Dr. Song Liu

Smart Protective Clothing: Responsive Barrier and Self-Decontaminating
Clothing materials are the last line of defense protecting the human body from exposure to any potential hazards. Because of this fact, protective clothing is designed as necessary personal protective equipment for many professionals such as healthcare workers, soldiers, and farm workers. Currently,  widely used protective clothing is made of barrier textile materials that can completely block penetration and permeation of chemical solutions or human fluids through the fabrics. But, the barrier properties of the protective clothing also strongly affect the transport of heat and moisture generated by wearers, resulting in heat stress and low work efficiency. Moreover, the pathogens are still alive (or pesticides are still toxic) on the contaminated clothing so that the potential of cross infection (or toxin exposure) remains.  My recent work reveals that an acyclic amide such as acrylamide grafted textiles can be activated by chlorination to form N-halamine which can demonstrate effective bacterial killing. The  similar N-halamine structure was also proven to be able to detoxify some carbamate pesticides upon contact.  Since crosslinked acrylamide can function as an absorbent to form a hydrogel, it is highly speculated that both a smart response and a biocidal/ detoxifying function can be combined together without compromising the comfort of the modified clothing. Acylamide or other acyclic amide can be radically grafted onto polypropylene or polyester and crosslinked in-situ to form a 3-D network on base materials. Following the grafting, primary amide can be converted to acyclic N-halamine to activate the biocidal/detoxifying function. Under normal conditions, grafted polymers collapse to retain the porous structure of the base fabrics. In contact with the biological fluids/pesticides, the grafted network responds by swelling.  More insidious fluids can be blocked physically and absorbed fluid will be decontaminated in situ.  With such “smart” dual protective functions, the clothing materials could have increased air and water moisture permeability, which will reduce heat stress and improve comfort performance for wearers.

Dr. Wen Zhong
Electrospun Nanofibers

• Both natural and synthetic polymers can be processed
• Ultrafine and ultra-soft
• High surface-to-volume ratio
• Forming highly porous mats with tunable pore sizes and distributions
  
  • Used as filters or protective devices
• Functionalized (loaded with drugs or other bioactive molecules) for biomedical uses:
  • Wound dressings
  • 3-dimensional scaffold for tissue engineering and regeneration

Dr. Mashiur Rahman

A unique surface modification technique for the Hydrolysis of medical grade polyester using ‘stress below the yield load (SBYL)’.
Poly(ethylene terephthalate) or PET is being used for various medical applications as implantable materials such as artificial tendon, artificial ligament, vascular grafts, artificial kidney, aortofemoral grafts, and many extra-anatomic bypass grafts due to its durable and biocompatible properties.

However, thrombosis (blood clotting) is one of the major and catastrophic complications of PET in graft applications, which is as high as 20% in some PET implantations.
Thrombosis may be reduced when the active groups on the surface of the polyesters react with the blood proteins. The active groups on the polyester surface can be generated using hydrolysis and other surface modification techniques.
However, the extent of hydrolysis of polyester is restricted due to surface damage in the form of transverse and axial cracks and physical properties changes which reduce the lifetime of polyester implants. This lower hydrolysis of polyesters limits the generation of active groups on the surface and hence the blood protein binding capability.
My recent work which was carried out in the Textile Testing Services Lab at the University of Manitoba showed that the extent of hydrolysis of polyester may be enhanced if hydrolysis is carried out using ‘stress below the yield load (SBYL)’.
This is a collaborative work with the Department of Human Nutritional Sciences (HNS) of University of Manitoba. This research will develop and optimize a unique surface modification technique that will create maximum active groups on the medical grade polyester, without deteriorating the surface or physical properties, to react with the blood proteins for clot prevention.
It will lead to creating a novel polyester that will be used for many areas of graft implantations where thrombosis is a critical problem that leads to numerous human deaths.