Hole structure and its formation in thin films of hydrolyzed poly(styrene maleic anhydride) alternating copolymers

Abstract

Maleic anhydride moieties on the backbone chains of poly(styrene maleic anhydride) alternating copolymer (SMA) hydrolyzed in a THF solution containing water and hydrochloric acid. Well-arrayed holes were obtained in spin-cast thin hydrolyzed SMA films on a single crystal silicon wafer, and the hole diameter and its distribution were measured with AFM data. Results showed that the hole size was almost uniform, and was influenced by water content when spin speed was kept unchanged. The THF solution with a SMA concentration of about 1 g/mL and weight ratio H 2 O/SMA of 1/3 produced holes having an average diameter of 0.60 m and depth of 206.12 nm, when cast at a spin speed of 1400 rpm. It was noted that the formation of the holes in thin hydrolyzed SMA film was different from the dewetting process in thin homopolymer films, but was associated with the intrinsic properties of the copolymer forming the films. The surfactant effect of hydrolyzed SMA was suggested to interpret the formation of the holes. The holes were described to be the traces of water droplets that were emulsified by the hydrolyzed SMA during casting.

Fabrication of Eco-Friendly Hydrolyzed Ethylene–Maleic Anhydride Copolymer–Avermectin Nanoemulsion with High Stability, Adhesion Property, pH, and Temperature-Responsive Releasing Behaviors

“…According to the literature [ 61 , 62 ], EMA (0.5 g, 4 mmol of acidic anhydride unit) was dissolved in anhydrous THF (10 g), heated, and stirred for 30 min in a three-necked reflux flask. After that, an appropriate amount of deionized water, NaOH (0.35 g, 8.7 mmol) as a reactant or hydrochloric acid (1 g) as a catalyst was added, refluxing at 80 °C for 1 h to obtain an orange–yellow sample solution (20 g).…”

Studies of Novel Copolymers for Deep-UV Photoresists. I. Synthesis and Properties of Poly(Styrene-co-Silicon-containing maleimide)

“…[10][11][12][13] This was mainly due to the electron-withdrawing effect of silane side chains to inhibit the carbonyl pairs withdrawing electron effect of double bond within maleimide. Besides, the polarity of styrenes was also affected by their deactivators.…”

“…The copolymerization behavior of truly alternating styrene-maleic anhydride copolymer has already been reported by many researches. [10][11][12][13] But, the silicon-containing AM systems are still rarely seen in literature.…”