Nanoscopic Aggregation in Amphiphilic Random Copolymer Bulk Films Studied with Photochemical Hole Burning

Nanoscopic Aggregation in Random Copolymer Bulk Films Studied with Photochemical Hole Burning and Transmission Electron Microscopy

“…We confirmed that PHB is very useful for studying the nanoenvironments around the chromophores. The nanoscopic aggregation in bulk films of the amphiphilic random copolymers already reported by TEM 11 has been recently confirmed by PHB temperature cycle experiments . The PHB measurements for the detection of nanoscale aggregation are based on the difference in structural relaxation of comonomer units and are independent of whether any of comonomer units can be dyed for TEM observation.…”

“…The nanoscopic aggregation in bulk films of the amphiphilic random copolymers already reported by TEM 11 has been recently confirmed by PHB temperature cycle experiments. 18 The PHB measurements for the detection of nanoscale aggregation are based on the difference in structural relaxation of comonomer units and are independent of whether any of comonomer units can be dyed for TEM observation. Thus, we can say that PHB is very attractive tool for studying nanoscopic aggregation in bulk films of the random copolymers and can be applied to wide varieties of comonomer combinations.…”

Structural changes on nanometric level in copolymers of methyl methacrylate with benzyl methacrylate as investigated by low frequency Raman scattering and small angle X-ray scattering

“…In the immiscible or partially miscible homopolymer blends a phase separated structure exhibits either two glass transitions temperatures (T g ) or one broader glass transition phenomenon, reflecting their heterogeneity on the molecular level. The morphology of a system exhibiting microphase separation or nanoscale aggregates can be revealed by fluorescence microspectroscopy, scanning electron or transmission electron microscopies, atomic force microscopy, as well as by the scattering methods [5][6][7][8][9].…”

“…In the case of statistical copolymers, the random distribution of the comonomers in the main chain prevents their macro phase separation yielding the dynamics of a single glass transition. However in the case of more incompatible systems such as random copolymers with hydrophilic and hydrophobic groups, a micellar-like microphase structure is possible, in the suitable composition range [8,9]. In the random copolymer bulk films of two miscible hydrophobic comonomers such as methyl methacrylate (MMA) with butyl methacrylate (n-BMA) and MMA with benzyl methacrylate (BzMA), a nanoscopic aggregation has been first suggested by structural relaxation measurements in photochemical hole burning spectroscopy [10].…”