TY - JOUR
T1 - Sequential coating of nanopores with charged polymers
T2 - A general approach for controlling pore properties of self-assembled block copolymer membranes
AU - Baettig, Julia
AU - Oh, Junki
AU - Bang, Joona
AU - Khan, Anzar
N1 - Funding Information:
1. Introduction This fascinating area of research is further enriched by the inspiring work of Abetz and coworkers who recently estab-The world of polyelectrolyte multilayers was introduced by Decher, lished methods of preparing球?-甃?and functionalizing甃?-?rob?ust who first presented the idea of producing ultrathin polyelec-and large area membranes from assembly of polystyrene-b-trolyte films through the alternating deposition of layers of poly( 瘁vinyl pyridine) (bP-SP-瘀ᤀP)-based diblock copolymer甃?. -甃? alternately charged polyelectrolytes.?This extraordinarily simple These membranes feature a well-ordered surface reminiscent method of making thin organic films opened up an entire new of the structures found in solvent annealed block copolymer arena of scientific research, to which a large number of studies thin films,甃?-瘃?sitting atop a less-ordered typical ‘phase inversion’ have been devoted over the past 球? years. A majority of these membrane structure.瘃?In the present study, therefore, we con-reports are, however, focused on the multilayer deposition on a sider pore structure modulation of such isoporous asymmetric flat substrate.琁?There are relatively few studies on polyelectro-membranes through a layer-by-layer assembly of polyelectrolyte deposition on a curved surface.码?In ?this context, of particular lytes (Scheme 猂I. The challenge in this case, however, is the interest are concave internal surfaces of a porous material.猃?-猃?small pore sizes (sub-? 爀 nm) of the isoporous materials. On a Polyelectrolyte coating on such surfaces will allow for modulating fundamental level, therefore, this research goal represents an the properties of the porous structure. Bruening and cowork-opportunity to fathom whether layer-by-layer assembly process ers have elegantly demonstrated this concept with the help of is still feasible in such a confined geometric space.瘃?Furthermore, microporous alumina membranes.猃?In terms of polymeric materi-from an applications perspective, if layer-by-layer assembly can als, track etched polymer membranes of large pore sizes have indeed be carried out within such small spaces then the nanopore been studied.猃?-球?Track etched membranes, however, suffer from size and chemistry can be systematically alerted in a general alow density and a dis-ordered nature of the pores. These defi-and modular fashion.瘃?This will allow for fabrication ofnanoporous ciencies are remedied through self-assembly of diblock copoly-all-polymer membranes with high performance in the areas of mers that afford highly ordered and dense porous structures.球?-球?separation, filtration, and catalysis.瘃?-眃?To achieve the afore-mentioned goal, we decided to utilize the hydrogen bond accept-Acknowledgments: This work was by National ResearchFoundation ing capability of the pyridine moieties of the P ? ? P copolymer of Korea grant funded by the Korea government (MSIP) (NRF-球爃猃-眀Rsegment.眃?-眃?For this, poly(acrylic acid) (PAA) was chosen as 猀D 猀A 猀A 爃猃? 眃礃礃笃砀 and 球? 猃眀R 猀A 琀GloAb 琀alAF r爃on猃tie爃r 爃砃th爃e 爃hy稂drI oagnedn bond donor. At neutral or slightly basic conditions, R&D Program (No. 球爃猃甀M 甀A 砀B 猃?礃稃稃砃笂I. thispolymeroffersamajorityofanionic(carboxylate)andaminority of neutral (carboxylic acid) moieties.眃?The neutral sites allow
Publisher Copyright:
© 2017, The Polymer Society of Korea and Springer Science+Business Media B.V.
PY - 2017/11/1
Y1 - 2017/11/1
N2 - A general approach is developed for controlling the pore size and pore chemistry of integral isoporous membranes derived from the assembly of polystyrene-b-poly-4-vinyl pyridine (PS-b-P4VP) diblock copolymer. In this approach, initially, the sub-50 nm pore surface, decorated with poly-4-vinyl pyridine (P4VP) polymer brush, is coated with polyacrylic acid (PAA). PAA offers a majority of anionic and a minority of neutral acid functionalities. The neutral acid groups adhere to the P4VP segments of the pore wall through hydrogen bonding interactions and the anionic sites remain free. The availability of the anionic sites sets the stage for a layer-by-layer deposition of cationic and anionic polymers, in a sequential manner, on the pore-wall surface through a continuous flow of a dilute polyelectrolyte solution through the nanoporous membrane. In this way, multiple layers, stabilized through electrostatic interactions, can be deposited leading to a continuous decrease in the pore size and a known surface charge. Due to the known facile nature of the large area isoporous asymmetric membrane formation and modular nature of the polyelectrolyte assembly, the present approach is anticipated to yield new block copolymer membranes with tailored separation, sensing, and catalytic properties.
AB - A general approach is developed for controlling the pore size and pore chemistry of integral isoporous membranes derived from the assembly of polystyrene-b-poly-4-vinyl pyridine (PS-b-P4VP) diblock copolymer. In this approach, initially, the sub-50 nm pore surface, decorated with poly-4-vinyl pyridine (P4VP) polymer brush, is coated with polyacrylic acid (PAA). PAA offers a majority of anionic and a minority of neutral acid functionalities. The neutral acid groups adhere to the P4VP segments of the pore wall through hydrogen bonding interactions and the anionic sites remain free. The availability of the anionic sites sets the stage for a layer-by-layer deposition of cationic and anionic polymers, in a sequential manner, on the pore-wall surface through a continuous flow of a dilute polyelectrolyte solution through the nanoporous membrane. In this way, multiple layers, stabilized through electrostatic interactions, can be deposited leading to a continuous decrease in the pore size and a known surface charge. Due to the known facile nature of the large area isoporous asymmetric membrane formation and modular nature of the polyelectrolyte assembly, the present approach is anticipated to yield new block copolymer membranes with tailored separation, sensing, and catalytic properties.
KW - block copolymer assembly
KW - deposition in nanopores
KW - integral asymmetric membranes
KW - layer-by-layer assembly of polyelectrolytes
KW - nanopore chemistry
KW - nanopore size
KW - nanoporous membranes
UR - http://www.scopus.com/inward/record.url?scp=85028975108&partnerID=8YFLogxK
U2 - 10.1007/s13233-017-5142-5
DO - 10.1007/s13233-017-5142-5
M3 - Article
AN - SCOPUS:85028975108
SN - 1598-5032
VL - 25
SP - 1091
EP - 1099
JO - Macromolecular Research
JF - Macromolecular Research
IS - 11
ER -