Font Size: a A A

Self-assembly of hybrid structures on nano templates

Posted on:2008-10-02Degree:Ph.DType:Thesis
University:Wayne State UniversityCandidate:Wang, RuomiaoFull Text:PDF
GTID:2441390005955630Subject:Engineering
Abstract/Summary:
This dissertation describes the investigation on the synthesis of hybrid structures on nano-templates. Fabrication of molecular nano-patterns of organic amphiphiles (e.g. fatty acids) by self-assembly has been discussed here, and their application as templates for two-dimensional in situ synthesis of metal soap molecular pattern has been demonstrated. The synthesis of nanoparticle---nanorod hybrid structure represents another effort to achieve hybrid materials. Therefore, methods to create complex inorganic---organic nano---hybrid are provided by this work.; AFM disclosed the pattern structures of the self-assembled monolayers as designed nanoscaled patterns. It is observed two pattern periodicities reflecting the head-to-head and head-to-tail molecular assembly tendencies of the fatty acids and their dependence on the molecular structure and chain length, which exhibits a linear increase in the periodicity with an increasing molecular chain length.; The investigation on molecular patterns of self-assembled monolayers of metal arachidates on graphite by AFM and FTIR is described. Metal arachidate self-assemblies show similar stripe pattern and periodicities as those of arachidic acid. The monolayer structure is mainly dictated by graphite, while the type of metal ions mainly affects the domain size, shape and regularity. The results of AFM and FTIR are correlated to the Irving-Williams Series, which predicts bond strength of the metal ions to ligands.; The spin coated films from binary solutions of nanoparticles and fatty acids with different chain lengths (Even number of carbon, C18--C26), have been used to study the effect of nanoparticles on self-assemble pattern of fatty acids. C18--C22 acids formed uniform nanorods attached and induced by nanoparticles, while the self-assembled stripe patterns of C24 and C26 were unaffected by the presence of nanoparticles. The nanoparticles were aligned on C26 monolayer. The seeded nucleation mechanism has been studied by AFM, TEM, UV-Vis and in situ EDS and it is disclosed the confinement effect of nanoparticles and the competition between template effects from nanoparticle and from graphite. This strategy is proven to be universal, and nano-hybrids have been fabricated using different nanoparticle seeds, fatty acids, and solvents.
Keywords/Search Tags:Hybrid, Fatty acids, Structure, Molecular, Pattern, AFM
Related items