Self-assembly of polystyrene- b -poly(2-vinylpyridine)- b -poly(ethylene oxide) triblock terpolymers

Abstract

Polystyrene-b-poly(2-vinylpyridine)-b-poly(ethylene oxide) (PS-b-P2VP-b-PEO)terpolymer is a versatile polymer to form isoporous films and membranes, due to the possibility of self-assembly control and the properties of the different blocks, such as the P2VP ability of complexation, and H-bond formation, and the PEO biocompatibility.Copolymers with different block ratios and sizes were synthesized. The correlation between their equilibrium bulk morphology, the self-assembly in dilute and semi-dilute solutions and the non-equilibrium porous structures of membranes, obtained by nonsolvent induced phase separation, was investigated and discussed in detail. The characterization was performed by small-angle X-ray scattering (SAXS), scanning (SEM)and transmission electron microscopy (TEM). Hexagonal, cubic and lamellar arrangements were observed. The preparation conditions were optimized and a regular, isoporous morphology, suitable for membrane application, was successfully obtained with PS 80.5k -b-P2VP 64.4k -b-PEO 16.1k .

Block Copolymer Membranes

“…Influence of the order in solution. The self-assembly in the casting solution of block copolymer isoporous membranes has been confirmed in detailed by small-angle x-ray scattering static [68][69][70] and time-resolved experiments, pioneered by KAUST and Cornell groups. [71] Experiments have been later conducted by different groups.…”

“…Even if in detail the interpretations might differ, the proposed relevance of the self-assembly in solution has been confirmed by all groups. [70,[72][73][74][75] By comparing a PS-b-P4VP diblock and the corresponding triblock copolymer with isoprene as the third block, it was observed that hexagonal or body centered cubic self-assembly in solution, as in Figure 5, were correlated to the same kind of pore arrangement in the membrane pore distribution. [68] Therefore not only the presence of order in solution is essential, but its kind.…”

Self-Assembly of Low-Molecular-Weight Asymmetric Linear Triblock Terpolymers: How Low Can We Go?

“…Table 1 summarizes the data on already reported linear triblock terpolymers in the literature [ 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 ], and, more specifically, block sequence, number (or weight) average molecular weight range and the annealing conditions used, together with the corresponding reference. It is straightf...…”

P (VDF‐co‐CTFE)‐g‐P2VP amphiphilic graft copolymers: Synthesis, structure, and permeation properties

“…The shoulder signals at 3.0 to 3.3 ppm in the P (VDF‐ co ‐CTFE) spectrum are assigned to the proton on vinylidene fluoride (VDF) adjacent to CTFE (‐CF 2 ‐CH 2 ‐CFCl‐CF 2 ‐). Two additional signals appeared at 6.5 and 8.4 ppm, which are attributed to the grafting of P2VP segments onto P (VDF‐ co ‐CTFE) main chains . These signals are assigned to protons in the pyridine rings of P2VP side chains.…”

“…Two multiple signals were observed at 2.2 to 2.7 and 2.7 to 3.2 ppm, corresponding to the tail-tail (-CF 2 -CH 2 - ppm, which are attributed to the grafting of P2VP segments onto P (VDF-co-CTFE) main chains. 40,41 These signals are assigned to protons in the pyridine rings of P2VP side chains. As the content of P2VP increased, these two signals became more prominent.…”