Surface composition control via chain end segregation in polyethersulfone solution cast films

Surface and interfacial segregation of polyethersulfone deuterated chain ends determined by neutron reflectivity

“…Functional OH chain ends of commercial PESU ( 6 ) were reacted with deuterated TNCO ( 5 ) and bSO 2 Cl ( 8 ) as shown in Schemes and , respectively. Prior to reaction, commercial PESU was fractionated into systems of controlled molecular weight and narrowed distribution via a fractional precipitation method outlined in a previous publication . The molecular weight, distribution, and polymer dimensions of the PESU fractions used in this study are summarized in Table .…”

“…We previously reported the preferential surface segregation of phenol and fluorescein isothiocyanate functionalized chain ends in solution cast PESU films, demonstrating a concentration gradient scaling with the radius of gyration ( R g ) using XPS coupled with ion beam etching . The measured length scale of the CE‐enriched surface layer is one R g, smaller than the 2 R g predicted by de Gennes for flexible polymer systems, attributed to the limited mobility of the rigid rod polymer chains .…”

Enhanced Surface Properties of Branched Poly(ether sulfone) from Semifluorinated Polyhedral Oligomeric Silsequioxanes

“…1 3 J FF = 12.0 Hz), −116.0 (d, 16F, 3 J FF = 10.9 Hz), −129.7 (s, 16F), −157.2 − (−157.3) (m, 8F). 29 Si (CDCl 3 , 99 MHz): δ 13.6, −108.2.…”

“…Commercial PESU was fractioned into systems of narrowed molecular weight distribution via a fractional precipitation method outlined in a previous publication. 29 A 50 mL RBF, equipped with a magnetic stir bar, was charged with DMF (10 mL), Cs 2 CO 3 (50 mg) and fractionated PESU (1 g) and stirred under N 2 until fully dissolved. Separately, PFCP−POSS (2) was dissolved in 5 mL of DMF under N 2 .…”

“…Solution cast films of PESU and FP-PESU were prepared from DMF solutions with 5 wt % polymer following a procedure outlined in a previous publication. 29 Thin FP-PESU films (100−200 nm) were prepared for neutron reflectivity by spin coating from DMF/dichlorobenzene solutions onto silicon wafers. Prior to spin coating, the silicon substrates were cleaned by an ozone plasma for 20 min, and were then boiled for 1.5 h at 90 °C in a bath of concentrated H 2 SO 4 / H 2 O 2 (70/30 v/v).…”