Water Contact Angle Measurements Research Articles

Optimized Antifouling γ-Al2O3/α-Al2O3 Nanofiltration Composite Membrane for Lignin Recovery from Wastewater

This study focuses on the development of nanofiltration (NF) membranes with enhanced antifouling properties, high flux, and low molecular weight cut-off (MWCO) for the separation of lignin from paper mill wastewater. Using a sol-gel method by dip-coating, alumina hollow fiber membranes were fabricated with an interlayer to reduce surface roughness. The interlayer improved mechanical properties, effectively covering the surface irregularities and allowing for the subsequent application of a thinner functional layer. This approach significantly reduced surface roughness, from 112.6 nm to 62.9 nm, enhancing contamination resistance and lifetime. Characterization techniques, including X-ray diffraction (XRD), scanning electron microscope (SEM), atomic force microscopy (AFM), and water contact angle measurements, confirmed the successful fabrication and enhanced properties of the membranes. The C2T6T3 membrane demonstrated the smallest roughness and the highest flux recovery rate (FRR) of 82.39% after cleaning with a 0.1 M NaOH solution. Performance evaluations showed that the developed membranes maintained high permeability (initial flux of 25.58 L·m⁻²·h⁻¹, decreasing to 14.06 L·m⁻²·h⁻¹ over time), achieved effective lignin rejection (consistently above 80%), and exhibited excellent long-term operational stability over 144 h of operation.

Development of photoactive biomaterial using modified fullerene nanoparticles

Medical device-associated biofilm infections continue to pose a significant challenge for public health. These infections arise from biofilm accumulation on the device, hampering the antimicrobial treatment. In response, significant efforts have been made to design functional polymeric devices that possess antimicrobial properties, limiting or preventing biofilm formation. However, until now none of the strategies showed a promissory effect. Thus, antimicrobial photodynamic therapy (aPDT) has been shown as a promising candidate to overcome this problem. Photosensitizers (PS) are the main key component for aPDT and fullerenes have been chosen as PS due to their good quantum yields and lifetimes spans. In this study, polylactic acid (PLA) surface was modified with fullerene (C60) and reaction was proven by XPS analysis. The biopolymer surface was characterized by AFM, SEM, and water contact angle measurements. The obtained results imply that the highest fullerene precipitation was attained when PLA was modified with ethylenediamine (EDA) before the reaction with C60, as the highest carbon increase was identified using XPS following reaction with C60. While samples’ hydrophobicity decreased after PLA modification with EDA, it increased after fullerene precipitation. Which implies that bacteria have a lower propensity to attach. Although the surface of the samples became smoother following PLA modification with EDA and reaction with 0.1% C60 precipitation, with 1% C60 precipitation the surface roughness was comparable to unmodified PLA, according to AFM and SEM analyses. Fullerene-based biopolymers could potentially be used in aPDT to make antimicrobial surfaces or medical devices.

A biomimetic approach towards a universal slippery liquid infused surface coating.

One biomimetic approach to surface passivation involves a series of surface coatings based on the slick surfaces of carnivorous pitcher plants (Nepenthes), termed slippery liquid-infused porous surfaces (SLIPS). This study introduces a simplified method to produce SLIPS using a polydopamine (PDA) anchor layer, inspired by mussel adhesion. SLIPS layers were formed on cyclic olefin copolymer, silicon, and stainless steel substrates, by first growing a PDA film on each substrate. This was followed by a hydrophobic liquid anchor layer created by functionalizing the PDA film with a fluorinated thiol. Finally, perfluorodecalin was applied to the surface immediately prior to use. These biomimetic surface functionalization steps were confirmed by several complimentary surface analysis techniques. The wettability of each surface was probed with water contact angle measurements, while the chemical composition of the layer was determined by X-ray photoelectron spectroscopy. Finally, ordering of specific chemical groups within our PDA SLIPS layer was determined via sum frequency generation spectroscopy. The hemocompatibility of our new PDA-based SLIPS coating was then evaluated by tracking FXII activation, fibrin generation time, clot morphology, and platelet adhesion to the surface. This hemocompatibility work suggests that PDA SLIPS coatings slow or prevent clotting, but the observation of both FXII activation and the presence of adherent and activated platelets at the PDA SLIPS samples imply that this formulation of a SLIPS coating is not completely omniphobic.

Photoelectrocatalytic degradation of organophosphate esters using tio2 electrodes produced from 3d-printed ti substrates.

3D printed electrode substrates with novel geometries may significantly improve the efficacy of photoelectrocatalysis for degradation of recalcitrant pollutants such as organophosphate flame retardants (OPFRs). However, the 3D printed substrates often have an irregular topology that can lead to a less uniform arrangement of nanotubes following anodisation. This study investigated the effect of polishing 3D-printed Ti substrates prior to anodisation to form TiO2 nanotube array electrodes, and their subsequent applicability for photoelectrocatalytic treatment of OPFRs in water matrices. Polished and non-polished electrodes exhibited differences in morphology in terms of average roughness, (0.38 and 3.10µm, respectively), leading to more uniform TiO2 nanotubes of the former. Water contact angle measurements revealed the non-polished electrode was super-hydrophilic and the polished electrode hydrophilic (water contact angles of 6.4˚ and 16.1˚, respectively). Despite these differences, the polished and non-polished electrodes exhibited very similar electrochemical responses. In fact, the purity and electrical conductivity of water matrices affected the photoelectrocatalytic performance more than the electrode morphology. The purified water (PW) matrix facilitated the highest degradation/removal of OPFRs, compared to tap water matrices. In particular, individual OPFR degradation levels in PW were 74% ± 9, 37% ± 10, 33% ± 9, 31% ± 11 and 3% ± 5 for triphenyl phosphate, tris(butyl) phosphate, tris(isobutyl) phosphate, tris(2-butoxyethyl) phosphate and tris(2-chloroisopropyl) phosphate, respectively. The removal of OPFRs was relative to their reactivity to hydroxyl radicals, which was higher for the aryl then alkyl straight-chain and then chlorinated compounds. This study reveals that polishing of electrode substrates is not required for the preparation of effective photoelectrocatalytic reactors to treat recalcitrant pollutants (e.g. OPFRs), Importantly, future development of novel high-profile 3D printed electrode will not be hindered by the requirement to polish the substrates prior to anodisation.

Sub-ambient water wettability of hydrophilic and hydrophobic SiO2 surfaces.

The wettability of SiO2 surfaces, crucial for understanding the phase transition processes of water, remains a topic of significant controversy in the literature due to uncertainties in experiments. Molecular dynamics (MD) simulations offer a promising avenue for elucidating these complexities, yet studies specifically addressing water contact angles on hydrophilic and hydrophobic SiO2 surfaces at sub-ambient temperatures are notably absent. In this study, we experimentally measured water contact angles of hydrophilic and hydrophobic SiO2 surfaces at ambient temperature and employed MD to investigate water contact angles on Q3, Q3/Q4, and Q4 SiO2 surfaces across temperatures ranging from 220 to 300K. We investigated the effects of the distribution of hydroxyl groups, droplet size, and hydroxyl density and found that the hydroxyl density had the largest impact on contact angle. Moreover, hydrogen bond analysis uncovered enhanced water affinities of Q3 and Q3/Q4 SiO2 surfaces at lower temperatures, and the spreading rate of precursor films reduced with decreasing temperature. This comprehensive study sheds light on the intricate interaction between surface properties and water behavior, promoting our understanding of the wettability of SiO2 surfaces.

Carboxymethyl chitosan/alendronate sodium/Sr2+ modified TiO2 nanotube arrays enhancing osteogenic activity and antibacterial property

Titanium and its alloys are widely used as orthopedic implants owing to their good mechanical properties and excellent corrosion resistance. However, the insufficient osteogenic activity and antibacterial properties hinder their clinical applications. To address these issues, TiO2 nanotube arrays (TNT) were first fabricated on the TA2 alloy surface via an anodizing technique, and strontium ions (Sr2+) were then loaded by hydrothermal reaction (TNT + Sr) and annealing treatment (TNT + A). Subsequently, the polydopamine layer (TNT + PDA) was constructed to immobilize the carboxymethyl chitosan and alendronate sodium (TNT + CA) mixture. The prepared coatings were thoroughly characterized by scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), X-ray photoelectron spectrometer (XPS), attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), X-ray diffractometer (XRD), and water contact angle measurement. The results confirmed that Sr2+ ions, polydopamine, and carboxymethyl chitosan/alendronate sodium were successfully immobilized on the nanotubes. The coating of TNT + CA significantly enhanced the hydrophilicity, and effectively delayed the release of Sr2+ and alendronate. The TNT + CA coating significantly promoted osteoblast adhesion and proliferation, and up-regulated the expressions of alkaline phosphatase (ALP), osteocalcin (OCN), and osteoblast-specific transcription factor (RUNX2). TNT + CA was able to rapidly induce in situ hydroxyapatite deposition from the simulated body fluid (SBF). Moreover, TNT + CA coating showed inhibition against Escherichia coli and Staphylococcus aureus (especially against Escherichia coli). The prepared TNT + CA coating provides a novel strategy for enhancing bone affinity, improving osteoblast behaviors, and antibacterial properties of titanium-based biomaterials.

Polycaprolactone-zinc oxide biocomposite membranes for wastewater treatment by ultrafiltration process: Synthesis, characterization and removal of inorganic pollutants

The severe droughts impacting North Africa have intensified the pressure on potable water supplies and agricultural irrigation, highlighting the urgent need for sustainable water management solutions. This study explores the potential of poly(ε-caprolactone)/zinc oxide (PCL/ZnO) biocomposites as ultrafiltration membranes for treating urban wastewater, with the goal of enabling water reuse in agriculture. PCL/ZnO membranes, fabricated using the solvent-casting method, were thoroughly characterized using FTIR, XRD, EDAX, SEM, AFM, DSC, TGA, and water contact angle (WCA) measurements. Key findings revealed that increasing ZnO content (1–4 wt%) significantly enhanced membrane thickness, crystallinity, mechanical robustness, and surface roughness, while lowering WCA values to improve hydrophilicity. These enhanced properties are critical for ultrafiltration, as they contribute to higher contaminant rejection and improved water permeability. Performance tests demonstrated ion retention rates of 32–61 % post-filtration, including for toxic metals, effectively reducing pollutant levels. Notably, the treated water met the Food and Agriculture Organization (FAO) standards for irrigation quality, indicating its suitability for agricultural applications. This work highlights the efficacy of PCL/ZnO membranes in facilitating sustainable wastewater recycling under drought conditions, presenting a promising, adaptable solution for water reclamation in water-scarce regions. The results underscore the potential of these biocomposite membranes to advance sustainable water treatment practices, supporting both environmental resilience and agricultural productivity.

Jade powder/PLGA composite microspheres for improved performance as potential bone repair drug carrier

Poly (lactic-co-glycolic acid) (PLGA) has been widely used as drug delivery carrier or scaffold for bone repair due to its good biocompatibility, biodegradability, and degradation rate controllability. However, defects, like acidic degradation by-products, are associated with PLGA and restrict its practical applications. Jade powder, leftover from jade polishing process, is a natural material rich in elements of Ca, Si, and Mg while biocompatible and antibacterial. Herein, jade powder/PLGA composite microspheres with different mass ratios were prepared by emulsion solvent evaporation method under the optimized conditions. Characterization from SEM, EDS, FTIR, and surface water contact angle measurements indicated jade powder was successfully combined with PLGA and improved the surface wettability of the microspheres. Moreover, it was proved, through in vitro simulated body fluid test as well as adipose stem cell osteogenesis analysis, that jade powder addition enhanced the pH buffering capacity of the composite microsphere for simulated body fluid, and promoted the in vitro osteogenic activity of adipose stem cells at a certain amount. This study provides new ideas to employ jade powder, a natural material otherwise thrown away as solid waste, for improvement on PLGA performance in bone repair or potentially other biomedical fields.

Development of polyvinyl alcohol/carboxymethylcellulose-based bio-packaging film with citric acid crosslinking and clove essential oil encapsulated chitosan nanoparticle pickering emulsion

This study developed polyvinyl alcohol (PVA)/carboxymethylcellulose (CMC)-based films, using citric acid (CA) as a non-toxic crosslinking agent, to enhance the shelf life of water-soluble packaging films. Clove essential oil (CEO)-loaded chitosan nanoparticles (CSNPs) were prepared via Pickering emulsion and incorporated into PVA/CMC/CA composite films. The encapsulation of CEO was confirmed by FTIR and optical microscopy. Thermal properties were analyzed using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), revealing improved thermal stability and a decrease in glass transition temperature (Tg) upon crosslinking. The formation of ester bonds was confirmed by ATR-FTIR and 13CNMR. Water contact angle (WCA) measurements showed a decrease in hydrophilicity, enhancing the barrier properties of the films. SEM images demonstrated good dispersion of CSNP/CEO within the matrix, improving mechanical and barrier properties. The films exhibited a 30 % reduction in water vapor permeability and water solubility. Controlled release studies indicated that the composite films sustained CEO release, extending the shelf life of cherry tomatoes. Thus, these PVA/CMC/CA-CSNP/CEO composite films offer strong potential for food preservation applications.

Preparation of PDMS permeation membrane by emulsion dilution method and its separation performance for aromatics

Natural aroma compounds are a kind of important food additive. Taking bis(2-ethylhexyl) sodium sulfosuccinate (AOT) as the surfactant, water-in-n-heptane emulsions were prepared. Then, the emulsions were adopted as the diluter to prepare polydimethylsiloxane (PDMS) pervaporation membranes using the emulsion templating method (ePDMS), of which the separation layer was controlled by the template action of emulsion drops. The ePDMS membranes were utilized to separate aroma compounds. Field-emission scanning electron microscope (FESEM) analysis revealed that the surface of the ePDMS membrane remained smooth, and white light interferometry confirmed the membrane’s surface smoothness. FESEM cross-sectional analysis exposed the voids left by the evaporation of the emulsion, rendering the separation layer of the ePDMS membrane more porous. Water contact angle measurements demonstrated the hydrophobicity of the ePDMS membrane, which is advantageous for the pervaporation of aromatic compounds. Fourier transform infrared spectrometry analysis confirmed the evaporation and separation of the emulsion, retaining the original chemical properties of the PDMS membrane. In an ethanol–water system, the permeation flux of ethanol in ePDMS membranes prepared with 1 emulsion (Vwater:Vn-heptane = 1:9; mass concentration of AOT of 1.0 mg/ml) is 90.6% higher than that in PDMS membranes, while the separation factor does not change obviously. The separation performance of ePDMS membranes for linalool in water was further studied. Results show that the permeation flux and separation factor of linalool in ePDMS composite membranes at 50 °C are 786 g m−2 h−1 and 17.69, which separately increase by 84.7% and 27.1% compared with those in PDMS membranes. This indicates that adding ethanol exerts a significant synergistic effect on the separation of linalool.

Analysis of Accelerated Weathering Effect on Polyethylene With Varied Parameters Using a Combination of Analytical Techniques

AbstractPlastics make up a great portion of solid waste that constitutes an emerging threat to the natural environment. Among plastics, polyethylene is the most widely used in the world. In this research, polyethylene materials with different densities designed for packaging applications are the subject of a degradation study. The materials were exposed to simulated solar exposure and were characterized by a combination of analytical techniques to compare both chemical and physical changes, including attenuated total reflection‐Fourier transform infrared spectroscopy (ATR‐FTIR), water contact angle measurements, Raman spectroscopy, grazing incidence X‐ray Diffraction (GIXRD) and nanoindentation tests. The experimental data were systematically analyzed using statistic methods. It was found that the extent of the increase of polar groups, hydrophilicity, crystallinity, and elastic modulus depends on both the density of polyethylene and the duration of UV aging. These changes result from photooxidation and the subsequent structure reorganization occurring in amorphous chains. The implementation of various analytical techniques and statistical analysis provides a holistic understanding of polyethylene degradation behaviors. The knowledge of increased hydrophilicity/polarity in polyethylene is crucial for understanding the fate of plastics in the environment because such polyethylene changes also facilitate the environmental biodegradation on initially non‐polar polyethylene.

Deposition of nanocomposite carbon-based thin films doped with copper and fluorine

This paper is focused on plasma-enhanced chemical vapor deposition (PECVD) of novel carbon-based thin films. Unique thin films were deposited from a mixture of methane, hydrogen, and a precursor containing fluorine and copper: (hfac)copperVTMS (hfac = hexafluoroacetylacetonato and VTMS = vinyltrimethylsilane). Using the (hfac)copperVTMS precursor in PECVD deposition results in the advantageous chemical composition of carbon-based thin films while maintaining sufficient mechanical properties. Furthermore, with optimized plasma parameters, the films deposited on the substrate exhibit a nanocomposite structure. This nanostructured surface can increase the surface area, which is beneficial for various applications, including antibacterial and antiviral properties. The radiofrequency glow discharge at low pressure (≈70Pa) and power P=25W and P=250W was used for deposition. Deposited thin films were analyzed using X-ray photoelectron spectroscopy, water contact angle measurement, atomic force microscopy, and nanoindentation techniques. Despite the doping of carbon-based thin films with soft copper, the prepared films exhibited sufficient mechanical properties, which are crucial for the future implementation of this deposition process.

Impact of monolayer WS2 surface properties on the gate dielectrics formation by atomic layer deposition

Two-dimensional transition metal dichalcogenides (2D TMDs), such as MoS2 and WS2, have emerged as promising channel materials for future generation transistors. However, carbon-based surface contaminants pose a significant challenge in the formation of high-quality metal–oxide–semiconductor gate stacks for 2D TMDs. Carbon-based surface contaminants are known to be present even on directly grown 2D TMDs that have not been in contact with polymers. These organic contaminants affect precursor adsorption during atomic layer deposition (ALD) of gate dielectrics on 2D TMDs and as such the 2D-dielectric interface. This study examines the effectiveness of predeposition annealing in mitigating carbon-based contaminants while maintaining the integrity of a directly grown WS2 monolayer on a SiO2 substrate. We show that a WS2 monolayer on a SiO2/Si substrate remains stable during vacuum annealing at temperatures up to 400 °C. Water contact angle measurements and x-ray photoelectron spectroscopy confirm that the surface concentration of carbon starts to decrease at 150 °C. Thermal anneal improves the surface coverage of Al2O3 for both conventional chemisorption-based ALD and physisorbed-precursor-assisted ALD processes by facilitating more effective Al2O3 nucleation on the WS2 monolayer. The impact of predeposition anneal on the Al2O3 growth behavior in both processes can be explained by changes in surface contaminant levels. Our results underscore the importance of surface pretreatment in dielectric deposition on 2D TMDs and demonstrate that predeposition anneal is an effective method to enhance ALD-based dielectric deposition on directly grown 2D TMDs.

Himalayan Sheep Wool Reinforced Composite- A Novel Sustainable Material for Future

Background: Sheep wool-reinforced composites offer a sustainable alternative with diverse applications. This study explores their properties, focusing on water absorption behavior and contact angle measurements. Objective: To investigate the properties of sheep wool-reinforced composites and evaluate their suitability for moisture-sensitive environments, with potential for patent protection. Methods: Wool fibres, known for their hydrophilic nature, were modified to be hydrophobic and incorporated into epoxy resin matrices. Different weaving patterns were utilized to create fibre mats reinforcing epoxy composites. Results: 2D plane weaving reinforcements exhibited superior in-plane properties compared to other reinforcements. Utilizing environmental sources like sheep wool in epoxy composites offers advantages such as low density, cost-effectiveness, and sustainability, potentially patentable innovations. Conclusion: The study demonstrates the developed composites' excellent resistance to water absorption, making them viable for moisture-sensitive applications. Contact angle measurements suggest strong interfacial adhesion between wool fibres and the epoxy matrix, highlighting patent-worthy advancements. These findings underscore the potential of sheep wool-reinforced composites in sustainable and moisture-resistant applications across various industries, including automotive, construction, and consumer goods, emphasizing the importance of patent protection for innovative technologies.

Corrosion resistance and biocompatibility of carbon ion implanted AZ31B magnesium alloy

The poor corrosion resistance of magnesium limits its clinical applications. Accordingly, in the present study, carbon ions were incorporated into a AZ31b magnesium alloy surface via carbon plasma immersion ion-implantation to improve its corrosion resistance and biocompatibility. The surface morphology and properties of the modified alloy were evaluated by field-emission scanning electron microscopy, water contact angle measurement, Raman scattering, X-ray photoelectron spectroscopy, and energy dispersive X-ray spectroscopy. Furthermore, compositional depth profiles were obtained by glow discharge optical emission spectroscopy, revealing a Gaussian-like distribution of carbon concentration. Electrochemical and hydrogen-evolution analysis demonstrated the successfully improved corrosion resistance of the AZ31b Mg alloy, while its biocompatibility was demonstrated by MTT and cell-adherence assays.

Fabrication of gallic acid containing poly(vinyl alcohol)/chitosan electrospun nanofibers with antioxidant and drug delivery properties

Chitosan-based nanofibers with excellent properties are attractive materials for specific industrial applications of contemporary interest. This work aims to fabricate functional nanofibers based on poly(vinyl alcohol)/chitosan (CS) with an antioxidant and model drug molecule, gallic acid (GA), by electrospinning, followed by cross-linking through glutaraldehyde (PVA-CS-GAs). PVA-CS-GAs were electrospun at two different concentrations by the adjustment of the CS feeding ratio. The detailed characteristics of the as-prepared electrospun nanofibers were elucidated by Fourier Transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), water contact angle (WCA) measurements, thermogravimetric and differential scanning calorimetry (TGA and DSC) analyses. SEM images indicated that the average fiber diameter distribution was in the range of 90–110 nm. The results show that morphology, mean diameter, wettability, and thermal characteristics of the composite nanofibers were affected by the CS feeding ratio. Although the increase in the amount of polar -OH groups with the addition of GA caused an improvement in the hydrophilicity and thermal stability of the electrospun nanofibers, it also caused a decrease in the thermal transition temperatures. Furthermore, antioxidant tests based on DPPH radical scavenging ability and in vitro release studies demonstrated that the cross-linked PVA-CS-GA composite nanofibers have good antioxidant activity and a pH-dependent drug release rate, indicating their potential for implementation in wound healing and drug delivery applications.

Exploring NRB Biofilm Adhesion and Biocorrosion in Oil/Water Recovery Operations Within Pipelines.

Microbially influenced corrosion represents a critical challenge to the integrity and durability of carbon steel infrastructure, particularly in environments conducive to biofilm formation by nitrate-reducing bacteria (NRB). This study investigated the impact of NRB biofilms on biocorrosion processes within oil/water recovery operations in Algerian pipelines. A comprehensive suite of experimental and analytical techniques, including microbial analysis, gravimetric methods, and surface characterization, were employed to elucidate the mechanisms of microbially influenced corrosion (MIC). Weight loss measurements revealed that carbon steel samples exposed to injection water exhibited a corrosion rate of 0.0125 mm/year, significantly higher than the 0.0042 mm/year observed in crude oil environments. The microbial analysis demonstrated that injection water harbored an average of (4.4 ± 0.56) × 106 cells/cm2 for sessile cells and (3.1 ± 0.25) × 105 CFU/mL for planktonic cells, in stark contrast to crude oil, which contained only (2.4 ± 0.34) × 103 cells/cm2 for sessile cells and (4.5 ± 0.12) × 102 CFU/mL for planktonic cells, thereby highlighting the predominant role of injection water in facilitating biofilm formation. Contact angle measurements of injection water on carbon showed 45° ± 2°, compared to 85° ± 4° for crude oil, suggesting an increased hydrophilicity associated with enhanced biofilm adhesion. Scanning electron microscopy further confirmed the presence of thick biofilm clusters and corrosion pits on carbon steel exposed to injection water, while minimal biofilm and corrosion were observed in the crude oil samples.

The role of lignin as interfacial compatibilizer in designing lignocellulosic-polyester composite films

Advancing nanocomposites requires a deep understanding and careful design of nanoscale interfaces, as interfacial interactions and adhesion significantly influence the physical and mechanical properties of these materials. This study demonstrates the effectiveness of lignin nanoparticles (LNPs) as interfacial compatibilizer between hydrophilic cellulose nanofibrils (CNF) and a hydrophobic polyester, polycaprolactone (PCL). In this context, we conducted a detailed analysis of surface-to-bulk interactions in both wet and dry conditions using advanced techniques such as quartz crystal microbalance with dissipation (QCM-D), atomic force microscopy (AFM), water contact angle (WCA) measurements, broadband dielectric spectroscopy (BDS), and inverse gas chromatography (IGC).QCM-D was employed to quantify the adsorption behavior of LNPs on CNF and PCL surfaces, demonstrating LNPs’ capability to interact with both hydrophilic and hydrophobic phases, thereby enhancing composite material properties. LNPs showed extensive adsorption on a CNF model film (1186 ± 178 ng.cm−2) and a lower but still significant adsorption on a PCL model film (270 ± 64 ng.cm−2). In contrast, CNF adsorption on a PCL model film was the lowest, with a sensed mass of only 136 ± 35 ng.cm−2. These findings were further supported by comparing the morphology and wettability of the films before and after adsorption, using AFM and WCA analyses. Then, to gain insights into the molecular-level interactions and molecular mobility within the composite in dry state, BDS was employed. The BDS results showed that LNPs improved the dispersion of PCL within the CNF network. To further investigate the impact of LNPs on the composites’ interfacial properties, IGC was employed. This analysis showed that the composite films containing LNPs exhibited lower surface energy compared to those composed of only CNF and PCL. The presence of LNPs likely reduced the availability of surface hydroxyl groups, thus modifying the physicochemical properties of the interface. These changes were particularly evident in the heterogeneity of the surface energy profile, indicating that LNPs significantly altered the interfacial characteristics of the composite materials.Overall, these findings emphasize the necessity to control the interfaces between components for next-generation nanocomposite materials across diverse applications.

Development of Functionalized Polylactide Thin Films Using Poly(methylhydrogenosiloxane) Sol-Gel Process with Improved Antifouling Properties.

Biobased polylactide (PLA) films were modified with low reticulate polysiloxane gel acting as a scalable platform for the hydrophilization of polymeric film surface. The PLA thin film was first coated with poly(methylhydrogenosiloxane) (PMHS) by the sol-gel transition via the condensation of diethoxymethylsilane (DH) and triethoxysilane (TH) using trifluoromethanesulfonic acid as a catalyst. Then, hydrosilylation of Si-H bonds in the presence of Karstedt's catalyst allowed the covalent grafting of hydrophilic alkene-containing molecules, i.e., triethylene glycol monomethyl allyl (TEGMEA) and a new zwitterionic allylcarboxybetaine (ACB) synthesized for the first time by the quaternization of dimethyl allyl amine (DMAA) with β-propiolactone. PMHS coating on the PLA film was evidenced by Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The observation by atomic force microscopy (AFM) revealed a homogeneous coating with low roughness (RMS = 0.29 nm). The hydrophilicity of functionalized PLA films was determined by water contact angle (WCA) measurements using the captive bubble method. A large increase in wettability properties was observed for both grafting with TEGMEA (WCA = 38°) and ACB (WCA = 42°) in comparison with the native PLA film (WCA = 80°). Moreover, the biocompatibility and antifouling efficiency of functionalized PLA films were evaluated by protein adsorption, bacterial adhesion, and cytotoxicity tests. The results indicate that the grafting of the two types of hydrophilic compounds does not affect the biocompatibility of PLA while significantly reducing protein adsorption and bacterial adhesion, thus showing the great potential of this surface functionalization strategy for applications in the medical field.

Utilization of Tea Polyphenols as Color Developers in Reversible Thermochromic Dyes for Thermosensitive Color Change and Enhanced Functionality of Polyester Fabrics

Thermochromic textiles possess the capability to indicate ambient temperature through color changes, enabling real-time temperature monitoring and providing temperature warnings for body heat management. In this study, three thermochromic dyes—blue, red, and yellow—were synthesized using crystalline violet lactone (CVL), 6′-(diethylamino)-1′,3′-dimethyl-fluoran (DDF), and 3′,6′-dimethoxyfluoran (DOF) as leuco dyes, respectively, with biomass tea polyphenol serving as the color developer and tetradecanol as the phase change material. The chemical structures of these dyes were characterized using UV spectroscopy, infrared spectroscopy, Raman spectroscopy and 1H NMR. The thermochromic mechanisms were investigated, revealing that the binding bonds between the leuco dyes and the color developer broke and reorganized with temperature changes, imparting reversible thermochromic property. Polyester fabrics were dyed using an impregnation method to produce three reversible thermochromic fabrics in blue, red, and yellow. The structure and properties of these fabrics were analyzed, showing a significant increase in the UPF value from 26.3 to approximately 100, indicating enhanced UV resistance. Water contact angle measurements revealed that the contact angle of undyed polyester fabrics was 139°, while that of dyed polyester fabrics decreased by about 40°, indicating improved hydrophilicity. Additionally, the fabric inductive static tester showed that the static voltage half-life of dyed polyester fabric was less than 1 s, demonstrating a significant antistatic effect. Infrared thermal imaging results indicated that during the warming and cooling process, the thermochromic polyester fabric exhibited specific energy storage and insulation effects at 38 °C, close to the human body temperature. This study presented a novel approach to developing smart color-changing textiles using biomass-derived thermochromic dyes, offering diverse materials for personal thermal management, and intelligent insulation applications.