Graphene as a photothermal actuator for control of lipid mesophase structure.

The optical density of pristine graphene is high and broad in the near infrared region of the electromagnetic spectrum positioning this material as a highly efficient photothermal agent for in vivo applications. In this study, surfactant assisted exfoliated graphene was incorporated within bulk lipid samples of varying lipid types: glyceryl monoether, glyceryl monooleate and phytantriol. The pristine graphene sheets did not disrupt the packing of the liquid crystals while being in sufficiently intimate contact to provide localized heating and induce phase transitions.

Photothermal Breaking of Emulsions Stabilized with Graphene.

Pristine graphene particles prepared using an aqueous phase exfoliation technique have been used to promote the stabilization of emulsions through adsorption at the oil-water interface. Highly localized phase separation of these ultrastable emulsions could, however, be induced through photothermal heating of the graphene particles at the interface exposed to near-infrared light. The graphene wettability, which is a key determinant in preventing droplet coalescence was altered through the adsorption of nonionic block copolymer surfactants.

Graphene Induces Formation of Pores That Kill Spherical and Rod-Shaped Bacteria.

Pristine graphene, its derivatives, and composites have been widely reported to possess antibacterial properties. Most of the studies simulating the interaction between bacterial cell membranes and the surface of graphene have proposed that the graphene-induced bacterial cell death is caused either by (1) the insertion of blade-like graphene-based nanosheets or (2) the destructive extraction of lipid molecules by the presence of the lipophilic graphene. These simulation studies have, however, only take into account graphene-cell membrane interactions where the graphene is in a dispersed form.

Lipid Liquid-Crystal Phase Change Induced through near-Infrared Irradiation of Entrained Graphene Particles.

Lipid packing is intimately related to the geometry of the lipids and the forces that drive self-assembly. Here, the photothermal response of a cubic liquid-crystalline phase formed using phytantriol in the presence of low concentrations of pristine graphene was evaluated. Small-angle X-ray scattering showed the reversible phase changes from cubic to hexagonal to micellar due to localized heating through irradiation with near-infrared (NIR) light and back to cubic after cooling.

Aqueous dispersions of exfoliated molybdenum disulfide for use in visible-light photocatalysis.

Single and few layer molybdenum disulfide (MoS2) was exfoliated from the bulk form through a liquid phase exfoliation procedure. Highly concentrated suspensions were prepared that were stabilized against reaggregation through adsorption of nonionic polymers to the sheet surface. These exfoliated particles showed strong photoluminescence at an energy of 1.