Xiaodan Zhang, studying under Dr. Yulin Deng, expects to receive her PhD with a major in Polymer, Textile & Fiber Engineering later this year.  During her time at Georgia Tech/IPST, she has completed several projects in paper science and engineering, polymer science and engineering.  Most of her work has focused on the promising aspects of cellulose-based electronic devices.

Because cellulose is abundant, low-cost, and more environmentally friendly than other materials used in electronic devices, it is a candidate as a new material in electronic devices.  Currently used supercapacitors are liquid-based, causing limitations in sealing and demanding ample space for their location.  In her work, Xiaodan created a cellulose-based supercapacitor.  The cellulose-based supercapacitor is solid, flexible, and high-strength.  Because it is cellulose-based, it is more environmentally compatible than other supercapacitors now in use.  The fabricated supercapacitors showed good tensile strength and Young’s modulus (elasticity) even when bent to different curvatures.

In addition to the cellulose-based supercapacitors, Xiaodan successfully created flexible and transparent cellulose-based ionic diodes that exhibited excellent rectification ratios, and silver-polyaniline-cellulose aerogel supercapacitors that showed competitive specific capacitance.

Dye-sensitized solar cells have attracted considerable interest as an alternative to silicon solar cells because of their low cost, but their energy conversion must be improved for successful commercialization. Xiaodan fabricated tandem solar cells that enabled the cells to absorb light over a broader region of solar spectrum to obtain high conversion efficiency.

Xiaodan says, “Cellulose-based electronics show great promise.  They have good characteristics of being low-cost. They are green and flexible.  My work shows they have potential in a variety of electronic applications such as supercapacitors, transistor, solar cells, and the like.”

In addition to her work with potential electronic applications of cellulose-based materials, Xiaodan explored the mechanical properties of microcrystalline cellulose.  Previous work has recognized the potential of microcrystalline cellulose for its potential as a reinforcement material. Xiaodan used melt spinning to prepare high-strength cellulose/polypropylene fibers. This solvent-free method is environmentally safer and simpler, compared to the traditional gel-spinning method.

Xiaodan has found her time at IPST interesting and rewarding.  “I enjoyed working with Dr. Deng and his group.  I have learned good research practices and have had a variety of experiences.”

Following receipt of her degree, she plans to continue to work on bio-based polymer materials. “I think sustainability is definitely going to be the direction we are heading to. Bio-based polymer is a very promising field and there is a lot to dig into it. I want to dedicate myself further to developing new generation of bio-polymer based materials and devices.”

Xiaodan commenced her studies at IPST in 2009. She received a BE in polymer science and engineering from the Beijing University of Chemical Technology in Beijing.

The poster for her supercapacitor work can be found at ipst.gatech.edu/students/posters/2013/zhang_xiaodan.pdf