Thomas E Mallouk

Learn More
Nanoscale, zero-valent iron is a promising reagent for in situ reduction of a variety of subsurface contaminants, but its utility in full-scale remediation projects is limited by material costs. Iron nanoparticles (20-100 nm diameter) supported on carbon (C-Fe0) were synthesized by reacting iron salts, adsorbed or impregnated from aqueous solutions onto 80(More)
Unilamellar colloids of graphite oxide (GO) were prepared from natural graphite and were grown as monolayer and multilayer thin films on cationic surfaces by electrostatic selfassembly. The multilayer films were grown by alternate adsorption of anionic GO sheets and cationic poly(allylamine hydrochloride) (PAH). The monolayer films consisted of 11-14 Å(More)
Powering nanoscale machinery by nanosized motors that move by in situ conversion of stored chemical energy is one of the most interesting challenges facing nanotechnology. Such a procedure would circumvent the need for an external macroscopic power source. In nature, nanoscale motors typically operate by energy derived from the enzymatic catalysis of(More)
Anionic, hydrophilic carbon (Fe/C) and poly(acrylic acid)-supported (Fe/PAA) zerovalent iron nanoparticles were studied as a reactive material for the dehalogenation of chlorinated hydrocarbons in groundwater and soils. The transport of Fe/C nanoparticles was studied by elution through columns packed with model soils from different regions of the USDA soil(More)
Rod-shaped particles, 370 nm in diameter and consisting of 1 microm long Pt and Au segments, move autonomously in aqueous hydrogen peroxide solutions by catalyzing the formation of oxygen at the Pt end. In 2-3% hydrogen peroxide solution, these rods move predominantly along their axis in the direction of the Pt end at speeds of up to 10 body lengths per(More)
High surface-area nickel-iron nanoparticles (1:3 Ni:Fe) have been studied as a reagent for the dehalogenation of trichloroethylene (TCE). Ni-Fe (0.1 g) nanoparticles reduced TCE from a 40-mL saturated aqueous solution (24 ppm) to <6 ppb in 120 min. The dehalogenation reaction, based on the surface area normalized rate constant, was 50-80 times slower using(More)
Small-scale synthetic motors capable of generating their own motive forces by exploiting the chemical free energy of their environment represent an important step in developing practical nanomachines. Catalytic particles are capable of generating concentration and other gradients that can be used to self-propel small objects. However, the autonomous(More)
Bimetallic nanorods are propelled in aqueous solutions by the catalytic decomposition of hydrogen peroxide to oxygen and water. Several mechanisms (interfacial tension gradients, bubble recoil, viscous Brownian ratchet, self-electrophoresis) have been proposed for the transduction of chemical to mechanical energy in this system. From Tafel plots of anodic(More)
We have explored the role of electrokinetics in the spontaneous motion of platinum-gold nanorods suspended in hydrogen peroxide (H2O2) solutions that may arise from the bimetallic electrochemical decomposition of H2O2. The electrochemical decomposition pathway was confirmed by measuring the steady-state short-circuit current between platinum and gold(More)
We consider two systems of active swimmers moving close to a solid surface, one being a living population of wild-type E. coli and the other being an assembly of self-propelled Au-Pt rods. In both situations, we have identified two different types of motion at the surface and evaluated the fraction of the population that displayed ballistic trajectories(More)