Graphene-enabled adaptive infrared textiles

Interactive clothing requires sensing and display functionalities to be embedded on textiles. Despite the significant progress of electronic textiles, the integration of optoelectronic materials on fabrics remains as an outstanding challenge. In this Letter, using the electro-optical tunability of graphene, we report adaptive optical textiles with electrically controlled reflectivity and emissivity covering the infrared and near-infrared wavelengths. We achieve electro-optical modulation by reversible intercalation of ions into graphene layers laminated on fabrics. We demonstrate a new class of infrared textile devices including display, yarn, and stretchable devices using natural and synthetic textiles. To show the promise of our approach, we fabricated an active device directly onto a t-shirt, which enables long-wavelength infrared communication via modulation of the thermal radiation from the human body. The results presented here provide complementary technologies which could leverage the ubiquitous use of functional textiles

Covalent Patterning of 2D MoS2

The development of an efficient method to patterning 2D MoS2 into a desired topographic structure is of particular importance to bridge the way towards the ultimate device. Herein, we demonstrate a patterning strategy by combining the electron beam lithography with the surface covalent functionalization. This strategy allows us to generate delicate MoS2 ribbon patterns with a minimum feature size of 2 m in a high throughput rate. The patterned monolayer MoS2 domain consists of a spatially well-defined heterophase homojunction and alter- nately distributed surface characteristics, which holds great interest for further exploration of MoS2 based devices

Graphene oxide containing self-assembling peptide hybrid hydrogels as a potential 3D injectable cell delivery platform for intervertebral disc repair applications.

Cell-based therapies have shown significant promise in tissue engineering with one key challenge being the delivery and retention of cells. As a result, significant efforts have been made in the past decade to design injectable biomaterials to host and deliver cells at injury sites. Intervertebral disc (IVD) degeneration, a major cause of back pain, is a particularly relevant example where a minimally-invasive cellular therapy could bring significant benefits specifically at the early stages of the disease, when a cell-driven process starts in the gelatinous core of the IVD, the nucleus pulposus (NP). In this present study we explore the use of graphene oxide (GO) as nano-filler for the reinforcement of FEFKFEFK (β-sheet forming self-assembling peptide) hydrogels. Our results confirm the presence of strong interactions between FEFKFEFK and GO flakes with the peptide coating and forming short thin fibrils on the surface of the flakes. These strong interactions were found to affect the bulk properties of hybrid hydrogels. At pH 4 electrostatic interactions between the peptide fibres and the peptide-coated GO flakes are thought to govern the final bulk properties of the hydrogels while at pH 7, after conditioning with cell culture media, electrostatic interactions are removed leaving the hydrophobic interactions to govern hydrogel final properties. The GO-F820 hybrid hydrogel, with mechanical properties similar to the NP, was shown to promote high cell viability and retained cell metabolic activity in 3D over the 7 days of culture and therefore shown to harbour significant potential as an injectable hydrogel scaffold for the in-vivo delivery of NP cells. Statement of Significance: Short self-assembling peptide hydrogels (SAPHs) have attracted significant interest in recent years as they can mimic the natural extra-cellular matrix, holding significant promise for the ab initio design of cells’ microenvironments. Recently the design of hybrid hydrogels for biomedical applications has been explored through the incorporation of specific nanofillers. In this study we exploited graphene oxide (GO) as nanofiller to design hybrid injectable 3Dscaffolds for the delivery of nucleus pulposus cells (NPCs) for intervertebral disc regeneration. Our work clearly shows the presence of strong interactions between peptide and GO, mimicking the mechanical properties of the NP tissue and promoting high cell viability and metabolic activity. These hybrid hydrogels therefore harbour significant potential as injectable scaffolds for the in vivo delivery of NPCs

Influence of defect density on the gas sensing properties of multi-layered graphene grown by chemical vapor deposition

Chemical vapor deposition (CVD) has been demonstrated as a highly promising technique for the production of graphene on large scale and enabling tunability of the intrinsic defects of the films during the synthesis.In this work, we report on the correlation between the density of defects (DoD) and the kinetics of interaction of multi-layered graphene (MLG) with nitrogen dioxide (NO2) used as a target gas. We grow MLG on a pre-patterned molybdenum (Mo) catalyst layer, tailoring the DoD while growing MLG at temperatures from 850 °C to 980 °C. Analysing the Raman spectra, we show the lowering of the DoD as well as a quality dependence of MLG as a function of the growth temperature. The chemi-resistors based on MLG grown at different temperatures unambiguously highlight that, both during the exposure and the subsequent purge phase, the more defective the MLG, the more intense the NO2’s molecules interaction with MLG. Our results significantly mark a step forward in tuning the sensing properties of MLG without the need of any post-processing of the material after synthesis.Electronic InstrumentationElectronic Components, Technology and Material

Covalent Bisfunctionalization of Two‐Dimensional Molybdenum Disulfide

Covalent functionalization of two‐dimensional molybdenum disulfide (2D MoS(2)) holds great promise in developing robust organic‐MoS(2) hybrid structures. Herein, for the first time, we demonstrate an approach to building up a bisfunctionalized MoS(2) hybrid structure through successively reacting activated MoS(2) with alkyl iodide and aryl diazonium salts. This approach can be utilized to modify both colloidal and substrate supported MoS(2) nanosheets. We have discovered that compared to the adducts formed through the reactions of MoS(2) with diazonium salts, those formed through the reactions of MoS(2) with alkyl iodides display higher reactivity towards further reactions with electrophiles. We are convinced that our systematic study on the formation and reactivity of covalently functionalized MoS(2) hybrids will provide some practical guidance on multi‐angle tailoring of the properties of 2D MoS(2) for various potential applications