Effect of selective solvent on the aggregate behavior of the mixed Langmuir monolayers of PS-b-PEO and PS-b-PMMA

Abstract

An interesting way to control morphology evolution in the mixed LB films was performed by mainly using a selective spreading solvent. Furthermore, a peculiar hysteresis phenomenon in the polymeric Langmuir monolayers is reported.

Aggregation behavior of the blends of PS-b-PEO-b-PS and PS-b-PMMA at the air/water interface

“…3, obvious hysteresis occur in the monolayers of SEOS69K-20% and SEOS69K-80% compressed to the p max ¼ 30 mN m À1 , and the expansion isotherms cross their corresponding compression isotherms at 8.47 and 12.40 mN m À1 , and nally surface pressures remain at 1.65 and 5.35 mN m À1 , respectively. It is a little similar to the hysteresis curves of SMMA34K and the SEO19K/SMMA34K blends spread with toluene, 38 but quite different from those of neat SEOS69K (Fig. 2), amphiphilic diblock copolymers, 20,22 and polymer blends.…”

“…However, negligible hysteresis (DA 0 of 1.60 nm 2 ) for SMMA34K is observed when the p max increases to 30 mN m À1 and nally surface pressure almost returns to its p ini , which is much different from that spread with a selective solvent toluene. 38 When the p max is 10 mN m À1 , no hysteresis occur in the mixed Langmuir monolayers of SEOS69K-20% and SEOS69K-80%, and their hysteresis curves (see ESI, Fig. S7 †) are similar to those of their neat components SMMA34K and SEOS69K, respectively.…”

“…25 There are more and more work focus on the interfacial behaviors of polymer blends composed of two homopolymers, [26][27][28][29][30] a homopolymer and a block copolymer, [31][32][33] and two block copolymers. [34][35][36][37][38] Sasaki et al studied the mixed Langmuir monolayers of PMMA and poly(n-nonyl acrylate) (PNA) and received a hierarchical phase separation which was completely reversible and a true thermodynamic transition. 26 Kawaguchi et al studied the surface morphology of the mixed LB lms of poly(vinyl acetate) (PVAc) and poly(methyl acrylate) (PMA).…”

“…37 More recently, we performed an interesting way to control progressive morphology evolution in the mixed LB lms of PS-b-PEO/PS-b-PMMA by mainly using a selective spreading solvent. 38 In order to further explore the aggregation mechanisms of the mixed polymeric Langmuir monolayers and enrich the structures of their corresponding LB lms, a predominantly hydrophilic triblock copolymer PS-b-PEO-b-PS with the hydrophilic middle block PEO and hydrophobic terminal blocks PS was chosen to mix with an amphiphilic diblock copolymer PS-b-PMMA. As far as we know, no work on the LB lms of neat PS-b-PEO-b-PS and its corresponding blends was reported.…”

Dewetting behavior of Langmuir−Blodgett films of polystyrene‐b‐poly(methyl methacrylate) induced by solvent vapor annealing

“…It is well known that self‐assembly of amphiphilic BCPs at the air/water interface and morphologies of Langmuir−Blodgett (LB) films have been widely studied in recent years, in which most of the studies focus on the systems of polystyrene‐ block ‐poly(ethylene oxide) (PS‐ b ‐PEO), PS‐ b ‐PMMA and PS‐ b ‐P2VP . Morphology and structure of LB films are variable and controlled by many factors, such as the relative block length, molecular weight, solvent nature, subphase temperature, and spreading solution concentration .…”