Structural Analysis of Nano-materials using Synchrotron X-ray Scattering and Coherent X-ray Scattering Simulation

Abstract

Morphological and structural parameters of polymer self-assembly, polymer crystal, or nano-materials were examined by X-ray scattering analysis. Especially, structure of materials and polymer thin film were measured and analyzed by grazing incidence X-ray scattering (GIXS) and GIXS equations. In chapter II, a series of miktoarm star polymers, [poly(n-hexyl isocyanate)(12K)]-[poly(ε-caprolactone)1-3(5K)] (composed of a rigid, self-assembling poly(n-hexyl isocyanate) : PHIC) arm and one to three flexible crystallizable poly(ε-caprolactone) : PCL) arms, were characterized for their nanoscale thin film morphologies. The resulting thin film morphologies were examined in detail using synchrotron grazing incidence X-ray scattering (GIXS) measurements and quantitative data analysis. All of the miktoarm star polymer films formed vertically well-oriented lamellar structures. These structures were quite different from the cylindrical structures commonly observed in conventional flexible diblock copolymer films having comparable volume fractions (73 : 27). These characteristics were driven by the formation of PHIC lamellae and fringed micelle-like PCL crystals of orthorhombic lattice, which were confirmed by quantitative analysis of GIWAXS. In chapter III, well-defined hollow nanochanneled-silica nanospheres were analyzed quantitatively. At first, positively charged styrene copolymer nanospheres which were core was confirmed having very narrow size distribution using GIXS measurement and analysis. And, size of core/shell, and size distribution of core-shell material which had styrene core and surfactant/silica composite shell was measured and analyzed using GIXS. Finally, the structural information about size of core/shell and size distribution, and morphology and size of nanochannel in hollow nanochanneled-silica nanosphere which were burned organic template was investigated using GIXS measurement and analysis. In chapter IV, Poly( N -(1-hexylheptyl)- N ′-(12-oxydodecyl)perylene-3,4,9,10-tetracarboxyldiimideacrylate) (PAcPDI), a perylene diimide (PDI) containing brush polymer, was synthesized. After making thin film having 18-31 nm thinkness using the polymer, GIXS measurement and analysis were examined. As-cast films of PAcPDI are completely amorphous and the PDI units nevertheless formed π–π stacks favorably. However, the PAcPDI molecules can self-assemble via thermal annealing, developing a well-ordered horizontal lamellar structure with monomorphic or polymorphic monoclinic PDI crystals. In chapter V, simple model simulation and pattern analysis algorithm had been developed based on the coherent X-ray scattering. At first, after making 1-dimensional arrangement using carbon, nitrogen, oxygen, coherent X-ray scattering pattern was made using various combinations, and then, analysis algorithm program were developed. Second, after making 1-, 2-, and 3-dimensional arrangement using sphere, analysis algorithm program was also developed. In 1-dimensional arrangement, simulation pattern was produced using different distance and radius of each spheres. In 2-dimensional arrangement, simulation pattern was made using hexagonally arrangement having different distance and radius of each spheres. In 3-dimensional arrangement, scattering patterns were generated using simple orthorhombic which had different a, b, c length and orientation. The position, distance, radius and orientation information extracted from the simulated patterns were confirmed to be similar to or match the original values using analysis program.