Polylactide (PLA) and its copolymers are a type of hydrophobic aliphatic polyester based on hydroxyalkanoic acids. They possess exceptional qualities: biocompatibility; FDA approval for clinical use; biodegradability by enzyme and hydrolysis under physiological conditions; low immunogenicity; and good mechanical properties. These critical properties have facilitated their value as sutures, implants for bone fixation, drug delivery vehicles, and tissue engineering scaffolds in pharmaceutical and biomedical applications.

Scope:

1. Synthesis of well-controlled PLA-based amphiphilic block copolymers. The copolymers may contain poly(ethylene glycol), polypeptides, polysaccharides or polyurethanes as the hydrophilic components.

2. Self-assembly of PLA-containing nanoparticles.

3. Study of morphology and properties.

4. If have time, explore their bio-related applications including drug delivery and imaging.

A study on the effectiveness of UV stabilizer for UV curable resin

It is known that polymer will degrade, turn yellowish and brittle faster when used in outdoor applications such as in signboard, shelter housing, etc. due to the attack of UV light from the sun.  The free radicals formed will cause polymer chains to breakdown.  To prolong the life span of polymers for such applications, UV stabilizers are normally added into the polymers as free radical scavengers.  On the other hand, in a typical UV curable resin, photo initiator at concentration ranging from 1% to 4% is added in to generate free radicals for resin curing to take place. A typical UV curing process takes less than 5 sec whereby free radicals formed during this time works to polymerise the oligomers and monomers instantly.  In this study, the effectiveness of UV stabilizers on UV curable resin system will be evaluated.  UV curable resins with different photo-initiator concentration and UV explosure time will be considered in this study.   

POSS-based block copolymers for controlled release and delivery of active ingredients

It is a formidable challenge to develop well-controlled release and delivery systems for consumer cares, which can improve the efficacy and reduce cost and environmental pollution significantly. Smart and bio-related functional materials are good candidates for preparation of well-controlled delivery systems. Polyhedral Oligomeric Silsesquioxane (POSS) has attracted considerable interest in materials science due to its well-defined nano-scale organic–inorganic structure, which makes it an ideal building block for constructing nano-structured hybrid materials. POSS has been reported to enhance the biocompatibility of nanocomposites when used as tissue implants. It is a super hydrophobic component that allows for the entrapment of drugs by hydrophobic interactions. In this project, the well-controlled release and delivery systems will be prepared by self-assemblies of amphiphillic POSS based block copolymer. The systems can be applied for controlled release and delivery of silicon oil, and nutrients for different consumer cares such as hair care, skin care and dish washing products.

Magnetic Liquid Marbles and Metal-Organic Framework nanoparticles

Synthesis of MOF nanoparticles with magnetic properties and subsequent hydrophobization via post-synthetic modification. These nanoparticles will then be used to prepare liquid marbles to make MOF shells.

Fabrication and characterization of nanoporous hybrid mats

Nanoporous organic-inorganic hybrid mats will be prepared using an electrospinning-assisted process. The focus of the project is to manipulate the morphology of the mats by adjusting processing conditions. The structures and properties of the hybrid mats will also be characterized to explore their potential applications.

Synthesis of layered double hydroxides (LDH) and LDH-based hybrids

LDH is an unusual class of layered materials with positively charged layers and charge balancing anions located in the interlayer region. LDHs are commonly represented by the formula [Mz+1-xM3+x (OH)2]q+(Xn-)q/n·yH2O. Most commonly, M2+ = Ca2+, Mg2+, Mn2+, Fe2+, Co2+, Ni2+, Cu2+ or Zn2+. In this project, LDH with different dimensions and formula will be synthesized for preparation of polymer nanocomposites and hybrid materials.

Polyurethane/dopamine-modified LDH nanocomposites as shape memory materials

LDH of different dimensions will be synthesized and surface-modified with dopamine, a compound that mimics mussel adhesive proteins.  The modified LDH will be dispersed in the polyurethane to form nanocomposites. The structure, morphology and shape memory properties of the nanocomposites will be studied.

Carbon nanofiber-filled epoxy resins will be prepared and characterized.  The effect of surface-modified carbon nanofibers on cure kinetics of the epoxy resins will be studied, and the properties, especially electrical and thermal conductivity, of the nanocomposites will be characterized and correlated to the structure of the materials.

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