Decrease In Water Contact Angle Research Articles

Poly(2-hydroxyethyl methacrylate-co-methacrylated hyaluronan-β-cyclodextrin) hydrogel: A potential contact lens material with high hydrophilicity, good mechanical properties and sustained drug delivery.

A novel poly(2-hydroxyethyl methacrylate-co-methacrylated hyaluronan-β-cyclodextrin) [p(HEMA-co-mHA-β-CD)] hydrogel was developed as a potential contact lens for ophthalmic disease. The hydrogel was synthesized from the copolymerization of 2-hydroxyethyl methacrylate (HEMA) monomer and mHA-β-CD as a hydrophilic macromolecular crosslinker. By adjusting the methacrylate substitution degree in hyaluronan (20-29%) and the mHA-β-CD content (5-11%), transparent p(HEMA-co-mHA-β-CD) hydrogels were achieved. p(HEMA-co-m20HA-β-CD) hydrogels exhibited an enhanced tensile modulus (from 0.35 to 0.88MPa) with a decreased elongation at break (from 255% to 108%), meanwhile they showed increased hydrophilicity with a decreased water contact angle (from 83.4° to 48.6°) and an increased equilibrium water content (from 38.2% to 46.4%). Increasing the mHA-β-CD content resulted in a higher encapsulation and cumulative release of hydrophilic levofloxacin hydrochloride or hydrophobic puerarin, due to the improved hydrophilicity and the formation of β-CD/drug inclusion complexes. Compared with pHEMA hydrogel, p(HEMA-co-m20HA-β-CD) hydrogels better inhibited the deposition of lysozyme and bovine serum albumin, and the bacterial adhesion against S. aureus and E. coli. The hydrogels were stable at physiological conditions and non-toxic to immortalized human keratinocytes. With good mechanical properties, tear protein deposition resistance, antibacterial activity, and sustained drug delivery capabilities, p(HEMA-co-m20HA-β-CD) hydrogels were identified as a promising contact lens material for eye diseases.

Novel visible-light-driven antibacterial film grafted with 3,3,4,4-benzophenone tetracarboxylic acid (BPTCA) for chilled meats preservation

To improve long-term stability and low-toxicity active packaging systems, three visible-light-driven antibacterial packaging films from chitosan (CS), silk fibroin (SF), polyvinyl alcohol (PVA) and 3,3,4,4-benzophenone tetracarboxylic acid (BPTCA) were fabricated in this study. First, CS/PVA, SF/PVA and CS/SF/PVA films by solution casting method, and enhance their water solubility by glutaraldehyde (GA) cross-linking to obtain CS/PVA-G, SF/PVA-G and CS/SF/PVA-G. Then, BPTCA was covalently immobilized onto CS/PVA-G, SF/PVA-G and CS/SF/PVA-G through the esterification to obtain CS/PVA-B, SF/PVA-B and CS/SF/PVA-B, respectively. The chemical structure, photophysical properties, and antibacterial capacities are characterized. The FTIR revealed that BPTCA is covalently grafted with the polymer matrix via ester bond. Furthermore, grafting of BPTCA enhanced the film's UV-blocking, decreased water contact angle, water vapor permeability, and possessed moderate mechanical properties. Meanwhile, CS/SF/PVA-B has the best reactive oxygen species generation ability and antibacterial activity (against Escherichia coli, Staphylococcus aureus, Salmonella enteritidis), and can recycle four times, overall migration value of BPTCA was within the limits of 10 mg/dm2. We apply CS/SF/PVA-B films combined with palletized packaging to different chilled-meat preservation applications, and measure physicochemical changes and microbial counts. Shelf lives of chilled mutton are extended by 3 d and chicken by 6 d, compared with controls without CS/SF/PVA-B film. A covalent immobilized visible-light-driven antibacterial packaging may improve the long-term quality of chilled meats.

Development of SBS composite modified asphalt incorporating polydopamine-enhanced MoS2

This study investigated the development of a novel composite modified asphalt incorporating PDA-MoS2 into styrene-butadiene-styrene (SBS) modified asphalt. The successful synthesis of PDA-MoS2 was confirmed through various characterization techniques. The incorporation of PDA-MoS2 into SBS modified asphalt resulted in significant improvements in performance properties. With a PDA-MoS2 content of 0.7 wt%, the modified asphalt showed a notable 15.1% rise in softening point and a 24% drop in penetration in comparison to the control SBS modified asphalt. Dynamic Shear Rheometer tests revealed a 2.4-fold increase in the rutting factor at 60°C. Multiple Stress Creep Recovery tests demonstrated enhanced rutting resistance, with a 72.2% reduction in nonrecoverable creep compliance at 0.1 kPa stress level. Electrochemical measurements showed improved corrosion resistance, evidenced by lower current densities and higher charge transfer resistance. Microstructural analysis revealed well-dispersed PDA-MoS2 particles forming a compact network structure within the asphalt matrix. The hydrophilicity of the modified asphalt increased, with a 35.3% decrease in water contact angle. The synergistic effect between PDA-MoS2, SBS, and asphalt components, facilitated by enhanced interfacial interactions and chemical bonding, contributed to the observed performance improvements. The results indicate that PDA-MoS2 has the potential to improve the characteristics of SBS modified asphalt as a modifier.

Evaluation of Additives on the Cell Metabolic Activity of New PHB/PLA-Based Formulations by Means of Material Extrusion 3D Printing for Scaffold Applications

In this study, specific additives were incorporated in polyhydroxyalcanoate (PHB) and polylactic acid (PLA) blend to improve its compatibility, and so enhance the cell metabolic activity of scaffolds for tissue engineering. The formulations were manufactured through material extrusion (MEX) additive manufacturing (AM) technology. As additives, petroleum-based poly(ethylene) with glicidyl metacrylate (EGM) and methyl acrylate-co-glycidyl methacrylate (EMAG); poly(styrene-co-maleic anhydride) copolymer (Xibond); and bio-based epoxidized linseed oil (ELO) were used. On one hand, standard geometries manufactured were assessed to evaluate the compatibilizing effect. The additives improved the compatibility of PHB/PLA blend, highlighting the effect of EMAG and ELO in ductile properties. The processability was also enhanced for the decrease in melt temperature as well as the improvement of thermal stability. On the other hand, manufactured scaffolds were evaluated for the purpose of bone regeneration. The mean pore size and porosity exhibited values between 675 and 718 μm and 50 and 53%, respectively. According to the results, the compression stress was higher (11–13 MPa) than the required for trabecular bones (5–10 MPa). The best results in cell metabolic activity were obtained by incorporating ELO and Xibond due to the decrease in water contact angle, showing a stable cell attachment after 7 days of culture as observed in SEM.

Analysis of discharge parameters of an argon cold atmospheric pressure plasma jet and its impact on surface characteristics of White Grapes

An argon cold atmospheric-pressure plasma (CAP) jet operated using bipolar pulsed power supply has been characterised electro-optically and the discharge parameters are optimized. An analysis has been done on the impact of the argon CAP jet treatment on the surface properties of white grapes for different treatment time period. The developed argon CAP jet is a plasma source based on dielectric barrier discharge (DBD) that has been tuned at various input parameters including applied voltage, frequency, average power consumption, and argon flow rate. Optical Emission Spectroscopy (OES) is used to identify the generated species along with plasma parameters. The collisional–radiative (CR) model is employed to extract the electron density (ne) and electron temperature (Te) from the spectra at the optimised applied voltage of 4 kV, frequency 20 kHz and argon flow rate of 4 slpm. The OES results coupled with the CR model (ne ∼ 1014 cm−3 and Te ∼ 1 eV) and the plasma gas temperature measurement through OH (A-X) transitions (Tg ∼ 310.5 K) show the non-equilibrium nature of the argon CAP jet. A comparative analysis between untreated and treated white grapes reveals that the argon CAP jet treatment influences surface microstructure, increasing hydrophilicity (with a ∼49.3% decrease in water contact angle) along with slight changes in surface temperature (∼5 °C increase), colour (ΔE* < 1.5), and physiochemical properties such as chemical composition (no change) and Total Soluble Solid (TSS) content (∼8.3%). It is inferred that this type of CAP jet treatment of white grapes only affects the physical characteristics of the grape surface and does not alter any chemical compositions.

Biomimetic Ag-modified core-shell nanofibrous membrane with enhanced solar absorption and water replenishment for efficient clean water production and antibacterial activity

Microorganism contamination of evaporators can deteriorate their performance during solar-driven water evaporation. Herein, we developed a biomimetic core-shell nanofibrous membrane with enhanced solar absorption, water replenishment, and antimicrobial properties via modification of silver nanoparticles (Ag-NPs). By mimicking the core-shell structure of natural pine needles, (1) the core of polyvinylidene fluoride hexafluoropropylene (PVDF-HFP) nanofiber, like the xylem of pine needles, can act as a support skeleton for dimensional stability; and (2) the shell of Ag-NPs-modified copper oxide (CuO) crystals (Ag@CuO), like the mesophyll of pine needles (photosynthesis for pine growth), can perform the photothermal and antimicrobial properties. The Ag@CuO nanofibrous membrane achieved increased solar absorption from 92.44 % to 95.88 % and decreased water contact angle from 36.1° to 0° after the incorporation of Ag-NPs. Furthermore, the Ag@CuO nanofibrous membrane exhibited stable evaporation rates of 1.31 kg⋅m−2⋅h−1 for 3.5 wt% saline water and 1.27 kg⋅m−2⋅h−1 for actual dye wastewater. Moreover, the nanofibrous membrane possessed excellent flexibility and robust adhesion of Ag-NPs due to the strong interfacial bonding induced by polydopamine. In addition, inhibition rates above 99.97 % against Staphylococcus aureus and Escherichia coli demonstrated the outstanding antimicrobial properties of the Ag@CuO membrane. In conclusion, the high evaporation performance, excellent flexibility, and outstanding antimicrobial properties enable the Ag@CuO nanofibrous membrane to be a good option for sustainable clean water production by treating evaporation media containing microorganisms.

Surface Tuning of Transparent Electrodes with Atmospheric Pressure Plasma for Third Generation Photovoltaics

Transparent semiconductor thin films such as indium tin oxide (ITO) and fluorine-doped tin oxide (FTO) are commonly used in optoelectronic devices due to their favorable properties such as high conductivity and transparency and suitable work function [1]. Their use ranges from light-emitting diodes through flat panel displays up to solar cells. In this context, surface stoichiometry plays a crucial role in influencing the final properties of the final device. Therefore, efficient surface treatment has been a topic in research for years, covering a wide range of approaches from wet and dry treatments. Among these possibilities, plasma treatment remains today the most effective. In several studies [2, 3], atmospheric pressure plasma shown an increase of surface energy, decrease the contamination while enhancing the work function of both ITO and FTO. Low temperature, fast processing times, and no special requirements for working gas are the main advantages of this approach.In this study, the authors compare the effects of cold (<100°C) atmospheric pressure plasma on ITO and FTO after air and nitrogen treatment to provide deeper insight into the interaction of discharge with semiconductive materials during treatment. A coplanar dielectric barrier discharge has been used for the surface modification (more information available in [4]). For this configuration both electrodes lay in one plane, and the discharge occurs on the top of the barrier. Chemical changes in the surface were also evaluated as a function of plasma parameters without any pre-treatment of the substrates. For both studied materials, similar trends were observed at fast treatment times (<60s of plasma exposure). The plasma treatment resulted in a decrease of water contact angle from the initial 90° for ITO to 10° after 30 seconds of exposure. For FTO, the initial angle 60° was lowered to 10° after just 5 seconds of exposure, and complete hydrophilicity was obtained after 30 seconds of plasma treatment. An interesting trend in oxygen concentration measured by XPS was observed for ITO but not FTO samples. From a physical point of view, the interaction with the conductive sample affects the orientation of filaments during the surface modification. Additionally, the results suggest that for small working distances, the physical regime can vary from coplanar to volume discharge as shown in Figure 1. All changes were observed with ICCD imaging (Pi-Max 4, Princeton Instruments). Regarding the physical changes over the surface, the plasma treatment resulted in decreased roughness with no significant effect on conductivity.In conclusion, the results obtained in this study can be utilized in the manufacturing process of microelectronic devices and provide a deeper insight into how the treatment process influences discharge parameters.[1] Armstrong et al. https://doi.org/10.1016/j.tsf.2003.08.067[2] Šimor et al. https://doi.org/10.1063/1.1513185[3] Donley et al. https://doi.org/10.1021/la011101t[3] Chaney et al. https://doi.org/10.1016/S0169-4332(03)00617-2 Figure 1

Multifunctional surface treatment of boron nitride nanotube‐coated polyimide films with atmospheric‐pressure cold plasma

AbstractPolyimide (PI) surfaces coated with and without boron nitride nanotubes (BNNTs) were treated using an atmospheric‐pressure cold plasma in open air. This treatment increased the surface wettability of the PI, measured by a decrease in water contact angle from 68° to 16°, resulting in a more uniform BNNT coating and improved surface adhesion. The plasma treatment of the BNNT‐coated PI surfaces also effectively removed residual polymer surfactants used for BNNT dispersion in water, without causing any thermal damage due to the low plasma and PI's surface temperatures of 350 and 300 K, respectively. The reactive oxygen species in the plasma, such as hydroxyl molecules and oxygen atoms, played an important role in these processes. Atmospheric‐pressure plasma can be employed in various applications in which thermally weak polymer‐based substrates are coated with BNNTs.

Rapid attainment of full wettability through surface PEGylation of hydrophobic polyvinylidene fluoride membranes via spray-coating for enhanced anti-biofouling performances

This manuscript explores the development of antifouling membranes fabricated by vapor-induced phase separation (VIPS) process and their spray-coating modification with an aqueous solution of a copolymer comprising butyl methacrylate and poly(ethylene glycol) methyl ether methacrylate, designated as poly(BMA-r-PEGMA). An initial optimization phase focused on improving the modification quality, with the aim of enhancing the wettability on both the top and bottom surfaces of the membranes, despite spraying on the top surface only. Our findings reveal that a sprayed solution concentration of 10 mg/mL, a pressure of 0.25 MPa, and a scan rate of 3000 mm/min achieved a decrease in water contact angle to 0 in less than 12 s for both membrane surfaces (the top surface directly exposed to the spray, and the bottom surface facing the instrument stage), suggesting that the spray-coating modifies the entire membrane’s bulk. The presence of the copolymer on both surfaces was also evidenced by FTIR and XPS tests. Further biofouling assessments demonstrated the performances of the optimized membrane (OM). In static attachment tests, the OM exhibited a high reduction in Escherichia coli adhesion, with less than 10 % adhering bacteria, compared to unmodified membranes. During the filtration of bacteria-containing wastewater, the OM boasted a flux recovery ratio approaching 60 % (against less than 40 % for a commercial hydrophilic membrane), a rejection rate of 99.3 %, and a water permeability of 2500 LMH/bar. Moreover, the OM was stable over a 4-week period, with a resistance to E. coli attachment remaining similar to prior immersion. These findings underscore the significant potential of spray-coating to develop stable and effective antifouling microfiltration membranes for the removal of microorganisms from wastewater.

Mesoporous Mg–Al–Ti composite oxide incorporated mixed matrix ultrafiltration membrane with superior multi-heavy metal removal capacity, anti-fouling & anti-microbial property

Mesoporous Mg–Al–Ti ternary composite oxide nano-adsorbents have demonstrated an exceptional performance to remove multiple heavy metals (As, Pb, Cd, Cr). Incorporation of these nanoparticles (NPs) in polysulfone membrane created a multifunctional mixed matrix membrane (MMM) with heavy metal adsorption capacity (both cationic and anionic species), enhanced hydrophilicity, anti-fouling property, and anti-microbial activity. The best heavy metal removal performance was shown by the membrane incorporated with 0.8 wt% NPs. Hydrophilicity improvement was studied through the decrease in water contact angle from 71° to 57° and surface probing using atomic force microscopy (AFM). With a maximum As(III) adsorption capacity of 256.6 mg/g, the membrane had a breakthrough volume of 25L and could provide safe drinking water for 19 h from a real Arsenic (As) contaminated groundwater sample with a flux of 48 l/m2-h. Beyond that, >90 % removal of Cd, Pb & Cr was also observed with maximum adsorption capacity of 652.9 mg/g, 332.5 mg/g, and 89.4 mg/g respectively. 92.5 % flux recovery after filtering a 1000 ppm bovine serum albumin showed the anti-fouling property. Successful inhibition of both gram-positive and gram-negative bacterial growth, and >99.99 % removal of colony forming units (CFU/ml) in the filtration process confirmed the anti-microbial resistance. With its multifunctionality, these membranes hold great potential for practical water treatment applications.

Tailoring surface properties of Poly(caprolactone)/Hydroxyapatite scaffolds through aminolysis and multi-walled carbon nanotube coating for bone tissue engineering

In this study, the effects of surface modification on the physicochemical properties, degradation behavior, and cellular responses of poly(caprolactone) (PCL)/hydroxyapatite (HAp) scaffolds using carboxylated multi-walled carbon nanotubes (MWCNTs) were investigated. The scaffolds were prepared using the fused deposition modeling (FDM) technique, followed by aminolysis for 15, 30, and 60 minutes. Subsequently, the scaffolds were immersed in MWCNT solutions with concentrations of 0.1 %, 0.5 %, and 1 % g/mL to achieve the desired coating. Various characterization techniques were employed to evaluate the surface morphology, chemical composition, and structural changes induced by the coating. FESEM images revealed a uniform MWCNT coating on the PCL/HAp scaffolds at an optimal concentration of 0.5 % g/mL, while lower concentrations resulted in incomplete coating and higher concentrations led to MWCNT agglomerations. The MWCNT coating successfully enhanced the conductivity of the scaffolds, with electrical conductivity increasing from near zero for the non-coated PCL/HAp scaffolds to 5 × 10−5 S/m for the MWCNT-coated scaffolds. Additionally, the coating exhibited improved wettability, as demonstrated by decreased water contact angles from 67.71° for non-coated surfaces to 51.50° for the MWCNT-coated surfaces. Furthermore, the in vitro degradation studies showed that HAp in the PCL matrix accelerated the hydrolysis rate, resulting in higher degradation rates for the PCL/HAp scaffolds than pure PCL scaffolds. The MWCNT coating further influenced the degradation behavior, with variations in degradation rates depending on the MWCNT concentration. Cell viability assays using MG-63 cells revealed improved cell viability and adhesion on the MWCNT-coated PCL/HAp scaffolds compared to plain PCL and PCL/HAp scaffolds. The cell viability increased from 84 % for plain PCL and 103 % for PCL/HAp to 109 % for the MWCNT-coated scaffolds. Moreover, FESEM images showed increased cell adhesion on the MWCNT-coated surfaces, with optimal adhesion observed on the scaffolds coated with 0.5 % g/mL MWCNTs. The results of this study highlight the potential of MWCNT coatings to improve the surface properties of PCL/HAp scaffolds, making them excellent choices for bone tissue engineering applications.

Enhancing CFRP laminates with plasma jet arrays: A study of interlaminar mechanical properties

AbstractThis study delves into the efficacy of plasma jet array treatment in bolstering the interlaminar toughness of Carbon Fiber Reinforced Polymer (CFRP) prepregs, a crucial parameter for their deployment in high‐performance domains. Employing high‐frequency pulsed microsecond plasma jet arrays for surface modification, this research not only demonstrated a 19.49% upsurge in peak load capacity but also a remarkable 29.94% enhancement in Mode I interlaminar fracture toughness, as evident from Double Cantilever Beam (DCB) tests. Furthermore, the surface wettability improvements were underscored by a substantial decrease in water contact angle from 108.33° to 31.45° and a total surface energy augmentation from 12.20 to 64.16 mN/m, post a 1‐min plasma treatment. X‐ray Photoelectron Spectroscopy (XPS) results indicated an appreciable rise in oxygen functionalities, suggesting enhanced resin‐fiber bonding. Additionally, Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) analyses revealed notable decreases in surface roughness and microscale defects, contributing to smoother surfaces conducive to better adhesive bonding and reduced manufacturing defects. These multifaceted improvements, stemming from alterations in surface chemistry and topography, underpin the significant potential of plasma treatment in advancing CFRP laminate applications requiring superior durability and mechanical resilience.Highlights A plasma jet arrays method to enhance CFRP's interlaminar properties was studied. The influence mechanism of plasma modification was revealed in detail. The interlayer toughening mechanism of CFRP after plasma modification is proposed.

Isolation, characteristics, and poly(butylene adipate-co-terephthalate) (PBAT) degradation mechanism of a marine bacteria Roseibium aggregatum ZY-1

Marine microorganisms have been reported to degrade microplastics. However, the degradation mechanisms are still poorly understood. In this study, a bacterium Roseibium aggregatum ZY-1 was isolated from seawater, which can degrade poly(butylene adipate-co-terephthalate) (PBAT). The PBAT-PLA(polylactic acid, PLA) films, before and after degradation, were characterized by scanning electron microscope (SEM) and Fourier transform infrared spectrometer (FTIR), the weight loss rate and water contact angle were measured. The results indicate that ZY-1 colonized on PBAT-PLA film, changed the functional groups and decreased water contact angle of PBAT-PLA film. Moreover, liquid chromatography mass spectrometry (LC-MS) analysis reveales that PBAT was degraded into its oligomers (TB, BTB) and monomers (T, A) during 10 days, and adipic acid (A) could be used as a sole carbon source. The whole genome sequencing analyses illustrate the mechanisms and enzymes such as PETase, carboxylesterases, arylesterase (PpEst) and genes like pobA, pcaBCDFGHIJKT, dcaAEIJK, paaGHJ involved in PBAT degradation. Therefore, the R. aggregatum ZY-1 will be a promising candidate of PBAT degradation.

Fabrication optimization of polyethersulfone adsorptive mixed matrix membrane for enhanced dynamic methylene blue removal: Response surface methodology approach

AbstractIn the present study, the polyethersulfone (PES)/graphene oxide (GO)/polyethylene glycol 200 (PEG‐200) adsorptive mixed matrix membranes (AMMMs) were fabricated using a non‐solvent induced phase inversion method. According to the design of experiments using response surface methodology (RSM), PES concentration (15, 17.5, and 20%), PEG‐200 concentration as a pore former additive (0.5, 2.5, and 4.5%), and GO nanosheet loading percent (0, 0.5, and 1%) were varied during fabrication. A green solvent, dimethyl sulfoxide, was used as an alternative to conventional solvents, while it exhibited better membrane performance. Methylene blue (MB) removal was optimized in PES AMMM synthesis using RSM. Attenuated total reflectance Fourier transform infrared spectroscope confirmed the presence of GO functional groups in the optimum membrane. Scanning electron microscopy analysis revealed the optimum membrane was thicker than the neat membrane and atomic force microscopy analysis demonstrated higher surface roughness. The membranes hydrophilicity increased, with a decrease in water contact angle from 61.1 ± 0.2° (neat PES) to 54.4 ± 0.9° (optimal membrane). Pure water flux of 524.8 L m−2 h−1 and MB rejection of 97.46% were obtained for the optimum membrane. Furthermore, the optimum PES AMMM demonstrated a greater dynamic adsorption capacity in comparison to the unmodified PES membrane.Highlights The optimization of the polyethersulfone (PES) adsorptive mixed matrix membranes (AMMM) for methylene blue removal was performed utilizing the response surface methodology. The calculation of the dynamic adsorption capacity (DAC) was performed through the breakthrough curves. The integration of graphene oxide into the AMMM resulted in an enhanced DAC of the AMMM. The PES AMMM performance is based on Donnan electrostatic exclusion.

Improvement of biocompatibility of high molecular weight poly-3-hydroxybutyrate by blending with its functionalized oligomers

Oligomers of poly-3-hydroxybutyrate (PHB) were prepared by aminolysis of high molecular weight PHB with ethylenediamine and 1,4-diaminobutane. Polymer-oligomer blends (10, 30, and 50% content of the oligomers) were prepared as films by solution casting. As the content of oligomers increased, a gradual increase in the hydrophilicity of the polymer surface was observed, resulting reflected in the water contact angle decrease from 84° to 72–76°. In addition, a moderate decrease in elongation at break, Young's modulus, and tensile strength for the blends were observed as more oligomer was added to the film. Finally, the viability of NIH-3T3 mouse fibroblasts was higher compared to intact PHB when growing in non-prepared polymer/oligomer mixtures. These findings confirm the benefits of the introduction of a hydrophilic functionalized oligomer into the PHB matrix in terms of improving the biocompatibility of the resulting polymer/oligomer blends.

Cold plasma treatment boosts barley germination and seedling vigor: Insights into soluble sugar, starch, and protein modifications

This study investigates the impact of three cold plasma treatments on barley seed germination: direct treatment of dry seeds (DDS), direct treatment of water-soaked seeds (DWS), and indirect treatment of seeds using plasma-activated water (IPAW). Our findings reveal that while DDS maintained the seed's imbibition structures, DWS significantly reduced water uptake. Notably, DWS-treated seeds exhibited a substantial increase in moisture content, potentially leading to an oxygen-deficient environment within the seed. This condition appeared to hinder germination, contrasting with the beneficial effects observed in DDS-treated seeds. Analyses of surface hydrophilicity, phenolic compounds, carbohydrate composition, protein storage and seedling growth were conducted. Interestingly, cold plasma treatment enhanced seed surface hydrophilicity, as evidenced by a decrease in water contact angles, particularly for DWS. We observed specific reductions in flavonoids and total phenolics, alongside shifts in carbohydrate composition, including increased sugar content up to 15.1% (DDS) and 13.5% (DWS), accompanied by a decrease in starch content to 189.00 ± 7.86 mg/g FM for DWS. Protein storage assessments revealed declines in albumin, globulin and prolamin fractions post-CP exposure. Finally, DDS and IPAW treatments markedly improved seedling shoot growth (from two to three-fold), underscoring the potential of these treatments in enhancing barley germination.

Fabrication, characterization, and application of pea protein-based edible film enhanced by oregano essential oil (OEO) micro- or nano-emulsion

Pea protein isolate (PPI)-based active films were prepared by incorporating 0.5 %, 1.0 %, or 2.0 % of oregano essential oil (OEO), either in the form of micro-emulsion (MOEO) or nano-emulsion (NOEO). The particle size and polydispersity index of OEO droplets were 2755.00 nm and 0.63 for MOEO, and 256.30 nm and 0.20 for NOEO. The surface and cross-sectional SEM results revealed the presence of holes and internal pores within the film upon the addition of OEO. The molecular interaction between PPI and OEO was confirmed by FTIR. The addition of OEO significantly increased film thickness, decreased water contact angle, and imparted a more yellow color. At a low concentration (0.5 %), the addition of OEO significantly improved the water vapor barrier and mechanical properties of the film. However, at higher concentrations, these film properties were significantly weakened. Additionally, the film antimicrobial properties were assessed after OEO addition. In vitro inhibition zone results indicated that a 2.0 % addition of OEO significantly suppressed the growth of three Salmonella strains [Salmonella Typhimurium (ATCC14028), Salmonella Infantis 94-1, and Salmonella Enteritidis PT-30]. Application of pea protein-based film with 2.0 % OEO on chicken breast demonstrated significant reduction in microbial count. Our results further showed that reducing the particle size of OEO from micrometer-scale to nanometer-scale in the PPI film matrix did not significantly alter film properties or antimicrobial activities. The study demonstrated that the antibacterial film based on pea protein and OEO is an innovative food packing material for prohibiting bacteria growth on poultry products.

Biocompatibility, anti-hemolytic, and antibacterial assessments of electrospun PCL/collagen composite nanofibers loaded with Acanthophora spicifera extracts mediated copper oxide nanoparticles

Research in the advancement of wound dressings strives to address specific issues related to infections, speed up the healing process, and enhance patient wellness, all of which will lead to improved wound care procedures. This study investigates the synthesis and characterization of electrospun Polycaprolactone (PCL)/Collagen (Col) nanofibers incorporated with Acanthophora spicifera extracts mediated copper oxide nanoparticles (CuO NPs) and to evaluate their biocompatibility, anti-hemolytic properties, and antibacterial efficacy. The synthesized copper oxide nanoparticles were spherical and 58 ± 17 nm in size as evidenced by the field emission scanning electron microscopy. The fiber diameter of PCL, PCL/Col, PCL/Col/CuO 1%, PCL/Col/CuO 2%, and PCL/Col/CuO 5% was found to be 373 ± 141 nm, 281 ± 46 nm, 221 ± 57 nm, 173 ± 40 and 162 ± 47 nm respectively. Contact angle measurements revealed that the addition of copper oxide nanoparticles into Polycaprolactone/Collagen nanofibers resulted in a decrease in water contact angle from 86.9° to 50.8°. The biocompatibility of the composite nanofibers was evaluated in vitro using mouse fibroblast cells. The results established that copper oxide-imbued nanofibers were non-toxic and biocompatible. The hemolytic index for PCL/Col, PCL/Col/CuO 1%, PCL/Col/CuO 2%, and PCL/Col/CuO 5% scaffolds was 0.91 ± 0.14, 0.76 ± 0.14, 1.21 ± 0.19, and 1.52 ± 0.08 % respectively which was below the permissible value. Furthermore, the PCL/Col/CuO 5% nanofibers exhibited bactericidal properties against Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, and Escherichia coli. These findings suggest the potential applications of copper oxide-infused nanofibers in various biomedical fields, including tissue engineering, antimicrobial coatings, and wound healing.

Transition of Carbon Nanotube Sheets from Hydrophobicity to Hydrophilicity by Facile Electrochemical Wetting

The present study delves into the transformative effects of electrochemical oxidation on the hydrophobic-to-hydrophilic transition of carbon nanotube (CNT) sheets. The paper elucidates the inherent advantages of CNT sheets, such as high electrical conductivity and mechanical strength, and contrasts them with the limitations posed by their hydrophobic nature. A comprehensive investigation is conducted to demonstrate the efficacy of electrochemical oxidation treatment in modifying the surface properties of CNT sheets, thereby making them hydrophilic. The study reveals that the treatment not only is cost-effective and time-efficient compared to traditional plasma treatment methods but also results in a significant decrease in water contact angle. Mechanistic insights into the hydrophilic transition are provided, emphasizing the role of oxygen-containing functional groups introduced during the electrochemical oxidation process.

Radiation-induced graft polymerization acrylamide on PVDF membrane for cation dye removal

A preliminary study of the use of radiation-induced admicellar polymerization to modify PVDF film surfaces was conducted using gamma irradiation at 30 kGy and 0.5–1.5 M of acrylamide. The surface properties were studied in detail and characterized using FESEM, the water contact angle, surface tension, and mercury porosity. Furthermore, the point of zero charges of the grafted PVDF were determined before and after graft admicellar polymerization. The degree of polyacrylamide increased with increments of its concentration at 30 kGy. Increments in the degree of grafting created dense surfaces, as proven by the FESEM morphology. The porosity of the PVDF after grafting reduced slightly, leading to decreased water contact angles. The surface tension also increased due to the high density of the grafted polyacrylamide on the PVDF surfaces. The dye absorption showed that a higher amount of polyacrylamide removed more dye. This work indicates that radiation-induced admicellar polymerization is a suitable method for changing the PVDF surface and it could also be used for other monomers.