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Interfacially confined microenvironments have recently gained attention in catalysis, as they can be used to modulate reaction chemistry. The emergence of a 2D nanospace at the interface between a 2D material and its support can promote varying kinetic and energetic schemes based on molecular level confinement effects imposed in this reduced volume. We report on the use of a 2D oxide cover, bilayer silica, on catalytically active Pd(111) undergoing the CO oxidation reaction. We "uncover" mechanistic insights about the structure–activity relationship with and without a 2D silica overlayer using in situ IR and X‐ray spectroscopy and mass spectrometry methods. We find that the CO oxidation reaction on Pd(111) benefits from confinement effects imposed on surface adsorbates under 2D silica. This interaction results in a lower and more dispersed coverage of CO adsorbates with restricted CO adsorption geometries, which promote oxygen adsorption and lay the foundation for the formation of a reactive surface oxide that produces higher CO2 formation rates than Pd alone. [ABSTRACT FROM AUTHOR]

Hydroxypropyl methylcellulose (HPMC)/sodium citrate (SC)/lipid tea polyphenol (LTP) photophobic films with different pore sizes from micron scale to nanometer scale were prepared by regulating the SC content (1–7%). The microstructures, physical and sustained antioxidant properties of these films were studied by using wide angel X-ray diffraction, small angle X-ray scattering (SAXS), scanning electron microscope, whiteness meter, ultraviolet spectrophotometer, texture analyzer and peroxide value test. Composite films with higher SC content showed larger pore size and whiteness. With the increasing SC content, crystallinity first increased then decreased. The addition of SC decreased the D s (surface fractal dimension) value, smoothness of the cross-section structure, tensile strength, elongation and modulus of composite films. HPMC/SC/LTP microporous films possessed control-release property in oil system, reflected by the lowest peroxide value of peanut oil enclosed in film with 3% SC during three weeks, meaning this film showed the best sustained antioxidant property. [ABSTRACT FROM AUTHOR]

Two series of photoreactive discotic liquid crystals consisting of a triphenylene core and six cinnamate units with one (TPC1n) or two (TPC2n) n‐alkoxy groups (CnH2n+1O; n = 10–14), respectively, as peripheral groups are synthesized. Both of them are polymerized into fibers up to 2 mm long by UV irradiation in liquid paraffin in the columnar LC temperature ranges. The fiber structures seem to be preconstructed in liquid paraffin. In addition, TPC2n are shown to form microporous films up to 15 μm in diameter by simply casting the solutions of some solvents followed by drying for several minutes in air at room temperature. Photoirradiation of the films in the LC temperature range converts them to polymeric ones while preserving the microporous and hexagonally ordered structure. From comparison with TPC1n and the hydrogenated derivative of TPC212, the porous film‐forming property is suggested to result from the combination of the double bond of the cinnamoyl group and the two long alkoxy chains on the phenyl ring. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 605–612 Triphenylene‐derived liquid crystals (TPC1n and TPC2n [n = 12–14]) are shown to self‐assemble to fibers in liquid paraffin at the columnar liquid crystalline temperature range and also to form microporous films for TPC2n by casting its solutions at room temperature. They can be crosslinked to polymers, preserving their morphology, fibers, and films, by the [2 + 2] photocyclization of cinnamate units in the periphery by UV irradiation in the columnar liquid crystalline states. [ABSTRACT FROM AUTHOR]

A simplified one-pot and less harmful method has been introduced for the synthesis of borinic acid monomer. The corresponding borinic acid polymer (PBA) has been prepared by reversible addition-fragmentation chain transfer polymerization. Property investigations confirm the characteristics of PBA as a new type of 'smart material' in the field of thermo-responsive polymer. The potential application of PBA in the field of enzymatic biofuel cell has been illustrated with a wide open circuit potential of 0.92 V. [ABSTRACT FROM AUTHOR]

Abstract: Two types of microporous polymeric networks have been prepared from monomers containing N-tert-butoxycarbonyl-protected pyrrole by FeCl3-mediated oxidative coupling polymerization. These materials were predominantly microporous (with BET surface areas of 828 m2 g−1 and 1408 m2 g−1), exhibiting high CO2 uptake capacities (1.96 mmol g−1 and 2.69 mmol g−1 at 273 K, 1 bar). Novel microporous polymeric films (with BET surface areas of 570 m2 g−1 and 593 m2 g−1) were fabricated through in situ polymerization of monomers on a flat glass dish using a sol–gel process catalyzed by trifluoroacetic acid. [Copyright &y& Elsevier]

Abstract: This work reports a surface ion imprinting strategy in electropolymerized microporous poly(2-mercaptobenzothiazole) (MPMBT) films at the surface of glassy carbon electrode (GCE) for the electrochemical detection of Hg(II). The Hg(II)-imprinted MPMBT/GCE exhibits larger binding to functionalized capacity, faster binding kinetics and higher selectivity to template Hg(II) due to their high ratio of surface-imprinted sites, larger surface-to-volume ratios, the complete removal of Hg(II) templates and larger affinity to Hg(II). The square wave anodic stripping voltammetry (SW ASV) response of the Hg(II)-imprinted MPMBT/GCE to Hg(II) is ca. 3.0 and 5.9 times larger than that at the direct imprinted poly(2-mercaptobenzothiazole) modified GCE and non-imprinted MPMBT/GCE sensor, respectively; and the detection limit for Hg(II) is 0.1nM (which is well below the guideline value given by the World Health Organization). Excellent wide linear range (1.0–160.0nM) and good repeatability (relative standard deviation of 2.5%) were obtained for Hg(II). The interference experiments showed that mercury signal was not interfered in the presence of Pb(II), Cd(II), Zn(II), Cu(II) and Ag(I), respectively. These values, particularly the high sensitivity and excellent selectivity compared favorably with previously reported methods in the area of electrochemical Hg(II) detection, demonstrate the feasibility of using the prepared Hg(II)-imprinted MPMBT/GCE for efficient determination of Hg(II) in aqueous environmental samples. [Copyright &y& Elsevier]

The adverse effects of using calcium oxide (CaO) (quicklime) as a water absorber on polyethylene (PE) microporous film under actual production conditions are studied. A twin-screw extruder was used for compounding the calcium carbonate (CaCO3)/PE blend into pellets containing low-density polyethylene, linear low-density polyethylene, ground calcium carbonate, antioxidants, and lubricant. Two dehumidifying methods, hot air and CaO absorber, were used before film casting in a production line equipped with a stretching unit. Physical properties of two microporous films were compared with hydrostatic pressure, scanning electron microscopy, thermogravimetric analysis, and Fourier transform infrared analyses. The microporous film with CaO dehumidifier showed lower hydrostatic pressures on average with much greater variation and is prone to degradation versus the hot air dried resin. The results indicate that adverse effects occur due to the high alkaline basicity of CaO. [ABSTRACT FROM AUTHOR]

Microporous films from immiscible blends were produced via melt processing and post-step treatments. Polystyrene (PS)/polypropylene (PP) and poly(ethylene terephthalate) (PET)/polypropylene blend systems with different viscosity ratios were studied. The blends were first compounded in a co-rotating twin-screw extruder and subsequently extruded through a sheet die to obtain the precursor films. These were uniaxially or biaxially drawn (100–400%) with respect to the original dimension to induce microporous structure and post treated at elevated temperature to maintain the porous structure which consisted of uniform microcracks in the order of a few hundred nanometers. The fabrication process here is shown to be a promising technique for producing microporous films that can be used for liquid and gas separations. [ABSTRACT FROM PUBLISHER]

• HMDS molecules can penetrate open micropores and react with surface silanols. • Silylation with HMDS reduces porosity, but pore size distribution remains unchanged. • –CH 3 groups introduced by HMDS have limited time-dependant temperature stability. • Annealing after HMDS vapour treatment leads to micropore wall strengthening. • Annealing of porous BTESB film at 390 °C in N 2 causes aromatic ring destruction. This study aims hydrophobisation of a microporous phenylene-bridged organosilicate film via its surface modification with hexamethyldisilazane (HMDS) vapour to adapt it for use as a low dielectric constant material for advanced microelectronics technology. The microporous organosilicate film was spin-coated with 1,4-bis (triethoxysilyl) benzene, followed by soft baking at 120–200 °C and annealing at 390 °C in N 2. Subtractive porosity was added using a sacrificial template — Brij® L4. This 1,4-phenylene-bridged film possessed a large Young's modulus and small pore size. However, due to steric effects during the film formation, a large amount of unreacted silanol remained on the surface. The HMDS-induced hydrophobisation reduced the number of residual silanols and adsorbed water molecules, despite the small pore size. A decrease in the hydrophilicity of the film surface led to an increase in the WCA value as well as a decrease in the dielectric constant and dielectric loss tangent. Ellipsometric porosimetry showed that the open porosity decreased without changes in the pore size distribution as a result of silylation by the HMDS vapour. However, the Fourier transform infrared spectra showed limited time-dependant temperature stability of the –CH 3 groups introduced by the HMDS vapour treatment. The decrease in open porosity during the heat treatment of the hydrophobised film was significantly reduced because of the strengthening of the pore walls. Consequently, this film demonstrated lower shrinkage and larger Young's modulus. [ABSTRACT FROM AUTHOR]

4,4′-(4,4′-isopropylidenediphenoxy)bis(phthalic anhydride) (BPADA) as a dianhydride and bis(3-aminophenyl) sulfone (APS) and bis(3-amino-4-hydroxyphenyl) sulfone (APS-OH) as diamines were used to synthesize two types of poly(amic acid) (PAA). Varying amounts (0–5.0 wt%) of water-soluble poly(vinyl alcohol) (PVA) were mixed with PAA, and the resulting blend was heat-treated at different stages to obtain the colorless and transparent polyimide (CPI) blend films. The synthesized blended film completely removed water-soluble PVA in water. The possibility as a porous membrane according to the pore size varied according to the amount of PVA was investigated. The dispersibility and compatibility of CPI containing APS-OH monomer were higher than those of the APS monomer. This could be attributed to the hydrogen-bonding interactions between the CPI main chains and PVA. Scanning electron microscopy was conducted to characterize the material. The results revealed that the pore size of the CPI blend film increased as the PVA concentration increased. It was confirmed that uniform pores of μm-size were observed in CPI. The thermal stabilities, morphologies, optical properties, and solubilities of two CPIs obtained using APS and APS-OH monomers were investigated and their properties were compared with each other. [ABSTRACT FROM AUTHOR]