Macromolecules Innovation Institute (MII)
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The Macromolecules Innovation Institute at Virginia Tech (MII) is a university-wide research and education institute, representing a group of faculty, students, and staff dedicated to fostering an interdisciplinary understanding of the macromolecular sciences and technologies. Collectively, we offer a variety of educational, research, and professional interaction opportunities to our students. We also provide industry collaborators with training opportunities through short courses and offer opportunities for unique collaboration through sharing our laboratories, facilities, and expertise.
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Browsing Macromolecules Innovation Institute (MII) by Content Type "Article"
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- GSA Tomorrow: An Open Challenge to Promote the Future of GeoscienceDorfler, Kristin M.; Friedrich, Anke M. (Geological Society of America, 2018-11-20)The future of geoscience rests on your shoulders. Geologists are passionate about their science and discuss their interests with vigor, firmly understanding why geoscience is as important to society as physiology, agriculture, or engineering. In many cases, non-geologists don’t see the clear importance and implication of the profession, outside of natural disasters and events that have immediate and apparent human effects. Countless geoscientists1, including professionals, academics, and students, are already vocal self-advocates; however, in our currently digital world, where information can be instantly disseminated at the push of a button, it is time we took a collective effort as the Geological Society of America to actively emphasize the importance of science to the non-geologist, forming a movement to assertively advocate for our field. We invite you to contribute to this discussion by responding with succinct, measurable, and clear reasons on how what you do affects society. Our collective views could be used to guide non-geologists to advocate for geoscience just as non-physicians advocate for medical advances. GSA is as effective as its members, who make up 21 Scientific Divisions, which have numerous, tangible impacts on society. As GSA continues focusing efforts on the advancement of the Society into the twenty-first century, we are taking a critical look at what the Society is doing, whom it is doing it for, and how it could be doing it better.
- Mechanically cycling gelatin bilayersHanzly, Laura E.; Chauhan, Natasha; Barone, Justin R. (2022-01-11)There is a growing interest in making stimuli-responsive polymer systems, particularly ones that are bio-inspired/biomimetic and could perform mechanical work. Here, a biological device made from gelatin is described that can mechanically cycle back and forth in response to solution pH or ionic strength changes. The gelatin bilayer has one layer of Type A gelatin and the other of Type B gelatin, which have 2 different isoelectric points and therefore ionization states at a given solution pH. The bilayer mechanically cycles back and forth when one layer swells more than the other layer, which occurs because of solution pH or ionic strength change. Maximum bilayer bending occurs at pH 10, when the Type B gelatin layer swells significantly more than the Type A layer. The results show the ability to use the unique properties of different sources of gelatin to design a simple biological machine.
- Mitigation of bidirectional solute flux in forward osmosis via membrane surface coating of zwitterion functionalized carbon nanotubesZou, Shiqiang; Smith, Ethan D.; Lin, Shihong; Martin, Stephen M.; He, Zhen (Elsevier, 2019-07-08)Forward osmosis (FO) has emerged as a promising membrane technology to yield high-quality reusable water from various water sources. A key challenge to be solved is the bidirectional solute flux (BSF), including reverse solute flux (RSF) and forward solute flux (FSF). Herein, zwitterion functionalized carbon nanotubes (Z-CNTs) have been coated onto a commercial thin film composite (TFC) membrane, resulting in BSF mitigation via both electrostatic repulsion forces induced by zwitterionic functional groups and steric interactions with CNTs. At a coating density of 0.97 gm⁻², a significantly reduced specific RSF was observed for multiple draw solutes, including NaCl (55.5% reduction), NH₄H₂PO₄(83.8%), (NH₄)₂HPO₄ (74.5%), NH₄Cl (70.8%), and NH₄HCO₃ (61.9%). When a synthetic wastewater was applied as the feed to investigate membrane rejection, FSF was notably reduced by using the coated membrane with fewer pollutants leaked to the draw solution, including NH₄⁺-N (46.3% reduction), NO₂⁻₋N (37.0%), NO₂⁻₋N (30.3%), K⁺ (56.1%), PO₄³⁻₋P (100%), and Mg²⁺ (100%). When fed with real wastewater, a consistent water flux was achieved during semi-continuous operation with enhanced fouling resistance. This study is among the earliest efforts to address BSF control via membrane modification, and the results will encourage further exploration of effective strategies to reduce BSF.
- Structure and properties of flax vs. lyocell fiber-reinforced polylactide stereocomplex compositesZhang, Huihui; Li, Qiao; Edgar, Kevin J.; Yang, Gesheng; Shao, Huili (Springer, 2021-07-28)A commonly used natural cellulose fiber (flax) and a regenerated cellulose fiber (Lyocell) were used at 20 wt% to reinforce polylactide stereocomplex (sc-PLA) composites. Composites were prepared by melt compounding cellulose fibers and an equivalent proportion of PLLA/PDLA, followed by injection molding. The structures and properties of these two kinds of cellulose fiber/sc-PLA composites were compared and evaluated. The results showed that the total crystallinity and stereocomplex crystallite content of composites could be increased by reinforcing with cellulose fibers, and Lyocell fibers were more effective in accelerating crystallinity and the formation of stereocomplex crystallites than flax fibers. Mechanical properties of Lyocell fibers were much poorer than those of flax fibers, and the interfacial adhesion values of Lyocell/sc-PLA composites were inferior to those of flax/sc-PLA composites. Lyocell/sc-PLA composites showed higher impact strength and similar tensile strength vs. flax/sc-PLA composites, but the Young’s modulus values of Lyocell/sc-PLA composites were lower than those of flax/sc-PLA composites. The Vicat softening temperatures of both flax/sc-PLA and Lyocell/sc-PLA composites were increased to nearly 100 °C higher than that of PLLA. Lyocell/sc-PLA composites showed the highest Vicat softening temperature of ~ 170 °C.