Novel applications of surface-modified sporopollenin exine capsules

Huang, Youkui

Abstract

The external shell (exine) of plant spores and pollen grains is composed of sporopollenin, which is an organic polymer renowned for its exceptional resistance to physical and chemical attack. The resilience of sporopollenin to high temperature, pressures, acidic and basic corrosion is proved by its survival in some sedimentary rocks, which are 500 million years old.

Solid phase organic synthesis is a process where molecules or reagents are used whilst attached to an insoluble and filterable solid support. Sporopollenin could have a series of advantages over commercial resins if it can be applied to solid phase synthesis as it has a constant chemical structure, constant pore size, and in particular chemical and physical stability.

In this study sporopollenin was first extracted from fresh pollen and spores, and then modified to make a basic form by attachment of alkyldiamines, and an acidic form by treatment with chlorosulfonic or sulfuric acid. Detailed studies were undertaken regarding the use of the base form of sporopollenin in Schotten-Baumann type acylations and Knoevenagel condensations, and the acidic form of sporopollenin in the isopropylidene protection of mannose and preparation of cyclic acetal. As a result, aminated sporopollenin particles were shown to be effective scavengers in Schotten-Baumann acylation and they catalyse Knoevenagel condensation successfully.The sulfonated sporopollenin particles also reveal their ability in catalysing relative reactions.

Raw spores and simply extracted sporopollenin has been investigated for the stabilization of Pickering emulsion by Binks et al. In this work, sporopollenin was aminated and their behaviour as emulsifiers has been studied. The amino groups on the surface of sporopollenin will change the hydrophilicity of the particles and affect their behaviour in the emulsions.

Citation

Huang, Y. (2013). Novel applications of surface-modified sporopollenin exine capsules. (Thesis). University of Hull. Retrieved from https://hull-repository.worktribe.com/output/4215614

• Thesis Type: Thesis
• Deposit Date: Apr 29, 2014
• Publicly Available Date: Feb 23, 2023
• Keywords: Chemistry
• Public URL: https://hull-repository.worktribe.com/output/4215614
• Additional Information: Department of Chemistry, The University of Hull
• Award Date: Dec 1, 2013