Semicarbazide organogels containing inorganic nanoparticles : new supramer particle hybrid systems

This thesis deals with the synthesis, characterisation, self-assembly behaviour of mono- and bis(semicarbazide) organogelators, and the mineralisation behaviour of inorganic nanoparticles in gels formed by these semicarbazide compounds. The amphiphilic structure of these semicarbazide compounds leads to the possibility of formation of hydrogen bonds to neighbouring molecules in organic liquids, which allow them to self-assemble into supramolecular structures with fibre-like architecture. Small amounts of semicarbazide gelator in an organic liquid are sufficient to cause gelation of organic solvents. These compounds have been equipped with various functionalities. Due to the functionalisation, the outer surface of the fibres is changed and, thus, the interaction between fibre and solvent is affected, which changes the gelling properties of these compounds in organic solvents. The fibre-like semicarbazide self-assemblies possess unique features, such as their thermo-reversibility. The gel systems show a clear appearance and are of impressive robustness. The fibre network percolates the whole gel body. Since these fibre networks possess a large inner surface, these systems were judged to be interesting as templates for the mineralisation of inorganic nanoparticles. The objective of the work described in this thesis is to study the mineralisation behaviour of inorganic nanoparticle material in order to investigate their possible future application in electronic devices or as catalysts. The semicarbazide fibres may serve as templates for the inorganic material since the inorganic material is expected to rearrange on or in the vicinity of the fibre material resulting in organic-inorganic composite materials. In this context, the functionalities have been introduced to the semicarbazide fibre surface to create interaction sites on the fibre for the nanoparticle material. The functionalities vary from non-polar alkyl chains of variable chain length, to double-bond terminated alkyl chains, and to alkyl chains which are terminated by polar hydroxyl or thiol groups. The observation that a structural change of the semicarbazide units considerably enhanced the gel stability in comparison to the commonly-used semicarbazide compounds made these compounds even more interesting as mineralisation templates.

Grantor dc:publisher

Publikationsserver der RWTH Aachen University

Year dc:date

2009

Author dc:creator

• Noppeney, Yvonne Maria Laurentia

Contributors dc:contributor

• Möller, Martin

• info:eu-repo/classification/ddc/540
• Gel
• Nanopartikel
• Gold
• Chemie
• Semicarbazid Organogel
• semicarbazide organogel
• nanoparticle

Statement dc:rights

• info:eu-repo/semantics/openAccess

Language dc:language

eng

Identifier

https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-113424%22

OAI record oai:identifier

https://publications.rwth-aachen.de/oai2d?verb=GetRecord&metadataPrefix=oai_dc&identifier=oai%3Apublications.rwth-aachen.de%3A51107