Water Absorption Ability Research Articles

A dual-functional lignin containing pulp foam for solar evaporation and contaminant adsorption

Recently, solar-driven evaporator has been widely investigated as an environmentally benign and sustainable method in water desalination and purification, but its evaporation efficiency is highly reliant on solar intensity, and the increased contamination in water can hinder the production of clean water. Herein, we designed a novel and scalable polydopamine-functionalized lignin containing pulp (LPNR@PDA) foam evaporator with the dual-purpose of high-efficiency desalination and multi-contaminant adsorption. With excellent light absorption (90 %), high water absorption ability (9.5 g g−1), low thermal conductivity (0.1 W mK−1) and chelation capabilities, the LPNR@PDA foam evaporator synergized solar evaporation and contaminant adsorption with one another, making the LPNR@PDA foam evaporator a desirable material with the capability of continuous clean water production in all-weather conditions. Additionally, the LPNR@PDA foam evaporator with unique porous structure presented potential applications in treatments of metal ion concentration and contaminated seawater, and also the LPNR foam exhibited excellent biodegradability in the natural environment compared to polystyrene foam. Therefore, this novel foam material will shine a new light for developing multifunctional photothermal system for solar-driven water purification.

Effect of Cement kiln dust on some properties of self-compacting concrete

In the paper, Feasibility of preparing self-compacting concrete (SCC) was evaluated. Six mixes are designed to replace part of the cement with cement kiln dust (CKD). The first mix without replacement is the control mixt through which the rest of the mixtures are compared. As for the remaining five mixtures, part of the cement was replaced with CKD, and the replacement ratios are (2.5, 5, 7.5, 10, 12.5) % sequentially. Where the ratio of water to cement was constant is 0.3 in all mixes SCC. Then the viscosity, flow ability, passing ability and segregation properties of all mixes were examined, and then some mechanical properties (compressive resistance, dry density, ability of water absorption ) were examined for all mixes. The results indicate a decrease in the workability (passing ability, flow ability, and segregation) and mechanical properties (compressive strength and density) and also led to an increase in the viscosity of T500, as well as an increase in the water absorption ability of SCC. In general, the mechanical properties of some mixes are acceptable compared to the reference mix, especially when it is replaced by a few percentages

Construction of Carbon Dots@LiCl-polyacrylamide with Humidity-Induced Ultralong Room-Temperature Phosphorescence to Fluorescence and Rigid-to-Flexible Transition Behavior.

The continuous advancement of luminescent materials has placed increasingly stringent requirements on dynamic color-tunable ultralong room-temperature phosphorescence (URTP) materials that can respond to external stimuli. Nevertheless, endowing URTP materials with stimuli-response-induced dynamic color tuning is a challenging task. This study introduces a carbon dots (CDs)@LiCl-polyacrylamide (PAM) polymer system that switches from URTP to fluorescence under humidity stimuli, accompanied by a transition from rigidity to flexibility. The obtained rigid CDs@LiCl-PAM exhibits ultralong green phosphorescence with a lifetime of 560ms in the initial state. After absorbing moisture, it becomes flexible and its phosphorescence switches off. Moreover, the emission of the CDs@LiCl-PAM film depends on the excitation wavelength. This property can potentially used in multicolored luminescence applications and displays. Moreover, multicolor luminescent patterns can be constructed in situ using the water-absorption ability of the obtained thin film and the Förster resonance energy-transfer strategy. The proposed strategy is expected to promote the interdisciplinary development of intelligent information encryption, anti-counterfeiting, and smart flexible display materials.

STRENGTH-DURABILITY PROPERTIES AND MICROSTRUCTURAL ANALYSIS OF CONCRETE CONTAINING COW BONE ASH AND BENTONITE

One of the major agricultural wastes discarded from abattoirs in large quantities is the cow bone. Thus, there is need to find alternative means of promoting cleaner environment which is critical for environmental sustainability. This study aims to establish the viability of using cow bone ash and bentonite as partial replacement for cement improve the properties of concrete. Chemical composition examined on the CBA and BT showed that the materials have potential to serve as supplementary cementing material in concrete. In this study cement was partially replaced with cow bone ash and bentonite at 5% interval from 5 – 20%. Mix with 10% CBA/BT had the highest compressive strength across all curing ages. At 7, 14, 21, 28 and 56days 10% CBA/BT replacement recorded a 1, 49, 23, 14 and 8% increase in compressive strength respectively, similar flexural and split tensile strength examined also showed increase in strength. Water absorption test recorded a decrease in water absorption as the CBA/BT content increased. Acid resistance test showed that the concrete specimen reduced in compressive strength of at an average of 39%. The microstructure analysis of the concrete specimen revealed an improved micro packing of aggregate resulting in a denser and increased strength of concrete. The study finds that at optimal dosage of 10% CBA/BT, the concrete had an improved mechanical strength, lower water absorption ability and a better interlocking particle arrangement at microstructural level.

Advanced composite membranes based on multifunctional fillers constructed by covalently linking phosphotungstic acid with mesoporous carbon nitride for high-performance and durable fuel cell under low humidity

Two-dimensional (2D) nanosheets possessing large specific surface area and high aspect ratio can serve as proton-conduction accelerators owing to their continuous proton transport feature. Herein, phosphotungstic acid (HPW) is chemically grafted to mesoporous carbon nitride nanosheets (CN) via a hydrothermal process to produce water-insoluble HPW/CN (PCN) nanofillers, and subsequently embedded into sulfonated poly(arylene ether sulfone) (SPAES) to develop a long-range proton transport channels for high-performance composite membranes. The loading of hydrophilic HPW enhances the dispersivity and compatibility with the SPAES polymer and improves the mechanical-dimensional-chemical stability of the composite membranes. The formed hydrogen-bonding networks and acid-base interactions between fillers and polymers could endow the SPAES/PCN membranes with favorable water-absorption ability and proton-conducting performance. Besides, the excellent interfacial interactions working as a “bridge” facilitates the formation of well-defined phase-separation structure and constructs long-range ionic/water channels at the SPAES-PCN interface. Moreover, the strong acidic HPW on surface and mesoporous structure of CN enhance effectively water-retention ability of the composite membranes, which is specially contribute to rapid proton transport at low humidity. The proton conductivity of the SPAES/PCN-7.5 membrane reaches up to 250 mS cm−1 at 90 °C, hydrous condition, and 46 mS cm−1 at 80 °C, 50 % RH, which are 42 % and 84 % higher than those of the control SPAES membrane, respectively. The SPAES/PCN-7.5 membrane achieves highest maximum power density of 404–824 mW cm−2 at 80 °C and 50%–100 % RH, exceeding that of the SPAES membrane (207–546 mW cm−2) and Nafion® 112 (359–723 mW cm−2). It still remains stable cell performance, as well as undergoes lower voltages loss and hydrogen permeation after the durability test (144 h, 80 °C/60 % RH). In addition, molecular dynamics simulation analysis is performed to offer new insight into elucidating the structure-property relationships of the composite membrane. These results indicate that the SPAES/PCN composite system is an advanced membrane for the practical applications of fuel cells.

Antifouling Zwitterionic Nanofibrous Wound Dressing for Long-Lasting Antibacterial Photodynamic Therapy.

Nanofibrous mats as a wound dressing have received great attention in recent year. The development of biocompatible dressings with antibiofouling capability and long-lasting antibacterial properties is important but challenging. Antibacterial photodynamic therapy (aPDT) effectively eliminates pathogens via a photodynamic process that can circumvent the emergence of antibiotic-resistant pathogens. In this study, we integrated the zwitterionic materials (2-methacryloyloxyethyl phosphorylcholine (MPC) moiety) and aPDT photosensitizer, methylene blue (MB), to fabricate a long-lasting antibacterial nanofibrous mat using electrospinning technology. The prepared nanofibers possessed an appropriate water absorption and retention ability, superior cytocompatibility, and antibiofouling ability against both proteins and L929 cell adhesion. MB-loaded nanofibrous mats have exhibited superior aPDT against Gram-positive Staphylococcus aureus compared to Gram-negative Escherichia coli under moderate irradiation (100 W m-2) due to the presence of an extra outer membrane of Gram-negative bacteria serving as a protective barrier. In vitro release study demonstrated that the nanofibrous mat had a long-lasting drug release profile, which can efficiently suppress bacterial growth via aPDT. The antibacterial ability of the MB-loaded nanofibrous mat was commensurate or slightly inferior to antibiotics such as tetracycline and kanamycin, suggesting that it has the potential to be used as an antibiotic alternative. Overall, this zwitterionic nanofibrous mat with long-lasting aPDT function and nonadherent properties has potential as a promising antibacterial wound dressing.

Characterization and Properties of Durian Skin Fiber Filled Polylactic Acid/Polypropylene Compatibilized with Glut Palmitate Salt

PLA matrix provides good mechanical, physical and degradability properties, but somehow PLA alone is not good enough to produce a product as PLA has poor toughness resulting a brittle material. Natural fiber such as Durian skin fiber (DSF) can be incorporated into PLA/PP as a biopolymer to achieve the desired properties and better degradation which resulting a good bio-composite. Therefore, the study was carried out to produce bio-composite of DSF filled with PLA/PP and glut palmitate (GP) salt as compatibilizer. The bio-composites was successfully developed using different filler (DSF) loadings (0 php, 15 php, 30 php, 45 php and 60 php) with melt mixing blending. The FTIR analysis showed the new peak existed at 1595 cm-1 revealed a good interaction in the composite system which come from the bending of NH2 vibration from GP. The mechanical properties (tensile properties) and physical properties (water absorption ability and density) of prepared bio-composite were determined. Increasing of DSF filler loading to 60 php DSF in PLA/PP bio-composite with the addition of GP increased in tensile strength (5.06 ± 0.09 MPa) and elongation at break (3.74 ± 0.18%) due to enhanced interfacial bonding and strong adhesion between the polymer matrix and the filler due to the presence of compatibilizer. However, increased filler loading to 60 php DSF, showed a decreasing trend in the tensile modulus which represents high flexibility of the bio-composites. Furthermore, PLA/PP/DSF bio-composites absorption of water increases with the increasing filler loading until it reaches at saturation point. The study concludes that the DSF reinforced PLA/PP with the addition of GP was suitable to be used in the production of bioplastic by many industries which can promote a sustainable environment for society.

Using the Water Absorption Ability of Dried Hydrogels to Form Hydrogel-Supported Lipid Bilayers.

The formation of supported lipid bilayers (SLBs) on hydrogels can act as a biocompatible anti-fouling interface. However, generating continuous and mobile SLBs on materials other than conventional glass or mica remains a significant challenge. The interaction between lipid membrane vesicles and a typical hydrogel is usually insufficient to induce membrane vesicle rupture and form a planar lipid membrane. In this study, we demonstrate that the water absorption ability of a dried polyacrylamide (PAAm) hydrogel could serve as a driving force to facilitate the formation of the hydrogel-SLBs. The absorption driving force vanishes after the hydrogels are fully hydrated, leaving no extra interaction hindering lipid lateral mobility in the formed SLBs. Our fluorescence recovery after photobleaching (FRAP) results show that SLBs only form on hydrogels with adequate absorption abilities. Moreover, we discovered that exposure to oxygen during drying could lead to the formation of an oxidized crust on the PAAm hydrogel surface, impeding SLB formation. Therefore, minimizing oxygen exposure during drying is crucial to achieving high-quality hydrogel surfaces for SLB formation. This water absorption method enables the straightforward fabrication of hydrogel-SLBs without the need for additional substrates or charges, thereby expanding their potential applications.

Drought tolerance in dipterocarp species improved through interspecific hybridization in a tropical rainforest

Gene transfer through interspecific hybridization can enhance functions such as growth performance, although its role in the ecophysiological functions of tropical tree species remains unclear. Hybrid seedlings of genus Shorea (Dipterocarpaceae), which dominates the canopy layer, are found in fragmented tropical rainforests in Southeast Asia. To elucidate changes in dipterocarp environmental adaptability due to hybridization, we studied the ecophysiological traits of dipterocarp seedlings including leaf morphology, photosynthesis, and drought tolerance in two parent species (Shorea curtisii and Shorea leprosula) and their hybrids, including F1 and backcross hybrids. Then, we induced drought stress to investigate drought tolerance in these seedlings. Photosynthetic ability was higher in S. leprosula than in S. curtisii, with the F1 and backcross hybrids showing intermediate characteristics. By contrast, drought tolerance, as indicated by stem hydraulic safety, cuticle thickness, and leaf mass per area, was higher in S. curtisii, lower in S. leprosula, and intermediate in their hybrids. The leaf turgor loss point decreased in S. curtisii due to osmotic adjustment under drought conditions, which led to lower predawn leaf water potential and higher water absorption ability from drier soil. By contrast, these changes were smaller and drought tolerance was weaker in S. leprosula. The hybrids including backcrosses had higher drought tolerance than S. leprosula, suggesting that gene transfer through introgression may facilitate the acquisition of drought tolerance. Although increased drought stress due to climate change and forest degradation are likely to limit seedling regeneration in S. leprosula, drought-tolerant genes obtained through hybridization with S. curtisii may contribute to its survival.

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.

Fabrication andin vitroevaluation of photo cross-linkable silk fibroin - epsilon-poly-L-lysine hydrogel for wound repair.

An optimal wound-healing hydrogel requires effective antibacterial properties and a favorable cell adhesion and proliferation environment. AlthoughBombyx morisilk fibroin (SF) possesses inherent wound-healing properties, it lacks these essential qualities. This study aimed to fabricate a novel photo-polymerizable hydrogel by utilizing SF's wound-healing efficiency and the epsilon-poly-L-lysine (EPL) antimicrobial activity. The SF was modified with three different concentrations of glycidyl methacrylate (GMA) to obtain SF-GMA(L), SF-GMA(M), and SF-GMA(H). A methacrylated EPL (EPL-GMA) was also produced. Then, SF-GMA was mixed with EPL-GMA to produce photo-crosslinkable SF-GMA-EPL hydrogels. The SF-GMA(L)-EPL, SF-GMA(M)-EPL, and SF-GMA(H)-EPL hydrogels, fabricated with 20% EPL-GMA, demonstrated maximum antimicrobial activity and mammalian cell adhesion ability. The hydroxyl radical (•OH) scavenging efficiency of the hydrogels was tested and shown to be between 69% and 74%. These hydrogels also exhibited 60% efficiency in removing bacterial lipopolysaccharides. The water absorption ability of the hydrogels was consistent with the size of their internal pores. The hydrogels exhibited a slow degradation fashion, and their degradation products appeared cytocompatible. Finally, the elastomeric properties of the hydrogels were determined, and a storage modulus (G') of 300-600 Pa was demonstrated. In conclusion, the hydrogels created in this study possess excellent biological and physical properties to support wound healing.

Controllable release of nitric oxide from an injectable alginate hydrogel

Currently, the controlled release of nitric oxide (NO) plays a crucial role in various biomedical applications. However, injectable NO-releasing materials remain an underexplored research field to date. In this study, via the incorporation of S-nitroso-N-acetyl-penicillamine (SNAP) as an NO donor, a family of NO-releasing injectable hydrogels was synthesized through the in situ cross-linking between sodium alginate and calcium ion induced by D-(+)-gluconate δ-lactone as an initiator. Initially, the organic functional groups and the corresponding morphologies of the resulting injectable hydrogels were characterized by IR and SEM spectroscopies, respectively. The NO release times of hydrogels with different SNAP loading amounts could reach up to 36–47 h. Due to the release of NO, the highest antibacterial rates of these injectable hydrogels against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were up to 95 %, respectively. Furthermore, the matrix of these hydrogels demonstrated great water absorption ability, swelling behavior, and degradation performance. Finally, we expect that these NO-releasing injectable hydrogels could have great potential applications various biomedical material fields.

The Effects of Crystalline Admixture on the Self-Healing Performance and Mechanical Properties of Mortar with Internally Added Superabsorbent Polymer.

Crystalline admixture (CA) can be incorporated into concrete to achieve self-healing of concrete cracks. In this study, both CA and superabsorbent polymer (SAP) were used as self-healing agents to investigate the effects of CA on the self-healing performance and mechanical properties of mortar with internally added SAP at different self-healing ages. The healing effect of cracks in mortar is assessed by crack observation and impermeability. The structure and composition of the filler in the cracks were analyzed by microscopic experiment. The experimental results indicate that CA enhances the healing of cracks in mortar specimens. The chemical reactions of CA primarily contribute to significantly improving the early-age crack-healing ability of the specimens, and the water absorption and expansion ability as well as the internal curing effect of SAP also facilitate the crack-healing process. Increasing the CA content leads to an increase in the Ca/Si ratio of C-S-H, causing a transition from a layered structure to a more compact needle-like structure. When 4% CA was added to the mortar, it resulted in an adequate formation of needle-like C-S-H structures, which eventually penetrate and fill the pits formed by SAP, compensating for the strength loss caused by SAP.

Design of amphoteric micro/nanofiber-coupling fabric for ultrafast, precise, and robust removal of water droplets from oils

The main problem affecting oil applications is water contamination, which causes reduced oil film strength, additive failure, oil foaming, lubricating oil mildew, etc., with serious impacts on the industry and the environment. However, the use of existing filtration-based or adsorption-based oil–water separation technologies to simultaneously achieve rapid, precise, and sustainable removal of water droplets from oil is extremely challenging. Herein, we designed and constructed a robust amphoteric micro/nanofiber coupling fabric (AMCF) that combines the advantages of traditional filter type and adsorption type oil–water separation materials to achieve rapid, accurate, and efficient removal of water mixed in oil. Compared to traditional oil–water separation materials, the AMCF enables the ultrafast and precise removal of small water droplets (3 mL) in various oils within 1–3 s. Importantly, the outer layer, separation flux up to 33,792 L·h−1·m−2, can resist extremely harsh mechanical and chemical damage, while the inner layer has excellent water absorption ability, ensuing the AMCF with robust water removal ability after multiple cycles of drying state–water absorption saturation state. This work provides insights into the design of systems for removing water from oil in complex environments, with a promising potential for real-world applications.

Tannic acid-functionalized 3D porous nanofiber sponge for antibiotic-free wound healing with enhanced hemostasis, antibacterial, and antioxidant properties

Developing an antibiotic-free wound dressing with effective hemostasis and antibacterial and antioxidant capacity is highly desirable. In this work, a three-dimensional (3D) chitosan/polyvinyl alcohol-tannic acid porous nanofiber sponge (3D-TA) was prepared via electrospinning. Compared with two-dimensional (2D) fiber membrane, the unique fluffy 3D-TA nanofiber sponge had high porosity, water absorption and retention ability, hemostatic capacity. Furthermore, the 3D sponge functionalized by tannic acid (TA) endow the sponge with high antibacterial and antioxidant capacity without loading antibiotics. In addition, 3D-TA composite sponges have shown highly biocompatibility against L929 cells. The in vivo experiment shows the 3D-TA is enable to accelerate wound healing. This newly 3D-TA sponges hold great potential as wound dressings for future clinical application.

Low-Grade Waste Heat Enabled Over 80 L M-2 H-1 Interfacial Steam Generation Based on 3d Superhydrophilic Foam.

Clean water scarcity and energy shortage have become urgent global problems due to population growth and human industrial development. Low-grade waste heat (LGWH) is a widely available and ubiquitous byproduct of human activities worldwide, which could provide an effective power to address the fresh water crisis without additional energy consumption and carbon emissions. In this regard, three-dimensional (3D) superhydrophilic polyurethane/sodium alginate (PU/SA) foam and the LGWH driven interfacial water evaporation system have been developed, which can precipitate over 80 L m-2 h-1 steam generation from seawater and has favorable durability for purification of high salinity wastewater. The excellent water absorption ability, unobstructed water transport and uniform thin water layer formed on 3D skeletons of PU/SA foam ensure the strong heat exchange between LGWH and fluidic water. As a result, the heat-localized PU/SA foam enables the efficient energy utilization and ultrafast water evaporation once LGWH is introduced into PU/SA foam as heat flow. In addition, the precipitated salt on PU/SA foam can be easily removed by mechanical compression, and almost no decrease in water evaporation rate after salt precipitation and removal for many times. Meanwhile, the collected clean water has high ions rejection of 99.6% that meets the World Health Organization (WHO) standard of drinking water. Above all, this LGWH driven interfacial water evaporation system presents a promising and easily accessible solution for clean water production and water-salt separation without additional energy burden for our society. This article is protected by copyright. All rights reserved.

Influence of cooking and texture attributes of far infrared radiated Japonica rice during storage

The impact of ceramic far infrared radiation drying (IRD) pretreatment method on cooking and texture properties based on stabilization of rice protein throughout the storage (8 months) of rough japonica rice was determined. Kinetic analysis showed that IRD significantly reduced the production of carbonyl compounds and free sulfhydryl groups by oxidation of byproducts. This may because of IRD prevented the transformation of ordered secondary structures into disordered, with a 3.3% and 6.6% increase in the content of α-helix and β-fold and the exposed hydrophobic area is reduced. During 8 months of storage at 35 °C, water uptake ratio and volume expansion ratio are 13.5% and 74.3% lower than that of air drying. Therefore, IRD can slow down protein oxidation of stored rice and promote the water absorption ability, expansion of rice kernel during gelatinization, and improve rice cooking quality and texture characteristics.

The synthesis of oxalate-modified pyrite/chitosan as an antibacterial composite

The combination of organic and inorganic components has produced bioactive materials with excellent properties. Chitosan is a widely used organic component that has received recognition as a biocompatible material. In contrast, naturally occurring pyrite has so far received limited exposure as a biomaterial, despite its great antibacterial activity. Hence, the incorporation of pyrite into the chitosan matrix is expected to highlight the usage of pyrite as a bioactive material, particularly in antibacterial response. In this research, chitosan and oxalate-modified pyrite were combined to form beads at wt% pyrite loadings of 1, 3 and 5%. Energy-dispersive X-ray spectroscopy analysis could confirm the loading of pyrite into the bead matrix. The beads exhibit a high water absorption ability. With the addition of pyrite, the absorption of water could increase up to 37% compared with that of blank chitosan beads. The immersion of beads in simulated body fluid shows the bioactivity of beads by formation of apatite. Microbial activity against Escherichia coli and Staphylococcus aureus is exhibited by all composite beads containing oxalate-modified pyrite, particularly by beads containing 5 wt% oxalate–pyrite.

Physiological mechanism of melatonin attenuating to osmotic stress tolerance in soybean seedlings.

Drought is one of the most significant abiotic stress threatening to crop production worldwide. Soybean is a major legume crop with immense economic significance, but its production is highly dependent on optimum rainfall or abundant irrigation. As the global climate changes, it is more important to find solutions to make plants more resilient to drought. The prime aimed of the study is to investigate the effect of melatonin on drought tolerance in soybean and its potential mechanisms. Soybean seedlings were treated with 20% polyethylene glycol 6000 (PEG 6000) and subjected to osmotic stress (14 days) with or without 100 μM melatonin treatment. Our results revealed that melatonin supplementation significantly mitigated PEG-induced growth retardation and increased water absorption ability. Foliar application of melatonin also increased gas exchange and the chlorophyll fluorescence attributes by the mitigation of the osmotic-induced reduction of the reaction activity of photosystems I and II, net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), electron transport activity, and photosynthetic efficiency. In addition, PEG-induced elevated production of reactive oxygen species (ROS) and malondialdehyde (MDA) content were significantly reversed by melatonin treatment. Equally important, melatonin boosted the antioxidant activities of soybean plants. Moreover, osmotic stress substantially increased abscisic acid (ABA) accumulation in roots and leaves, while melatonin-received plant leaves accumulated less ABA but roots content higher ABA. Similarly, melatonin significantly suppressed ABA biosynthesis and signaling gene expression in soybean exposed to drought stress. Furthermore, osmotic stress significantly suppressed plasmalemma (GmPIPs) and tonoplast aquaporin (GmTIPs) genes expression, and their transcript abundance was up-regulated by melatonin co-addition. Taken together, our results indicated that melatonin potentially improves drought tolerance of soybean through the regulation of ABA and aquaporin gene expression, increasing photosynthetic efficiency as well as enhancing water uptake efficiency.

Sugar palm (Arenga p innata) thermoplastic starch nanocomposite films reinforced with nanocellulose

Abstract The growing consciousness about global environmental concerns, particularly landfills, in conjunction with the rapid use of petroleum-based plastics, is a key factor behind the use of natural and biodegradable polymers in short-life applications like food packaging, container, and tray. Sugar palm stem is a biomass that has proven the potential to produce biodegradable polymers such as sugar palm starch. Nevertheless, their applications were limited due to their low tensile strength and excessive hydrophilicity. Plasticization using polyols, reinforcement with sugar palm fiber, cellulose, microcrystalline cellulose, or nanocellulose, blending with thermoplastic polymer, and addition of essential oils has been used to maximize the functional qualities of the starch biopolymer. As the content of plasticizers grew, the glass transition temperature and water absorption ability decreased. Furthermore, the addition of sugar palm nanocellulose to sugar palm starch improves the performances of sugar palm starch-based films as a packaging material. Addition of essential oil contributes to antibacterial properties and slightly improved tensile strength of the film. A comprehensive understanding on the interaction of starch-based biodegradable polymer and nanocellulose constituents for enhancing the physico-chemical properties of starch-based films is prerequisite for researchers in the design of industrial products with enhanced functional attributes. To address the knowledge gap, more studies including the reinforcement of new types of biodegradable polymer and nanocellulose derived from natural sources should be conducted in order to continually populate the database for research purposes.