Study on the efficiency of ethylene vinyl acetate–fly ash composites for the uptake of phenols from synthetic waste water

In this study, ethylene vinyl acetate–fly ash (EVA‐FA) composites were prepared by the melt mixing technique using a rheomixer for the purpose of removing 2,4,6‐trichlorophenol (TCP) and p‐nitrophenol (PNP) from water. The fly ash was characterized by X‐ray fluorescence spectroscopy, scanning electron microscopy (SEM) and X‐ray diffraction (XRD); the composites were characterized using SEM and XRD. Brunauer, Emmett, and Teller (BET) measurements revealed a surface area (S_BET) of 0.07110 m²/g for the fly ash. The adsorption of TCP and PNP were monitored by UV–Vis spectrophotometer. The maximum adsorption of PNP was obtained at pH 5 after a contact period of 12 h, whereas that of the TCP was obtained at pH 4 after a period of 10 h has elapsed. The equilibrium adsorption data were evaluated using Langmuir and Freundlich adsorption isotherm models. The Langmuir adsorption model gave the better correlation coefficients for the equilibrium adsorption data. The kinetics data followed the pseudo‐second‐order model for both TCP and PNP. The theoretical maximum adsorption capacity (q_max) of the adsorbent used in the study was found to be 3.424 mg/g and 2.544 mg/g for TCP and PNP, respectively. The desorption of the phenols from the composites was performed using 0.2M NaOH. About 82.6% and 76.3% of TCP and PNP were recovered, respectively. The study showed that the pH of the solution and contact time play a significant role in the adsorption process. Furthermore, we have demonstrated that EVA‐FA composites have the potential to adsorb phenols from acidic water solutions. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Optimization of elution conditions of chitosan gel and the study of its adsorbent mechanism

Chitosan gel was prepared by crosslinking method. To make use of chitosan gel, the optimization of elution conditions and the adsorbent characteristics of chitosan gel were discussed in this article. The optimum elution conditions were c (NaCl) = 0.05 mol/L in Tris‐HCl (pH, 9.05) at the flow rate of 2.0–3.0 mL/min with chitosan gel (particle sizes, 120–140 μm). The effects of contact time, pH, initial BSA concentration, and temperature on adsorption were studied. The equilibrium data could be described well by Langmuir, Freundlich, and Redlich–Peterson models. Adsorption dynamics had been successfully studied by Langergren, intraparticle diffusion model and Avrami model. The thermodynamics parameters ΔG°, ΔH°, and ΔS° were calculated. The spectra studies indicated that the interaction between gel and protein was chiefly through electrostatic attraction in the shape of hydrogen bond. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1495–1506, 2007     

Hierarchical Self‐Assembly of Poly(Urethane)/Poly(Vinylidene Fluoride‐co‐Hexafluoropropylene) Blends into Highly Hydrophobic Electrospun Fibers with Reduced Protein Adsorption Profiles

Electrospinning of blend systems, combining two or more polymers, has gained increasing interest for the fabrication of fibers that combine properties of the individual polymers. Here, a versatile method to produce hydrophobic fibers composed of poly(vinylidene fluoride‐co‐hexafluoropropylene) (PVDFhfp) and polyurethane (PUR) is presented. PVDFhfp containing fibers are expected to reduce protein adsorption. In a one‐step process, blend solutions are electrospun into homogeneous nonwoven membranes with fiber diameters in the range of 0.6 ± 0.2 to 1.4 ± 0.7 µm. Surface fluorine concentrations measured by X‐ray photospectroscopy show an asymptotic dependency in function of the PVDFhfp to PUR ratio, reaching values close to pure PVDFhfp at a weight per weight ratio of 10% PVDFhfp to 90% PUR. This fluorine enrichment on the surface suggests a gradient structure along the fiber cross‐section. At increased surface fluorine concentration, the contact angle changes from 121 ± 3° (PUR) to 141 ± 4° (PUR/PVDFhfp). Furthermore, these highly hydrophobic fibers present significantly reduced fibrinogen or albumin adsorption compared to PUR membranes.     

Effect of β‐tricalcium phosphate on the thermal foaming behavior of poly(vinyl alcohol)/water system

Poly(vinyl alcohol) (PVA)/β‐tricalcium phosphate (β‐TCP, Ca₃ (PO₄)₂) porous composite, which has potential application in articular cartilage repair, was prepared through thermal foaming using water as both plasticizer and physical blowing agent. The effects of β‐TCP content on the foaming behavior, the structure and properties of the porous composites were studied. The results showed that β‐TCP could form hydrogen bonds or coordination interaction with PVA and water; with the incorporation of β‐TCP, the content of nonfreezable bound water in system increased, the water evaporation reduced, beneficial to the controllable foaming of water. The interactions between PVA‐β‐TCP led to the enhanced melt viscosity of PVA. Simultaneously, the β‐TCP particles in matrix could act as heterogeneous nucleation agent to increase the cell density. When β‐TCP content was 7.4 wt %, the porous composite showed the optimal cell structure, i.e., 250 μm average cell size and 87% porosity. The dynamic modulus of the porous composites increased with β‐TCP content and showed frequency‐dependence. The surface contact angle and permeability of the porous composites varied with β‐TCP content, which ranged from 35° to 48° and 11 × 10^?14 to 27 × 10^?14 m², respectively. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44737.     

Visualization study of flow condensation in hydrophobic microchannels

A visualization study on flow condensation in hydrophobic rectangular silicon microchannels with hydraulic diameter of approximately 150 μm is conducted. Thin Au film with thickness of 200 nm is sputtered on channel surfaces to create a hydrophobic surface with an equilibrium contact angle of approximately 96°. In addition to traditional droplet flow, droplet‐annular compound flow, droplet‐injection compound flow, and droplet‐bubble/slug compound flow are also observed. The results indicate that injection location is postponed, and injection frequency increases with increasing inlet vapor Reynolds number and condensate Weber number. An empirical correlation of the injection location and injection frequency are presented and discussed. In particular, for a larger inlet vapor Reynolds number, the injection flow is closer to the channel outlet and the condensation heat transfer is enhanced. © 2014 American Institute of Chemical Engineers AIChE J, 60: 1182–1192, 2014     

Equilibrium,kinetics, and thermodynamics of Pd(II) adsorption onto poly(m‐aminobenzoic acid) chelating polymer

This study describes the equilibrium, kinetics, and thermodynamics of the palladium(II) (Pd(II)) adsorption onto poly(m‐aminobenzoic acid) (p‐mABA) chelating polymer. The p‐mABA was synthesized by the oxidation reaction of m‐aminobenzoic acid monomer with ammonium peroxydisulfate (APS). The synthesized p‐mABA chelating polymer was characterized by FTIR spectroscopy, gel permeation chromatography (GPC), thermal analysis, potentiometric titration, and scanning electron microscopy (SEM) analysis methods. The effects of the acidity, temperature, and initial Pd(II) concentration on the adsorption were examined by using batch adsorption technique. The optimum acidity for the Pd(II) adsorption was determined as pH 2. In the equilibrium studies, it was found that the Pd(II) adsorption capacity of the polymer was to be 24.21 mg/g and the adsorption data fitted better to the Langmuir isotherm than the Freundlich isotherm. The kinetics of the adsorption fitted to pseudo‐second‐order kinetic model. In the thermodynamic evaluation of the adsorption, the ΔG° values were calculated as ?16.98 and ?22.26 kJ/mol at 25–55°C temperatures. The enthalpy (ΔH°), entropy (ΔS°), and the activation energy (E_a) were found as 35.40 kJ/mol, 176.05 J/mol K, and 61.71 kJ/mol, respectively. The adsorption of Pd(II) ions onto p‐mABA was a spontaneous, endothermic, and chemical adsorption process which is governed by both ionic interaction and chelating mechanisms. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42533.     

Synthesis and properties of ultralow dielectric constant porous polyimide films containing trifluoromethyl groups

In this research, a series of porous copolyimide (co‐PI) films containing trifluoromethyl group (CF₃) were facilely prepared via a phase separation process. The co‐PI were synthesized by the reaction of benzophenone‐3,3′,4,4′‐tetracarboxylic dianhydride (BTDA) with two diamines of 4,4′‐diaminodiphenyl ether (ODA) and 3‐trifluoromethyl‐4,4'‐diaminodiphenyl ether (FODA) with various molar ratios. The flexible and tough porous co‐PI films with about 300 μm thickness and 8～10 μm average diameter could be obtained by solution casting conveniently. The thermal properties of the obtained porous co‐PI films were excellent with a glass transition temperature at 270 °C ～ 280 °C and only 5% weight loss in temperature from 530 °C to 560 °C under nitrogen atmosphere. In addition, the dielectric and hydrophobic properties of porous co‐PI films were remarkably improved owing to the presence of trifluoromethyl groups (CF₃) in the polymer chains. Moreover, our synthesized porous co‐PI films also showed good mechanical properties. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44494.     

Thermoresponsive and magnetic molecularly imprinted polymers based on iron oxide encapsulated carbon nanotubes as a matrix for the selective adsorption and controlled release of 2,4,5‐trichlorophenol

Thermoresponsive and magnetic molecularly imprinted polymers (TMMIPs) based on magnetic carbon nanotubes (MCNTs) were prepared and applied to the switched recognition and controlled release of 2,4,5‐trichlorophenol (2,4,5‐TCP) from aqueous solution. In this study, MCNTs were first synthesized via the encapsulation of Fe₃O₄ nanoparticles into the tunnel of carbon nanotubes by a wet impregnation technology. Then, the TMMIPs were synthesized with N‐isopropyl acrylamide as a thermal functional monomer by free‐radical polymerization. The magnetic sensitivity and stability of the prepared materials were tested with a vibrating sample magnetometer (saturation magnetization = 1.4 emu/g) and atomic absorption spectrophotometer (in the pH range 3.0–8.0), respectively. The thermoresponsive properties of the TMMIPs were evaluated by two means, including the results of ultraviolet–visible spectroscopy and the controlled release of 2,4,5‐TCP at 30 and 40°C, respectively. The effects of the pH, initial concentration, and contact time on adsorption were examined with batch mode experiments, and several other compounds were selected as model analytes to evaluate the selective recognition performance of the TMMIPs. This demonstrated that the TMMIPs had a higher affinity for 2,4,5‐TCP than did the thermoresponsive and magnetic nonimprinted polymers. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42087.     

Adsorption of pigments and free fatty acids from shea butter on activated Cameroonian clays

Adsorption of pigments and free fatty acids from shea butter on acid‐activated Cameroonian local clays was investigated. The adsorption of the pigments was followed by the reduction of the absorbance of the shea butter at 295 nm. The kinetic study revealed that both the temperature at which the experiment was performed and the degree of activation of the clays influence the time of contact required to reach adsorption equilibrium of the pigments and the amount of pigments adsorbed. Thus, at 90 °C, the time required was 30 min for the clays activated with 0.5 M (A0.5M) and 1.0 M solutions (A1M) of sulphuric acid, and 45 min for the clay activated with a 2.0 M solution (A2M) of sulphuric acid. At 80 °C, the adsorption equilibrium was reached after 45 min for clays A0.5M and A1M, and 60 min for clay A2M. At 65 °C, the contact time to reach adsorption equilibrium was longer than 75 min for all the adsorbents used. At 90 °C, the amount of pigments adsorbed at equilibrium by clay A2M was about two thirds of that adsorbed by clay A0.5M, and one half of the amount adsorbed by clay A1M. For each adsorbent, the amount of pigment adsorbed decreased with temperature. A1M was the most efficient local clay for the adsorption of shea butter pigments and compared favourably with the industrial clay used as reference. The same evolution was observed with the adsorption of free fatty acids on different clays. The contact time needed for the elimination of peroxides was 40 min for all the clays used. The most efficient adsorbents for the adsorption of the pigments and free fatty acids were also the ones that gave the best results in the elimination of peroxides. The energy of activation for the adsorption of the pigments, as determined by the adsorption kinetic model of Brimberg, were 61 ± 9 kJ/mol, 73 ± 11 kJ/mol, 67 ± 10 kJ/mol, and 47 ± 7 kJ/mol for the industrial adsorbent (EN) and clays A0.5M, A1M and A2M, respectively. These values of activation energies indicate that the shea butter pigments are chemisorbed on acid‐activated clays. It was found that the adsorption isotherms follow the Freundlich equation.     

Electrophoretic deposition of surface-modified titanate nanosheets via layer-by-layer assembly and deposited film properties

The surface of H₂Ti₄O₉·xH₂O titanate nanosheets was modified using the sulfonated tetrafluoroethylene-based polymer Nafion^®, via layer-by-layer assembly. The surface modification allowed the titanate nanosheets to be highly dispersed in hydrophobic organic solvents. Thick films of surface-modified nanosheets were prepared on indium tin oxide (ITO)-coated glass substrates as a negative electrode by electrophoretic deposition. The thickness of the films increased with increasing deposition time and grew to more than 8 μm in 600 s under potentiostatic conditions at 7.5 V. The electrophoretically deposited thick films showed significant hydrophobicity with contact angle for water 95°, and enhanced adsorption and higher photocatalytic activity for hydrophobic dyes such as thionine than those of thick films prepared from unmodified titanate nanosheets.     

Preparation of composite‐crosslinked poly(N‐isopropylacrylamide) gel layer and characteristics of reverse hydrophilic–hydrophobic surface

The composite‐crosslinked poly(N‐isopropylacrylamide) (PNIPAAm) gels were prepared by grafting N‐isopropylacrylamide on the surface of glass plates modified by organosilanes. The glass plates as the substrate increase the mechanical strength of composite PNIPAAm gel layers. We investigated the effects of a series of organosilanes and the reaction time of organosilanes on surface characteristics, such as the static contact angle and the layer thickness. We discuss the equilibrium swelling ratio and the water release behavior of the gel layers in terms of the crosslinking density of the composite gels. The composite gels exhibit not only the characteristics of remarkable water release but also the reversed hydrophilic–hydrophobic surface properties. The gel layers are hydrophilic under 25°C and change to hydrophobic above 40°C. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 1–11, 1999     

Dependence of morphological changes of polymer particles on hydrophobic/hydrophilic additives

Fairly uniform microspheres of poly(styrene‐co‐methyl methacrylate) were prepared by employing a microporous glass membrane [Shirasu porous glass (SPG)]. The single‐step SPG emulsification, the emulsion composed mainly of monomers, hydrophobic additives, and an oil‐soluble initiator, suspended in the aqueous phase containing a stabilizer and inhibitor, was then transferred to a reactor, and subsequent suspension polymerization followed. The droplets obtained were polymerized at 75°C under a nitrogen atmosphere for 24 h. The uniform poly(styrene‐co‐methyl methacrylate) microspheres with diameters ranging from 7 to 14 μm and a narrow particle‐size distribution with a coefficient of variation close to 10% were prepared by using SPG membrane with a pore size of 1.42 μm. The effects of the crosslinking agent and hydrophobic additives on the particle size, particle‐size distribution, and morphologies were investigated. It was found that the particle size decreased with a narrower size distribution when the additives were changed from long‐chain alkanes to long‐chain alcohols and long‐chain esters, respectively. Various microspheres with different morphologies were obtained, depending on the composition of the oil phase. The spherical poly(styrene‐co‐methyl methacrylate) particles without phase separation were obtained when using an adequate amount of the crosslinking agent and methyl palmitate as an additive. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 1013–1028, 2000     

Antimicrobial polyethylene wax emulsion and its application on active paper‐based packaging material

Antimicrobial polyethylene wax (PEW) emulsions, prepared by emulsifying polyethylene wax grafted with polyhexamethylene guanidine hydrochloride (PEW‐g‐PHGH), were used as wet‐end additives or coating materials for fabricating hydrophobic and anti‐mold hand‐sheets or paper. To obtain PEW‐g‐PHGH, maleic anhydride (MAH) was adopted as a bridging agent. The melt or solution grafting of MAH to PEW was performed to achieve the appropriate grafting degree and grafting efficiency. The resulting PEW‐g‐PHGH was emulsified using a homogenizer by means of surfactants, and the resulted emulsions were characterized in terms of particle size, zeta potential, charge density, minimal inhibitory concentration (MIC), and adsorption capacity. After that the hydrophobicity of emulsion treated hand‐sheets was determined by measuring water contact angle (WCA). The morphology of the hand‐sheets treated by the emulsion was revealed using scanning electron microscope (SEM) and atom force microscope (AFM). Finally, the antimicrobial properties of the emulsion treated hand‐sheets were investigated by anti‐mold tests against Aspergillus niger and Chaetomium globosum. Results indicated that the PEW‐g‐PHGH emulsions exhibited good stability, high fiber adsorption capacity, and antimicrobial activity. The WCAs of the treated hand‐sheets reached 82°–140° with 80%～99.9% growth inhibition against fungi. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42214.     

Effects of micro and nano β‐TCP fillers in freeze‐gelled chitosan scaffolds for bone tissue engineering

Tissue engineering holds an exciting promise in providing a long‐term cure to bone‐related defects and diseases. However, one of the most important prerequisites for bone tissue engineering is an ideal platform that can aid tissue genesis by having biomimetic, mechanostable, and cytocompatible characteristics. Chitosan (CS) was chosen as the base polymer to incorporate filler, namely beta‐tri calcium phosphate (β‐TCP). This research deals with a comparative study on the properties of CS scaffolds prepared using micro‐ and nano‐sized β‐TCP as filler by freeze gelation method. The scaffolds were characterized for their morphology, porosity, swelling, structural, chemical, biodegradation, and bioresorption properties. Rheological behavior of polymer and polymer‐ceramic composite suspensions were analyzed and all the suspensions with varying ratios of β‐TCP showed non‐Newtonian behavior with shear thinning property. Pore size, porosity of micro‐ and nano‐sized composite scaffolds are measured as 48–158 μm and 77% and 43–155 μm and 81%, respectively. The scaffolds containing nano β‐TCP possess higher compressive strength (～2.67 MPa) and slower degradation rate as compared to composites prepared with micro‐sized β‐TCP (～1.52 MPa). Bioresorbability, in vitro cell viability by 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) assay, proliferation by Alamar blue assay, cell interaction by scanning electron microscope, and florescence microscopy further validates the potentiality of freeze‐gelled CS/β‐TCP composite scaffolds for bone tissue engineering applications. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41025.     

Preparation and characterizations of activated carbon from kenaf fiber for equilibrium adsorption studies of copper from wastewater

The potential of activated carbon prepared from kenaf fiber (KF) to remove copper (II) from aqueous effluents was investigated. The fibers were first semi-carbonized, then impregnated with potassium hydroxide (KOH) and finally activated by using carbon dioxide (CO₂) gas to produce activated carbon. Pore structure and physical characteristics of the prepared kenaf fiber activated carbon (KFAC) were determined. Adsorption studies for divalent copper (Cu) ions were carried out to delineate the effect of contact time, temperature, pH and initial metal ion concentration on equilibrium adsorption capacity. The experimental data followed pseudo-second-order kinetics and Elovich Model than pseudo-first-order. Langmuir, Freundlich and Temkin models were implemented to analyze the parameters for adsorption at 30 °C, 50 °C and 70 °C. Thermodynamic parameters such as ??G ^o , ??H ^o and ??S ^o which represent Gibbs free energy, enthalpy and entropy, respectively, were evaluated. It was concluded that activated carbon from kenaf fiber (KFAC) can be used as an efficient adsorbent for removal of Cu (II) from synthetic wastewater.     

Spray‐dried microparticles composed of cinnamoyl poly(N‐isopropylacrylamide‐co‐hydroxyethylacrylate) and gold nanoparticle

Temperature‐ and NIR irradiation‐responsive microparticles composed of cinnamoyl poly(N‐isopropylacrylamide‐co‐hydroxyethylacrylate) [CinP(NIPAM‐HEA)] and gold nanoparticle (GNP) were prepared by a spray‐drying method. According to the cloud points determined by an optical method, the HEA content in P(NIPAM‐HEA) had no marked effect on the lower critical solution temperature (LCST). However, the cinnamoyl group content in CinP(NIPAM‐HEA) had a significant effect on the LCST. The LCSTs determined by a calorimetric method was in agreement with those determined by an optical method. The hydrodynamic mean diameter of gold nanoparticle (GNP) prepared by reducing gold ions was about 30 nm and it seemed to be a nanosphere on TEM photo. Spray‐dried CinP(NIPAM‐HEA) microparticles containing GNP was 1.5 μm to 12 μm in diameter on SEM photo. Gold was detected on the energy‐dispersive X‐ray spectrum of the microparticles. The amount of FITC‐dextran released for 12 h from the microparticles was much higher at temperatures above the LCST (at 37 °C and 45 °C) than below the LCST (at 20 °C and 25 °C). The cumulative release amount in 12 h was only about 3% without NIR irradiation, whereas the value was about 26.5% when NIR was irradiated to the microparticle suspension. The photothermal energy generated by GNP was believed to render the thermosensitive copolymers de‐swollen and hydrophobic, allowing for the active release of dye from the microparticles. The NIR irradiation‐responsive GNP‐loaded microparticles could be applied to the development of NIR‐responsive drug carriers which release their contents in response to an external stimulus (i.e., NIR irradiation). © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44141.     

Production of superhydrophobic polymer fibers with embedded particles using the electrospinning technique

Superhydrophobic materials are currently used for their water‐repelling, self‐cleaning and anti‐fouling properties but are also potentially attractive to prevent snow or ice accumulation on exposed structures. Using the electrospinning technique, polymer mats made of polystyrene and poly[tetrafluoroethylene‐co‐(vinylidene fluoride)‐co‐propylene] (PTVFP) were prepared. They were found to show highly hydrophobic properties, water contact angle (CA) between 130 and 150°, when a dual fiber–bead microstructure was observed. Superhydrophobicity, CA > 150°, was reached when PTVFP mats were electrospun from a polymer solution containing dispersed polytetrafluoroethylene (PTFE) nanoparticles. Using atomic force microscopy imaging, protruding nanosized asperities on fiber and bead surfaces were observed and this structure led to superhydrophobic properties. Materials prepared from a high‐viscosity PTVFP/ethyl acetate solution with PTFE particles, 200 nm diameter and 8% (w/w), showed an 11.2% improvement in hydrophobicity, CA = 161°, compared to the materials obtained from a particle‐free polymer solution (CA = 143°). Copyright © 2007 Society of Chemical Industry     

Hydrophobically modified nano-SiO2 in situ loaded on polyurethane foam as a potential carrier for marine oil spill

In order to enhance the oil–water separation properties of polyurethane foam (PFU), hydrophobic silica nanoparticles (H-SiO₂ NPs) were firstly prepared by incorporating long alkyl chains into silica nanoparticles, and then, it was combined with PFU by in situ loading to fabricate a hydrophobic PFU (H-SiO₂ NPs/PUF). When the loading amount of H-SiO₂ NPs was 10%, the water contact angle of the modified foam H-SiO₂ NPs/PUF-10 reached 147 ± 1°, which proved it was highly hydrophobic. The elongation at break of the foam was increased by 202%, which indicated that it had better resilience and recyclability. In addition, the total pore area and porosity were increased to 16.24 m²/g and 88.43% from 5.46 m²/g and 2.11%, which provided more storage space for adsorption. The oil–water separation experiment showed that the adsorption capacity for most light oils was 11–13 g/g, and that for dichloromethane was as high as 40.5 g/g. After 10 adsorption–desorption cycles, the adsorption capacity only decreased from 15.6 to 14.5 g/g, which was still 93% of the initial adsorption capacity. H-SiO₂ NPs/PUF represents good adsorption capacity, recyclability, and recyclability, so it as a carrier has a potential application in the treatment of marine oil spills.     

NI/NI‐YSZ Current Collector/Anode Dual Layer Hollow Fibers for Micro‐Tubular Solid Oxide Fuel Cells

A co‐extrusion technique was employed to fabricate a novel dual layer NiO/NiO‐YSZ hollow fiber (HF) precursor which was then co‐sintered at 1,400 °C and reduced at 700 °C to form, respectively, a meshed porous inner Ni current collector and outer Ni‐YSZ anode layers for SOFC applications. The inner thin and highly porous “mesh‐like” pure Ni layer of approximately 50 μm in thickness functions as a current collector in micro‐tubular solid oxide fuel cell (SOFC), aiming at highly efficient current collection with low fuel diffusion resistance, while the thicker outer Ni‐YSZ layer of 260 μm acts as an anode, providing also major mechanical strength to the dual‐layer HF. Achieved morphology consisted of short finger‐like voids originating from the inner lumen of the HF, and a sponge‐like structure filling most of the Ni‐YSZ anode layer, which is considered to be suitable macrostructure for anode SOFC system. The electrical conductivity of the meshed porous inner Ni layer is measured to be 77.5 × 10⁵ S m^–1. This result is significantly higher than previous reported results on single layer Ni‐YSZ HFs, which performs not only as a catalyst for the oxidation reaction, but also as a current collector. These results highlight the advantages of this novel dual‐layer HF design as a new and highly efficient way of collecting current from the lumen of micro‐tubular SOFC.     

High‐Speed Preparation of Highly (100)‐Oriented CeO2 Film by Laser Chemical Vapor Deposition

CeO₂ films were prepared at deposition temperature ranged from 947 to 1096 K (corresponding laser power was from 52 to 185 W) on (100) LaAlO₃ single crystal substrate by laser chemical vapor deposition. At deposition temperature of 1027–1096 K (laser power was from 115 to 185 W), highly (100)‐oriented CeO₂ films with wedge‐caped columnar grains were prepared, whose epitaxial growth relationship was CeO₂ [100]//LAO [100] (CeO₂ [010]//LAO [011]). Their full width at half maximum of the ω‐scan on the (200) reflection and that of the ?‐scan on the (220) reflection were 0.8°–1.8° and 0.7°–1.2°, respectively. The highest deposition rate at which CeO₂ film with pure (100) preferred orientation could be obtained was 30 μm h^?1.