[{"key":"dc.contributor.author","value":"Cao, Matthew","language":null},{"key":"dc.date.accessioned","value":"2026-04-16T20:15:41Z","language":null},{"key":"dc.date.available","value":"2026-04-16T20:15:42Z","language":null},{"key":"dc.date.issued","value":"2026","language":"en"},{"key":"dc.identifier.uri","value":"http:\/\/hdl.handle.net\/2429\/94131","language":null},{"key":"dc.description.abstract","value":"Betulin is a naturally occurring pentacyclic triterpenoid abundant in birch bark and characterized by a rigid hydrophobic backbone with polar functionalities at terminal positions. These structural features make betulin a promising molecular building block for supramolecular assembly and soft material formation. Despite its abundance and well-documented biological activity, the supramolecular behaviour of betulin and its potential to form structured soft materials remain to be elucidated.\r\nThis thesis investigates betulin through two complementary studies: (1) the solvent-directed self-assembly of betulin molecules and (2) the formation of betulin-based organogels. In the first study, crude betulin extracted from birch bark was purified through two successive recrystallization steps, yielding highly ordered crystals with an overall recovery of 67.15%. The spontaneous self-assembly of betulin was then examined in a range of organic solvents at concentrations defined relative to their solubility limits. Scanning electron microscopy revealed diverse supramolecular morphologies, including spherical, flower-like, and fibrillar assemblies, demonstrating that solvent properties and saturation levels strongly influence the resulting structures.\r\nIn the second study, betulin organogels were prepared in isopropyl myristate through a heating-cooling process. Rheological analyses confirmed the formation of viscoelastic networks, with storage modulus increasing with gelator concentration. Structural characterization via polarized optical microscopy, Fourier transform infrared spectroscopy, powder X-ray diffraction, and differential scanning calorimetry indicated that gelation arises from crystalline needle-like morphologies of betulin. This work establishes betulin as a versatile supramolecular building block capable of forming solvent-directed assemblies and functional organogels, providing new insight into triterpenoid self-assembly and expanding the potential of bio-derived molecules for soft material applications.","language":"en"},{"key":"dc.language.iso","value":"eng","language":"en"},{"key":"dc.publisher","value":"University of British Columbia","language":"en"},{"key":"dc.rights","value":"Attribution-NonCommercial-NoDerivatives 4.0 International","language":"*"},{"key":"dc.rights.uri","value":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/","language":"*"},{"key":"dc.title","value":"Betulin from birch bark : molecular self-assembly, organogel formation, and functional materials","language":"en"},{"key":"dc.type","value":"Text","language":"en"},{"key":"dc.degree.name","value":"Master of Science - MSc","language":"en"},{"key":"dc.degree.discipline","value":"Forestry","language":"en"},{"key":"dc.degree.grantor","value":"University of British Columbia","language":"en"},{"key":"dc.contributor.supervisor","value":"Rojas, Orlando J.","language":null},{"key":"dc.contributor.supervisor","value":"Foster, E. Johan","language":null},{"key":"dc.date.graduation","value":"2026-05","language":"en"},{"key":"dc.type.text","value":"Thesis\/Dissertation","language":"en"},{"key":"dc.description.affiliation","value":"Forestry & Environmental Stewardship, Faculty of","language":"en"},{"key":"dc.degree.campus","value":"UBCV","language":"en"},{"key":"dc.description.scholarlevel","value":"Graduate","language":"en"}]