymers; hydrogen bond
• ISSN: 1944-8244; 1944-8252; 1944-8252
• DOI: 10.1021/am401497m

Hydrogen-bond formation between polystyrene-b-poly (4-vinylpyridine) (PS-b-P4VP) block copolymer (BCP) and −OH/–COOH functionalized organic molecules was used to tune morphology of asymmetric nanoporous membranes prepared by simultaneous self-assembly and nonsolvent induced phase separation. The morphologies were characterized by field emmision scanning electron microscopy (FESEM) and atomic force microscopy (AFM). Hydrogen bonds were confirmed by infrared (IR), and the results were correlated to rheology characterization. The OH-functionalized organic molecules direct the morphology into hexagonal order. COOH-functionalized molecules led to both lamellar and hexagonal structures. Micelle formation in solutions and their sizes were determined using dynamic light scattering (DLS) measurements and water fluxes of 600–3200 L/m2·h·bar were obtained. The pore size of the plain BCP membrane was smaller than with additives. The following series of additives led to pores with hexagonal order with increasing pore size: terephthalic acid (COOH-bifunctionalized) < rutin (OH-multifunctionalized) < 9-anthracenemethanol (OH-monofunctionalized) < 3,5-dihydroxybenzyl alcohol (OH-trifunctionalized).