Graphene Sheets with Modified Surface by Sodium Lauryl Sulfate Surfactant for Biomedical Applications

This work describes synthesis of graphene sheets with modified surface by sodium lauryl sulfate (SLS) surfactant using one-pot solvothermal reaction method. Effect of sodium lauryl sulfate surfactant amount on surface modification level of graphene sheets was investigated. Ether (-S-OR- at 762 cm-1 - 863 cm-1), thiocarbonyl (=C=S at 1050 cm-1 - 1176 cm-1) and sulfoxide (S-O, Vs and Vas at 1030 cm-1 - 1450 cm-1) functional groups released from sodium lauryl sulfate (SLS) surfactant during solvothermal reaction and attached on the surface of graphene sheets were detected by (attenuated total reflectance-fast Fourier infrared) ATR-FTIR spectroscopy. (Atomic force microscope) AFM observations revealed apparent surface of graphene sheets modified by surfactant molecules with an average multiple profile of graphene nanosheets ≈ 4.8 nm high. This synthesis way of surface modified graphene sheets can be considered as easy, one-step and cheap method for manufacturing of novel biosurface with graphene, as reinforcement for biopolymer coatings such as ultra-high molecular weight polypropylene (UHMWPE), metallic biomaterials (Ti and Ti alloys) and bioceramics as hydroxyapatite (HA).

Development of RuS_(2) for near-infrared photodetector by atomic layer deposition and post-sulfurization

The chalcogenides of platinum-group metals(PGMs)have been known to be present in minerals and the intermediate products of refining.Over recent years,their applications in various fields,including catalysis,have been explored.Given that certain PGM chalcogenides behave as compound semiconductors,they can be used as materials for photodetectors.In this study,RuS_(2),featuring a bandgap suitable for near-infrared photodetectors,was prepared by forming Ru on a SiO_(2)/Si substrate via the atomic layer deposition method using[Ru(TMM)(CO)_(3)]as the precursor.Annealing was conducted at 800℃ for 1 h under H_(2)S flow.High-resolution transmission electron microscopy(HRTEM)and X-ray diffraction(XRD)analysis clearly confirmed that the as-deposited hexagonal close-packed(hcp)Ru transformed to cubic RuS_(2) after post-annealing.The surface morphologies,chemical states,and electrical and optical properties of RuS_(2) were investigated.The influence of the metallic Ru surface morphology prior to sulfurization on the reaction between Ru and H_(2)S was also discussed.To evaluate the potential of using RuS_(2) as a photodetector,a photodetector was fabricated by forming electrodes on RuS_(2) to measure its photocurrent under near-infrared light.Thus,RuS_(2) was proven to exhibit a short response time(59μs)and generate a photocurrent of 84 nA under near-infrared light at 940 nm.