Simultaneously Promoted Water Resistance and CO2 Selectivity in Methanol Oxidation Over Pd/CoOOH: Synergy of Co-OH and the Pd-Olatt-Co Interface.

Catalytic purification of industrial oxygenated volatile organic compounds (OVOCs) is hindered by the presence of water vapor that attacks the active sites of conventional noble metal-based catalysts and the insufficient mineralization that leads to the generation of hazardous intermediates. Developing catalysts simultaneously with excellent water resistance and a high intermediate suppression ability is still a great challenge. Herein, we proposed a simple strategy to synthesize a Pd/CoOOH catalyst that contains abundant hydroxyl groups and lattice oxygen species, over which a negligible effect was observed on CH3OH conversion with 3 vol % water vapor, while a remarkable conversion reduction of 24% was observed over Pd/Co3O4. Moreover, the low-temperature CO2 selectivity over Pd/CoOOH is significantly enhanced in comparison with Pd/Co(OH)2. The high concentration of surface hydroxyl groups on Pd/CoOOH enhances the water resistance owing to the accelerated activation of H2O to generate Co-OH, which replaces the consumed hydroxyl and facilitates the quick dissociation of surface H2O through timely desorption. Additionally, the presence of Pd-Olatt-Co promotes electron transport from Co to Pd, leading to improved metal-support interactions and weakened metal-O bonds. This in turn enhances the catalyst's capacity to efficaciously convert intermediates. This study sheds new insights into designing multifunctional catalytic platforms for efficient industrial OVOC purification as well as other heterogeneous oxidation reactions.

Clinical Effects of Voice Therapy on Vocal Outcomes in Unilateral Vocal Fold Paralysis: Proof-of-Concept Study for Two SOVT-Based Treatment Protocols.

BACKGROUND: Studies on treatment efficacy in unilateral vocal fold paralysis (UVFP) often lack a predetermined treatment protocol, and little is known about the effects of specific vocal techniques on vocal outcomes and quality of life in UVFP patients. The purpose of this preliminary proof-of-concept study is to investigate the effects and feasibility of two intensive treatment protocols based on water-resistance therapy (WRT) and vocal function exercises (VFE). METHODS: Ten participants with acute or chronic UVFP/paresis were recruited in the study and randomly assigned to the WRT or VFE group. Three of these participants presented with aphonia and could not complete the program as prescribed. The remaining participants completed an intensive therapy program with the assigned vocal technique. Before, during, and after the program, a multidimensional voice assessment was performed. Maximum phonation time, acoustic, perceptual, and patient-reported outcome measures (PROMs) were obtained. RESULTS: WRT and VFE had positive clinical effects on instrumental and auditory-perceptual voice quality, glottal closure, and PROMs, but interindividual variability was high. Studies with larger sample sizes are necessary to confirm or refute these findings. CONCLUSION: The WRT- and VFE-based therapy programs are both feasible and seem to elicit positive clinical changes in UVFP patients. Suggestions on how to improve the programs are provided, as well as considerations for implementation in clinical practice. Follow-up research is needed to examine the efficacy of both programs on group level.

Tuning the Properties of Xylan/Chitosan-Based Films by Temperature and Citric Acid Crosslinking Agent.

Petroleum-based food packaging causes environmental problems such as waste accumulation and microplastic generation. In this work, biobased films from stable polyelectrolyte complex suspensions (PECs) of xylan and chitosan (70 Xyl/30 Ch wt% mass ratio), at different concentrations of citric acid (CA) (0, 2.5, 5, 7.5 wt%), were prepared and characterized. Films were treated at two temperatures (135 °C, 155 °C) and times (30 min, 60 min) to promote covalent crosslinking. Esterification and amidation reactions were confirmed by Fourier Transform Infrared Spectroscopy and Confocal Raman Microscopy. Water resistance and dry and wet stress-strain results were markedly increased by thermal treatment, mainly at 155 °C. The presence of 5 wt% CA tended to increase dry and wet stress-strain values further, up to 88 MPa-10% (155 °C for 60 min), and 5.6 MPa-40% (155 °C for 30 min), respectively. The UV-blocking performance of the films was improved by all treatments, as was thermal stability (up to Tonset: 230 °C). Contact angle values were between 73 and 84°, indicating partly wettable surfaces. Thus, thermal treatment at low CA concentrations represents a good alternative for improving the performance of Xyl/Ch films.

Integrating Bioinspired Natural Adhesion Mechanisms into Modified Polyacrylate Latex Pressure-Sensitive Adhesives.

For polyacrylate latex pressure-sensitive adhesives (PSAs), high peel strength is of crucial significance. It is not only a key factor for ensuring the long-lasting and effective adhesive force of polyacrylate latex PSAs but also can significantly expand their application scope in many vital fields, such as packaging, electronics, and medical high-performance composite materials. High peel strength can guarantee that the products maintain stable and reliable adhesive performance under complex and variable environmental conditions. However, at present, the peel strength capacity of polyacrylate latex PSAs is conspicuously insufficient, making it difficult to fully meet the urgent market demand for high peel strength, and severely restricting their application in many cutting-edge fields. Therefore, based on previous experimental studies, and deeply inspired by the adhesion mechanism of natural marine mussels, in this study, a traditional polyacrylate latex PSA was ingeniously graft-modified with 3,4-dihydroxybenzaldehyde (DHBA) through the method of monomer-starved seeded semi-continuous emulsion polymerization, successfully synthesizing novel high-peel-strength polyacrylate latex pressure-sensitive adhesives (HPSAs) with outstanding strong adhesion properties, and the influence of DHBA content on the properties of the HPSAs was comprehensively studied. The research results indicated that the properties of the modified HPSAs were comprehensively enhanced. Regarding the water resistance of the adhesive film, the minimum water absorption rate was 4.33%. In terms of the heat resistance of the adhesive tape, it could withstand heat at 90 °C for 1 h without leaving residue upon tape peeling. Notably, the adhesive properties were significantly improved, and when the DHBA content reached 4.0%, the loop tack and 180° peel strength of HPSA4 significantly increased to 5.75 N and 825.4 gf/25 mm, respectively, which were 2.5 times and 2 times those of the unmodified PSA, respectively. Such superior adhesive performance of HPSAs, on the one hand, should be attributed to the introduction of the bonding functional monomer DHBA with a rich polyphenol structure; on the other hand, the acetal structure formed by the grafting reaction of DHBA with the PSA effectively enhanced the spatial network and crosslink density of the HPSAs. In summary, in this study, the natural biological adhesion phenomenon was ingeniously utilized to increase the peel strength of pressure-sensitive adhesives, providing a highly forward-looking and feasible direct strategy for the development of environmentally friendly polyacrylate latex pressure-sensitive adhesives.

Eco-Friendly Waterborne Polyurethane Coating Modified with Ethylenediamine-Functionalized Graphene Oxide for Enhanced Anticorrosion Performance.

This study explores the potential of graphene oxide (GO) as an additive in waterborne polyurethane (WPU) resins to create eco-friendly coatings with enhanced anticorrosive properties. Traditionally, WPU's hydrophilic nature has limited its use in corrosion-resistant coatings. We investigate the impact of incorporating various GO concentrations (0.01, 0.1, and 1.3 wt%) and functionalizing GO with ethylenediamine (EDA) on the development of anticorrosive coatings for carbon steel. It was observed, by potentiodynamic polarization analysis in a 3.5% NaCl solution, that the low GO content in the WPU matrix significantly improved anticorrosion properties, with the 0.01 wt% GO-EDA formulation showing exceptional performance, high Ecorr (-117.82 mV), low icorr (3.70 × 10-9 A cm-2), and an inhibition corrosion efficiency (η) of 99.60%. Raman imaging mappings revealed that excessive GO content led to agglomeration, creating pathways for corrosive species. In UV/condensation tests, the 0.01 wt% GO-EDA coating exhibited the most promising results, with minimal corrosion products compared to pristine WPU. The large lateral dimensions of GO sheets and the cross-linking facilitated by EDA enhanced the interfacial properties and dispersion within the WPU matrix, resulting in superior barrier properties and anticorrosion performance. This advancement underscores the potential of GO-based coatings for environmentally friendly corrosion protection.

Modifying Polyvinylidene Chloride Resin with Fluorine Monomer and Cross-Linking Monomers.

Modified polyvinylidene chloride (PVDC) resin was prepared using octafluoropentyl methacrylate and trimethylolpropane trimethacrylate as modifying monomers through seeded emulsion polymerization. The successful incorporation of octafluoropentyl methacrylate into the PVDC resin was confirmed by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analyses. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and XPS were utilized to investigate the element distribution in the modified monomer emulsion and the mechanism of monomer modification. The results demonstrated that the fluorine monomer was reacted in the resin, and mainly concentrated on the surface of the resin. The addition of octafluoropentyl methacrylate and trimethylolpropane trimethacrylate improved the water resistance of the resin. Compared to unmodified PVDC resin, the contact angle of the modified PVDC resin increased from 89.46° to 109.51°, and the water resistance at room temperature increased from 120 to 500 h. Furthermore, the modified resin exhibited excellent mechanical properties, thermal stability, and storage stability.

The Effects of Metakaolin on the Properties of Magnesium Sulphoaluminate Cement.

Magnesium sulphoaluminate (MSA) cement has good bonding properties and is suitable as an inorganic adhesive for repairing materials in civil engineering. However, there are still some problems with its use, such as its insufficient 1 day (d) strength and poor volumetric stability. This paper aims to investigate the influences of metakaolin (MK) on the physical and mechanical properties of magnesium sulphoaluminate (MSA) cement. The hydration products and microstructures of typical MSA cement samples were also analysed using X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). The results showed that the addition of metakaolin reduces the fluidity and shortens the setting time of the MSA cement. The initial setting time and final setting time shortened maximally by 15-27 min and 25-48 min, respectively, with the addition of 10-30% metakaolin. Moreover, the compressive strength and flexural strength of the MSA cement improved significantly with the addition of 10-30% metakaolin at a curing age of 1 d. Compared with the compressive and flexural strengths of the control sample at 1 d, the compressive strengths of the modified samples showed obvious increases of 98%, 101%, and 109%, and the flexural strengths increased by 39%, 31%, and 26%, respectively, although they decreased slightly when the curing ages were 7 d, 14 d, and 28 d. The addition of 10% metakaolin improved the water resistance of the MSA cement immersed in water for 7 d and resulted in even higher water resistance at 28 d. The addition of 10-30% metakaolin improved the volumetric stability of the MSA cement with increasing dosages before 28 d of ageing. XRD and SEM-EDS analyses showed that the metakaolin accelerated the early hydration reaction and optimised the phase composition of the MSA cement. The results indicate that the addition of 10-20% metakaolin improved the strength after 1 d of ageing, water resistance, and volumetric stability of the MSA cement, providing theoretical support for the application of MAS cement as an inorganic bonding agent for repairing materials.

Enhanced Water Resistance of TiO2-GO-SMS-Modified Soil Composite for Use as a Repair Material in Earthen Sites.

Most earthen sites are located in open environments eroded by wind and rain, resulting in spalling and cracking caused by shrinkage due to constant water absorption and loss. Together, these issues seriously affect the stability of such sites. Gypsum-lime-modified soil offers relatively strong mechanical properties but poor water resistance. If such soil becomes damp or immersed in water, its strength is significantly reduced, making it unviable for use as a material in the preparation of earthen sites. In this study, we achieved the composite addition of a certain amount of sodium methyl silicate (SMS), titanium dioxide (TiO2), and graphene oxide (GO) into gypsum-lime-modified soil and analyzed the microstructural evolution of the composite-modified soil using characterization methods such as XRD, SEM, and EDS. A comparative study was conducted on changes in the mechanical properties of the composite-modified soil and original soil before and after immersion using water erosion, unconfined compression (UCS), and unconsolidated undrained (UU) triaxial compression tests. These analyses revealed the micro-mechanisms for improving the waterproof performance of the composite-modified soil. The results showed that the addition of SMS, TiO2, and GO did not change the crystal structure or composition of the original soil. In addition, TiO2 and GO were evenly distributed between the modified soil particles, playing a positive role in filling and stabilizing the structure of the modified soil. After being immersed in water for one hour, the original soil experienced structural instability leading to collapse. While the water absorption rate of the composite-modified soil was only 0.84%, its unconfined compressive strength was 4.88 MPa (the strength retention rate before and after immersion was as high as 93.1%), and the shear strength was 614 kPa (the strength retention rate before and after immersion was as high as 96.7%).

Super-exchange interaction enables Fe2-xMnxO3 perovskite with excellent catalytic oxidation activity toward hexabromocyclododecane under humidity.

Although enhancing the catalytic oxidation activity is a hotspot in thermal-driven catalytic disposal of persistent organic pollutants, few studies have managed to improve catalysts' water-resistance properties. Herein, we developed Fe2-xMnxO3 perovskite to boost the catalytic oxidation of hexabromocyclododecane under humidity by modulating its super-exchange interaction (SEI, Fe3+ + Mn3+ → Fe2+ + Mn4+). Fe0.4Mn1.6O3, with the strongest SEI, exhibits the biggest oxidation rate-constant, which is 3 times higher than that of commonly used Fe2O3 without SEI. Notably, unlike Fe2O3 which deactivates at a relative humidity of 5 %. Fe0.4Mn1.6O3 maintains its activity and is even boosted by 22 % compared to dry conditions. Mechanistic insights reveal that SEI between Fe and Mn enhances the reactivity of Mn4+- linked Olatt by lowering the reductive temperature from Mn4+ to Mn3+. Meanwhile, SEI promotes the adsorption of the associatively adsorbed H2O (HOH-type water) by reducing adsorption energy, thereby facilitating the formation of hydroxyl species, which are crucial for the oxidation process under humidity.

Direct Measurement of the Diffusion Coefficient of Adhesives from Moisture Distribution in Adhesive Layers Using Near-Infrared Spectroscopy.

In this study, we used near-infrared spectroscopy to measure the moisture penetration in epoxy adhesives and investigated the difference in the diffusion coefficients between the bulk and the adhesive layer. Moisture diffusion was evaluated under 100% RH and water immersion conditions. First, the effects of the curing agents and additives on moisture diffusion in the bulk were gravimetrically evaluated using epoxy-coated quartz glass plates. Different diffusion behaviors were observed depending on the curing agent used. The presence of additives resulted in higher diffusion coefficients, whereas the overall moisture content was low. Next, the moisture distribution in the adhesive layer was visualized using a specimen sandwiched between the quartz glass plates, and the diffusion coefficient of the adhesive layer was calculated. The diffusion coefficient in the adhesive layer was larger than that in the bulk. For adhesives cured with hydrophobic diamine, the diffusion coefficient within the adhesive layer increased by approximately 1.5 times compared with that in the bulk, regardless of the exposure environment. The adhesive, composed of a resin, Dicyandiamide, and additives, showed a 2-fold increase in the diffusion coefficient under high-humidity exposure conditions but no significant change under the water immersion condition. Therefore, these results suggest that, for an accurate analysis of moisture distribution, it is important to measure the diffusion coefficient of the adhesive layer directly rather than using the diffusion coefficient of the material itself.

Enhancement of Mineralization Ability and Water Resistance of Vanadium-Based Catalysts for Catalytic Oxidation of Chlorobenzene by Platinum Loading.

The design of a catalyst with multifunctional sites is one of the effective methods for low-temperature catalytic oxidation of chlorinated volatile organic compounds (CVOCs). The loss of redox sites and competitive adsorption of H2O prevalent in the treatment of industrial exhaust gases are the main reasons for the weak mineralization ability and poor water vapor resistance of V-based catalysts. In this work, platinum (Pt) is selected to combine with the V/CeO2 catalyst, which provides more redox sites and H2O dissociative activation sites and further enhances its catalytic performance. The results show that PtV/CeO2 achieves 90% of the CO2 yield at 318 °C and maintains excellent catalytic activity rather than continuous deactivation within 15 h after water vapor injection. The formation of Pt-O-V bonds enhances the redox ability and promotes deep oxidation of polychlorinated intermediates, accounting for the significantly improved mineralization ability of PtV/CeO2. The dissociative activation effect of Pt on H2O molecules strengthens the migration and activation of V-adsorbed H2O, precluding V-poisoning and notably improving water resistance. This study lays a solid foundation for the efficient degradation of chlorobenzene under humid conditions.

A water-resistant egg white/chitosan/pectin blending film with spherical-linear molecular interpenetrating network strengthened by multifunctional tannin-nisin nanoparticles.

Edible films are effective alternatives to plastic packaging, however, the hydrophilicity of edible films based on protein and polysaccharide limits the application. Therefore, we fabricated a water-stable hybrid film with a linear-spherical interpenetrating molecular topology network using egg white (EW), chitosan (CS), and pectin. Meanwhile, the nisin-tannin acid self-assembly complex nanoparticles were employed as a multifunctional cross-linker, antibacterial and antioxidant agent to improve the performance of films. The FTIR, XRD, and SEM analysis revealed that the conformation and crystalline structure rearrangement of chitosan induced by the alkaline environment provided by egg white enhanced the network structure of films, effectively avoided the addition of modifying reagents. The proposed hybrid films exhibited excellent properties, with EW/TNPCS3 showing the best overall performance. The water contact angle (WCA) increased to 105.27 ± 1.62°, and its dissolution and swelling rates were significantly lower than pure egg white and pure chitosan films. Moreover, tannin-nisin (TN) nanoparticles endowed the films with excellent antimicrobial activity against the common Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. Thus, the prepared blending films have great application potential in food preservation, especially to maintain stable performance in high humidity environment.

Effect of fly ash and curing temperature on the properties of magnesium phosphate repair mortar.

This article is aimed at discussing the combined effect of mineral admixture and servicing temperature, especially in cold environment, on the properties of magnesium phosphate repair mortar (MPM). The influence mechanism of fly ash content on the microstructure and performance of MPM were firstly investigated, and then the evolution rules in properties of fly ash modified MPM cured at - 20 °C, 0 °C, 20 °C and 40 °C were further revealed. The results show that the incorporation of fly ash has no significant effect on the setting time and fluidity of MPM. When MPM is modified with 10 wt% and 15 wt% fly ash, its mechanical properties, adhesive strength, water resistance, and volume stability are effectively improved. Fly ash reduces the crystallinity and continuity of struvite enriched in hardened MPM, and its particles are embedded among struvite and unreacted MgO. The compressive strength of MPM-10 cured for various ages increases with the elevating of curing temperature, while the flexural strength, interfacial bonding strength, strength retention and linear shrinkage exhibits the opposite laws. When cured at 0 °C and - 20 °C, MPM-10 still has good early strength, water resistance and interfacial bonding properties, which indicates that MPM-10 provides with an ability of emergency repair of cracked components served in cold environments.

Continuously enhanced versatile nanocellulose films enabled by sustaining CO2 capture and in-situ calcification.

Cellulose possesses numerous favorable peculiarities to replace petroleum-based materials. Nevertheless, the extremely high hygroscopicity of cellulose severely degrades their mechanical performance, which is a major obstacle to the production of high-strength, multi-functional cellulose-based materials. In this work, a simple strategy was proposed to fabricate durable versatile nanocellulose films based on sustaining CO2 capture and in-situ calcification. In this strategy, Ca(OH)2 was in-situ formed on the films by Ca2+ crosslinking and subsequent introduction of OH-, which endowed the films with high mechanical strength and carbon sequestration ability. The following CO2 absorption process continuously improved the water resistance and durability of the films, and enabled them to maintain excellent mechanical properties and promising light management ability. After a 30-day CO2 absorption process, the water contact angle of the films can be increased from 43° to 79°, and the weight gain rate of the films in a 30 h water-absorption process can be sharply decreased from 331.2 % to 52.2 %. The films could maintain a high tensile strength of 340 MPa, and result in a CO2 absorption rate of 3.5 mmol/gcellulose after 30 days. In this study, the improvement of durability and carbon sequestration of nanocellulose films was achieved by a simple and effective method.

Gum Arabic microgel-based biomimetic waterborne anticorrosive coatings with reinforced water and abrasive resistances.

The inadequate water resistance and mechanical properties of waterborne anticorrosive coatings is a serious problem that leads to coating failure. When the bark of acacia trees sustains damage, the liquid Gum Arabic (GA) that oozes from the trunk coagulates at the site of injury to safeguard it, which is called "gummosis" self-protection. Inspired by this, biomimetic GA microgel-based waterborne anticorrosive coatings are designed. Microgel exhibits a crosslinked polymer network structure with a combination of advantageous characteristics derived from both solids and liquids. By encapsulating the liquid corrosion inhibitors (MeBT) within the solid microgel matrix, the coating system is endowed with self-protective capabilities. The as-prepared GAMG-MeBT microgels are introduced into waterborne epoxy (WE) matrix and sprayed onto the surface of Q235 steel. Corrosion studies reveal the 3.0-wt% GAMG-MeBT/WE coating exhibits an impedance modulus value in the low-frequency region (Z0.01Hz) of 1.37 × 109 Ω cm2 after immersing in 3.5-wt% NaCl solution for 60 days, which is nearly two orders of magnitude higher than that of the pure WE coatings. Moreover, the coatings display improved water resistance, enhanced abrasive resistance, and active corrosion protection. This work provides a new approach to solving the failure of WE anticorrosive coatings.

Lattice matching enables construction of CaS@NaYF4 heterostructure with synergistically enhanced water resistance and luminescence for antibiotic detection.

Rare earth (RE)-doped CaS phosphors have been widely used as light-emitting components in various fields. Nevertheless, the application of nanosized CaS particles is still significantly limited by their poor water resistance and weak luminescence. Herein, a lattice-matching strategy is developed by growing an inert shell of cubic NaYF4 phase on the CaS luminescent core. Due to their similarity in crystal structure, a uniform core-shell heterostructure (CaS:Ce3+@NaYF4) can be obtained, which effectively protects the CaS:Ce3+ core from degradation in aqueous environment and enhances its luminescence intensity. As a proof of concept, a label-free aptasensor is further constructed by combining core-shell CaS:Ce3+@NaYF4 and Au nanoparticles (AuNPs) for the ultrasensitive detection of kanamycin antibiotics. Based on the efficient FRET process, the detection linear range of kanamycin spans from 100 to 1000 nM with a detection limit of 7.8 nM. Besides, the aptasensor shows excellent selectivity towards kanamycin antibiotics, and has been successfully applied to the detection of kanamycin spiked in tap water and milk samples, demonstrating its high potential for sensing applications.

Water-resistant and barrier properties of poly(vinyl alcohol)/nanocellulose films enhanced by metal ion crosslinking.

Polyvinyl alcohol (PVA) is a promising alternative to non-biodegradable flexible packaging materials, and nanocellulose is often used to enhance the properties of PVA films, but the composite films still have poor water resistance and barrier properties. To address this issue, iron ions (Fe3+) were introduced into PVA/cellulose nanofibrils (CNF) films, and Fe3+ formed coordination bonds with carboxyl and hydroxyl groups on the surface of CNF and PVA chains. Therefore, constructing a strong coordination crosslinking network within the film and improving the interfacial interaction between PVA and CNF. The water resistance, mechanical and barrier properties of the crosslinked films were significantly improved. Compared with the un-crosslinked film, the oxygen transmission rate (OTR) was decreased by up to 67 %, and the water swelling ratio was significantly reduced from 1085 % to 352 %. The tensile strength of the film with 1.5 wt% Fe3+ reached 41.93 MPa, which was 62 % higher than that of the un-crosslinked film. Furthermore, the composite film demonstrated good recyclability, almost recovering its original mechanical properties in two recycling tests. This simple and effective method for preparing water resistance and barrier films shows potential applications in flexible packaging areas.

Double-Phase-Networking Polyimide Hybrid Aerogel with Exceptional Dimensional Stability for Superior Thermal Protection System.

Polyimide aerogels have been extensively used in thermal protection domain because they possess a combination of intrinsic characteristics of aerogels and unique features of polyimide. However, polyimide aerogels still suffer significant thermally induced shrinkage at temperatures above 200 °C, restricting their application at high temperature. Here, a novel "double-phase-networking" strategy is proposed for fabricating a lightweight and mechanically robust polyimide hybrid aerogel by forming silica-zirconia-phase networking skeletons, which possess exceptional dimensional stability in high-temperature environments and superior thermal insulation. The rational mechanism responsible for the formation of double-phase-networking aerogel is further explained, generally attributing to chemical crosslinking reactions and supramolecular hydrogen bond interactions derived from the main chains of polyimide and silane/zirconia precursor/sol. The as-prepared aerogels exhibit excellent high-temperature (270 °C) dimensional stability (5.09% ± 0.16%), anti-thermal-shock properties, and low thermal conductivity. Moreover, the hydrophobic treatment provides aerogels high water resistance with water contact angle of 136.9°, further suggestive of low moisture content of 3.6% after exposure to 70 °C and 85% relative humidity for 64 h. The proposed solution for significantly enhancing high-temperature dimensional stability and thermal insulation provides a great supporting foundation for fabricating high-performance organic aerogels as thermal protection materials in aerospace.

Fabrication of flame-retardant and water-resistant nanopapers through electrostatic complexation of phosphorylated cellulose nanofibers and chitin nanocrystals.

Biogenic, sustainable two-dimensional architectures, such as films and nanopapers, have garnered considerable interest because of their low carbon footprint, biodegradability, advanced optical/mechanical characteristics, and diverse potential applications. Here, bio-based nanopapers with tailored characteristics were engineered by the electrostatic complexation of oppositely charged colloidal phosphorylated cellulose nanofibers (P-CNFs) and deacetylated chitin nanocrystals (ChNCs). The electrostatic interaction between anionic P-CNFs and cationic ChNCs enhanced the stretchability and water stability of the nanopapers. Correspondingly, they exhibited a wet tensile strength of 17.7 MPa after 24 h of water immersion. Furthermore, the nanopapers exhibited good thermal stability and excellent self-extinguishing behavior, triggered by both phosphorous and nitrogen. These features make the nanopapers sustainable and promising structures for application in advanced fields, such as optoelectronics.

Development of environmentally friendly glyoxal-based adhesives with outstanding water repellency utilizing wheat gluten protein.

To reduce the release of volatile organic compounds (VOCs) from formaldehyde-based adhesives at the source, the use of low-toxicity and biodegradable glyoxal instead of formaldehyde for the preparation of novel urea-glyoxal resins is a simple and promising strategy. The limited water resistance and adhesive strength of the new urea-glyoxal resins (UG) restrict their extensive application. This study prepared a high-performance, water-resistant WP-UG wood adhesive by combining UG prepolymer with wheat gluten protein (WP). FTIR, XRD, and XPS confirmed the existence of a chemical reaction between the two components, and thermal analysis showed that WP-UG plywood had better thermal stability. Evaluation of the gluing properties revealed that the dry and wet strengths of WP-UG adhesive bonded plywood reached 1.39 and 0.87 MPa, respectively, which were significantly higher than those of UG resin by 35 % and 314 %. The bond strength increased from 0 to 0.89 MPa after immersion in water at 63 °C for 3 h. The results indicated that the introduction of WP promoted the formation of a more complex and tightly packed crosslinking network and developed a glyoxal-based adhesive with high bond strength and water resistance. This study provides a new green pathway for novel urea-formaldehyde binders to replace harmful formaldehyde-based binders, which helps to increase their potential application value in the wood industry.