The thermal properties of epoxy‐based binary composites comprised of graphene and copper nanoparticles are reported. It is found that the “synergistic” filler effect, revealed as a strong enhancement of the thermal conductivity of composites with the size‐dissimilar fillers, has a well‐defined filler loading threshold. The thermal conductivity of composites with a moderate graphene concentration of fg = 15 wt% exhibits an abrupt increase as the loading of copper nanoparticles approaches fCu ≈ 40 wt%, followed by saturation. The effect is attributed to intercalation of spherical copper nanoparticles between the large graphene flakes, resulting in formation of the highly thermally conductive percolation network. In contrast, in composites with a high graphene concentration, fg = 40 wt%, the thermal conductivity increases linearly with addition of copper nanoparticles. A thermal conductivity of 13.5 ± 1.6 Wm−1K−1 is achieved in composites with binary fillers of fg = 40 wt% and fCu = 35 wt%. It has also been demonstrated that the thermal percolation can occur prior to electrical percolation even in composites with electrically conductive fillers. The obtained results shed light on the interaction between graphene fillers and copper nanoparticles in the composites and demonstrate potential of such hybrid epoxy composites for practical applications in thermal interface materials and adhesives.

We report results regarding the electron transport in vertical quasi-2D layered 1T-TaS2 chargedensity-wave devices. The low-frequency noise spectroscopy was used as a tool to study changes in the cross-plane electrical characteristics of the quasi-2D material below room temperature. The noise spectral density revealed strong peaks -changing by more than an order-of-magnitude -at the temperatures closely matching the electrical resistance steps. Some of the noise peaks appeared below the temperature of the commensurate to nearlycommensurate charge-density-wave transition, possibly indicating the presence of the debated "hidden" phase transitions. These results confirm the potential of the noise spectroscopy for investigations of electron transport and phase transitions in novel materials. / R. Salgado et al., Low-Frequency Noise Spectroscopy of CDW Phase Transitions in Vertical Quasi-2D Devices / UCR 2 | P a g eThe charge-density-wave (CDW) phase is a macroscopic quantum state consisting of a periodic modulation of the electronic charge density accompanied by a periodic distortion of the atomic lattice in metallic crystals [1][2][3]. Recently, the field of CDW materials and devices experienced a true renaissance [4][5][6][7][8][9][10][11][12][13][14][15][16]. The renewed interest has been driven by layer-control of CDW materials, such as quasi-two-dimensional (2D) crystals of 1T-TaS2 and other transition metal dichalcogenides (TMDs). Unlike classical bulk CDW materials with the quasi-1D crystalline

In this work, by fully exploring the stimulus response of infinite coordination polymer nanoparticles (ICPs) and by taking advantage of the particular optical properties of ICP guest tetra­(4-sulfophenyl)­ethene (TPE-TS) with adjustable monomer emission (ME) and aggregation-induced emission (AIE), we demonstrated a novel sensing mechanism for an anthrax biomarker dipicolinic acid (DPA) based on the competitive coordination interaction regulating the structure of TPE-TS@Eu/GMP ICPs. The double ratiometric fluorescence stemmed from triple response of TPE-TS@Eu/GMP ICPs without spectral cross-interference (ME and AIE from TPE-TS and sensitized emission from Eu/DPA) and a corresponding blue-to-red fluorescent color change, which not only benefited the direct detection of DPA with high sensitivity and selectivity, but also offered a great opportunity to realize real-time monitoring of DPA released by Bacillus subtilis spores. Furthermore, the coffee ring deposition patterns on a test paper were innovatively tuned by the quantity and morphology changes of TPE-TS@Eu/GMP ICPs during their stimulus response toward DPA, which could be exploited as expanded signal channels. By integrating a multichannel responsive coffee ring test kit with image recognition and processing application installed on smartphones, point-of-use analysis of DPA could be realized in a low-cost and high-throughput fashion.

In this work, 1,1,2,2-tetra­(4-carboxylphenyl)­ethylene (H4TCPE) was selected as the guest and incorporated into a Eu/AMP ICP host to establish a “lab-on-an-AIE@Ln/ICP” sensor array for identifying and sensing environmental antibiotics simultaneously. First, on the basis of a theoretical study of the antenna effect and reductive photoinduced charge transfer between the as-prepared H4TCPE@Eu/AMP ICPs and antibiotics, respectively, the response from the sensitized time-resolved fluorescence of the host and the unique aggregation-induced emission (AIE) of the guest were selected as the main sensing elements for the sensor array. With the regulation of pH, the diverse fluorescence responses for antibiotics with either structural differences (flumequine, oxytetracycline, and sulfadiazine) or structural similarities (oxytetracycline, tetracycline, and doxycycline) were recorded and processed by principal component analysis; systematic analysis of environmental antibiotics was therefore realized. Encouraged by the superior anti-aggregation-caused quenching effect of H4TCPE@Eu/AMP ICPs on the test strip, the distinct fluorescence color changes of the “lab-on-an-AIE@Ln/ICP” sensor array were further explored with the aid of smartphones. The fingerprinting pattern of the sensor array on test paper eventually holds great potential for the point-of-use systematic analysis of environmental antibiotics even in complicated real samples.

Gold islands are typically associated with high binding affinity to adsorbates and catalytic activity. Here we present the growth of dispersed nanoscale gold islands on single layer MoS 2 , prepared on an inert SiO 2 /Si support by chemical vapor deposition (CVD). This study offers a combination of growth process development, optical characterization, photoelectron spectroscopy at sub-micron spatial resolution, and advanced density functional theory modeling for detailed insight into the electronic interaction between gold and single-layer MoS 2. In particular, we find the gold density of states in Au/MoS 2 /SiO 2 /Si to be far less well-defined than Au islands on other 2-dimensional materials such as graphene, for which we also provide data. We attribute this effect to the presence of heterogeneous Au adatom/MoS 2-support interactions within the nanometer-scale gold cluster. Theory predicts that CO will exhibit adsorption energies in excess of 1 eV at the Au cluster edges, where the local density of states is dominated by Au 5d z 2 symmetry.