Self‐Assembled Structures in Block Copolymer Blends: SAXS, SANS and TEM Study

Abstract

Phenomena associated with the order‐disorder transition, microdomain morphology and phase behavior of a deuterated block copolymer (BCP) blend I/II (where I is dPS‐block‐dPMMA and II is dPS‐block‐PI) were studied by SAXS, SANS and TEM. The studied, almost symmetric, copolymers differ essentially in microdomain morphology. One of them (I) is in disordered microdomain state, while the other (II) displays lamellar morphology at ordinary temperatures. Self‐assembled structures in blends were investigated as a function of concentration of the added microphase‐separated copolymer and temperature. The ODT positions were located in all the blends, the position of ODT depending only slightly on the concentration of the ordered copolymer. A systematic increase in long period D of the lamellar phase is observed with the growing content of the disordered copolymer. The evaluation of TEM shows the gradual diminishing of macrophase separated regions of disordered copolymer I with growing content of the lamellar copolymer II.magnified image

Morphology determination of defect-rich diblock copolymer films with time-of-flight grazing-incidence small-angle neutron scattering

“…For this reason, scattering techniques are commonly applied to gain such statistically relevant structural information. Small-angle X-ray and neutron scattering (SAXS and SANS) can be utilized to detect the microphase separation structure in diblock copolymer films, as long as the film thickness is sufficient to give a scattering signal larger than that from the substrate (Holoubek et al, 2007). However, the domain sizes in the case of less ordered films or near-interface structures are inaccessible because of a lack of resolution towards large-scale structures (small values of the scattering vector are shielded by the direct beamstop) and because of the low surface sensitivity.…”

Studies on the structural heterogeneities of poly(dimethylsiloxane) networks modified with poly(phenylsilsesquioxane)s using small-angle X-ray scattering and dynamical mechanical analysis

“…Small-angle X-ray scattering, SAXS, provides information about the morphology of polymeric materials [4,[21][22][23][24][25][26]. The heterogeneities in the electronic densities of the materials promoted the scattering in the incident X-rays, giving rise to characteristic patterns.…”

In situ characterization of block copolymer ordering on chemically nanopatterned surfaces by time-resolved small angle x-ray scattering

“…Attempting to understand the block copolymer annealing process, others have studied block copolymer annealing in the bulk [13][14][15][16][17][18][19] and in thin films on unpatterned [20][21][22][23][24] and topographically patterned surfaces. [25][26][27][28] The mechanisms described in these studies were based on the annihilation of defects through diffusion, which are generally slow to occur.…”