Shaoqin ( Gong - US grants

This research project aims to advance the fundamental knowledge and process technology for mass-production of lightweight, high-performance injection molded parts by creating synergistic marriage of two emerging technologies, i.e., nanocomposites and microcellular injection molding. Systematic experimental, analytical, and modeling studies will be conducted to identify the key processing parameters for microcellular injection molding with nanocomposites and their effects on materials properties and to advance the understanding and mathematical modeling of cell nucleation and growth in microcellular plastics with micro-/nano-scale particles and fibers. Since 1976, plastics have been the most widely used materials in the U.S., surpassing steel, copper, and aluminum combined by volume. Among the various plastics processing methods, injection molding accounts for one-third of all polymers processed.

These research activities and results will be incorporated into the polymer engineering curricula to stimulate students' interest in advanced research and education. Students of underrepresented groups will be recruited to participate in the research through the Research Experiences for Undergraduates (REU) supplement. Close collaboration with industrial partners via the industrial consortium and the Engineering Outreach Program will be emphasized to facilitate sharing of expertise and resources, validation of research outcome, transfer of technology, education of the workforce, and assessment of the economic gain. Successful execution of this research will have broad impacts in extending the industrial applications and adoption of nanocomposites and microcellular injection molding, ultimately helping the U.S. plastics industry to gain competitive edge in the global marketplace.

The objective of this research is to advance the fundamental understanding and processing technology of, and to develop three-dimensional modeling and simulation tools for, the mass production of lightweight, high-performance biobased/biodegradable components via microcellular injection molding. The approaches are to (1) achieve a better understanding of the biobased/ biodegradable plastic-supercritical fluid solution behavior utilizing an in-house designed novel in-line high-pressure slit die rheometer mounted on the microcellular injection molding machine; (2) establish guidelines for processing biobased/biodegradable plastics via design of experiments; (3) advance the understanding of cell nucleation and growth mechanisms by employing various nanoparticles and biofibers as fillers, and develop state-of-the-art, three-dimensional modeling and simulation tools; and (4) establish the composition-process-structure-property relationship of various microcellular biobased/biodegradable plastics via extensive characterization and analytical modeling.

Human society has benefited tremendously from the use of petroleum-based plastics. However, this prosperity has come at the expense of adverse environmental impacts and at the mercy of depleting fossil-based resources. Although biodegradable biobased plastics have been successfully produced from renewable resources, their commercial application has been limited due to inferior material properties, narrow processing windows, and relatively high material costs. This research could enable a larger processing window for biobased plastics and realize the mass production of environmentally benign biobased/biodegradable plastic components with complex geometries, improved material properties, and reduced material costs, thus broadening their application in many industrial sectors and ultimately helping the U.S. plastics industry gain a competitive edge in the global market. Moreover, research results and activities will be incorporated into existing and new manufacturing engineering curricula, helping to educate students regarding the growing importance of developing environmentally friendly materials and processes. Students of underrepresented groups will be recruited through the Research Experiences for Undergraduates supplement to participate in this research.

Active Nanotube-Liquid Crystalline Elastomer Nanocomposites
Abstract
This project aims to advance the fundamental understanding of novel carbon nanotube (CNT)-liquid crystalline elastomer (LCE) nanocomposites. The major innovation is to covalently couple the carbon nanotubes (CNTs) to the liquid crystalline elastomers (LCEs) using a unique nanotube chemistry platform to achieve strong synergies among CNTs, mesogenic units, and LCE networks. Systematic experimental and analytical work will be conducted to (1) rationally engineer the CNTs' surfaces with the designed functional groups that can facilitate their dispersion and form covalent bonding to the LCE network; (2) synthesize novel CNT-LCE composites with CNTs at different loading levels and interfacial structures; (3) systematically characterize the material properties of various types of CNT-LCE composites; (4) fabricate and characterize various CNT-LCE actuators via different external stimuli, including electrical field and remote IR irradiation; and (5) establish the composition-synthesis-structure-property-function relationship.
The strong synergies between CNTs with various characteristics and LCEs could generate many novel properties and functions. The advances in fundamental understanding of CNT-LCE composites will have a significant impact on the field of smart materials and lead to numerous potential applications ranging from actuators and artificial muscles to micro- and nano-machines. The resultant knowledge will be integrated into a new U/G course at the University of Wisconsin-Milwaukee to educate students about the growing importance of nanomaterials. In addition, students of underrepresented groups will be recruited through the Research Experiences for Undergraduates (REU) supplement to participate in this research.

This Faculty Early Career Development (CAREER) grant provides funding to (1) advance the fundamental understanding and processing technology for mass-producing, cost-effective, and high-performance biobased plastics components; and (2) to design, synthesize, characterize, and evaluate new types of biodegradable photopolymerizable macromers with desired material properties for scaffold applications in tissue engineering. The first research focus will build a scientific foundation to better understand the unique composition process structure property relationships for biobased plastics that can serve as guidelines to formulate and process cost-effective and high-performance biobased polymer blends, composites, and nanocomposites. The second research focus will lead to a new family of biodegradable photopolymerizable macromers with a broad spectrum of material properties that not only will fill the urgent needs faced by tissue engineering for suitable materials for targeted tissue regeneration, but also provide a means to elucidate the complex relationships between the cell functions and the characteristics of biomaterials and scaffolds. This new family of biomaterials also can be used for drug delivery and wound-healing applications. The proposed research activities will be integrated with various educational efforts. Especially, the plastics program at UW-Milwaukee will be strengthened through new course development, involving both undergraduate and graduate students in research and collaborating with the local plastics industries. Educational opportunities in engineering for women and minorities also will be improved through outreach activities.

Broader impact: The first research focus will broaden the applications of biobased plastics and help to transform today's oil-based economy to a more sustainable and eco-friendly biobased economy in the 21st century while improving our national security by reducing dependency on foreign oil. The second research focus will help to improve the quality of life for millions of people around the world and reduce the cost for treating debilitating diseases. The educational efforts will lead to a stronger plastics program at UW-Milwaukee that will provide a workforce much needed by the local plastics industries and will motivate more women and minority students for a career in engineering.

The 2009 ACS Stimuli-Responsive Polymeric Materials Symposium will be held August 16-20, 2009, in Washington D.C. during the 238th ACS National Meeting & Exposition. Stimuli-responsive polymeric materials is a multidisciplinary research field involving chemistry, material science, physics, biological science, and engineering. The purpose of this symposium is to bring together scientists working in this diverse and fast-growing research field to share their important and exciting research advances through oral presentations, posters, and face-to-face communication. This symposium will emphasize new chemistry to synthesize, new strategies to formulate, new tools to characterize, and new theories/models to understand the stimuli-responsive polymeric materials, as well as new devices made of such materials including sensors, actuators, and smart drug delivery systems. A number of prominent researchers worldwide from academia and industry will be invited to present their cutting-edge research topics and discuss the potential opportunities and grand challenges in this field.

The participation of young researchers, including graduate students and postdoctoral researchers, as well as women and those from underrepresented minority groups, will be strongly encouraged. If successful, this symposium will help to (1) identify various new strategies to develop novel stimuli-responsive polymers; (2) stimulate new applications of such materials; (3) strengthen interdisciplinary research; and (4) train the new-generation researchers in this diverse field.

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The research objective of this award is to more fully understand carbon nanotube (CNT)-liquid crystalline elastomer (LCE) nanocomposites and their actuation behaviors. Adding a small amount of properly functionalized CNTs into the LCE will create a new class of CNT-LCE actuators that can be stimulated via an electrical field, electrical Joule heating, and remote IR irradiation with excellent actuation performance and improved mechanical properties. Pure LCE actuators can only be actuated by changing the temperatures of their surroundings. In order to uniformly disperse the CNTs in the LCE matrix and to achieve strong coupling between the CNTs and the LCE, the surfaces of the CNTs will be engineered rationally with various types of functional materials. The effects of CNT chemistry and loading on the structure and the material properties of the CNT-LCE nanocomposites will be established. The actuation behaviors of the CNT-LCE actuators under different stimuli including electrical field and remote IR irradiation will be investigated.
A greater understanding of this new class of CNT-LCE composites will have a significant impact on the field of smart materials. The strong synergies between CNTs with various characteristics and LCEs can generate many novel properties and functions, and lead to practical applications in actuators, artificial muscles, micropumps, and micromotors. The technological results will be shared with industry partners, and the knowledge gained will be integrated into newly established courses to educate students about the growing importance of nanomaterials. Particular emphasis will be placed on developing research experiences for students of underrepresented groups and for middle/high school students enrolled in various science programs at UWM to introduce the concept of nanotechnology and to expand their interest in science.

This award by the Biomaterials program in the Division of Materials Research to University of Wisconsin-Milwaukee is to study self-assembled drug nanocarriers, including liposomes, polymer micelles, and vesicles, exhibit poor in vivo stability, leading to poor targeting and reduced therapeutic effect. This award will help to develop multifunctional unimolecular micelles with excellent in vivo stability, passive and active tumor-targeting abilities, desirable particle size, high drug loading capacity, controlled drug release, and long circulation time, thereby greatly increasing the efficacy of targeted cancer therapy and minimizing undesirable side effects. These unique unimolecular micelles are based on novel biodegradable and/or biocompatible, multi-arm hyperbranched amphiphilic block copolymers with active tumor-targeting ligands. A hyperbranched polyester with 64 hydroxyl groups will be used as the initiator for the polymerization of the amphiphilic block copolymer arms. The relationship among the molecular structure, micelle property, and drug delivery behavior will be systematically investigated. Both undergraduate and graduate students will be trained with various cutting-edge techniques related to biomaterials research. The resultant knowledge will improve the design of next-generation drug nanocarriers for targeted cancer theranostics and be integrated into relevant courses established by the PIs

Despite continuous and intensive efforts to discover highly effective cancer drugs, conventional chemotherapeutic agents still exhibit poor specificity in reaching tumor tissue and are often restricted by dose-limiting toxicity. Nanoparticulates are desirable anticancer drug carriers due to their passive and active tumor-targeting ability, thereby allowing anticancer drugs to be delivered specifically to the cancer cells and minimizing harmful toxicity to non-cancerous cells adjacent to the target tissue. However, one major limitation with self-assembled drug nanocarriers is in vivo instability, which leads to poor therapeutic effects. This award will help to develop a multifunctional unimolecular micelle drug delivery system with many desirable characteristics for targeted cancer therapy, thereby greatly improving the quality of cancer patient care. The resultant technology will be transferred to interested companies, further promoting economic growth in the U.S. Educational outreach activities will be conducted with Milwaukee-area middle/high school students through the various outreach programs at UW-Milwaukee.

Inorganic aerogels such as silica, clay, and metal oxide have been extensively studied during the last 70 years. One major disadvantage of inorganic aerogels is that they are brittle. Organic aerogels generally are more flexible, but their mechanical moduli and strengths tend to be lower. The uniqueness of the team's nanofibrillated cellulose fiber (NFC)-based organic aerogels is that with optimized material formulations and processes, they can be both flexible and strong. The specific mechanical properties of the team's polyvinyl alcohol (PVA)-NFCgraphene oxide (GO) aerogels are favorable in comparison with the specific mechanical properties of other types of aerogels reported in the literature. Furthermore, NFCs are made from sustainable and abundant biomass, thus making it a more environmentally friendly material than petroleum-based products. In addition, these NFC-based aerogels are prepared using a freeze-drying process, which uses water instead of organic solvents. Freeze-drying has the potential to allow for easy scale-up.

Aerogels have drawn significant attention due to their unusual and interesting material properties, including a high porosity (typically 90% to 99%), ultra-low density, high specific surface area, and very low thermal, acoustic, and electrical conductivities. The sustainable NFC-based aerogels the team fabricates using an environmentally friendly and scalable process in the lab have excellent flexibility and specific compressive strength, extremely low thermal conductivity and water absorption, and good thermal stability. As such, they can be used for a wide range of thermal insulation applications such as homes and buildings, industrial equipment, and clothing. This I-Corps project will help the team deepen their understanding of the aerogel density and material property relationship, which can provide a guideline, if successful, for material selections for various applications.