Cellulose Nanocrystals (CNCs) Nanocomposite Films for Sustained Release of CNCs and Enhanced Anti-biofouling Property

• Author / Creator

  Liu, Tong

• Cellulose nanocrystals (CNCs) are nanoparticles with high aspect ratios and excellent surface tunability and are processed from renewable bioresource. CNCs possess unique surface and colloidal properties which makes it an efficient depletion inducer for flocculating colloidal sized bacteria from its colloidal dispersion. Efforts were made to utilize this property to develop disinfecting technology suitable for biomedical applications, particularly for biofilm prevention on indwelling catheters. Fabrication of nanocomposites incorporating CNCs and other biopolymers offers a new opportunity to develop CNCs based antifouling materials with long-lasting performance, low toxicity, and minimized environmental problems. In this study, nanocomposite films incorporating natural rubber (NR) latex and CNCs were developed to achieve sustained release of CNCs from the materials and to improve the antifouling performance against bacteria. The nanocomposite films were prepared by a facile approach of casting and evaporation. The obtained nanocomposite films were characterized by various analytical techniques. The release behaviours of CNCs from the nanocomposite films was studied by fluorescein labeling techniques based on the use of 5-(4, 6-Dichlorotriazinyl) aminofluorescein (DTAF), and the release process in various aqueous mediums was modeled by modified first-order mass transport model. Materials characterizations were conducted to understand the nanoparticles (CNCs) release mechanisms: the intermolecular interactions between the CNCs and NR latex were studied by FT-IR, the morphology and microstructure were observed by scanning electron microscope (SEM); the mechanical and thermal properties of the nanocomposite films were tested by dynamic mechanical analysis (DMA).

  In the second part, the obtained NR/CNCs nanocomposite films were incorporated with silver particles to further enhance their long-term antifouling performance. NR/CNCs nanocomposite films were used as template materials for the synthesis and deposition of nano to micro-sized silver particles. A green synthesis approach based on reaction between the nanocomposite films and silver nitrate solution were employed. The impact of CNCs contents, green synthesis reaction time, on the silver particles formation were evaluated. The silver release behavior of the silver particle modified nanocomposite films were studied by a seven-day silver release test facilitated by ICP-OES. The antifouling performance of all nanocomposite films was evaluated by bacteria adhesion assays conducted under static and continuous flow settings.

• Subjects / Keywords

  • Cellulose Nanocrystals
  • Natural Rubber
  • Nano-composites
  • Organic synthesis
  • Nanoparticles Release
  • Biofilm Inhibition

• Graduation date

  Fall 2022

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-3bvk-7e09

• License

  This thesis is made available by the University of Alberta Library with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.