Hydrophilic Poly Vinyl Alcohol Research Articles

Visual colorimetric label for real-time monitoring of SO2 concentration change in grape and mango during storage

Sulfur dioxide (SO2) is widely utilized as a preservative in food transportation and storage, but excessive consumption poses health risks. This study presents a novel and efficient method for the real-time detection of SO2 using a sensor named TK, synthesized from triphenylamine and 2-cyanomethyl-1-methyl-quinolinium. The core mechanism involves the Michael addition reaction of the CC bond in TK with SO2, which disrupts the intramolecular charge transfer process, resulting in a significant color change and a blue shift in fluorescence emission. Methodologically, the sensor's response was quantified by the change in fluorescence intensity ratio (I425/I647) within a SO2 concentration range of 0–180 μM. The sensor exhibited high sensitivity and selectivity. For practical application, TK was incorporated into hydrophilic polyvinyl alcohol to create a smart label capable of visual colorimetry and fluorescence analysis. SO2 concentration changes were monitored by using this label, demonstrated by the color transition from burgundy red to colorless, yielding a maximum color difference (ΔE) of 73.6. The smart label was successfully used to monitor the quality of various grapes and mangoes during long-term storage, providing a reliable, equipment-independent method suitable for household use. The study offers a new tool for enhancing food safety and mitigating health risks associated with SO2 exposure.

Synthetic Extracellular Matrix of Polyvinyl Alcohol Nanofibers for Three-Dimensional Cell Culture.

An ideal extracellular matrix (ECM) replacement scaffold in a three-dimensional cell (3D) culture should induce in vivo-like interactions between the ECM and cultured cells. Highly hydrophilic polyvinyl alcohol (PVA) nanofibers disintegrate upon contact with water, resulting in the loss of their fibrous morphology in cell cultures. This can be resolved by using chemical crosslinkers and post-crosslinking. A crosslinked, water-stable, porous, and optically transparent PVA nanofibrous membrane (NM) supports the 3D growth of various cell types. The binding of cells attached to the porous PVA NM is low, resulting in the aggregation of cultured cells in prolonged cultures. PVA NMs containing integrin-binding peptides of fibronectin and laminin were produced to retain the blended peptides as cell-binding substrates. These peptide-blended PVA NMs promote peptide-specific cell adherence and growth. Various cells, including epithelial cells, cultured on these PVA NMs form layers instead of cell aggregates and spheroids, and their growth patterns are similar to those of the cells cultured on an ECM-coated PVA NM. The peptide-retained PVA NMs are non-stimulatory to dendritic cells cultured on the membranes. These peptide-retaining PVA NMs can be used as an ECM replacement matrix by providing in vivo-like interactions between the matrix and cultured cells.

Using a Carbon Quantum Dot Suspension as a New Solvent for Clear Hydrophobic Surface Coating on Hydrophilic PVA Films.

Polyvinyl alcohol (PVA) is a popular material used in the packaging industry. However, it is vulnerable to moisture, which can affect its performance and durability. Introducing hydrophobic substances, such as tetraethyl orthosilicate (TEOS) and hexadecyltrimethoxysilane (HDTMS), on the top layer of PVA can help maintain the excellent properties of PVA under high-humidity conditions. The low compatibility of hydrophobic materials with the hydrophilic layers allows them to aggregate more easily. To overcome these issues, we focused on the effects of particle size when increasing the coating suspension's dispersibility. A carbon quantum dot (CQD) suspension is an appropriate novel solvent for hydrophobic TEOS/HDTMS coating suspensions because its particles are small and light and exhibit good dispersibility. The CQD suspension formed a smooth hydrophobic coating on the TEOS/HDTMS materials. Furthermore, the uniformly coated PVA with the CQD suspension exhibited a water contact angle of 110°. The water droplets remained intact without being absorbed, confirming the effectiveness of the surface coating facilitated by CQDs. These results suggested that CQDs improved the dispersibility and enhanced the coating quality of TEOS/HDTMS on PVA. Enhancing the hydrophobicity of PVA is ideal for applications in packaging and other fields.

Selective extraction of lithium from salt lake brine by in situ crosslinked stable three-dimensional network film electrodes

Water-soluble binders for electrode preparation offer advantages over traditional PVDF, including environmental benefits, improved electrochemical performance, and improved mechanical properties. The trend is to find environmentally friendly binders that are compatible with water-based processes. In this context, we designed and synthesized aqueous binders with three-dimensional crosslinked structures. These structures are based on highly branched, hydrophilic polyvinyl alcohol and lithium carboxymethyl cellulose, which facilitates Li+ transport. Furthermore, LiMn2O4/C/PVA-c-CMCLi film electrodes were prepared through covalent crosslinking. The film electrode was superior to the LiMn2O4/C/PVDF film electrode in terms of adsorption capacity (25.53 mg·g−1), but comparable to the LiMn2O4/C/PVDF film electrode in terms of cyclic stability (96.38 % capacity retention after 50 CV cycles). They also showed a shorter time to reach the adsorption equilibrium (2 h) and high selectivity for Li+ in simulated brine with a high Mg2+/Li+ ratio (40) from East Taijiner. This is attributed to the synergistic effects of the improved electrolyte wettability, enhanced adhesion strength through covalent crosslinking, and increased Li+ transport rate facilitated by -COOLi in CMCLi. These results indicate that this binder has the potential to replace PVDF in the preparation of film electrodes for extracting Li+ from brine with high Mg2+/Li+ ratios.

Enhancing polyvinyl alcohol surface properties through pre-drying treatment and modified electrospun polycaprolactone nanofibers

The application of polyvinyl alcohol (PVA) as a biodegradable polymer is restricted by its low water resistance, particularly for the packaging of moisture-sensitive products. In this paper, we report on a surface-modification approach for PVA films using electrospinning of beeswax-modified polycaprolactone (PCL) following a 10 min pre-drying process. The pre-drying process led to physical binding between the hydrophobic PCL/beeswax nanofibers and the hydrophilic PVA substrate while the addition of beeswax to PCL improved its physical properties, leading to larger surface roughness and lower wettability of the PVA film. In particular, by adding a proper amount of beeswax to PCL, a PVA/PCL/beeswax composite film showed high hydrophobicity with a water contact angle of 144.1°, demonstrating a significant improvement in the surface properties compared to the hydrophilic bare PVA film. Moreover, the oxygen permeability of the PVA film decreased from 5.5 to 2.2 cc.m−2.day−1 after electrospinning the PCL/beeswax, which was related to the rougher surface morphology generated by the electrospun nanofibers. Therefore, our cost-effective approach has the potential to modify the physical properties of hydrophilic polymers and to broaden their industrial applications.

The preparation of electrically-enhanced and hydrophilic CNTs-PVDF composite hollow fiber membranes for fouling resistance

The anaerobic membrane bioreactor has great potentials to treat the wastewater with high organic matter due to the efficient anaerobic digestion process and high biomass retention. However, the existence of membrane fouling significantly increases the maintenance cost, and always requires frequent and complex cleaning process to recover the membrane performance. Thus, it is significant to fabricate a membrane with excellent anti-fouling performance for the application in membrane bioreactors. Herein, we prepared the CNTs-PVDF hollow fiber membrane with fouling resistance via loading the conductive CNTs coating on the surface of commercial PVDF membrane by a simple cross-linking reaction with hydrophilic polyvinyl alcohol and succinic acid. “Dual defense” was constructed by the combination of the hydrophilic surface and conductive CNTs coating, which lifted the anti-fouling performance of this membrane. In the assistance of electrical effect, the permeance of the membrane with −1.2 V bias could be recovered to 95 % of original state by simple hydraulic cleaning, while that of the membrane without bias was only 58 % after filtrating the sludge of 2000 mg/L. Furthermore, this membrane also exhibited the superior stability and fouling resistance in the operation of anaerobic electrochemical membrane bioreactor, which was promising for the advanced water treatment.

New Surface Modification of Hydrophilic Polyvinyl Alcohol via Predrying and Electrospinning of Hydrophobic Polycaprolactone Nanofibers.

Despite the excellent oxygen barrier and biodegradability of polyvinyl alcohol (PVA), its poor physical properties owing to its inherent hydrophilicity limit its application. In this paper, we report a novel surface modification technique for PVA films, involving the control of the predrying conditions (i.e., amount of residual solvent) of the coated PVA film and adjusting the electrospinning process of hydrophobic polycaprolactone (PCL) nanofibers onto the PVA films. The residual solvent of the coated PVA film was varied by changing the predrying time. A shorter predrying time increased the residual solvent content significantly (p < 0.05) and the flexibility of the coated PVA film. Moreover, scanning electron microscopy depicted the improved physical binding of hydrophobic PCL nanofibers to the hydrophilic PVA surface with increased penetration depth to the PVA film with shorter drying times. The PVA/PCL composite films with different predrying times and electrospun PCL nanofibers exhibited an apparent increase in the contact angle from 8.3° to 95.1°. The tensile strength of the pure PVA film increased significantly (p < 0.05) from 7.5 MPa to 77.4 MPa and its oxygen permeability decreased from 5.5 to 1.9 cc/m2·day. Therefore, our newly developed technique is cost-effective for modifying the surface and physical properties of hydrophilic polymers, broadening their industrial applications.

Air/water vapor control with lithium chloride/polyvinyl alcohol/sulfone composite films

With the burgeoning membrane market focusing on moisture control applications, air/water filtered membranes find increasing use in diverse fields from electronics to food preservation. Fabrication and investigations of lithium chloride (LiCl)/Polyvinyl Alcohol (PVA)/sulfone composite films designed to dehumidify the surrounding air have been conducted. These films combine hydrophilic PVA with sulfone, a material known for its water vapor selectivity. Additionally, this research analyzes the impact of LiCl concentration on the film's performance, revealing that an optimal balance between water permeability and air blockage can be achieved by adjusting material compositions. Various material characterizations, including X-ray diffraction (XRD), secondary ion mass spectrometry (SIMS), Raman spectroscopy, photoluminescence (PL) spectroscopy, transmission electron microscopy (TEM), optical microscopy (OM), and confocal optical surface measurements, shed light on the film's surface morphology, lattice structure, and optical properties. The results demonstrate that the LiCl/PVA/sulfone composite films hold promise as effective dehumidifying components with potential applications in air conditioning and smart wearable garments.

Preparation of PVDF/PVA composite films with micropatterned structures on light-cured 3D printed molds for hydrophilic modification of PVDF

Abstract Polyvinylidene fluoride (PVDF) is widely used in biotechnology due to its excellent biocompatibility, high temperature and pressure resistance, and outstanding mechanical properties. However, the hydrophobic nature of PVDF surface hinders the attachment of biological proteins. In order to enhance the wettability of PVDF surfaces, this study prepared composite films by blending PVDF with polyvinyl alcohol (PVA), and micro-patterned structures were fabricated on the material surface using a mold-replication method based on digital light processing (DLP) photopolymerization printing technology. A series of characterization techniques including surface morphology analysis, chemical composition analysis, and wettability testing were employed. The surface morphology analysis results indicated that the method of using DLP photopolymerization technology to print mold replicas and create micro-patterned structures was indeed effective in creating micro-patterned structures on both PVDF and PVDF/PVA composite films. The chemical composition analysis showed that the spin-coating of PVDF powder material resulted in PVDF β-phase crystalline structure, which has a positive effect on cell growth. Furthermore, the introduction of hydrophilic groups was achieved by mixing PVDF with PVA. Wetting test results indicate that the incorporation of the hydrophilic material PVA and micro-patterned surfaces both contribute to the improved hydrophilicity of the material. The water contact angle of the micro-patterned PVDF/PVA composite film reached 30.8°, exhibiting excellent hydrophilic properties. This study achieved the optimization of PVDF surface properties through micro-patterned surface modification and material composition design, providing novel insights for the further development of PVDF materials in the field of biotechnology.

Commercial polyethylene supported thin-film composite membranes within 10 µm thickness for organic solvent forward osmosis

Organic solvent forward osmosis (OSFO) as a promising separation process for the pharmaceutical industry. The practicality and suitability of OSFO membrane are significant for the OSFO process. In this study, we developed and characterized an ultrathin (<10 µm) and solvent-resistant thin-film composite (TFC) membrane for use in the OSFO process. The commercialized polyethylene (PE) membrane with thicknesses of 5 and 9 μm were selected as a novel substrate, and hydrophilic polyvinyl alcohol was introduced on its surface to enhance hydrophilicity and structural attributes. After interfacial polymerization reaction, the utilization of the 5 μm PE substrate elevates water and alcohol fluxes, while the 9 μm PE substrate possesses the higher rejection for salts and APIs. Notably, following a 2-hour DMF activation process, the resulting TFC5-0.05 membrane attains a noteworthy ethanol flux of 2.6 L m–2h−1, along with a robust oxytetracycline rejection of > 95 % during 10-hour continuous operation. These findings underscore the favorable permselectivity of the ethanol and oxytetracycline and solvent stability of the ultrathin PE-PA TFC membrane on the commercial substrates for OSFO process.

Hydrophilic and Hydrophobic Composite Microporous Layer Coated Gas Diffusion Layers for Performance Enhancement of Polymer Electrolyte Fuel Cells

A novel microporous layer (MPL) coated gas diffusion layer (GDL) is developed to improve water management of polymer electrolyte fuel cells (PEFCs) by incorporating hydrophobic and hydrophilic pores within the same layer. This MPL expels excess water at the interface between the catalyst layer and MPL through hydrophilic pores while maintaining efficient oxygen transport through hydrophobic pores, reducing oxygen transport resistance under high humidity conditions. The water permeability and relative oxygen permeance tests demonstrate the presence of separate hydrophobic and hydrophilic pores in the appropriate composite MPL. The effects of combinations of hydrophilic and hydrophobic binders used in the composite MPLs on the oxygen transport resistance are evaluated. The hydrophobic polytetrafluoroethylene (PTFE) binder and the hydrophilic polyvinyl alcohol (PVA) binder cannot enhance performance due to mismatched sintering temperatures. Although the hydrophobic polyvinylidene fluoride (PVDF) and PVA binders have the same sintering temperature, the performance was degraded due to the strong hydrophilicity of PVA. Another combination of composite MPL incorporates hydrophobic PVDF and Nafion binders. Hydrophilic TiO2 particles are introduced in the Nafion binder to reinforce the hydrophilicity. The appropriate composite MPL significantly reduced the total oxygen transport resistance compared to those obtained with the hydrophobic MPL.

Synthesis of sulfonated graphene oxide loaded polyvinyl alcohol membranes for esterification of ethyl propionate in a pervaporative catalytic membrane reactor system: Experimental and modelling

Ethyl propionate was produced using pervaporative catalytic membrane reactor-separator (PCMR) system. The reaction and separation were carried out by sulfonated graphene oxide (SGO) incorporated polyvinyl alcohol (PVA) membranes. The catalyst was prepared by sulfonation of graphene oxide using chlorosulfonic acid to achieve the desired degree of sulphonation. The catalyst and membranes were characterized by various techniques like Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), Energy dispersive fluorescence spectroscopy (EDXRF), etc. Various parameters including catalyst loading, reaction time, reaction temperature, molar ratio, downstream pressure, etc. were studied. The PVA membrane crosslinked with fumaric acid was synthesized with different SGO catalyst loading. The prepared membrane was used to perform esterification of ethyl propionate in batch mode with PCMR system. Modelling and simulation studies were carried out to compare the experimental and predicted results. The heterogeneous Eley-Rideal kinetic model was fitted to obtain the conversion values with time and compared with the experimental results. Compared to the batch reactor the conversion was 17–41 % more in PCMR for different molar ratios and temperatures. The water flux was varied from 1.92 to 8.8 mol /m2h with time. Maximum conversion (98 %) occurred at higher temperatures, about 90 % conversion was achieved in the study at 60 ℃ in 8.5 h. The highest selectivity of water was obtained as 145 at a pressure of 6 mmHg with the hydrophilic PVA membrane.

Bioactive Fe Foam for Degradable Bone Graft Cages

Fe foams when combined with a proper surface coating can be effectively used as a biodegradable metal with improved biocompatibility and bioactivity. Herein, Fe foams prepared via powder metallurgy route coated with two different bioactive coatings namely polyvinyl alcohol (PVA)/bioglass (BG) and polylactic acid (PLA)/BG are investigated. The effect of hydrophilic PVA and hydrophobic PLA, in conjunction with BG, has been examined. The study of biomineralization, degradation, and weight loss of the composite‐coated material over a period of 28 days is compared with that of the uncoated Fe foam samples in simulated body fluid. The composite coatings on the Fe foam effectively tailor the degradation with enhanced biomineralization. The composite‐coated material exhibits viability toward the L929 fibroblast cell line. The work reveals the great potential of Fe foams to be used as a biodegradable metallic material for temporary implant applications such as bone graft cages.

Facilitated water transport in composite reduced graphene oxide pervaporation membranes for ethanol upgrading

High purity ethanol is one of the most sought-after renewable energy sources. However, standard production methods yield ethanol of insufficient quality. Membrane processes such as pervaporation are recognized as a viable method for upgrading ethanol. Their performance and selectivity depend solely on membrane employed. Hydrophilic polyvinyl alcohol (PVA) membranes are used industrially for this purpose, but there is a trade-off between selectivity and permeability. Among other materials, chemically converted graphene attracts particular attention due to its exceptional water transport properties, however its application is limited by the fabrication of free-standing membranes. In this study, a composite reduced PVA/graphene oxide (rGO) membranes with different rGO content (up to 49 wt%) was synthesized. Polyvinyl alcohol acted as a mediator to improve the mechanical stability of membrane layers by crosslinking rGO flakes with hydrogen bonds. The resulting membranes were fully characterized by scanning electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, water contact angle and mechanical tests. Pervaporation tests with water/ethanol mixtures (10/90 wt%) at temperatures between 20 and 50 °C demonstrated an excellent selectivity (over 12000) of membranes and satisfactory flux, even at high temperatures. The total permeate flux for membranes varied slightly as a function of operating temperature, demonstrating a good thermostability of the reduced graphene oxide-based membranes. The pervaporation separation index (PSI) of synthesized membrane exceed 5000 and surpassed majority of rGO containing membranes reported in the literature. Results indicate that rGO membranes noncovalently strengthened with PVA are a promising material for selective ethanol dehydration via pervaporation.

Photocrosslinkable and hydroplasicable UV-shielding nanocellulose films facilitated by hydroxyl-yne click reaction

Sustainably-sourced functional nanocellulose materials are vitally important for the green and sustainable development. Herein, we reported photocrosslinkable and hydroplasticable TEMPO-oxidized cellulose nanofiber phenyl propylene ketone ethers (TOCNPPK) films with excellent ultraviolet (UV) shielding, highly reversible processability, and extended mechanical properties, which were facilitated by green hydroxyl-yne click reaction. The introduction of conjugated aromatic ring and vinyl bonds (-C=C-) had been demonstrated the key for the improved overall performance of resultant TOCNPPK, which not only endowed the TOCNPPK with nearly 100 % UV shielding, but also enabled it to be formed into diverse 3D shapes (helix, ring and letters “N, F, U”) via the facile hydrosetting method. The photocrosslinkable-enhanced mechanical performance of TOCNPPK films was also attributed to -C=C- which could crosslink via [2π + 2π] cycloaddition reactions under UV-irradiation. The ultimate stress of TOCNPPK films was as high as 210.0 ± 22.8 MPa and the Young's modulus was 11.5 ± 0.7 GPa, much superior to those of 128.6 ± 8.5 MPa and 9.2 ± 0.6 GPa for pristine TOCN films. Furthermore, the TOCNPPK had been demonstrated as efficient nanofillers for both hydrophilic polyvinyl alcohol and lipophilic polycaprolactone to develop advanced biodegradable composite films with the integration of good water-wetting resistance, excellent UV blocking, and photo-enhanced mechanical performance.

Graphene oxide composited with different size of organic molecules for hydrogen isotopic water separation in membrane distillation

Developing an efficient light water/tritiated water (H2O/HTO) separation process to meet environmental regulations is important in the nuclear energy field. The membrane distillation processes for the separation of H2O/D2O (deuteriated water), which is usually served as the laboratory model process for H2O/HTO separation, showed good separation performance with graphene oxide (GO)-based membranes. Here, the approach to enhance the H2O/D2O separation performance was explored through regulating interlayer spacing and physicochemical properties of membranes, for which two types of GO membranes were prepared and applied in air-gap membrane distillation: (i) small molecules of urea (UR) or ethanediamine (EDA) were cross-linked with GO platelets to obtain GO-framework (GOF) membranes designated as GO-UR or GO-EDA with varied interlayer spacing. The GO-EDA membrane with a permeation flux of 0.95 L·m−2·h−1 gave higher separation performance than the pristine GO membrane; (ii) macromolecules of hydrophilic polyvinyl alcohol (PVA) or hydrophobic polymethyl methacrylate (PMMA) were intercalated into GO laminates to adjust interlayer spacing and physicochemical properties of membranes. The resultant GO-PVA membrane exhibited a higher permeation flux of 0.94 L·m−2·h−1 and similar separation factor compared with the pristine GO membrane. Moreover, long-term process stability of H2O/D2O separation in membrane distillation was demonstrated using GO-EDA membrane for a 28-h process. Therefore, the results demonstrated that regulating interlayer spacing and physicochemical properties of membranes can provide a facile route to improve performance of GO-based membrane distillation processes for the separation of H2O/D2O, which may be applied to H2O/HTO separation process needed for the treatment of tritiated water in the nuclear energy field.

Strategies to overcome the limitations of cross-linked hydrophilic PVA membranes; carboxy methyl cellulose blending for epichlorohydrin-isopropanol-water pervaporation dehydration

Sodium carboxyl methyl cellulous (NaCMC)/Polyvinyl alcohol (PVA) coated Alumina hollow fiber (AHF) membrane was developed and applied to dehydration of ECH-IPA-water ternary feed mixture. CMC40 membrane, including 40 wt% of NaCMC showed the highest flux of 0.416 kg/m2h and a separation factor of 898 due to optimized packing density between PVA and the NaCMC polymer chain and relatively higher hydrophilic nature for PV separation to ECH-IPA-water ternary feed. After that, CMC40-coated AHF membrane was prepared according to the number of CMC40 coating and baking temperature. With an increase in baking temperature to 170 °C, the separation factor was significantly improved, while the flux decreased slightly. Moreover, NaCMC40-AHF showed robust properties with stable performance in the 50-h long-term PV test.

Salt-blocking three-dimensional Janus evaporator with superwettability gradient for efficient and stable solar desalination

Solar interfacial steam power generation is a prospective method for seawater desalination. In this work, a salt-blocking three-dimensional (3D) Janus evaporator with a superhydrophobic to superhydrophilic gradient was fabricated by spraying a composite dispersion of multi-walled carbon nanotubes/polydimethylsiloxane (CNTs/PDMS) onto the top side of a polyurethane (PU) foam and polyvinyl alcohol (PVA) solution onto the bottom side. The CNTs/PDMS composite dispersion with nanostructured CNTs and low surface energy PDMS combined with the porous structure of the PU foam rendered the top side superhydrophobic. Therefore, a layer suitable for photothermal conversion was obtained. The hydrophilic PVA combined with the porous structure of the foam rendered the bottom side superhydrophilic, facilitating water absorption and transportation. The asymmetric wettability gradient of the CNTs/PDMS-PU-PVA as a 3D evaporator caused the evaporation rate and transportation speed of water to reach a balance, and the salt was quickly dissolved at the superhydrophilic interface. This 3D salt-resistant Janus evaporator achieved an evaporation rate of 2.26 kg m-2 h−1 under 1 kW m−2 illumination.

The application of hydrophilic polyvinyl alcohol coatings filled with different loadings of zinc oxide nanoparticles to mitigate salinity stress of the wheat seeds

AbstractIn this work the effects of wheat seeds coating with polyvinyl alcohol (0 and 1.5 wt.%) and zinc oxide nanoparticles (0, 2, 4, and 6 wt.% of the amount of polyvinyl alcohol) under salinity stress (0 and 2 ds/m) to increase the seed resistance under non‐biological stresses and to improve its productivity were studied. To evaluate the properties of the applied coating on the studied seeds, films consisting of polyvinyl alcohol and zinc oxide nanoparticles were also prepared and characterized by tensile tests, differential scanning calorimeter, Fourier transform infrared spectroscopy, Atomic force microscopy, moisture absorption, hardness, contact angle measurements, and scanning electronic microscope. A laboratory study was conducted as factorial in a completely randomized design with three replications to evaluate the germination indices. The films containing nanoparticles had a higher modulus and elongation at break. However, increasing the nanoparticles to 6 wt.% reduced the tensile strength by 29%. In addition, the application of nanoparticles caused an increase in film hardness, a decrease in moisture absorption, and an increase in contact angle. As results, the mechanical properties of the seed polymer coating were introduced as one of the most influential factors in seed germination performance. Regarding the effect of nanoparticles, zinc oxide nanoparticles significantly reduced the adverse effects of salinity stress.

Facile engineering 3-D photothermal laser induced graphene for efficient steam generation

Solar driven steam generation is a typical application of solar energy harvesting for clean water production, which has undergone a long-term development. Up to now, a desirable evaporation efficiency has been achieved in lab-scale via advanced materials and structural design However, to maintain a stable performance for long-term practical application, the simplicity of fabrication process, the cost of the raw material and the salt accumulation issue have to be taken into consideration. Here, this research proposed an efficient solar evaporator based on laser induced graphene (LIG) and the commercialized nickel foam. The nickel foam was preferred as the skeleton of the evaporator coupling with hydrophilic polyvinyl alcohol (PVA) to provide sufficient water pathways with reduced water vaporization enthalpy in the bottom layer of the solar evaporator. In addition, plasmonic antimony doped tin oxide (ATO) nanoparticles were introduced into the porous graphene to further enhance the solar absorption and photothermal conversion. Thus, the 3D evaporator exhibits a high evaporation efficiency of 2.21 kg m −2 h −1 in salt water (20 wt% NaCl) under 1 solar irradiation (1 kw m −2 ). Moreover, the evaporator enables a stable evaporation performance upon the saline water during a 120 h test, with no salt crystals accumulated on the surface of evaporator. It is believed that this work presents a potential simple pathway to design and fabricate a portable and efficient evaporator equipped with efficient LIG nanocomposite as an efficient solar absorber. • A novel LIG-ATO nanocomposite has been facilely synthesized vis a one-step laser deposition for a portable solar evaporator.