报告题目一：Aqueous graphene dispersions--Optical properties and stimuli responsive phase transfer
报告人：Prof. John Texter (Eastern Michigan University)
报告地点：907楼1445
报告时间：7月9日（星期三）下午2:00 - 3:00
Stimuli responsive triblock surfactants and nanolatexes derived from reactive ionic liquids are demonstrated to be the most effect stabilizers reported for dispersing graphene at 1% to 5% by weight in water. These results surpass most reports by 10 to 1000-fold and result in long time (>6 month) stabilization. Optical data in the visible show that our dispersions are also predominantly single sheet and bilayer, as deduced from analysis of concentrated dispersions and from layer-by-layer coatings. The visible extinction at 500 nm in suspension is shown experimentally to be 49 cm2/mg graphene, and this result is shown to be rigorously consistent with fundamental studies of macroscopic single-layer graphene and its fine structure constant, a = e2/hc. The mechanism of exfoliation is presented in terms of highly activated exfoliation with strong adsorption of stabilizer withsp2 graphene surfaces. Interesting controlled sedimentation, coating, rheo-optical, and phase transfer phenomena are demonstrated. These methods will make it possible to produce highly dispersed and concentrated graphene using scalable manufacturing methods.
报告题目二：Solvent-Free Nanofluids
报告人：Prof. John Texter (Eastern Michigan University)
报告地点：907楼1549
报告时间：7月10日（星期四）下午2:00 - 3:00
Nanofluids are solvent-free viscous liquids composed of suitably surface functionalized nanoparticles. Some few examples are uncharged, but the majority of examples reported to date may be viewed as supramolecular ionic liquids. Applications in producing new materials include magnetic fluids, novel resins, nanoinks for additive microprinting, and tunable particles for reformulating particle-particle interaction potentials. Such nanofluids may be viewed as 100% concentrated dispersions (all nanoparticles – no solvent). Previously reported nanofluids have been derived by surface modifying core nanoparticles to produce a shell or corona that induces viscous liquid behavior with apparently classical glass transition and melting transitions. We show that by adding additional surface functionality, newe classes of resins may be created. Such materials may also be used to formulate curable inks for additive microprinting technologies. We also show that direct auto-condensation of suitable alkoxysilanes produce core-free nanofuids that exhibit lambda transitions in heat capacity centered around both a glass transition (Tg) and melting transition (Tm). These nanoflluid nanoparticles may be synthesized as bulk condensation products, and a recent example is illustrated in Fig. 1. Such dispersions are being investigated as carriers for metal catalysts in formulating advanced catalytic monoliths, as gene transfection carriers, and as new classes of ferrofluids, quantum dot carriers, and supramolecular reaction media.
欢迎感兴趣的老师和学生参加！
