Thermal Stability Of Membranes Research Articles

X-ray standing wave characterization of the strong metal-support interaction in Co/TiOx model catalysts.

The strong metal-support interaction (SMSI) is a phenomenon observed in supported metal catalyst systems in which reducible metal oxide supports can form overlayers over the surface of active metal nanoparticles (NPs) under a hydrogen (H2) environment at elevated temperatures. SMSI has been shown to affect catalyst performance in many reactions by changing the type and number of active sites on the catalyst surface. Laboratory methods for the analysis of SMSI at the nanoparticle-ensemble level are lacking and mostly based on indirect evidence, such as gas chemisorption. Here, we demonstrate the possibility to detect and characterize SMSIs in Co/TiOx model catalysts using the laboratory X-ray standing wave (XSW) technique for a large ensemble of NPs at the bulk scale. We designed a thermally stable MoNx/SiNx periodic multilayer to retain XSW generation after reduction with H2 gas at 600°C. The model catalyst system was synthesized here by deposition of a thin TiOx layer on top of the periodic multilayer, followed by Co NP deposition via spare ablation. A partial encapsulation of Co NPs by TiOx was identified by analyzing the change in Ti atomic distribution. This novel methodological approach can be extended to observe surface restructuring of model catalysts in situ at high temperature (up to 1000°C) and pressure (≤3 mbar), and can also be relevant for fundamental studies in the thermal stability of membranes, as well as metallurgy.

A Comprehensive Study on the Effect of Plasticizers on the Characteristics of Polymer Inclusion Membranes (PIMs): Exploring Butyl Stearate as a Promising Alternative.

This study investigated the influence of various plasticizers commonly used in the manufacture of polymer inclusion membranes (PIMs), such as 2-nitrophenyl octyl ether (NPOE), phthalates, adipates, and sebacates on the mechanical, thermal, and transport properties of membranes. Additionally, butyl stearate (BTS), chosen for its non-toxic nature compared to phthalates and its cost-effectiveness relative to adipates and sebacates, was evaluated as a plasticizer in PIMs for the first time. All plasticizers were incorporated in PIMs made of either cellulose triacetate (CTA) or poly(vinyl chloride) (PVC) as the base polymers and the task-specific ionic liquid trioctylmethylammonium thiosalicylate (TOMATS) as the carrier. The plasticizers were found to significantly affect the characteristics of membrane hydrophilicity, mechanical flexibility, and thermal stability. Transport experiments using Hg(II) as a model target ion revealed that, for CTA-based PIMs, the plasticizer did not significantly affect transport efficiency. However, for PVC-based PIMs, BTS exhibited better efficiency when compared to NPOE. These findings highlight the potential of BTS as an attractive alternative to currently used plasticizers in PVC-based PIM formulations.

Preparation and characterization of high flux cellulose acetate/hydroxyapatite composite ultrafiltration membranes for water treatment

In this study, we prepared cellulose acetate/hydroxyapatite (CA/HA) composite ultrafiltration membranes for water treatment. The organic-inorganic composite ultrafiltration membranes were prepared by doping different contents of HA nanoparticles into the CA by phase inversion method. The structure and morphology of the HA nanoparticles and membranes were characterized by X-ray diffraction, Fourier infrared spectroscopy and Scanning electron microscopy. Thermogravimetric analysis was used to describe thermal characteristics. The contact angle value and wettability test were used to determine the hydrophilicity of the polymer membrane. In addition, fluxes and rejection rates were tested at different pollutant concentrations and different pH values. The pore size and porosity gradually increased and the hydrophilicity and thermal stability of membrane were improved with the deposited HA content. With the addition of 5 wt% HA, the tensile strength of the membrane reached a maximum value of 2.80 MPa. The fluxes of pure water, CR, MB and BSA were 152.23, 111.25, 125.69 and 87.47 L/(m2·h), while the rejection rates of CR, MB and BSA were 99.99 %, 92.91 % and 99.99 %, respectively. In addition, the rejection decreased with increasing dye concentration and showed higher rejection under alkaline conditions. On the whole, the produced CA/HA composite membranes exhibited significantly higher permeability and rejection rates, offering them a lot of potential for water treatment applications.

Clay powder in polymer composite membranes enhanced the performance of direct methanol fuel cells

Polyvinyl alcohol has the potential to be used in fuel cell membranes due to its chemical, mechanical, and membrane-forming capabilities, as well as its higher hydrophilicity and low methanol permeability. However, the pure PVA membrane has a lower proton conductivity than the NafionTM membrane. With the addition of some ceramic fillers, PVA can be a possible alternative to NafionTM membranes. Therefore, we used the solution method to prepare three polyvinyl alcohol-based composite membranes with the following compositions: a) 5 wt% PVA (polyvinyl alcohol), b) 5 wt% PVA/2 wt % PEG (polyethylene glycol)/wt.1% silicon dioxide (SiO2) nanoparticles, and c) 5 wt% PVA/2 wt% PEG/wt.1% clay powder. The membranes were characterized using Fourier Transform Infrared Spectroscopy (FTIR), Thermal Gravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), Energy dispersive X-ray (EDX), oxidative stability, ion exchange capacity, water absorption characteristics, conductivity, and permeability. FITR, EDX, and SEM confirmed the successful fabrication of the composite membrane, while TGA demonstrated membrane thermal stability and other parameters relevant to fuel cell membranes. The methanol permeability of the membrane is pure 5 wt % PVA, 5 wt%PVA/2 wt%/1 wt% SiO2, and 5 wt% PVA/2 wt% PEG/wt.1% Clay measured 2.37 × 10−6 cm2/s, 2.89 × 10−6 cm2/s, and 1.57 × 10−6 cm2/s, respectively. The methanol permeability of 5 wt% PVA/2 wt% PEG/wt.1% Clay is better than of Nafion117 (5.16 × 10−6 cm2/s as reported). The membrane 5 wt% PVA/2 wt% PEG/1% Clay exhibits satisfactory levels of oxidative stability (RW% = 94.09 at 1.32 h), IEC (0.232 meq/g), conductivity (0.00432 S/cm), methanol permeability (1.57 × 10−6 cm2/s), selectivity (3.63 × 10−4 Ss/cm3), and better water uptake properties at fuel cell operating temperature. As a result, it is reasonable to expect that PVA-based modified membranes will outperform NafionTM membranes in the future.

Mass transport to generate the channels in cellulose polymers by vacuum-assisted process

This study developed a pore-connected PP-CA membrane by coating cellulose acetate onto a polypropylene filter. A new method was proposed to attach a CA/glycerin coating layer to a porous PP support without a separate binder. The pores of CA and PP were interconnected using a vacuum filtration device. By adding glycerin to the CA chains, the membrane region became more flexible due to glycerin plasticization. Water passed through the membrane under pressure differences, resulting in the formation of interconnected pores between cellulose acetate and polypropylene. The pore size and quantity could be adjusted by varying the molar ratio of glycerin. Fourier transform infrared spectroscopy revealed the interaction between CA and glycerin, while thermogravimetric analysis showed that the membrane's thermal stability increased by approximately 20 °C after vacuum filtration. This simple and cost-effective manufacturing process holds potential for mass-producing separators in the lithium-ion battery industry.

Fabrication of the cross-linked PVA/TiO2/C nanocomposite membrane for alkaline direct methanol fuel cells

A crosslinked Poly(vinyl alcohol) based composite membrane was developed through a phase inversion process for use in alkaline direct methanol fuel cells (ADMFCs). The titanium dioxide (TiO2) and carbon nanoparticles (NPs) have been incorporated into the PVA polymer matrix to improve the mechanical and thermal properties. The membrane samples were further modified with maleic acid, a carboxylic acid acting as the cross-linker, under controlled temperature and time conditions to enhance electrochemical properties. The mechanical strength and thermal stability of membranes were determined using a Universal testing machine (UTM) and thermogravimetric analysis (TGA), while the crystallographic and morphological features were examined through X-ray diffraction (XRD) and Scanning electron microscopy (SEM), respectively. The proton conductivity (σ), methanol permeability, and water uptake (%) were also assessed. The XRD curves, SEM images, and TGA trends confirmed the successful cross-linking of maleic acid, uniform dispersion of nanoparticles (NPs), and excellent thermal stability in the crosslinked PVA-TiO2-C membrane. This sample also exhibited the highest tensile strength (163 MPa), and lower permeability (45000 Ss/cm3). Moreover, the ionic conductivity was obtained in the order of 10−2 S/cm. These combined characteristics position the cross-linked PVA-TiO2-C membrane as a promising candidate for application in alkaline direct methanol fuel cells (ADMFCs).

Preparation and characterization of unidirectional water-transported bilayer PLA/ZnO-PAN/SPA nanofibrous membrane for wound healing

Wound infection caused by excessive exudate leads to overhydration of wounds and prevents wound healing. Thus, there is a need for a wound dressing to be developed that can unidirectionally export excess biological fluid while inhibiting bacterial infection. Herein, a nanofibrous bilayer membrane with a unidirectional water transport function was fabricated by electrospinning as a novel wound dressing, which can export excess biological fluid efficiently and further inhibit bacterial infection. The inner layer of the bilayer nanofiber membrane is polylactic acid (PLA)-zinc oxide (ZnO) nanofibers, which are hydrophobic and antibacterial. The outer layer is polyacrylonitrile (PAN)-sodium polyacrylate (SPA) nanofibers, which are hydrophilic and liquid-absorbent. The bilayer nanofibrous membrane's morphology, mechanics, thermal stability, wettability, water absorption, gas permeability, and unidirectional water transport ability were characterized and evaluated. The study showed that the nanofibrous bilayer membrane exhibited excellent physicochemical properties and biological performance, and its mechanical properties can reach 4.6 MPa. In addition, when the thickness of the hydrophobic layer is 3 µm and the thickness of the hydrophilic layer is 44 µm, the double-layer fiber membrane can effectively export the excess biological fluid in 5.09 s and prevent the wound from wetting again. The nanofibrous bilayer membrane with excellent water absorption, air permeability, thermal stability, and mechanical strength provides a feasible solution for chronic wound healing.

Enhanced Membrane Fluidization and Cholesterol Displacement by 1-Heptanol Inhibit Mast Cell Effector Functions.

Signal transduction by the high-affinity IgE receptor (FcεRI) depends on membrane lipid and protein compartmentalization. Recently published data show that cells treated with 1-heptanol, a cell membrane fluidizer, exhibit changes in membrane properties. However, the functional consequences of 1-heptanol-induced changes on mast cell signaling are unknown. This study shows that short-term exposure to 1-heptanol reduces membrane thermal stability and dysregulates mast cell signaling at multiple levels. Cells treated with 1-heptanol exhibited increased lateral mobility and decreased internalization of the FcεRI. However, this did not affect the initial phosphorylation of the FcεRI-β chain and components of the SYK/LAT1/PLCγ1 signaling pathway after antigen activation. In contrast, 1-heptanol inhibited SAPK/JNK phosphorylation and effector functions such as calcium response, degranulation, and cytokine production. Membrane hyperfluidization induced a heat shock-like response via increased expression of the heat shock protein 70, increased lateral diffusion of ORAI1-mCherry, and unsatisfactory performance of STIM1-ORAI1 coupling, as determined by flow-FRET. Furthermore, 1-heptanol inhibited the antigen-induced production of reactive oxygen species and potentiated stress-induced plasma membrane permeability by interfering with heat shock protein 70 activity. The combined data suggest that 1-heptanol-mediated membrane fluidization does not interfere with the earliest biochemical steps of FcεRI signaling, such as phosphorylation of the FcεRI-β chain and components of the SYK/LAT/PLCγ1 signaling pathway, instead inhibiting the FcεRI internalization and mast cell effector functions, including degranulation and cytokine production.

Performance evaluation of polymer electrolyte membranes based on hydrogen sulfite ionic liquid for application in direct methanol fuel cell (DMFC)

Series of proton conductive membranes were prepared by mixing different weight ratio of 3-hexyl-1-methylimidazolium hydrogensulfite ([C6C1Imi][HSO3]), and N-hexyl-pyridinium hydrogensulfite ([C6Py][HSO3]) ionic liquids with poly vinyl alcohol (PVA) polymer. To characterize the PVA-ILs membranes, different methods have been used such as X-ray diffraction (XRD), Fourier-transform infrared (FTIR), and scanning electron microscope (SEM). Moreover, the water uptakes, ion exchange capacity, methanol permeability, and proton conductivity of prepared PVA membranes doped with different weight ratio of ILs have been investigated to find the optimum formulation to use as electrolytes membranes for direct methanol fuel cell. The proton conductivity and the ion exchange capacity were improved as the ILs content increased. At 25 °C, The PVA-60 wt.% of [C6C1Imi][HSO3] membrane had a maximum proton conductivity of 17,47 mS.cm−1, and a methanol permeability of 8.17 10−7 cm2.s − 1. Mechanical and thermal data confirmed that addition of ILs improve the membrane flexibility and thermal stability up to 200 °C.

Polyurethane Membranes From Red Seaweeds For Ammonia Adsorption

Polyurethane (PU) membranes were prepared from red seaweed (Gracilaria sp.), castor oil, Toluene Diisocyanate (TDI), and added benzoyl peroxide (BPO) additive to improve membrane performance. The membrane is applied for the adsorption of ammonia in the solution. FT-IR analysis showed the presence of functional group N = C = O at a wavenumber of 2276 cm-1 and the O-H functional group at a wave number of 3373.50 cm-1, indicating the urethane group's formation has been formed during membrane polymerization. SEM images showed the morphological structure of the PU membrane, where the more open structure of the PU membrane by the addition of BPO. The DSC and TGA results showed the membrane's thermal stability with the addition of BPO. The PU membrane has an optimum contact time for ammonia uptake of 40 minutes. The adsorption isotherm of ammonia by the PU membrane follows the Freundlich isotherm model. The adsorption capacity of the PU membrane with the addition of BPO additives was 13.2 mg/g, which shows that the adsorption capacity of the PU-BPO membrane has a better performance than a membrane without the addition of the BPO. The PU-BPO membrane could be used as an alternative method of ammonia removal.

Improving the decorative performance of UV-curable coatings with iridescent cellulose nanocrystal film.

Cellulose nanocrystals (CNC) possess remarkable mechanical properties, a high aspect ratio, a large specific surface area, and a unique nanostructure, making them a popular choice in various fields. In this study, a CNC suspension was prepared through acid hydrolysis, and subsequently, a film exhibiting iridescence and chiral nematic structure was formed on the cured UV-WA surface via evaporation-induced self-assembly. The mean diameter and length of CNC were determined to be 25.1-33.3 nm and 281.3-404.2 nm, respectively, through transmission electron microscope analysis. The experimental results revealed that the color of the film significantly changes with variations in the CNC suspension concentration. Notably, the formation of the iridescent film is dependent on the concentration of CNC, with concentrations between 1.2% and 2.9% being optimal, and the aspect ratio of the CNC nanoparticles being around 11.3. X-ray diffraction analysis confirmed that the CNC nanoparticles possess the same crystal structure as microcrystalline cellulose (cellulose I). Fourier transform infrared spectroscopy revealed that the C[double bond, length as m-dash]C bond present in the liquid UV-curable coating disappeared upon UV irradiation. The performance of the CNC iridescent film, with varying thickness, was evaluated using UV-vis spectroscopy. The thermogravimetric analysis results indicate that the addition of CNC enhances the membrane's thermal stability and heat resistance. The results indicate that as the thickness of the CNC iridescent film increases, the corresponding UV-vis spectra display a redshift. The UV-WA/CNC shows potential in the field of decoration and establishing a straightforward, cost-effective, and efficient method for producing photonic materials with structural colors.

Cellulose acetate/polyvinylidene fluoride based mixed matrix membranes impregnated with UiO-66 nano-MOF for reverse osmosis desalination

Reverse osmosis (RO) is considered a lifesaver technology to conquer the current catastrophic water shortage situation. However, reaching a competitive RO membrane is a challenging issue. Therefore, this study investigated the optimum polymeric blending ratio between cellulose acetate (CA) and polyvinylidene fluoride (PVDF) to have a new blended polymeric membrane named cellulose acetate polyvinyl (CAPV-X), where X is the PVDF concentration %, with enhanced properties. The optimum prepared CA/PVDF blended membrane was selected for further enhancement with nano sized metal organic framework (UiO-66 MOF). Selection was made depending on each membrane salt rejection. A membrane characterization was performed based on Fourier transform infrared (FTIR), X-ray diffractometer (XRD), scanning electron microscope, thermal gravimetric analysis, and contact angle. FTIR and XRD data confirmed the successful preparation of the blended polymeric membranes CAPV-5, CAPV-7 and CAPV-10. Further, they proved UiO-66 nanofiller impregnation in the hybrid CA/PVDF/UiO-66 membrane (CPU). The addition of PVDF and nano-MOF had a slight positive effect on the membrane thermal stability. The contact angle increased with increasing the PVDF concentration and decreased once more with the impregnation of UiO-66. The RO membrane performance revealed that the optimum CA/PVDF ratio was found to be 93/7% with around 80% salt rejection and a permeate water flux of 4 L/m2 h. CPU composite membrane was then fabricated to enhance salt rejection and permeate water flux. The testing data indicated that salt rejection and permeate water flux increased over blended CAPV-7 membrane by almost 12% and 42%, respectively. Overall, CPU hybrid membrane could be used for water desalination with a good salt rejection of 90.2% and a permeate water flux of 5.7 L/m2 h.Graphical abstract

Electrospun polymeric membranes: Potential removal of endocrine disrupting compounds using solid membrane extraction and filtration processes

AbstractThe present study aims to prepare polymeric membranes by electrospinning to apply in the removal of estrone (E1), 17β‐estradiol (E2), and 17α‐ethinylestradiol (EE2) in aqueous samples. Polymeric membranes of polyamide‐6 (PA6), polycaprolactone (PCL), polylactic acid (PLA), and poly (butylene adipate‐co‐terephthalate) (PBAT) were obtained, characterized, and tested as sorbent material in processes of solid membrane extraction (SME) and membrane filtration. The efficiencies of the membranes after washing and/or conditioning processes were compared. The characterizations showed membranes with nanometer‐diameter threads (between 250 and 1200 nm, on average). The four membranes' morphology, chemical composition, and thermal stability were like previous works. PBAT membranes were considered the most effective SME technique as a differential, with 44%–71% removal. For the membrane filtration process, the highest removal values were obtained for the PBAT membrane (82%–91%), which was also efficient in filtering a surface water sample from River Guaíba. PBAT polymeric membrane effectively removes and recovers the studied hormones, lowering production costs and allowing internal and external modifications. These aspects demonstrate that the obtained membranes offer an efficient material in extracting E1, E2, and EE2, of high simplicity, low cost, and green chemistry.

CNT@LDH functionalized poly(lactic acid) membranes with super oil–water separation and real‐time press sensing properties

AbstractControlling wettability is crucial to designing separation membrane with high performance. In order to achieve the goal, chain modification method is frequently utilized to optimize surface nature of raw materials. However, the development of the method is of significance but challenging due to the high processing cost and complexity. Herein, we developed a rough surface induction strategy to prepare poly(lactic acid) (PLA) membrane. Layered double hydroxides (LDH) were loaded with carboxylation carbon nanotubes (CNT), and the prepared CNT@LDH was surface modified with aminopropyltriethoxysilane. Then the CNT@LDH was blended with PLA to prepare composites and PLA electrospinning membranes. The morphology of synthesized CNT@LDH mimics “sea urchin” liked structure, which prevented the aggregation of LDH cubes, and induced an efficient conductive network. The combination of CNT@LDH greatly changed the membranes' porous structure, thermal stability, and crystallization properties. The hydrophilicity of PLA membranes increased 112.74%, whereas the pore size and fiber diameter decreased 76.43% and 79.56%, respectively. The oil absorption capacity of the composite membrane was up to 35 g/g with a high absorption speed. Meanwhile, the prepared PLA membrane had a quick response of press‐sensing. This research provides a method for designing separation membranes with high separation efficiency, great selectivity, environment friendliness, and real‐time pressure monitor function, which is considered as a potential material in intelligent oil–water separation or wearable electronics fields.

Preparation and thermal stability of bio-based Na/Zn composite liquid stabilizers for poly(vinyl chloride)

In this work, the adduct of maleic anhydride and methyl eleostearate (MAME) and dimer fatty acid (DFA) were converted to the sodium and zinc salts (L-Zn-MAME, L-Na-MAME, L-Zn-DFA, and L-Na-DFA), respectively, which were subsequently turned into Na/Zn composite liquid stabilizers(LTS-Na/Zn-MAME and LTS-Na/Zn-DFA) by formula combination. Na salts, Zn salts and mixed Na/Zn salts from these fatty acid salts were used as thermal stabilizers for poly(vinyl chloride) (PVC). The chemical structures of MAME, DFA, and their liquid zinc and sodium salts were verified using Fourier transform infrared (FTIR) spectra. Thermal stability and mechanical properties of the sodium and zinc salts, and their Na/Zn composite liquid stabilizers derived from MAME and DFA for PVC were investigated using discoloration and dynamic mechanical analyses, TGA-FTIR-MS, thermal decomposition kinetics, and Congo red and tensile tests. Thermal stability of pure PVC is poor, but membrane thermal stability can be improved by integrating thermal stabilizers. Results show that L-Na-MAME has an outstanding synergistic effect with the commercial general calcium/zinc stearate composite heat stabilizer(CaSt2/ZnSt2). CaSt2/ZnSt2/LTS-Na-MAME, LTS-Na/Zn-MAME and CaSt2/LTS-Zn-DFA/LTS-Na-DFA also have a better heat-stabilizing impact on PVC than CaSt2/ZnSt2, especially LTS-Na/Zn-MAME can more effectively enhance the primary coloring of PVC. In comparison to blank PVC and PVC/CaSt2/ZnSt2, both PVC/LTS-Na/Zn-MAME and PVC/LTS-Na/Zn-DFA display a larger elongation at break and acceptable tensile strength. The new stabilizers can largely enhance the heat stability of PVC resins, endowing PVC products with good plasticization performance, and can fully or partially replace the general calcium zinc stearate composite heat stabilizer and other heat stabilization products.

CF3-MOF enhanced pervaporation selectivity of PDMS membranes for butanol separation

Direct separating butanol from fermentation broth via pervaporation is considered as the most effective method to realize solvent enrichment, which is dominated by membranes. Herein, MOF (MAF-9) with CF3 group is doped into PDMS matrix to enhance the butanol pervaporation, especially selectivity. The super-hydrophobicity of MAF-9 caused by CF3 groups allows the preferential adsorption and permeation for butanol molecules, thus increasing the membrane selectivity; while its appropriate pore diameter renders the exquisite diffusion pathways towards the butanol molecules, thus increasing the membrane flux. Results show that the loading-optimized MAF-9/PDMS MMM has 53 of separation factor and 848 g m−2 h−1 of membrane flux, which are increased by 24% and 16%, respectively, compared with pure PDMS membrane. TGA, FT-IR, BET, and XRD are conducted to characterize the thermal stability, morphology and structure of MAF-9; PALS, SEM, AFM, SD and TGA are tested to evaluate the free volume property, morphology, adsorption capacity and thermal stability of membranes, respectively. Conditions including particle loading, feed temperature and feed concentration are also optimized in this study.

High performance of PES-GNs MMMs for gas separation and selectivity

In this study, graphene nanosheets (GNs) were incorporated into polyethersulfone (PES) by phase inversion approach for preparing PES-GNs mixed matrix membranes (MMMs). To investigate the impact of filler content on membrane surface morphology, thermal stability, chemical composition, porosity and mechanical properties, MMMs were constructed with various GNs loadings (0.01, 0.02, 0.03, and 0.04 wt%). ​The performance of prepared MMMs was tested for separation and selectivity of CO2, N2, H2 and CH4 gases at various pressures from 1 to 6 bar and temperature varying from 20 to 60 °C. It was observed that, compared to the pristine PES membrane, the prepared MMMs significantly improved the gas separation and selectivity performance with adequate mechanical stability. The permeability of CO2, N2, H2 and CH4 for the PES + 0.04 wt% GNs increases from 9 to 2246, 11 to 2235, 9 to 7151, and 3 to 4176 Barrer respectively, as compared with pure PES membrane at 1 bar and 20 °C due to improving the membrane absorption and porosity. In addition, by increasing the pressure, the permeability and selectivity of CO2, N2, H2 and CH4 are increased due to the increased driving force for the transport of gas via membranes. Furthermore, the permeability of CO2, N2, H2 and CH4 increased by increasing the temperature from 20 to 60 °C due to the plasticization in the membranes and the improvement in polymer chain movement. This result proved that the prepared membranes can be used for gas separation applications.

COMBINING ABILITY OF WATERLOGGING TOLERANCE IN WHEAT (TRITICUM AESTIVUM L.)

The mean performance and combining abilities of cross combinations derived from a complete diallel mating and their parents were evaluated under waterlogging conditions. Analysis of variance for combining abilities indicated significant GCA (general combining ability) and SCA (specific combining ability) for single spike yield, SPAD (soil plant analysis development) and leaf area; GCA for NDVI (normalised differences vegetation index) and SCA for Fe and Mn contents in roots and membrane thermal stability. The parents Stendal, Beşköprü and Pamukova 97 were the best combiners in terms of waterlogging tolerance, while Beşköprü × Pamukova 97, Pamukova 97 × Beşköprü, Stendal × Pamukova 97, Stendal × Beşköprü and Beşköprü × Hanlı were identified as the best cross combinations, with high positive specific combining ability effects for most waterlogging related characters.

CURRENT UNDERSTANDING OF THE MECHANISMS OF HEAT STRESS TOLERANCE IN RICE (Oryza sativa L.)

Various studies reported by scientific communities such as NASA’s Goddard Institute for Space Studies (GISS) indicated an increase in average global temperature by approx. 0.8 °C since 1880. Rice (Oryza sativa L.), a heat sensitive plant cereal crop could be greatly affected by heat stress due to global temperature rise. Thus, it is envisaged that rice productivity could markedly decrease due to a rise in mean atmospheric temperature. Different studies have been reported possible mechanisms of heat stress tolerance in Rice. The present review will therefore discuss the current fundamental understanding of heat tolerant mechanisms involving heat shock proteins, plant hormones, plant growth regulators, osmoprotectants, and the importance of membrane thermal stability in rice.

Enhancing Physicochemical Properties and Single Cell Performance of Sulfonated Poly(arylene ether) (SPAE) Membrane by Incorporation of Phosphotungstic Acid and Graphene Oxide: A Potential Electrolyte for Proton Exchange Membrane Fuel Cells.

The development of potential and novel proton exchange membranes (PEMs) is imperative for the further commercialization of PEM fuel cells (PEMFCs). In this work, phosphotungstic acid (PWA) and graphene oxide (GO) were integrated into sulfonated poly(arylene ether) (SPAE) through a solution casting approach to create a potential composite membrane for PEMFC applications. Thermal stability of membranes was observed using thermogravimetric analysis (TGA), and the SPAE/GO/PWA membranes exhibited high thermal stability compared to pristine SPAE membranes, owing to the interaction between SPAEK, GO, and PWA. By using a scanning electron microscope (SEM) and atomic force microscope (AFM), we observed that GO and PWA were evenly distributed throughout the SPAE matrix. The SPAE/GO/PWA composite membrane comprising 0.7 wt% GO and 36 wt% PWA exhibited a maximum proton conductivity of 186.3 mS cm−1 at 90 °C under 100% relative humidity (RH). As a result, SPAE/GO/PWA composite membrane exhibited 193.3 mW cm−2 of the maximum power density at 70 °C under 100% RH in PEMFCs.