Ladder-Structured Polysilsesquioxane/Al<Subscript>2</Subscript>O<Subscript>3</Subscript> Nanocomposites for Transparent Wear-Resistant Windows

As a protective layer for deformable displays, we synthesized ladder-type polysilsesquioxanes (LPSQs) containing cyclic epoxy as a curable unit. The mechanical properties after photo- and thermal-curing of LPSQs with a small amount of added Al₂O₃ nanoparticles were compared with those of the pure LPSQs. The prepared LPSQ-Al₂O₃ nanocomposites and the pure LPSQs exhibited comparable optical transparencies and thermal stabilities. In addition, the degree of conversion of the applied epoxy units in LPSQs and the resulting mechanical properties, as monitored by Fourier transform infrared spectroscopy and nanoindentation tests, indicated that the addition of nanoparticles to LPSQs moderately enhanced the epoxy conversion rate and remarkably improved the wear resistance, including hardness, after photo-/thermal-curing processes. The LPSQ-Al₂O₃ nanocomposites achieved higher wear resistance than epoxy-silica nanocomposites containing similar curable functional groups and reinforcing fillers (silica). The excellent mechanical properties of the LPSQ-Al₂O₃ nanocomposites could be attributed to three-dimensionally interconnected networks of organic-inorganic hybrid-type chemical structures in the LPSQ as well as additional reinforcement from amine-functionalized Al₂O₃ nanoparticles covalently interconnected with the LPSQ. We believe that the devised LPSQ-Al₂O₃ nanocomposites could serve effectively as a wear-resistant platform for deformable display windows.     

Preparation of magnetic and conductive graphite nanoflakes/SrFe<Subscript>12</Subscript>O<Subscript>19</Subscript>/polythiophene nanofiber-nanocomposites and its radar absorbing application

This study, we synthesized graphite-nanoflakes (GNFs) by acid treatment and thermal shock and then using the ultrasonic irradiation technique to exfoliate flake-carbon. The SrFe₁₂O₁₉ nanoparticles (NPs) were coated by co-precipitate method on GNFs after by alkaline treatment. Finally nanocomposite (GNF/SrFe₁₂O₁₉/PTh) was prepared by in-situ oxidative polymerization method in presence of thiophene (Th) as monomer. The magnetic and electrical conducting properties of the resulting nanocomposites were measured by using vibrating sample magnetometer and standard four-point-probe method, respectively. The synthesized nanocomposites were characterized by X-ray diffraction (XRD) and fourier transform infrared spectra (FTIR). In addition, morphological analyses were investigated by scanning electron microscopy (SEM). A minimum reflection loss (RL) of GNFs/SrFe₁₂O₁₉/PTh with 50 % wt GNFs/SrFe₁₂O₁₉ as core were observed ?28 and ?39 dB at 9.7 and 12 GHz for a 1.5 mm thickness. The results indicated that we can perform good microwave shielding in X-band (8–12 GHz) by these nanocomposites.     

Synthesis of Ag-Loaded TiO<Subscript>2</Subscript> Electrospun Nanofibers for Photocatalytic Decolorization of Methylene Blue

Titanium dioxide (TiO₂) is one of the excellent photocatalysts used for degradation of environmetal pollutants. In this work, 2.5, 5.0 and 7.5 wt.% of silver (Ag)-loaded TiO₂ nanofibers of mean size 52–134 nm were synthesized by electrospinning method. These electrospun nanofibers were calcined at 500 °C to enable the transformation of Rutile (R) phase to Anatase (A), elimination of reaction moieties from the TiO₂ matrix and subsequently formation of Ag clusters. The effect of Ag loading on the morphology, crystal structure, phase transformation, and band gap of these electrospun nanofibers have been characterized by scannining electron microscopy (SEM), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), raman spectroscopy and UV-visible spectroscopy. These nanofibers exhibited a red-shift in the absorbance edge and a significant enhancement of light absorption in the wavelength range of 250–550 nm. These electrospun nanofibers were investigated for photodecomposition of methylene blue (MB), and photocatalytic decolorization rates were determined by pseudo-first-order equation. The rate constants for the pure and those of 2.5, 5.0, and 7.5 wt% Agloaded TiO₂ nanofibers were computed to be 0.1439 min^-1, 0.1608 min^-1, 0.1876 min^-1, and 0.2251 min^-1 respectively.     

Fabrication and characterization of nano Al<Subscript>2</Subscript>O<Subscript>3</Subscript> filled PVA:NH<Subscript>4</Subscript>SCN electrolyte nanofibers by electrospinning

Present paper reports a method of preparing polymer composite electrolyte nanofiber mat using polyvinyl alcohol (PVA), ammonium thiocynate (NH₄SCN) salt, and aluminium oxide (Al₂O₃) nano particles based on electrospinning technique. Two-stage process of preparation of nanofibers, namely, preparation of nano particles filled PVA electrolyte gel solution followed by its electrospinning has been used. The so obtained nanofibers have been characterized by XRD, DSC, SEM, and Conductivity measurements. XRD patterns affirm the formation of nanocomposite while SEM pictures reveal formation of fibers on a nano scale format (300–800 nm). Fibers of the electrolytes are seen to be thermally stable. Ionic conductivity of electrolyte fiber is seen to improve in the presence of nano filler at room temperature with a maximum at 5.31×10⁻³ Scm⁻¹ for 4 wt% filler concentration, which is comparable to that for corresponding dried gel electrolyte films.     

Controlling the Properties of OPEFB/PLA Polymer Composite by Using Fe<Subscript>2</Subscript>O<Subscript>3</Subscript> for Microwave Applications

Microwave-absorptive polymer composite materials provide protection against interference to communication systems caused by microwave-inducing devices. Microwave-absorptive polymer composites were prepared from polylactic acid (PLA) biocomposite blended with oil palm empty fruit bunch (OPEFB) fiber and commercial Iron oxide (Fe₂O₃) as filler using the melt-blending method. The composites characterization was carried out using the scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses. The coefficient of reflection S₁₁ and coefficient of transmission S₂₁ of the composites for various Fe₂O₃ filler percentages were determined using a rectangular waveguide in connection with microwave vector network analyser (HP/Agilent model PNA N5227). These coefficients were then used to calculate microwave-absorption properties (in decibels). XRD analysis showed that increasing amounts of reinforced material (Fe₂O₃) reduces the crystallinity of the composites. SEM data indicated that Fe₂O₃ filler ratio increased in the composites, and adhesion to the cellulose fiber grew gradually until the highest percentage of filler was added. The complex relative permittivity and relative permeability were obtained within the broad frequency range of 8–12 GHz at room temperature for various percentages of filler and were measured by the transmission/reflection method using a vector network analyser. Fe₂O₃ embedment in OPEFB/PLA was observed to have resulted in enhancing the dielectric and magnetic properties. The values of permittivity and permeability increased with increasing Fe₂O₃ filler content. Theoretical simulation studied the relation between ε′ and ε″ of the relative complex permittivity in terms of Cole-Cole dispersion law. The result indicated that the processes of Debye relaxation in Fe₂O₃/OPEFB/PLA, the unique dielectric characteristics of Fe₂O₃ cannot be accounted for by both the Debye dipolar relaxation and natural resonance. Results further showed that the material transmission, reflection, and absorption properties could be controlled by changing the percentage of Fe₂O₃ filler in the composites.     

Immobilization of Cationic Titanium Dioxide (TiO<Subscript>2</Subscript><Superscript>+</Superscript>) on Electrospun Nanofibrous Mat: Synthesis,Characterization, and Potential Environmental Application

We report a facile approach to fabrication and characterization of cationic titanium dioxide (TiO₂⁺) on poly (vinyl alcohol)/poly (acrylic acid) (PVA/PAA) composite electro-spun nanofibrous mat. The aim of this study is to develop a “functional electrospun nanofibrous mat” as a sustainable approach to superior photocatalytic degradation of organic colorants. For that, the PVA/PAA nanofibrous mat was prepared by electrospinning of PVA and PAA solution according to an aspect ratio of 1:1 and later water stability was induced by the thermal cross linking at an elevated temperature of 145 °C for 30 minute. By means of electrostatic layer-by-layer (LbL) assembly, cationic titanium dioxide (TiO₂⁺, ~19 nm) was immobilized on the surface of the water stable nanofibrous mat. As functionalized composited nanofibrous mat was characterized by using scanning electron microscope (SEM), fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) analysis and thermogravimetric analysis (TGA). Superior competency of the functionalized nanofibrous mat towards photocatalytic degradation of organic dye (methyl blue) in aqueous solution was observed by using UV-visible spectrophotometer with quantitative measuring method. The result indicates a complete degradation of methyl blue within 40 mins and superior reusability upto 5 cycles application. The study signifies the prospect of using electrospun nanofibers to manipulate the catalytic activity, which could be a foundation for further rational design of various composite nanofibrous materials.     

Preparation and characterization of inner-pressure hollow fiber composite membrane via two-way coating technique for CO<Subscript>2</Subscript>/CH<Subscript>4</Subscript> separation

High-selectivity inner-pressure hollow fiber composite (HFC) membrane for CO₂/CH₄ separation was prepared through the Two-way coating (TWC) technique. The blends of poly(vinylamine) (PVAm)/polyvinyl alcohol (PVA) were coated onto porous hollow fiber polysulfone (PSF) ultrafiltration (UF) membrane with an effective membrane area of 0.4 m². The effects of fabrication parameters on the permselectivity of the resultant HFC membrane were investigated and the optimum preparation conditions were obtained as follows: coating time for 30 min and air blowing time for 30 min after the coating. The prepared HFC membrane showed the typical characteristic of fixed carrier membrane with a high selectivity of CO₂ and CH₄: the separation factor of CO₂/CH₄ (40 vol% CO₂ at 25 °C and 0.2 MPa) was 36.6 and the CO₂ permeability was 56.3 GPU. Field emission scanning electron microscopy (FESEM) images indicated that the HFC membrane prepared by TWC technique had a uniform coating layer along the whole hollow fiber. Membrane permselectivity showed almost no difference between different membrane sections. The HFC membrane showed a good stability during the continuous testing process of 540 h. And the HFC membrane preserved at 30 °C and 40 % humidity exhibited a good durability with a basically unchanged separation factor after 30 days.     

Effect of organic,inorganic and slow-release urea fertilisers on CH<Subscript>4</Subscript> and N<Subscript>2</Subscript>O emissions from rice paddy fields

Vietnam is one of the world’s top two rice exporting countries. However, rice cultivation is the primary source of agriculture’s greenhouse gas (GHG) emissions in Vietnam. In particular, strategies are required to reduce GHG emissions associated with the application of organic and inorganic fertilisers. The objective of this study was to assess the effects of various combinations of biochar (BIOC), compost (COMP) and slow-release urea (SRU) on methane (CH₄) and nitrous oxide (N₂O) emissions. In total, 1170 gas samples were collected from closed gas chambers in rice paddies at Thinh Long commune and Rang Dong farm in northern Vietnam between June and October 2014. The gas samples were analysed for CH₄-C and N₂O-N fluxes using gas chromatography. The application of BIOC alone resulted in the lowest CH₄ emissions (4.8–59 mg C m^?2 h^?1) and lowest N₂O emissions (0.15–0.26 µg N m^?2 h^?1). The combined application of nitrogen–phosphorus–potassium (NPK) + COMP emitted the highest CH₄ (14–72 mg C m^?2 h^?1), while ½NPK + BIOC emitted the highest N₂O (1.03 µg N m^?2 h^?1 in the TL commune), but it was the second lowest (0.495 µg N m^?2 h^?1) in the RD farm. Green urea and orange urea reduced N₂O emissions significantly (p < 0.05) compared to white urea, but no significant differences were observed with respect to CH₄ emissions. SRU fertilisers and BIOC alone measured the lowest greenhouse gas intensity, i.e. <2.5 and 3 kg CO₂ eq. kg^?1 rice grain, respectively. Based on these results, application of fertilisers in the form of BIOC and/or orange or green urea could be a viable option to reduce both CH₄ and N₂O emissions from rice paddy soils.     

Degradation and kinetic modeling of polyvinyl alcohol in aqueous solutions by a H<Subscript>2</Subscript>O<Subscript>2</Subscript>/Mn(II) system

This paper is about the degradation of polyvinyl alcohol (PVA) in aqueous solutions using a H2O2/Mn(II) system. Fourier transform infrared spectroscopy (FTIR) and gel permeation chromatography (GPC) were applied to analyze the degradation products of PVA, and the results revealed that the backbone chain of PVA could be effectively broken and oxidized. Several unsaturated degradation products, including carboxylic acids, ketones, aldehydes, olefins, and alkynes were also detected and identified by gas chromatography-mass spectrometry (GC-MS), which indicated that higher treatment temperatures would considerably promote the generation of lower molecular weight degradation products. According to the work presented in this paper, the degradation efficiency of PVA increased from 55 % at 60 oC to 99 % at 90 oC after treatment when the initial PVA concentration was 5 %, at pH=3 with a H2O2 and Mn(II) dose of 100 ml/l and 0.6 mol/l, respectively. In addition, kinetic modeling indicated that the experimental results were best fitted by the Page-modified model with an activation energy of 48.78 kJ/mol.     

The effect of floating vegetation on CH<Subscript>4</Subscript> and N<Subscript>2</Subscript>O emissions from subtropical paddy fields in China

Duckweed (Lemna minor), a floating macrophyte belonging to the Lemnaceae family, is commonly found in subtropical paddy fields. This plant rapidly takes up nutrients from water and forms dense floating mats over the water surface that may impact the biogeochemical processes and greenhouse gas production in paddy fields. In this study, we measured CH₄ and N₂O emissions from duckweed and non-duckweed plots in a subtropical paddy field in China during the period of rice growth using static chamber and gas chromatography methods. Our results showed that CH₄ emission rate ranged from 0.19 to 26.50 mg m^?2 h^?1 in the duckweed plots, and from 1.02 to 28.02 mg m^?2 h^?1 in the non-duckweed plots. The CH₄ emission peak occurred about 1 week earlier in the duckweed plots compared to the non-duckweed counterparts. The mean CH₄ emission rate in the duckweed plots (9.28 mg m^?2 h^?1) was significantly lower than that in non-duckweed plots (11.66 mg m^?2 h^?1) (p < 0.05), which might be attributed to the higher water and soil Eh in the former. N₂O emission rates varied between ?50.11 and 201.82 µg m^?2 h^?1, and between ?28.93 and 54.42 µg m^?2 h^?1 in the duckweed and non-duckweed plots, respectively. The average N₂O emission rate was significantly higher in the duckweed plots than in the non-duckweed plots (40.29 vs. 11.93 µg m^?2 h^?1) (p < 0.05). Our results suggest that the presence of duckweed will reduce CH₄ emission, but increase N₂O flux simultaneously. Taking into account the combined global warming potentials of CH₄ and N₂O, we found that growing duckweed could reduce the overall greenhouse effect of subtropical paddy fields by about 17 %.     

In situ loading TiO<Subscript>2</Subscript> and its photocatalysis and UV resistance on cotton fabric

Anatase TiO₂ nanoparticles was in-situ formed on the cotton fabric by using tetrabutyl titanate (TBT) as a precursor through the normal pressure hydrothermal method. X-ray diffraction (XRD), Scanning electron microscopy (SEM), UV visible spectra (UV-VIS), ATR-IR were used as the characterization techniques. Photocatalytic performance of TiO₂ on the fabric surface was evaluated by methylene blue (MB), 4 kinds of the common living stains and three dyes under ultraviolet and visible light radiation. XRD analysis found that the TiO₂ loaded on the fabric was mainly anatase crystalline phase with particle size of 6.4 nm. SEM observed that a large number of nano TiO₂ particles are distributed on the fabric surface. UV-VIS test indicated that theTiO₂-coated fabric possessed an obvious absorption for ultraviolet. ATR-IR analysis indicated that the nano-TiO₂ possesses a strong affinity with the hydroxyl group of the cotton fabric, and the soaping tests showed that the TiO₂ was firmly bonded with the fabrics. The treated fabrics have good degradation ability for MB aqueous solution, and could degrade azo, anthraquinone and phthalocyanine dyes. The order of degradation of the common life stains was: pepper oil> tea > coffee > soy sauce.     

Spherical Bacterial Cellulose/TiO<Subscript>2</Subscript> Nanocomposite with Potential Application in Contaminants Removal from Wastewater by Photocatalysis

Contaminants are often found in aquatic environments, for instance, heavy metals, dyes, parasites, pesticides, hormones and pharmaceuticals. Therefore, large amounts of these contaminants reaches wastewater via industrial and domestic effluents, causing major concern to human health. Heterogeneous photocatalysis is a technique for removing these contaminants in order to achieve better efficiency in water treatment. Then, bacterial cellulose (BC) produced in an agitated culture can form spherical bodies composed of nanofibers with high specific surface area. Moreover, Titanium dioxide (TiO₂) is a semiconductor containing high photocatalytic activity capacity. Thus, the main objective in this work was to produce spherical BC/TiO₂ nanocomposites for contaminants removal from wastewater by photocatalysis process. The incorporation of TiO₂ nanoparticles in the spherical BC matrix was performed by ex situ and in situ methods. In addition, Scanning Electron Microscope (SEM), Energy Dispersive Spectroscopy (EDS), Fourier Transform Infrared Spectroscopy (FTIR) and Thermogravimetric Analysis (TGA) were used as tools of morphological, chemical and thermal characterizations of the nanocomposites. Besides, photocatalysis tests were performed in order to evaluate the removal efficiency of methylene blue from aqueous solutions. The results of these tests exhibited a percentage of methylene blue removal of 70.83 and 89.58 % after 35 minutes for spherical BC/TiO₂ nanocomposites both, in situ and ex situ, respectively. Therefore, these results demonstrated that BC/TiO₂ to be a low cost material with high capacity of contaminants removing and a great potential for industrial applications.     

Preparation of TiO<Subscript>2</Subscript>-coated ZnO Nanoparticles and Their Effect on the UV Absorption of a Poly(vinyl alcohol) Composite Film

Titanium oxide (TiO₂) and zinc oxide (ZnO) composite structured nanoparticles were prepared by combining a sol-gel process and a solvothermal method. Titanium (IV) isoproxide (TTIP), used as a TiO₂ precursor, was dissolved in a colloidal ZnO nanoparticle solution synthesized by the sol-gel method, and TiO₂ was synthesized via solvothermal synthesis onto the ZnO nanoparticles. The effects of reaction conditions such as pH, reaction temperature, and reaction time on the morphology of the composite nanoparticles and the ultraviolet (UV) absorbance of their polymer composite films were investigated. The UV absorption of the poly(vinyl alcohol) (PVA) composite film with TiO₂-coated ZnO nanoparticles was higher than that of the TiO₂, ZnO, and ZnO-coated TiO₂ composite films. The reaction pH was found to have the strongest influence on the UV absorbance of the PVA/(TiO₂/ZnO) composite film. A pH of 7.0, reaction temperature of 250 °C, and reaction time of 24 h were the optimum conditions for UV absorption.     

Nitrogen Fertilizer Management Practices to Reduce N<Subscript>2</Subscript>O Emissions from Irrigated Processing Potato in Manitoba

Nitrogen fertilizer practices affect nitrous oxide (N₂O) emissions from agricultural soils. The “4R” nutrient stewardship framework of using N fertilizer at the right rate, right source, right placement and right time can reduce N₂O emissions while maintaining or improving yield of field crops, but understanding of how the various factors affect N₂O emissions from irrigated processing potato is lacking. We examined the effects of selected 4R practices on emissions, using results from two irrigated processing potato studies each conducted in 2011 and 2012 in Manitoba, Canada. Experiment 1 examined combinations of source (urea, ESN), placement (pre-plant incorporation [PPI], banding), and rate (100 and 200 kg N ha^-1) on a clay loam soil. Experiment 2 examined timing and source treatment combinations (urea PPI, ESN PPI, urea split, urea split/fertigation) on a loamy fine sandy soil. For Experiment 1, use of ESN at 200 kg ha^-1 did not reduce area-, yield- and applied fertilizer N- based N₂O emissions compared to urea at 200 kg ha^-1, irrespective of placement. Emissions from pre-plant banding ESN at 200 kg ha^?1, however, were 32% lower than from PPI ESN. For Experiment 2, compared to single pre-plant urea application, fertigation simulated by in-season application of urea ammonium nitrate (UAN) gave lower area-, yield- and applied fertilizer N- based emissions. Split urea ( \( \raisebox{1ex}{$2$}\!\left/ \!\raisebox{-1ex}{$3$}\right. \) pre-plant, \( \raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$3$}\right. \) hilling) also reduced area- and yield- based N₂O emissions compared to single pre-plant urea application. Emissions were generally lower at the site with loamy fine sandy soil than the site with clay loam soil. These results demonstrate that combinations of “4R” practices rather than source alone are best to achieve reductions in N₂O emissions from irrigated potato production.     

Multifunctional modification of wool fabric using graphene/TiO<Subscript>2</Subscript> nanocomposite

In this study, a new finishing technique is introduced through treatment of wool fabric with graphene/TiO₂ nanocomposite. Graphene oxide/titanium dioxide nanocomposite first applied on the wool fabric by hydrolysis of titanium isopropoxide in graphene oxide suspension and then this coating chemically converted by sodium hydrosulfite to graphene/TiO₂ nanocomposite. The homogenous distribution of the graphene/TiO₂ nanocomposite on the fiber surface was confirmed by field emission scanning electron microscopy (FE-SEM), Energy-dispersive X-ray spectroscopy (EDS) and X-ray mapping. X-ray diffraction patterns proved the presence of titanium dioxide nanoparticles with a crystal size of 127 Å on the treated wool fabric. Also, the defect analysis based on X-ray photoelectron spectroscopy (XPS) established the composition of the nanocomposite. Other characteristics of treated fabrics such as antibacterial activity, photo-catalytic self-cleaning, electrical resistivity, ultraviolet (UV) blocking activity and cytotoxicity were also assessed. The treated wool fabrics possess significant antibacterial activity and photo-catalytic self-cleaning property by degradation of methylene blue under sunlight irradiation. Moreover, this process has no negative effect on cytotoxicity of the treated fabric even reduces electrical resistivity and improves UV blocking activity.     

Electrospun poly(tetrafluoroethylene) nanofiber membranes from PTFE-PVA-BA-H<Subscript>2</Subscript>O gel-spinning solutions

As a kind of high-performance fibers, PTFE fiber has been widely used in many fields because of its unique characteristics. In this study, the poly(tetrafloroethylene) (PTFE) nanofibers manufactured by electrospinning method was reported. The gel-spinning solution of poly(tetrafluoroethylene)/poly(vinyl alcohol)/boric acid (PTFE/PVA/BA), which was prepared by the gel process of the mixture of PTFE, PVA, BA and redistilled water, was electrospun to form PTFE/PVA/BA composite nanofibers. After calcinating, the PTFE nanofibers with diameters of 200 nm to 1000 nm were obtained. The fibers before and after calcinating were characterized by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD), FT-IR spectrum analysis and X-ray photoelectron spectroscopy (XPS), respectively, and the mechanical and hydrophobic properties of the fibers were also investigated. The results showed that the PTFE nanofiber membranes could be electrospun effectively used the gel-spinning solution of PTFE/PVA/BA, and may realize the applications in the fields of high-temperature filtration, catalyst supports, battery separator and so on.     

A Novel Green Stabilization of TiO<Subscript>2</Subscript> Nanoparticles onto Cotton

Facile embedding of TiO₂ nanoparticles onto cotton fabric has been successfully attained by ultraviolet light irradiations. The adhesion of nanoparticles with fibre surface, tensile behaviour and physicochemical changes before and after ultraviolet treatment were investigated by scanning electron microscopy, energy dispersive X-ray and inductive couple plasma-atomic emission spectroscopy. Experimental variables i.e. dosage of TiO₂ nanoparticles, temperature of the system and time of ultraviolet irradiations were optimised by central composite design and response surface methodology. Moreover, two different mathematical models were developed for incorporated TiO₂ onto cotton and tensile strength of cotton after ultraviolet treatment and used further to testify the obtained results. Self-clean fabric through a synergistic combination of cotton with highly photo active TiO₂ nanoparticles was produced. Stability against ultraviolet irradiations and self-cleaning properties of the produced fabric were evaluated.     

Load of Ag<Subscript>3</Subscript>PO<Subscript>4</Subscript> Particles on Sulfonated Polyphenylene Sulfide Superfine Fibre with High Visible-light Photocatalytic Activity

Ag₃PO₄ was loaded on sulfonated polyphenylene sulfide (SPPS) superfine fibre by a facile precipitation method. Both the structure and properties of the as-synthesized Ag₃PO₄/SPPS composites were characterized via XRD, SEM, EDS, XPS, FTIR, and UV-vis. The photocatalytic performance of Ag₃PO₄/SPPS composites was investigated via degradation of Methylene blue(MB) solution under visible light irradiation. The degradation results revealed that the photocatalytic activity of Ag₃PO₄/SPPS composites was greatly enhanced by the incorporation of Ag₃PO₄ with SPPS superfine fibre. For concentrations of AgNO₃ and Na₂HPO₄ solutions of 0.3 M and 0.06 M in the preparation process, the Ag₃PO₄/SPPS composite showed higher photocatalytic activity under visible light irradiation.     

Polyaniline-doped TiO<Subscript>2</Subscript>/PLLA fibers with enhanced visible-light photocatalytic degradation performance

A simple and practical strategy has been developed for preparing polyaniline(PANi)-doped TiO₂/poly(l-lactide) (P@TiP-C) fibers by a combination of coaxial-electrospinning and in-situ polymerization. The TiO₂/PLLA composite fibers with TiO₂ located on the surface were fabricated by coaxial-electrospinning, with PLLA as the core phase and a dispersion of TiO₂ particles, a well-known photocatalyst, in the sheath phase. The aniline monomers were also located in the core phase and in-situ polymerized by ammonium persulfate (APS) after electrospinning. SEM images show that TiO₂ particles were located on the surface of PLLA fibers. Photocatalytic degradation tests show that the P@TiP-C fibers exhibit enhanced photocatalytic activity for degradation of methyl orange under visible light, likely due to the synergistic effect of PANi and TiO₂.     

Effects of rice straw,biochar and mineral fertiliser on methane (CH<Subscript>4</Subscript>) and nitrous oxide (N<Subscript>2</Subscript>O) emissions from rice (<Emphasis Type="Italic">Oryza sativa</Emphasis> L.) grown in a rain-fed lowland rice soil of Cambodia: a pot experiment

We studied the effects of water regimes and nutrient amendments on CH₄ and N₂O emissions in a 2 × 3 factorial, completely randomised growth chamber experiment. Treatments included continuously flooded (CF) and alternate wetting and drying (AWD), and three organic amendments: no amendment-control, rice straw (RS) and biochar (BC). Compound fertiliser was applied to all treatments. Rice was grown in columns packed with a paddy soil from Cambodia. Results revealed faster mineralisation of organic carbon (RS and BC) when applied in water-saturated conditions lasting for 2 weeks instead of flooding. This resulted in lower total CH₄ emissions in treatments under AWD than those under the CF water regime, namely 44 % in RS treatments and 29 % in BC treatments. Nitrous oxide fluxes were generally non-detectable during the experimental period except after fertilisation events, and the total N₂O–N emissions accounted for on average 1.7 % of the total applied mineral fertiliser N. Overall, the global warming potentials (GWPs) were lower in treatments under AWD than those under the CF water regime except for the control treatment with only mineral fertiliser application. Grain yields were slightly higher in treatments under AWD than the CF water regime. Hence, the yield-scaled GWP was also lower in the treatments under the AWD water regime, namely 51 % in RS, 59 % in BC and 17 % in control treatments. Control treatments had the lowest GWP, but provided the highest yield. The yield-scaled GWP under these treatments was therefore lower than under the other treatments.