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Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Photocatalytic nanomaterials have been widely used in the photocatalytic fields. However, traditional nanomaterials need to be dispersed in the solution and usually have some difficulties to be separated. Herein, a floating and stable g-C3N4/PMMA/CFs porous film was designed by a simple casting method. Chemically protonated g-C3N4 treated by H2SO4 has good dispersion and adhesion with PMMA. Cotton fiber solution (CFs) was added to improve the flexibility of the film. The g-C3N4/PMMA/CFs porous film provides an automatic photocatalytic reaction platform, which can float on the surface of water and absorb the sunlight easily. Furthermore, PMMA is transparent, which have negligible influence on the light absorption for g-C3N4. The photocatalytic activity of the g-C3N4/PMMA porous film showed that the film containing 6% of g-C3N4 can degrade 83% of 50 mL RhB solution (10 mg/L) in 180 min. The recyclability showed that about 97% of the photocatalytic activity can be retained after six times of reuse. The stability of the film showed that more than 90% of the photocatalytic activity can be retained after ultrasonication for 60 min. [ABSTRACT FROM AUTHOR]

The rheological properties of nematic liquid crystals (NLC) - a two-component mixture of 2/3 parts of p-n-butyl-p-methoxyazoxybenzene and 1/3 parts of p-n-butyl-p-heptanoylazoxybenzene (ZhK-440, NIOPIK) and 4-cyano-4'-pentylbiphenyl (5CB, Merck) filling a porous polymer (PET) matrix with submicron pore diameters are studied. The experiments were fulfilled using the decaying Poiseuille flow arising in a polymer porous film of 23 μm thickness under the action of hydrostatic pressure gradient decreasing with time. In this case a polymer matrix can be considered as a number of cylindrical capillaries connected by a parallel schema. It results in an essential decrease in the hydrodynamic resistance of the system in comparison with the resistance of each capillary. The Newtonian nature of the flow was established, and the effective shear viscosities of NLC for different temperatures were determined. An analysis of the experimental data was carried out taking into account the effect of weak surface anchoring on the orientational structure of the liquid crystals. The data obtained can be used to calculate the technical characteristics of liquid crystal photonic devices.

In this work, Bi 2 S 3 /MoS 2 /Bi 2 MoO 6 hetero-structured porous films were fabricated via a facile anion exchange process using the as-prepared Bi 2 MoO 6 nanoflake array film as substrate material. The formation of Bi 2 S 3 /MoS 2 /Bi 2 MoO 6 ternary hetero-structured porous film is both thermodynamically controllable and reaction time dependent. Systematic experiments were done to investigate the products at each reaction stage and disclose the relationships between the composite components and reaction temperature and time. The study showed that the energy barrier need to be overpassed when MoS 2 and Bi 2 S 3 were simultaneously produced. The optimized Bi 2 S 3 /MoS 2 /Bi 2 MoO 6 photoelectrode exhibited significantly higher photoelectrocatalytic efficiency than Bi 2 MoO 6 , binary Bi 2 S 3 /Bi 2 MoO 6 and Bi 2 S 3 /MoS 2 photoelectrodes. The remarkable degradation efficiency of the Bi 2 S 3 /MoS 2 /Bi 2 MoO 6 photoelectrode comes from the synergy of high quality assembly and heterostructure interfaces between the three components. The optimized film assembly and stepwise band alignment in the ternary heterostructure composite contribute to visible light utilization, transport and separation of charge carriers, mass transport, and accessibility of active sites. The generated active species such as superoxide anions (O 2 −) and holes were detected to promote the decomposition of organic pollutants. The reasonable photoeletrocatalytic degradation mechanism was also proposed. [ABSTRACT FROM AUTHOR]

• The PU/SF composite porous film act as a support for decoration with Ag@AgCl NPs. • The Ag@AgCl-PU/SF exhibit a good photocatalytic activity on degradation of RhB under the UV and visible light. • The Ag@AgCl-PU/SF has a good antibacterial activity against S. aureus and E. coli. • The Ag@AgCl-PU/SF can be recycled easily without centrifugation and filtration. • The prepared processes are conducted under normal temperature and pressure and no need of special equipment. An efficient Ag@AgCl-polyurethane/silk fibroin (Ag@AgCl-PU/SF) composite photocatalyst was synthesized by an eco-friendly and practical multistep route, including a wet phase inversion technique, to prepare polyurethane/silk fibroin (PU/SF) composite porous films as a substrate. An impregnation-precipitation-photoreduction process was used to decorate Ag@AgCl nanoparticles in situ on the PU/SF composite porous films. The obtained samples exhibited high photocatalytic activity for the degradation of Rhodamine B (RhB) under ultraviolet and visible light. Meanwhile, the photocatalytic activity of the samples decreased only slightly after 4 runs of photodegradation of RhB. Importantly, the Ag@AgCl-PU/SF films could be recycled without centrifugation and filtration. The Ag@AgCl-PU/SF films also exhibited excellent antibacterial activity. Possible mechanisms for photocatalysis were proposed. This work may provide a new approach for the design of novel porous polyurethane film photoreactors that possess excellent photocatalytic and antibacterial activities for multifunctional applications. [ABSTRACT FROM AUTHOR]

The microstructure and crystallographic orientation of aluminum have a significant effect on the morphology of porous alumina films grown on the surface of Al by anodizing. Most existing works regarding the regularities of aluminum anodizing consider metal foils as isotropic media. The novelty of this study lies in the characterization of porous alumina coatings formed on aluminum single crystals with the same orientation, Al(111). Experiments are carried out in 0.3 M oxalic acid in a wide range of anodizing voltages of 20–140 V. Using scanning electron and atomic force microscopy, the dependence on the anodizing voltage of the degree of porous ordering with the formation of a hexagonal array, as well as height-profile parameters of the metal–oxide interface, are shown. The thickness-to-charge ratio for the used anodizing conditions is determined. [ABSTRACT FROM AUTHOR]

An analysis is given of the thermal action on an MGA-95 composite porous film cellulose acetate industrial prototype by differential scanning calorimetry. Investigation of an air-dry sample and a water-saturated sample indicates redistribution of the relation in the quantity of perfect crystal structures in crystallites having different values for the enthalpy of melting, which decreases for the low-temperature phase from 6.06 to 0.99 kJ/kg, and for the high-temperature phase, from 1.99 to 1.72 kJ kg. The total melting enthalpy of the endothermic peaks measures from 8.57 to 6.55 kJ/kg, which points to a reduction in the crystallinity of the water-saturated MGA-95 polymer composite film sample. [ABSTRACT FROM AUTHOR]

• Microcellular aramid films have been obtained using exclusively ionic liquids. • Density has been diminished from 1.4 g⋅cm−3 down to 0.37 g⋅cm−3. • Average cell size lies in the microcellular range (between 1 and 8 μm). • Cellular morphology can be controlled through the ionic liquid proportion. • Thermally induced phase-separation process has been investigated. We prepared microporous aramid films through a simple, inexpensive and green way, using ionic liquids (IL) as porosity promoters. Commercial poly(m -phenylene isophthalamide) (MPIA) films with different IL proportions were prepared, and then microporous films were obtained by removing the IL in distilled water. Microporous films presented density values between 0.34 and 0.71 g⋅cm−3 (around five times lower to commercial MPIA), with a homogeneous and controlled cellular morphology dependent on the proportion of the IL, showing cell sizes in the microcellular range (radii between 1 and 8 µm). Thermal, mechanical and electrical properties (specifically ionic conductivity) of the aramid films were analyzed to evaluate the influence of the IL proportion. Finally, it was observed that the MPIA/IL system presented a reversible thermally induced phase-separation process around 60 °C, which was characterized through AFM-Raman images and spectra, together with the variation of the ionic conductivity. [ABSTRACT FROM AUTHOR]

Copyright of Rare Metal Materials & Engineering is the property of Northwest Institute for Nonferrous Metal Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Infrared (IR) spectroscopy is a powerful technique for observing organic molecules, as it combines sensitive vibrational excitations with a non-destructive probe. However, gaseous volatile compounds in the air are challenging to detect, as they are not easy to immobilize in a sensing device and give enough signal by themselves. In this study, we fabricated a thin nanocrystalline metal-organic framework (nMOF) film on a surface plasmon resonance (SPR) substrate to enhance the IR vibration signal of the gaseous volatile compounds captured within the nMOF pores. Specifically, we synthesized nanocrystalline HKUST-1 (nHKUST-1) particles of ca. 80 nm diameter and used a colloidal dispersion of these particles to fabricate nHKUST-1 films by a spin-coating process. After finding that benzene was readily adsorbed onto nHKUST-1, an nHKUST-1 film deposited on a plasmonic Au substrate was successfully applied to the IR detection of gaseous benzene in air using surface-enhanced IR spectroscopy. [ABSTRACT FROM AUTHOR]

Self-assembled three-dimensional (3-D) colloidal crystals have been extensively utilized in nanolithography for fabricating a wide spectrum of functional periodic nanostructures for important technological applications. Here a simple and versatile way is reported using silica colloids to prepare close-packed particle multilayers by the Langmuir– Blodgett technique to create highly ordered 3-D colloidal crystals with unusual nanoarrays on a large variety of substrates. Successive deposition of monolayers using amphiphilic molecules in this approach allows control of the layer thickness, particle size, and especially packing structure of them in each layer. It has been demonstrated that the Langmuir–Blodgett film’s transparency and high antiglare optical properties are preserved even after multiple colloidal particle transfers on both straight and curved surfaces. The surface prepared by the Langmuir–Blodgett technique shows remarkable sensitivity for potential biodetection applications. These colloidal templated films have an optical response time of less than 40 s against essential bioproduct vapors. It is shown that the results are consistent with the Kelvin equation (ln P/Po = –2 Vl γ/rRT) when the liquid water layer is getting thicker. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Ordered porous films of single walled carbon nanotubes (SWCNTs) modified with a cationic surfactant, dimethyldioctadecylammonium bromide (DODMAB), are prepared at the air/water interface. We determined the parameters for tuning the well-defined reproducible porous films adjusting the casting conditions, the solvent polarity and DODMAB concentration, etc. Double-chain cations, DODMA+, can be completely removed through an ionic exchange reaction to obtain the ordered porous films of SWCNTs only. Compared with SWCNTs, the ordered porous SWCNTs films exhibit excellent antibacterial activity and electric conductivity. The ordered porous SWCNTs films were used for self-patterning of Ag nanoparticles attached to SWCNTs films which efficiently possess the catalytic reduction of organic dyes. This work may provide new avenues for the preparation of ordered functional carbon materials and is also envisaged to find applications in catalytic chemistry. [ABSTRACT FROM AUTHOR]

Graphical abstract New ABA tri-block copolymers of poly(tert -butylacrylate)- b -poly(2,2,2-trifluoroethyl acrylate)- b -poly(tert -butylacrylate) were synthesized via RAFT polymerization. The fabrication of their micelles, hydrophobic porous films and electrospun fibers was investigated. Highlights • A new ABA tri-block copolymer was successfully synthesized by RAFT polymerization. • The effect of PTFEA/P t BA ratio on self-assembly was investigated. • Hydrophobic ordered porous films were fabricated via static breath-figure process. • Hydrophobic microfibers were fabricated by electrospinning technique. Abstract New ABA tri-block copolymers of poly(tert -butylacrylate)- b -poly(2,2,2-trifluoroethyl acrylate)- b -poly(tert -butylacrylate) (P t BA- b -PTFEA- b -P t BA) with controlled molecular weight (M n,GPC = 14,900–27,000 g·mol−1) and narrow molecular weight distribution (Ð = 1.09–1.33) were successfully synthesized for the first time by reversible addition-fragmentation chain transfer (RAFT) polymerization in the presence of macromlecular chain transfer agent P t BA-CTA, which was obtained by RAFT polymerization of t BA using S,S ′-bis(α,α ′-dimethyl- α ″-acetic acid) trithiocarbonate (BDTAC) as chain transfer agent. The chain structure and component of P t BA- b -PTFEA- b -P t BA tri-block copolymers were characterized by 1H NMR, 19F NMR, GPC, FT-IR, UV and elemental analysis. The self-assembly behavior of such triblock copolymers in THF/H 2 O (v : v = 3:7) was studied by dynamic self-organized precipitation (D-SORP) method. The micellar of P t BA- b -PTFEA- b -P t BA with different particle size profiles and morphologies (average particle diameter = 365.7–536.7 nm, particle size distribution = 0.134–0.159) were observed and determined by SEM, TEM and DLS, respectively. The P t BA- b -PTFEA- b -P t BA tri-block copolymers were fabricated not only to hydrophobic ordered porous films (average pore diameter of 1.24–1.77 μm, static water contact angle = 102–118°) via static breath-figure process, but also to hydrophobic microfibers (average diameter of 4.96 μm, static water contact angle = 133°) by electrospinning technique. [ABSTRACT FROM AUTHOR]

Abstract Because of their wide applications, the polymer porous films with regular patterned structure have attracted more and more attention. Herein, the porous films created from the poly(p-phenylene)s/CHCl 3 solutions have been self-assembled in an alcohol-water mixed vapor atmosphere. The results show that the patterns of the films depend on the polymer concentration and the ratio of alcohols to water. The introduction of a small amount of alcohols can improve the regular pore patterns of the porous films. Using the mixed water/methanol droplets as soft templates, the ordered porous films can be obtained from a high-concentration polymer solution. The low-concentration polymer solution and a high ratio of alcohol to water lead to form large pores in the films. The alcohol-controlled breath figure method is a facile way to design and fabricate ordered porous films based on a conjugated polymer. Highlights • Ordered porous PPP films were self-assembled in alcohol/H 2 O mixed vapor atmospheres. • The patterns of the porous films depend on the polymer concentration and the ratio of alcohols to water. • The ratios of alcohol and H 2 O can adjust the sizes and regularity of pores. • The ordered BF arrays were obtained from CHCl 3 solution with 10 mg mL−1 in the mixed vapor atmospheres. • The alcohol-controlled BF method is facile way to fabricate ordered porous films. [ABSTRACT FROM AUTHOR]

Abstract: Through electrodeposition at a high current density and controlling the produced hydrogen gas, nanostructured copper foams were fabricated on copper as high-performance electrodes for supercapacitors. The structure and morphology of copper foams were controlled by adjusting deposition parameters and addition of acid acetic as bubble stabilizer addition. Acid acetic reduced the hydrophobic force between individual bubbles, and thus allowed controlling the porosity of the thin foam. Electrochemical impedance spectroscopy (EIS) measurements, galvanostatic charge/discharge (GCD) and cyclic voltammetry were carried out to study the electrochemical behavior of copper foams. EIS results showed that thin copper foams deposited from 0.4 M CuSO4 and 0.1 M CH3COOH, at 3 A/cm2 for 20 s present the highest specific capacitance that was 102.68 F/g. GCD data for the same foam showed a capacitance of 95 F/g at 1 mA/cm2. Cycle life study exhibited 90% capacitance retention after 6000 cycles at high current density (20 mA/cm2).Graphical abstract: [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract The stable and efficient immobilization of silver nanoparticles (AgNPs) on/into processable biomass-based macro-support with porous networks is a promising and sustainable strategy to achieve both high catalytic activity and excellent reusability for heterogeneous catalysis. In this work, a collagenic composite film was facilely fabricated at room temperature, via the self-assembly of natural collagen fibers (CFs) and gallic acid modified silver nanoparticles (GA@AgNPs) induced by chromium (III) cross-linking in water. The morphology and microstructure of such GA@AgNPs-Cr-CFs composite film was investigated by Scanning Electron Microscope (SEM) and X-ray Photoelectron Spectroscopy (XPS), respectively. The results revealed that the cross-linking based on the coordinated complexation between chromium ions (Cr3+) and carboxyl groups on CFs and GA@AgNPs played the critical role in the interwoven of collagen fibers, leading to a three dimensional (3D) interconnected porous network of the composite film with simultaneously incorporation and high payload of silver nanoparticles. Furthermore, this GA@AgNPs-Cr-CFs composite film exhibited excellent catalytic activity toward the reduction of 4-nitrophenol (4-NP), taking the advantage of its high specific surface area given by the interwoven fibrous network structure. More than that, such sustainable composite catalyst could be easily recovered and reused for ten cycles because of its high stability based on cross-linking. This catalytic platform constructed by natural fibers, noble metal nanoparticles and trivalent metal ions showed a sustainable avenue for heterogeneous catalytic system. [ABSTRACT FROM AUTHOR]

Two‐dimensional transition‐metal carbides called MXenes are emerging electrode materials for energy storage due to their metallic electrical conductivity and low ion diffusion barrier. In this work, we combined Ti2CTx MXene with graphene oxide (GO) followed by a thermal treatment to fabricate flexible rGO/Ti2CTr film, in which electrochemically active rGO and Ti2CTr nanosheets impede the stacking of layers and synergistically interact producing ionically and electronically conducting electrodes. The effect of the thermal treatment on the electrochemical performance of Ti2CTx is evaluated. As anode for Li‐ion storage, the thermally treated Ti2CTr possesses a higher capacity in comparison to as‐prepared Ti2CTx. The freestanding hybrid rGO/Ti2CTr films exhibit excellent reversible capacity (700 mAh g−1 at 0.1 Ag−1), cycling stability and rate performance. Additionally, flexible rGO/Ti3C2Tr films are made using the same method and also present improved capacity. Therefore, this study provides a simple, yet effective, approach to combine rGO with different MXenes, which can enhance their electrochemical properties for Li‐ion batteries. Flexible freestanding hybrid rGO/MXene films with enhanced Li‐ion storage capacity are fabricated by vacuum‐assisted filtration method followed by a simple thermal treatment. In the hybrid films, reduced graphene oxide nanosheets act as a binder, which bridges electrochemically active conducting MXene particles. The effect of the surface functional group (‐OH) on Li‐storage performance of MXenes is evaluated. [ABSTRACT FROM AUTHOR]

Keywords: Covalent Organic Frameworks; Electrode; Electrogenerated Acid; Imine Bond; Porous Film EN Covalent Organic Frameworks Electrode Electrogenerated Acid Imine Bond Porous Film 1 1 1 09/27/23 20231002 NES 231002 B Imine-based covalent organic frameworks b (COFs) were successfully formed and immobilized on an electrode surface promoted by electrogenerated acids, as demonstrated by Shinsuke Inagi et al. in their Research Article (e202307343). Covalent Organic Frameworks, Electrode, Electrogenerated Acid, Imine Bond, Porous Film Inside Back Cover: Site-Selective Synthesis and Concurrent Immobilization of Imine-Based Covalent Organic Frameworks on Electrodes Using an Electrogenerated Acid (Angew. [Extracted from the article]

Covalent Organic Frameworks, Electrode, Electrogenerated Acid, Imine Bond, Porous Film Keywords: Covalent Organic Frameworks; Electrode; Electrogenerated Acid; Imine Bond; Porous Film EN Covalent Organic Frameworks Electrode Electrogenerated Acid Imine Bond Porous Film 1 1 1 09/27/23 20231002 NES 231002 B Imine-based covalent organic frameworks b (COFs) were successfully formed and immobilized on an electrode surface promoted by electrogenerated acids, as demonstrated by Shinsuke Inagi et al. in their Research Article (e202307343). [Extracted from the article]

Highlights • A double-cylinder electrolyte cell allows the distinctionbetween normal and parallel flux in a film applied on steel. • The three electrode arrangement assesses the impedance normal to the metal substrate. • The four electrode configuration evaluates the impedance parallel to the metal-coat interface. • The equivalent circuit employed to study the behaviour takes account the porosity character of the film. Abstract The assessment of the protection properties of an organic film applied on metallic substrate is still a challenge. Barrier features are currently studied by electrochemical impedance spectroscopy (EIS) technique, using a classical three electrode arrangement, where current flow normal to the metallic substrate is measured, nevertheless, any information about parallel ionic conductivity is not acquired. The present paper proposes the use of a double cylinder electrochemical cell, in which the combination of three and four electrode arrangements allows the measurement not only the current flow normal to the metallic substrate but also parallel to the metal-coating interface. The EIS experiments are performed in a thick epoxy resin film applied on carbon steel, during 60 days of immersion in a 0.1 M Na 2 SO 4 + NaOH solution. The impedance values measured using the three electrode configuration are much higher than those obtained by the four electrode arrangement. This result can be explained considering that a current fraction flows parallel to the metal-coating interface. The impedance evolution is explained considering the presence of diverse pore families, which evolve in different ways depending on the ionic motion direction, normal or parallel. Changings are more remarkable in the parallel direction, reflecting the anisotropic character of the film. [ABSTRACT FROM AUTHOR]

Polyhedral oligomeric silsesquioxane (POSS) and glycidyl methacrylate (GMA) are used to synthesize linear L-(PGMA-b-MA-POSS), dicephalous D-(PGMA-b-MA-POSS)2, and four-armed T-(PGMA-b-MA-POSS)4 through atom transfer radical polymerization (ATRP). These different structured POSS/GMA-containing copolymers are applied to build the porous films through breath-figures (BF) method. L-(PGMA-b-MA-POSS) is easy to form the ordered porous BF film, and T-(PGMA-b-MA-POSS)4 tends to form well-distributed BF film due to its high segment density which is beneficial to stabilize water drop. It is proven that solvent has a great effect on the morphologies of BF film. The perfect BF film is developed in the relatively wet atmosphere as 5-8 μm diameter of pores casted in THF and 2-4 μm diameter of pores casted in CH2Cl2 with regular morphology. The developed BF film has superior stability than the film developed in natural conditions due to the shorter stable balancing time. Therefore, it is believed that the obtained porous films show great potential in coating application. [ABSTRACT FROM AUTHOR]

This study presents composite electrode materials based on Electrochemically Reduced graphene oxide (ERGO) and Ni-Cu Foam for supercapacitor applications. Constant potential (CP) method was used to form reduced graphene oxide on Ni-Cu foam and characterized by scanning electron microscopy (SEM), powder X-ray diffraction (XRD), X-Ray Photoelectron Spectra (XPS), Raman Spectroscopy and electrochemical measurements. ERGO improves the electrical conduction leading to decrease of the internal resistance of the heterostructure. The ERGO served as a conductive network to facilitate the collection and transportation of electrons during the cycling, improved the conductivity of Ni-Cu foam, and allowed for a larger specific surface area. The irregular porous structure allowed for the easy diffusion of the electrolyte into the inner region of the electrode. Moreover, the nanocomposite directly fabricated on Ni-Cu foam with a better adhesion and avoided the use of polymer binder. This method efficiently reduced ohmic polarization and enhanced the rate capability. As a result, the Ni-Cu foam/ERGO nanocomposite exhibited a specific capacitance of 1259.3 F g −1 at 2 A g −1 and about 99.3% of the capacitance retained after 5000 cycles. The capacitance retention was about 3% when the current density increased from 2 A g −1 to 15 A g −1 . This two-step process drop cast and GO reduction by potentiostatic method is nontoxic and scalable and holds promise for improved energy density from redox capacitance in comparison with the conventional double layer supercapacitors. [ABSTRACT FROM AUTHOR]

Abstract: A single solvent‐based film casting process for fabricating porous polymer films is developed in this study. The porous film is produced by mixing concentrated polylactic acid (PLA)/chloroform solution (20 wt%) and fresh chloroform solvent is followed by film casting. The average pore sizes of the films produced are seen to increase from 2.1 (±0.1) µm to 6.4 (±0.2) µm with increasing ratio of concentrated PLA solution and fresh solvent from 1:2 to 1:4. Functional groups of PLA after casting into porous film are confirmed via Fourier transform infrared spectroscopy analysis. Cytocompatibility studies (via Alamar Blue assessment) utilizing MG‐63 cells on the porous PLA films reveal an increase in cell metabolic activity up to 8 d postseeding. In addition, these direct cell culture studies show that the porous membranes support cell adhesion and growth not only on the surface but also through the porous structures of the membrane, highlighting the suitability of these porous films in tissue engineering applications. [ABSTRACT FROM AUTHOR]

A new three-dimensional (3D) porous nano-Ni-Cu foam/electrochemically reduced Graphene Oxide (ERGO) electrode for high performance supercapacitors is represented. In this study, Graphene Oxide (GO) in the form of nanosheets was deposited (0 V to −1.5 V vs. Saturated Calomel Electrode (SCE)) and reduced by cyclic voltammetry method under different scan rates in the range of 10–100 mV/s on Ni-Cu foam. Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) indicated that the graphene structure was considerably restored in ERGO. ERGO deposited at the electrochemical scan rate of 50 mV/s presented the best capacitance performance. Notably, a high specific capacitance of the 1380.2 F/g at a discharge rate of 2 A/g and also an energy density of 30.01 W h kg −1 at a power density of 10.2 kW/kg was achieved for fabricated nano-Ni-Cu foam/ERGO composite film. Moreover, the designed composite provided an excellent cycling stability, which is a very important requirement for being used as electrodes for high-performance supercapacitors. This work introduces the 3D porous nano-Ni-Cu foam/ERGO procedure an impressive approach in the direction of supercapacitors with high energy and power densities. [ABSTRACT FROM AUTHOR]

Photonic crystals based on titanium oxide are promising for optoelectronic applications, for example as components of solar cells and photodetectors. These materials attract great research attention because of the high refractive index of TiO2. One of the promising routes to prepare photonic crystals based on titanium oxide is titanium anodizing at periodically changing voltage or current. However, precise control of the photonic band gap position in anodic titania films is a challenge. To solve this problem, systematic data on the effective refractive index of the porous anodic titanium oxide are required. In this research, we determine quantitatively the dependence of the effective refractive index of porous anodic titanium oxide on the anodizing regime and develop a model which allows one to predict and, therefore, control photonic band gap position in the visible spectrum range with an accuracy better than 98.5%. The prospects of anodic titania photonic crystals implementation as refractive index sensors are demonstrated.

In this study, we present the effects of the morphological modification of an oxygen-sensing film on improving the sensitivity of luminescent oxygen sensors. Pores were made inside the volume and on the external surface of the oxygen-sensing film consisting of platinum(II) octaethylporphyrin (PtOEP) oxygen-sensitive dye embedded in a polystyrene (PS) polymer matrix. The size of the pores with diameters from 300 nm to 1 μm was controlled through the phase separation of the ternary system of PS, polyethylene glycol (PEG), and chloroform. Photoluminescence (PL) intensity and oxygen accessibility of the oxygen-sensing film were considered the main factors affecting the sensitivity of the sensors. PL intensity was analyzed through the diffused reflectance and absorbance of the oxygen-sensing film. Oxygen accessibility was analyzed based on the Langmuir-Hill absorption theory by considering the sensitivity saturation behaviors of the oxygen-sensing film above the excitation light source intensity of 1000 cd/m 2 . The optimized porous-structured oxygen-sensing film showed 61% higher sensitivity than the solid oxygen-sensing film. According to the measurement results, the sensitivity enhancement in the porous sensing film was significantly more driven by the increase in oxygen accessible sites than the increase in PL intensity. Furthermore, the sensing film with pores only on its external surface and not inside its volume showed 72% enhanced sensitivity relative to the solid sensing film. Therefore, the external surface area of the sensing film affects the sensitivity of the oxygen-sensing film significantly more than the pores inside the volume of the sensing film because the external surface acts as an oxygen diffusion barrier that limits the amount of oxygen that can access the oxygen-sensitive dye embedded in the polymer matrix. [ABSTRACT FROM AUTHOR]

We scrutinized the roles of fabrication conditions in the morphological construction of electrodeposited Cu using generated H2 bubbles as dynamic negative templates. Adjusting the concentration of acetic acid changed the shapes of the deposited Cu particles, adding cetyltrimethylammonium bromide made the generated Cu easily deposit and grow on the stabilized bubbles for more formation of interconnected dendrites, and decreasing Cu2+ concentration resulted in rugged dendritic morphologies. Increasing potential/current densities facilitated the deposition of Cu within the interstitial spaces of smaller bubbles and leaded to the more formation of interlocked dendrites with smaller pores and Cu particles, while increasing deposition time increased the deposited Cu amount for more dendrites with longer trunks but unvaried branches and Cu particles in size. Based on these investigations, we facilely prepared three-dimensionally bi-continuous porous Cu films under an optimized electrodeposition condition. The films composed of ~300 nm interconnected particles had ~5 µm underneath pores and ~50 µm surface pores with ~10 µm pore wall thickness. Our research paves an avenue for easily fabricating porous metals by considering the effects of the preparation conditions on the morphological evolution of the deposited metals and optimizing the preparation conditions. [ABSTRACT FROM AUTHOR]

Porous anatase TiO 2 films with disparate submicron/nanoscale topographies were fabricated in this study. The wettability of the films could be regulated from super-hydrophilicity to hydrophobicity using a facile soft template route. The surface morphologies of the prepared films were investigated by FESEM and AFM, with the porous structures characterized via BET. The wetting property of the films with micro level morphology was studied by contact angle (CA) measurements. On the above basis, the macroporous surfaces (templated by triblock copolymer P123 or cetyltrimethylammonium tosylate (CTATos)) with superhydrophilicity (CA = 0°) and the mesoporous surface (templated by cetyltrimethyl ammonium bromide (CTAB)) with hydrophobic characteristic (CA = 96°) were detected. It is interesting to find that even though the chemical composition is hydrophilic, the hydrophobic surface could still be formed by the mesoporous topography with a possible wetting mechanism based on the Cassie model. Moreover, the morphology dominant hydrophobicity was well maintained after heating at 500 °C for 2 h (CA = 91°), bringing the material greater potential under harsh conditions. [ABSTRACT FROM AUTHOR]

Porous TiO 2 films were deposited onto FTO (fluorine doped tin oxide) substrate through dry deposition method, and polystyrene (PS) beads used as a sacrificial material. In addition, pore size was controlled by introducing 50-nm- and 300-nm-sized PS beads. Moreover, the improved porous film was obtained by varying weight ratios of TiO 2 and PS powders to enhance DSSCs (dye-sensitized solar cell) efficiency. The DSSC with improved porous structure has shown efficiency of 6.8% with weight ratio (71.5%), which higher than that of only TiO 2 layer (6.08%) and other compositions. The IPCE analysis showed the maximum absorbance over the wavelength range of 550–800 nm resulted in higher efficiency. EIS results indicated that the electron generation and transfer properties of porous films were better than that of the TiO 2 layer only. From photovoltage decay measurement, the carrier lifetime was found to be longer in the porous structure than that of TiO 2 layer only. Then, we proposed formation mechanism of porous films and their relation for effective scattering/absorbance of light. Moreover, the porous structure also enhances the specific surface area for higher amount of dye loading. Therefore, deposition of porous films could improve the efficiency of DSSCs using facile process. [ABSTRACT FROM AUTHOR]

Poly( ε-caprolactone)-graphene oxide (PCL-GO) honeycomb-patterned films were successfully fabricated by breath figure method for the first time by the simple blending of individual components in a water miscible solvent, tetrahydrofuran. PCL-GO films were reduced using sodium borohydride to obtain PCL-reduced graphene oxide (PCL-rGO) films. The films were characterized by their color, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). TGA result shows the improvement of the thermal properties of PCL by the incorporation of GO. The SEM image shows the formation of monodispersed porous honeycomb-patterned PCL-GO films, and these patterns are retained after the reduction of GO to PCL-rGO without any wreckage. The reduction of GO to rGO was confirmed from the color of the films and from the XPS analysis. The present methodology is expected to widen the use of breath figure technique to achieve a wide variety of functionalized films by simple blending using water miscible solvents, which would otherwise not be possible using water immiscible solvents. [ABSTRACT FROM AUTHOR]

Herein we report an easy and efficient approach to prepare lightweight porous polyimide (PI)/reduced graphene oxide (RGO) composite films. First, porous poly (amic acid) (PAA)/graphene oxide (GO) composite films were prepared via non-solvent induced phase separation (NIPS) process. Afterwards PAA was converted into PI through thermal imidization and simultaneously GO dispersed in PAA matrix was in situ thermally reduced to RGO. The GO undergoing the same thermal treatment process as thermal imidization was characterized with thermogravimetric analysis, Raman spectra, X-ray photoelectron spectroscopy and X-ray diffraction to demonstrate that GO was in situ reduced during thermal imidization process. The resultant porous PI/RGO composite film (500-µm thickness), which was prepared from pristine PAA/GO composite with 8 wt% GO, exhibited effective electrical conductivity of 0.015 S m−1 and excellent specific shielding efficiency value of 693 dB cm2 g−1. In addition, the thermal stability of the porous PI/RGO composite films was also dramatically enhanced. Compared with that of porous PI film, the 5% weight loss temperature of the composite film mentioned above was improved from 525°C to 538°C. Moreover, tensile test showed that the composite film mentioned above possessed a tensile strength of 6.97 MPa and Young's modulus of 545 MPa, respectively. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Mesoporous nanostructured titanium-dioxide (TiO 2 ) films, with high uniformity and low packing density, are synthesized in a stagnation swirl-flame setup under an applied electric field, with voltage bias on the substrate and the burner grounded. The effects of uniform external electric-field strength and polarity are studied for different substrate temperatures and precursor-loading concentrations. The results manifest considerable differences in film characteristics, for differing electric fields, with more columnar structures and higher porosities produced under low-magnitude substrate voltages up to |±400|V. Interestingly, films have higher packing density at higher magnitude voltages of |±800|V. At low substrate temperatures, the morphology and structure are more prominent owing to less on-substrate sintering of the nanoparticles. At low-magnitude substrate voltages, oppositely-charged particles are attracted to the substrate, increasing their electrophoretic velocity but decreasing their in-flame growth and agglomeration, resulting in smaller particle size. Along with van der Waals forces and induced dipole–dipole interactions, more columnar-structured growth with lower packing density results. At high-magnitude voltages, the particles seem to acquire the same charge polarity as the voltage bias applied, being repelled and residing in the flame longer, thus increasing in-flame agglomeration and particle size. More branched-structured film growth with high packing density develops. [ABSTRACT FROM AUTHOR]