Asymmetric porous membranes from binary polymer solution by physical gelation induced phase separation

High-performance light diffuser films by hierarchical buckling-based surface texturing combined with internal pores generated from physical gelation induced phase separation of binary polymer solution

“…The observed physical gelation induced phase separation mechanism is different from other well-known mechanisms of polymer phase separation such as thermally-induced phase separation (TIPS) or nonsolvent-induced phase separation (NIPS). The drying rate depends upon the content of solvent in the solution as shown in our previous work [19]. Accordingly, the pore size and its number density formed by physical gelation induced phase separation should depend on the solution concentration.…”

“…For the generation of pores in polymer film, a binary polymer solution is simply dried in contact with elastomer, polydimethylsiloxane (PDMS) in this work. The PDMS-assisted fast drying of polymer solution generates microscale pores inside the polymer due to physical gelation induced phase separation, as demonstrated in our recent work [19].…”

“…The generation of internal pores has been achieved by similar way to previous works [18,19]. Briefly, a known concentration of PMMA/toluene solution was dispensed onto substrate such as Si or cured slab of PDMS.…”

“…The PDMS-assisted fast drying of polymer solution has led to the formation of internal pores by physical gelation induced phase separation [19]. A rapid absorption of solvent into the elastomer in PDMS-assisted fast drying of polymer solution leads to the formation of glassy skin at the top surface.…”

“…For the volume diffusing effect, we introduce air pockets (or, pores) inside a polymer film [18,19]. Due to large difference in refractive index between air (n ¼ 1) and polymer (n ¼ 1.49 for PMMA in this work), the inclusion of pores can play the role of micro/nano particles in scattering the incident light.…”