The development of stimuli-responsive materials with the ability of controllable oil/water separation is crucial for practical applications. Here, a novel pH responsive nonfluorine-containing copolymer was designed. The copolymer together with silica can be dip-coated on different materials including cotton fabric, filter paper, and polyurethane foam. The coated materials exhibit switchable superhydrophilicity and superhydrophobicity and can be applied in continuous separation of oil/water/oil three phase mixtures, different surfactant stabilized emulsion (oil-in-water, water-in-oil, and oil-in-acidic water) as well as oil uptake and release via in situ and ex situ pH change. We expect that the coatings highlight the practical applications because of the cost-effective preparation process and fluorine-free strategy.Keywords: coating; copolymer; ex situ; in situ; oil/water separation; pH responsiveness

Fluorine-containing groups represent very promising functionalities because fluorine not only changes the physico-chemical properties of the graphene surface, it may also alter its electronic and magnetic properties. Herein, we describe, for the first time, the synthesis and characterization of the perfluoroalkyl functionalization of graphene oxide by a simple and general solution-based process using perfluorooctyl functionalized aniline (RF-NH2) as both reducing and grafting reagent. Importantly, the perfluoroalkyl functionalized graphene hydrogels (FGHs) could be achieved by a hydrothermal method. The as-fabricated FGHs exhibited outstanding absorption ability and electrochemical performances, including ultrahigh specific capacitances of 321.6 F g−1 and excellent cycling stability in aqueous and organic electrolytes. The changes in the electronic structure of the perfluoroalkyl functionalized graphene were also simulated by density functional theory.

A green approach to the preparation of reduced graphene oxide (RGO) films has been developed using L-ascorbic acid/water vapor as the reducing agent. Except for the use of gaseous hydrazine hydrate or hydroiodic acid, this is the first reported use of an environmentally friendly gaseous phase for the reduction of graphene oxide (GO) films into RGO films. The as-prepared RGO films were flexible and showed a high electrical conductivity of up to 3500 S m−1. The L-ascorbic acid/water vapor was able to penetrate into the GO films and reduce the Ag ions. The as-reduced RGO–Ag composite films could be used as effective surface-enhanced Raman scattering active substrates and the Raman signals could be adjusted by changing the amount of Ag ions. The RGO–Ag composites also showed antibacterial activity against Escherichia coli, Staphylococcus aureus and white rot fungi. This is a straightforward and green approach to fabricating RGO–Ag composites for use in biological applications and materials science.

Fluorine-containing groups represent very promising functionalities because fluorine not only changes the physico-chemical properties of the graphene surface, it may also alter its electronic and magnetic properties. Herein, we describe, for the first time, the synthesis and characterization of the perfluoroalkyl functionalization of graphene oxide by a simple and general solution-based process using perfluorooctyl functionalized aniline (RF-NH2) as both reducing and grafting reagent. Importantly, the perfluoroalkyl functionalized graphene hydrogels (FGHs) could be achieved by a hydrothermal method. The as-fabricated FGHs exhibited outstanding absorption ability and electrochemical performances, including ultrahigh specific capacitances of 321.6 F g−1 and excellent cycling stability in aqueous and organic electrolytes. The changes in the electronic structure of the perfluoroalkyl functionalized graphene were also simulated by density functional theory.