The pyrolysis of intumescent flame-retardant polypropylene (PP) composites was studied by synchrotron vacuum ultraviolet photoionization combined with molecular-beam mass spectrometry (SVUV-PIMS). Pyrolytic products of intumescent flame-retardant PP composite formed at certain temperature have been identified by the measurement of photoionization mass spectra at different photon energies. By using SVUV-PIMS, some isomers were identified. Meanwhile, the effect of high-efficient flame-retardant synergist–nanoporous nickel phosphate on pyrolytic products of intumescent flame-retardant PP composite was also studied. By analyzing the pyrolysis of the intumescent flame-retardant PP composites with or without the flame-retardant synergist, the synergistic flame-retardant mechanism was discussed as the condensed-phase flame-retardant mechanism not gas flame-retardant mechanism as expected. The studies in this work are much helpful for further understanding the flame-retardant mechanism of intumescent flame-retardant PP composites.

•MoS2 hollow microspheres were designed and prepared via a hydrothermal method.•MoS2 hollow microspheres can serve as a lubricating additive for liquid paraffin.•Worn MoS2 powders can serve as a photo catalyst for liquid paraffin degradation.Molybdenum disulfide (MoS2) hollow microspheres were prepared via a hydrothermal method, which were characterized by XRD, SEM, TEM and UV–vis spectroscopy. The tribological performances of liquid paraffin (LP) mixtures containing these hollow microspheres and the following photo-catalytic degradation behaviors of LP promoted by the worn MoS2 powders were investigated. The results indicate that 0.50 wt% of MoS2 hollow microspheres in LP can reduce the friction coefficient of the mixture remarkably, and the photo-catalytic degradation degree of LP also reaches a satisfactory level. MoS2 serves as both lubricating additives and photo catalysts at the different life stages, and related mechanisms have been discussed, which suggests potential values in the design of novel and sustainable lubricating systems.

Friction and wear are common physical phenomena in nature, while lubrication is an effective way to decrease unnecessary friction and wear. With the rapid development of environmental protection consciousness, designing novel lubricants or lubricating additives with excellent lubricating performance and little pollution is the increasing demand of the green tribology. In this work, nanoscale coral-like molybdenum disulfide (MoS2) was prepared via a hydrothermal method. It was first used as a lubricating additive for liquid paraffin (LP), and then, it acted as a catalyst for the photoinduced degradation of waste LP after testing. Many influencing factors (modification, concentration, morphology and temperature) that can influence the tribological properties and photocatalytic degradation level were investigated. Experimental results and related analyses indicate that modification by cetyltrimethylammonium bromide (CTAB) and a proper synthesis temperature are helpful to decrease the fiction coefficient, and organic modification, bigger surface area, narrower bandgap and more rim sites with oxidation activity are advantageous to achieve better LP degradation levels. Therefore, coral-like MoS2 can serve as both lubricating additive and photocatalyst at different working stages in the full life cycle of LP, which exhibits great potential in developing environment-friendly lubricating systems.

•The properties of LP containing coral-like MoS2 were systemically investigated.•Parameters for achieving the best friction performance were suggested.•A possible lubrication-wear mechanism of the coral-like MoS2 for LP was suggested.Coral-like MoS2 was prepared via a hydrothermal method and it was employed as an additive for liquid paraffin (LP). The influences of synthesis temperature, surfactant modification and concentration variation on the tribological properties of LP mixtures were investigated. The results showed that 0.40 wt% of MoS2 in LP can reduce the friction coefficient remarkably, which attributed to the adsorption of MoS2 generated from moderate tribo-chemical reaction. MoS2 without surfactant modification prepared at 220 °C worked better in reducing friction coefficient and showed better anti-wear performance comparing with those obtained at other temperatures. Furthermore, MoS2 modified by surfactant gave more excellent behavior in improving lubrication performance owing to its more oxidation resistance, better dispersion stability and easier exfoliation in LP.

Nowadays, novel nanocomposites including polyhedral oligomeric silsesquioxanes (POSS) are used to impart potential flame-retarded properties to polymers. In this work, polystyrene nanocomposites containing octa(tetramethylammonium) POSS and organic clay were prepared by melt mixing method, and their enhanced combustion and thermal properties were investigated and discussed. The microstructures of composites obtained by TEM characterization indicated that POSS and clay were dispersed in the base polymer homogeneously. The thermal and combustion behaviors of composites were investigated by thermal gravimetric (TG) analysis and cone calorimeter. TG results obtained under air atmosphere show that the char yield increases obviously. Heat release rate together with other combustion parameters (such as the release rates of CO and CO2, the concentration of CO and CO2 and the smoke production rate) of composites is enhanced effectively. More importantly, the results show that 5 % replacement of POSS by organic clay is very helpful to the further improvements in most of parameters and cut down the cost effectively. Of course, nanoscopic size and structure of POSS and clay together with their well dispersion contribute to these improved fire safety properties.

In the past few decades, nanopore based biosensing has attracted more and more attention. In this work, a novel fluidic sensor was fabricated using two separated liquid cells, which were linked by polycarbonate (PC) ultrafiltration membranes containing nanopore arrays. The trans-membrane ionic current generated by the applied voltage and the current changes modulated by a goat antibody to human immunoglobulin G (IgG) translocation were recorded simultaneously. The experimental results show that the ionic current is modulated by the physical place-holding effect generated by IgG translocation through nanopore arrays. For different temperatures (4 °C, 22 °C, and 45 °C) and different concentrations of the electrolyte (0.01 mol L−1, 0.10 mol L−1 and 1.0 mol L−1), the relative variance of the ionic current ((I0 − I)/I0) modulated by IgG translocation increases at first and then decreases and stabilizes. With the increase of the IgG concentration, there is an obvious “inflection point” corresponding to the maximum value of the relative variance of the ionic current. The concentration of the electrolyte does not affect the position of the “inflection point”, while temperature increment makes the “inflection point” shift to the high IgG concentration direction. Finally, a simplified model is suggested and the calculated results contribute to the understanding of the temperature induced IgG translocation behavior, which matches the ionic current changing tendency obtained in our experiments.

The separation and/or purification of biomolecules are of great importance in biotechnological analysis, characterization and related applications. In this work, a set of “U”-type devices containing a feed cell and a permeation cell connected by nanopore arrays was designed for controlled protein separation. Certain voltages (as a driving force) and pressure differences (ΔP, as resistance) were applied to make selected protein move from the feed cell into the permeation cell through nanopore arrays. The resultant driving forces applied to the proteins can be modulated by changing the parameters such as applied voltage, pH value and ΔP between two cells, thus, their translocation velocity can be controlled. By finding the P–V equilibrium points for bovine serum albumin (BSA) and bovine hemoglobin (Hb), the separation ratios (mass ratio) for BSA and Hb can be achieved as BSA:Hb = 12.5 and Hb:BSA = 14.3.

In recent years, two-dimensional (2-D) materials have attracted more and more attentions due to their 2-D anisotropy and special physicochemical properties. In this work, hexadecyltrimethoxysilane (HDTMS) and octyltrimethoxysilane (OTMS) were employed to modify graphite oxide (GO) nanosheets for potential applications as lubricating oil additives. The organically modified GO nanosheets were characterized by FTIR, XRD, TGA, UV-vis spectroscopy and SEM, which indicated that HDTMS and OTMS had successfully entered the GO layers. Furthermore, the tribological properties of liquid paraffin containing HDTMS and OTMS modified GO were investigated by a four-ball friction testing machine. The results show that ultra-low concentration (0.008 wt%, the optimal value) of HDTMS or OTMS modified GO in liquid paraffin can reduce the friction coefficients of the mixtures by 34.0% and 15.5% respectively. HDTMS, which possesses longer alkyl chains, is better for improving the organic compatibilities and helps GO nanosheets to exfoliate more significantly and disperse in paraffin more homogeneously, thus corresponding to better effectiveness in decrease the friction coefficient.

In this paper, we report one novel kind of organic–inorganic mesoporous hybrid from octa-anionic polyhedral oligomeric silsesquioxanes (POSS) and cationic surfactant. The mesoporous hybrid was achieved by two steps: first, lamellar precursor made of POSS and surfactant was prepared by template-directed synthesis; then mesoporous structure was obtained via the reformation of lamellar precursor under hydrothermal treatment. According to our experimental results (XRD, TEM and SEM), the lamellar-to-hexagonal mesophase transformation process and its mechanism was suggested. The thermal stability and degradation behavior of the mesoporous hybrid was also discussed based on TGA curves obtained under nitrogen atmosphere.