Water Contact Angle Measurements Research Articles

One-step fabrication of multifunctional TPU/TiO2/HDTMS nanofiber membrane with superhydrophobicity, UV-resistance, and self-cleaning properties for advanced outdoor protection

This study successfully fabricated thermoplastic polyurethane (TPU)-titanium dioxide (TiO2)-hexadecyltrimethoxysilane (HDTMS) composite nanofibrous membrane (CNM), exhibiting superhydrophobicity, robust UV resistance, and anti-fouling properties, via electrostatic spinning technology. The nanofibrous membranes' (NM) microstructures were meticulously characterized using techniques such as field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR), Raman scattering spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and 3D optical profiling. Performance evaluations included water contact angle measurement, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and uniaxial tensile and UV transmission tests. Results indicate that the CNM has an average fiber diameter of 179.28 nm, a static water contact angle (WCA) of 166.2 ± 0.5°, a sliding angle of 3.5 ± 0.8°, and a surface energy of 9.18 ± 0.6 mN/m. It also demonstrates commendable thermal stability with a tensile strength of 3.9 MPa, an elongation at break of 145.80 %, and an ultraviolet protection factor (UPF) of 1485 ± 13.2. It has considerable mechanical stability and can withstand 4000 tensile or 5000 compression cycles. The anti-fouling and moisture permeability tests reveal the membrane's superior functional performance. These attributes suggest a wide application potential for the CNM in anti-fouling outdoor protective clothing, sports footwear, and related fields.

ZrO2 Nanoparticles Filler-Based Mixed Matrix Polyethersulfone/Cellulose Acetate Microfiltration Membrane for Oily Wastewater Separation

Membrane technology has emerged as a dynamic field of study in academia and industry for treating produced oily wastewater. ZrO2 nanoparticles (ZrO2 NPs) filler-based mixed matrix polyethersulfone/cellulose acetate microfiltration membranes were fabricated and inspected in the oily wastewater remediation. The fabricated bare PES membrane, PES/CA blended polymers membrane, and PES/CA blended polymers incorporating ZrO2 NPs (ZrO2@PES/CA) membranes by phase inversion technique were inspected by field emission scanning electron microscopy, atomic force microscopy, Fourier-transform infrared spectroscopy, and measurement of water contact angle and porosity. The ZrO2@PES/CA membrane which consisted of 0.5 wt.% ZrO2 NPs (0.5%ZrPC) afforded increased hydrophilicity and reduced water contact angle from 70° for P membrane to 30.23°. Also, the 0.5%ZrPC membrane gave pure water flux of 88.89 L/m2.h, high oil rejection of 98.2% and showed remarkable antifouling capacity with a high flux recovery ratio of 89.3% and relative flux reduction of 34.3%. The effect of transmembrane pressure (1, 2, 3, and 4 bar), feed temperature (25, 40, and 50 °C), and an initial oil concentration (250, 500, 750, and 1000 mg/L) on the permeation flux and oil rejection of the 0.5%ZrPC membrane was investigated. The results revealed that ZrO2@PES/CA membranes have a significant potential for effective oil removal with high permeability and antifouling ability. The 0.5%ZrPC membrane confirmed its durability and reusability when kept an acceptable oil removal after 5 cycles.

Facile development of flexible cellulose acetate-lead dioxide membrane electrodes for supercapacitor applications

Current work focuses on the development of flexible membranes of cellulose acetate containing lead dioxide for supercapacitor applications. The functionality of cellulose acetate and lead dioxide are analyzed by Fourier transform infrared spectroscopy. The degree of crystallinity is studied using X-ray Diffraction. The degree of hydrophilicity is discussed by water contact angle measurements. A Universal Testing Machine is used to examine the mechanical properties. The electrochemical performances are illustrated using Cyclic voltammetry, Electrochemical impedance Spectroscopy and Galvanostatic charge-discharge techniques. The highest recorded specific capacitance is 148 F g−1 at a current density of 40 mA g−1 for a membrane of 1 wt% lead dioxide in cellulose acetate. Capacitance retention of 89% after 5000 cycles is attained. The power density of 56 W kg−1 and energy density of 10 Wh kg−1 is achieved. The cellulose acetate doped with lead dioxide membranes can provide a better electrode material matrix for flexible energy storage.

Effects of ultraviolet sterilization exposure on the structural and surface properties of graphite-/polymer-like carbon films

Existing research on the biological responses of amorphous carbon films has not adequately explored the influences of exposure to ultraviolet (UV) sterilization at 253.7 nm before cell culture. Thus, in this study, two types of amorphous carbon films, namely hydrogen-rich graphite-like carbon (GLC) and hydrogen-free polymer-like carbon (PLC) films, were deposited on Si substrates. The influences of different doses of UV sterilization exposure (at 253.7 nm) on the structures and surface properties of the amorphous carbon films were investigated. Spectroscopic ellipsometry and Raman analysis showed that there is no significant change in the optical constants and Raman spectra of GLC and PLC films. The surface properties of the amorphous carbon films, characterized by water contact angle measurements and X-ray photoelectron spectroscopy analysis, indicated that both types of films exhibited hydrophilicity and surface oxidation in response to UV sterilization. However, the effects of UV sterilization on PLC were more notable than those on GLC. Our findings highlight the need for standardization and optimization of UV sterilization conditions for specific films to promote the application of amorphous carbon film coatings in the medical domain.

Synthesis, characterization and corrosion inhibition evaluation of a new chalcone derivative 2-3-(3-hydroxyphenyl)-1-[4-(1H-imidazol-1-yl) phenyl] prop-2-en-1-one for mild steel corrosion in 1M HCl assessment with DFT and MD studies

The prime objective of the work focuses on the synthesis of novel chalcone derivative, the 2-3-(3-hydroxyphenyl)-1-[4-(1H-imidazol-1-yl) phenyl] prop-2-en-1-one (HIPP) and study its corrosion inhibition for mild steel in 1M HCl. Various spectroscopic techniques such as IR, 1H-NMR, 13C-NMR, and mass spectroscopy were used to confirm the formation of the synthesized chalcone. Distinct electrochemical techniques like potentiodynamic Tafel polarization and impedance spectroscopy were employed to investigate HIPP in 1M HCl as a mild steel corrosion inhibitor. The synthesized chalcone was checked in a temperature range varying from 30° C to 60° C. With increasing quantities of HIPP, it is noticed that there is an enhancement in calculated corrosion inhibition efficiency. The maximum inhibition efficiency obtained was found to be 94.3 % in the presence of 100 ppm at room temperature. Surface morphology of unhindered and inhibited HIPP was analysed using scanning electron microscopy (SEM), atomic force microscopy (AFM) and water contact angle (WCA) measurements. SEM investigation revealed that the inhibitor effectively protects the metal surface from aggressive corrosion. Atomic force microscopic images show the corroded MS surface roughness in the presence of HIPP reduced from 342.1 nm to 174.3 nm. Furthermore, the inhibitor's adsorption through electron-donor acceptor interactions was revealed by DFT calculations and MD studies.

Preparations of Polyurethane Foam Composite (PUFC) Pads Containing Micro-/Nano-Crystalline Cellulose (MCC/NCC) toward the Chemical Mechanical Polishing Process.

Polyurethane foam (PUF) pads are widely used in semiconductor manufacturing, particularly for chemical mechanical polishing (CMP). This study prepares PUF composites with microcrystalline cellulose (MCC) and nanocrystalline cellulose (NCC) to improve CMP performance. MCC and NCC were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD), showing average diameters of 129.7 ± 30.9 nm for MCC and 22.2 ± 6.7 nm for NCC, both with high crystallinity (ca. 89%). Prior to preparing composites, the study on the influence of the postbaked step on the PUF was monitored through Fourier-transform infrared spectroscopy (FTIR). After that, PUF was incorporated with MCC/NCC to afford two catalogs of polyurethane foam composites (i.e., PUFC-M and PUFC-N). These PUFCs were examined for their thermal and surface properties using a differential scanning calorimeter (DSC), thermogravimetric analysis (TGA), dynamic mechanical analyzer (DMA), and water contact angle (WCA) measurements. Tgs showed only slight changes but a notable increase in the 10% weight loss temperature (Td10%) for PUFCs, rising from 277 °C for PUF to about 298 °C for PUFCs. The value of Tan δ dropped by up to 11%, indicating improved elasticity. Afterward, tensile and abrasion tests were conducted, and we acquired significant enhancements in the abrasion performance (e.g., from 1.04 mm/h for the PUF to 0.76 mm/h for a PUFC-N) of the PUFCs. Eventually, we prepared high-performance PUFCs and demonstrated their capability toward the practical CMP process.

Assessing polylactic acid nanofibers with cellulose and chitosan nanocapsules loaded with chamomile extract for treating gram-negative infections.

This study presents the development and characterization of a novel nanocomposite wound dressing material based on polylactic acid (PLA) nanofibers incorporating chitosan nanocapsules loaded with chamomile extract and cellulose nanoparticles. The nanofibers were fabricated using a three-step synthesis and electrospinning techniques, resulting in uniform, bead-free fibers with an average diameter of 186 ± 56nm. Fourier-transform infrared spectroscopy confirmed the successful incorporation of all components, while tensile strength tests demonstrated improved mechanical properties by adding nanoparticles. Water contact angle measurements revealed enhanced surface wettability of the PLA-Cellulose-Chitosan complex compared to pure PLA nanofibers. In vitro biocompatibility assessments using MTT assays showed excellent cell viability and proliferation, with the optimized composite exhibiting the best performance. Scanning electron microscopy imaging confirmed robust cell adhesion and interaction with the nanofibers. The nanocomposite demonstrated significant antimicrobial activity against Escherichia coli, with a 20mm inhibition zone observed for chamomile extract-loaded samples. Additionally, the material showed superior hemostatic ability compared to commercial gauze and high hemocompatibility. These comprehensive results indicate that the developed nanocomposite is a promising candidate for advanced wound management applications, offering a multifunctional approach to wound healing by combining antimicrobial activity, cell compatibility, and hemostatic properties.

Synthesis of a new quaternary ammonium salt for efficient inhibition of mild steel corrosion in 15 % HCl: Experimental and theoretical studies

The corrosion phenomenon and its economic impacts can hardly be ignored in any application. This study synthesized a quaternary ammonium salt (3) containing hydrophobic dodecyl and electron-rich diallylbenzyl amine moieties to be used in 15 % HCl as a corrosion inhibitor of mild steel. Several techniques, such as 1H and 13C NMR, IR, TGA, and elemental analysis, have been used to characterize inhibitor 3. Popular corrosion measurement techniques, namely weight loss, potentiodynamic polarization techniques, and electrochemical impedance spectroscopy, have been used to determine the efficiency of inhibitor 3. At 303 K and a moderately low concentration of 50 ppm, the quaternary ammonium salt-based inhibitor demonstrated a maximum efficiency of ≈95.0 %. At elevated temperatures of 313, 323, and 333 K, the inhibition efficacy values were recorded as 91.3, 82.8, and 75.0 %, respectively. Adsorption isotherm study revealed that the adsorption of inhibitor 3 followed Langmuir adsorption isotherm. The value of ΔGads° was found to be – 40.19 kJ mol−1, indicating that inhibitor 3 became adsorbed via a mixed physi-chemisorption mechanism. A very high adsorption constant (Kads) of 1.53 × 105 L mol−1 suggested strong adsorption of inhibitor 3. The difference in activation energy (Ea) value of 42.4 kJ mol−1 between the control and the inhibited solution indicated an efficient adsorption of inhibitor 3. The ability of inhibitor 3 to retard both anodic and cathodic half-cell reactions was proved via open circuit potential and Tafel curves studies. Detailed discussions on the change in corrosion current densities (icorr), polarization (Rp) and charge transfer (Rct) resistances have been offered to discuss the inhibition efficiency. Water contact angle measurement showed a drastic increase in mild steel surface hydrophobicity following inhibitor 3 adsorption. SEM-EDX and XPS studies confirmed the definitive presence of inhibitor 3 on the mild steel surface. Density functional theory (DFT) studies revealed the frontier molecular orbitals with which the metal surface interacts. A detailed corrosion inhibition mechanism has been offered in the context of adsorption isotherm and DFT studies.

Synthesis of N, N,O and O-carboxymethyl chitosan derivatives of controllable substitution degrees and their utilization as electrospun scaffolds for bone tissue engineering

Most chitosan (CS) carboxymethylation approaches are weighed down by insufficient description protocols regarding the reaction specificity and the degree of substitution (DS). Here, we provide three carboxymethylation protocols of enhanced specificity towards the amine (N-), amine/hydroxy (N,O-) and hydroxy (O-) groups of CS. The DS for all samples was found to be ∼70 %, as confirmed by NMR analysis. To illustrate the modified materials' potential in bone tissue regeneration, each derivative was blended with poly(vinyl alcohol) to prepare scaffolds via electrospinning. Both materials and electrospun membranes were characterized in terms of their physicochemical properties by Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry and water contact angle measurements. The electrospun membranes' swelling ratio, degradation, tensile strength, as well as morphology were also examined through scanning electron microscopy before and after heat treatment at 120 °C, which was used as a method of physical stabilization, leading to significantly enhanced degradation rate and mechanical strength. The three electrospun scaffold types were loaded with MC3T3-E1 pre-osteoblastic cells and their cell adhesion, viability and growth rate were assessed. Finally, osteogenic differentiation was examined by means of alkaline phosphatase activity measurement, calcium mineralization and formation of extracellular matrix markers, with all materials showing promising prospects.

Leveraging colloid and interface science for long-term marine performance of hybrid coatings: Effects of different nanoparticles on anticorrosion and antifouling properties

This study leveraged the unique colloidal and interfacial properties of synthesized SiO2, ZnO, and carbon (CN) nanoparticles as effective nanofillers to enhance the anti-corrosion and antifouling properties of PMMA coatings. By optimizing nanoparticle dispersion, stability, and functional performance within the polymer matrix, we achieved improved surface roughness, hydrophobicity, mechanical stability, and antimicrobial properties. Hybrid coatings containing 1.5 wt% of these nanoparticles were applied to stainless steel (SS) substrates and evaluated through water contact angle measurements, pull-off adhesion strength tests, antibacterial assays, and electrochemical impedance spectroscopy (EIS). The results demonstrate that the synergistic effects of SiO2, ZnO, and CN nanoparticles significantly enhance the coatings' anticorrosion and antifouling characteristics by increasing hydrophobicity, total impedance, and antibacterial activity via reactive oxygen species generated by ZnO and CN. Additionally, over two years, the coating’s long-term protection was assessed by submerging coupons at a 6-meter depth in the Bocana Chica reef barrier, a site with rapid biofouling colonization, making this test a demanding evaluation.

Copper abietate/polyvinyl acetate composite film for enhanced humidity sensing in Chinese herbal medicine monitoring systems

Sensing materials derived from natural and biodegradable sources are increasingly being developed and applied to realize environmentally friendly technologies. In this paper, we present the synthesis, characterization, and application of a novel copper abietate/polyvinyl acetate (CuA/PVAc) composite film, specifically engineered to enhance the humidity-sensing capabilities of Chinese herbal medicine monitoring systems. The sensing material was synthesized by strategically melding copper abietate, a natural renewable material, with PVAc to exploit their combined synergistic properties for optimal humidity-sensing performance. Comprehensive characterization techniques, including inductively coupled plasma optical emission spectrometry (ICP-OES), field-emission scanning electron microscopy (FESEM), water contact angle measurements, and Fourier transform infrared (FT-IR) spectroscopy, were employed to confirm the formation of CuA/PVAc composites. These analyses confirmed the homogeneity and intended chemical composition of the composite films.The resultant CuA-1/PVAc-4 (0.4 μg/μL) composite film exhibited a good logarithmic relation (0.9988) with relative humidity (RH) over a wide range (11 %–97 %) and high sensitivity (24.55 Hz/%RH). Moreover, this study introduces a novel, eco-friendly approach by integrating the CuA/PVAc composite with a quartz crystal microbalance (QCM) sensor and a sophisticated wireless circuit that enables real-time, Wi-Fi-based humidity monitoring tailored for the preservation of Chinese herbal medicines. The implementation of this wireless humidity detection system represents a significant advancement in the application of environmentally friendly materials in sensor technology and offers a practical and scalable approach for precise environmental monitoring.

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.

Cornstarch as a green binder in supercapacitors: Understanding the effect of binder on the charge storage mechanism

This study used a scalable process to fabricate activated carbon (AC) supercapacitor electrodes with cornstarch as a green binder. A vital aspect of this study was comparing its performance with synthetic binders like polyvinylidene fluoride (PVDF) and Nafion. The chemical and physical properties of the AC were characterized using Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), Raman spectroscopy, and Field Emission Scanning Electron Microscopy (FE-SEM). Water contact angle measurements evaluated the hydrophilicity of AC-based electrodes with different binders. Their electrochemical characteristics were studied using open circuit potential (OCP), cyclic voltammetry (CV), galvanic charge/discharge (GCD), and electrochemical impedance spectroscopy (EIS) in 1 M NaSO4 electrolyte, and the charge storage mechanism was discussed in detail. The starch binder significantly facilitated the charge storage mechanism by suppressing diffusion limitations compared to other binders. The fabricated symmetric supercapacitor device of starch-based electrodes exhibited the highest Cs of 120 F/g at a specific current of 1 A g-1 with a high energy density of 135 Wh/kg and an exact power density of 750 W/kg. The starch-based supercapacitor device exhibited a capacitance retention of 104 % and 65.5 % at specific currents of 2 A g-1 and 10 A g-1 after 10,000 cycles of charging/discharging, respectively.

Mixed microalgal culture enhances biofilm adhesion during treatment of livestock wastewater: The role of extracellular polymeric substances

Microalgal biofilm can remove nutrients and refractory pollutants from livestock wastewater, transforming them into biomass or fuel. However, these applications are hampered by biofilm shedding. Coculture enhances effects, and its influence on the adhesion of attached microalgal biofilms requires exploration. In this study, two unicellular algae, Euglena (E) and Chlorella pyrenoidosa (C). and two filamentous algae, Klebsodium sp. (K) and Phormidium sp. (P), were paired two by two, aiming to investigate the effect of mixing on the adhesion of microalgal biofilm. The results showed that suitable microalgal combinations significantly enhanced the performance of the co-cultured microalgal biofilm. Biomass enhancement of 35 % and 21.9 % was observed in the PC group compared to the individual P and C groups, respectively. The content of tightly bound extracellular polymeric substances (TB-EPS) and its protein and polysaccharide content significantly correlating with the net biomass increase in all treatments, p < 0.05. Furthermore, measurement of zeta potentials and water contact angles indicated that alterations in protein secondary structures contributed to a lower intermolecular repulsion and greater hydrophobicity of the TB-EPS, which together with the stability provided by the higher β-glucan content supported the adhesion of the co-cultured microalgal biofilm.

Effect of PFDTS/TiO2 Coating on Microstructure and Wetting Behavior of Phosphogypsum.

Phosphogypsum (PG) constitutes a form of solid byproduct emanating from the manufacturing process of wet-process phosphoric acid. The fabrication of one metric ton of wet-process phosphoric acid entails the generation of approximately five tons of phosphogypsum, a highly prolific and economically viable waste stream. If we can effectively solve the problem of poor hydrophobicity of phosphogypsum, it is possible to replace cement and other traditional cementitious materials. In this way, we can not only improve the utilization rate of phosphogypsum but also obtain significant economic and environmental benefits. In the present investigation, hydrophobic surface coatings were synthesized and applied onto the surface of α-hemihydrate phosphogypsum (α-HPG) utilizing sol-gel processing and impregnation techniques. After hydroxylating α-HPG with alkaline solution (OH-α-HPG), titanium dioxide nanoparticles (TiO2) hybridized with perfluorodecyltriethoxysilane (PFDTS) were grafted on its surface. The assessment of the hydrophobic properties of the coatings was conducted through water contact angle measurements, Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM) analyses. The contact angle remained above 124.2° after strong acidic and alkaline immersion and 50 tape adhesion experiments with good chemical stability and durability, and the mechanism of surface hydrophobicity modification was discussed. The experimental outcomes demonstrated a notable increase in the hydroxyl group concentration on the α-HPG surface following hydroxylation, significantly enhancing the attachment rate of PFDTS and TiO2 onto the HPG surface. PFDTS and TiO2 can undergo chemical interaction with hydroxyl groups, facilitating their robust adsorption onto the surface of OH-α-HPG through chemisorption mechanisms. After bonding the OH-α-HPG surface with PFDTS and TiO2 via hydrogen bonding, the otherwise hydrophilic α-HPG surface acquired excellent hydrophobicity (OH-α-HPG-PT, contact angle (CA) = 146.7°). The surface modification of α-HPG through hydroxylation and hydrophobicity enhancement significantly augmented the compatibility and interfacial interplay between α-HPG and PT. This research successfully enhanced the hydrophobic properties of α-HPG, profoundly showcasing its immense potential within the construction industry and the realm of comprehensive solid waste utilization.

Facile preparation of graphene oxide/Poly (N‐Isopropylacrylamide‐co‐acrylic acid) composite thin film and its quartz crystal microbalance humidity sensing property

AbstractThe composite microgels were synthesized from N‐Isopropylacrylamide (NIPAM) and acrylic acid (AA) monomers in the presence of graphene oxide (GO) using an in situ radical copolymerization method. The successful preparation of these composite microgels was investigated through Fourier transform infrared spectroscopy (FTIR), ultraviolet visible absorption spectroscopy (UV–vis), and Raman spectroscopy. Due to the hydrophilic properties of GO and the microgels containing oxygenated groups (OH, COOH, and CONH2), quartz crystal microbalance (QCM) sensors can be fabricated by spraying the GO/P(NIPAM‐co‐AA) dispersion onto QCM sensors as sensitive coating materials. The results indicate a notable enhancement in the performance of GO/P(NIPAM‐co‐AA) modified QCM humidity sensor, compared to QCM sensors modified with either GO or P(NIPAM‐co‐AA) microgels alone. This improvement is mainly evidenced by higher sensitivity and reduced moisture hysteresis. The humidity sensing mechanism is based on the combined effect of GO and P(NIPAM‐co‐AA) microgels, which synergistically enhance the sensor's performance. Additionally, the results from water contact angle measurements, laser scanning confocal microscopy (LSCM), and scanning electron microscope (SEM) show that GO/P(NIPAM‐co‐AA) exhibits greater roughness and stronger hydrophilicity than either GO or P(NIPAM‐co‐AA) microgels alone. These properties make GO/P(NIPAM‐co‐AA) an effective moisture‐sensitive material for QCM sensors.

Dialysis treatment, in vitro, and anticoagulation activity of polysulfone-polyacrylamide based-blend membranes: an experimental study.

The majority of treatments are performed with polysulfone (PSf) membranes. The main issue of the PSf membrane is its lack of endothelial function, leading to various processes like platelet adhesion, protein adsorption, and thrombus formation when comes in contact with blood. The crucial aspect in the development of hemodialysis (HD) membrane materials is a biocompatibility factor. This study aims to improve the performance and biocompatibility of PSf membranes by utilizing polyethylene glycol (PEG) as a pore-forming agent and polyacrylamide (PAA) as a multifunctional modifying additive owing to its non-toxic, and biocompatible nature. The formulated HD membranes were characterized using Fourier Transform Infrared (FTIR) spectroscopy, Scanning Electron Microscopy (SEM), and Water Contact Angle (WCA) measurements. The biocompatibility results showed that PSf-PAA membranes reduced the adsorption of bovine serum albumin (BSA) protein, hemolysis process, thrombus formation, and platelets adhesion with improved in vitro cytotoxicity results as well as anticoagulation performance. The protein separation results showed that PSf-PAA membranes were able to reject 90.1% and 92.8% of BSA protein. The membranes also showed better uremic waste clearance for urea (76.56% and 78.24%) and creatinine (73.71% and 79.13%) solutes, respectively. It is conceivable that these modern-age membranes may surpass conventional HD membranes regarding both efficiency and effectiveness.

Visualisation of surface coating distribution patterns on modified CaCO3

In this work, the surface modification of calcite-type calcium carbonate using the anionic surfactant sodium stearate was studied. The optimal amount of surfactant and its distribution on the surface of calcium carbonate is of great significance to the actual production. Various techniques were used to characterize these important parameters such as Fourier-transform infrared spectroscopy (FTIR), water contact angle measurements, Raman Mapping visualizationimaging, Raman depth profiling, thermogravimetric analysis (TGA), and atomic force microscopy (AFM). The results of the Fourier Transform Infrared (FTIR) suggest the formation of a coating on the surface of the modified calcium carbonate. Water contact angle measurements, Raman Mapping visualizationimaging, and TGA indicate that the optimal initial dosage of sodium stearate required to form a monolayer coating is about 2 wt%. Here, the hydrophilic heads of the sodium stearate are arranged vertically on the calcium carbonate surface forming the monolayer. As the concentration of sodium stearate increases, the hydrophobic tails of the sodium stearate or calcium stearate connect each other, forming bilayer or multilayer coatings. Furthermore, the surface coating on calcium carbonate originates from the edge vertices and gradually spreads towards the central region as the amount of sodium stearate increases until complete coverage is achieved. Raman depth profiling and AFM visualization results suggest that the thickness of the monolayer coating is approximately 5.25 nm.

The Effect of Cigarettes Smoke on the Color and Properties of a Silicone for Maxillofacial Prostheses.

Although deterioration of silicone maxillofacial prostheses is severely accentuated in smoking patients, the phenomenon has not been systematically studied. To address a gap in the literature concerning the stability of maxillofacial prostheses during service, in this contribution, the effect of cigarette smoke on the aspect and physical properties of M511 silicone elastomer was evaluated. The aspect, surface, and overall properties of the silicone material, pigmented or not, were followed by AFM, color measurements, FTIR, water contact angle measurements, TGA-DTG and DSC, hardness and compression stress-strain measurements. The types of the contaminants adsorbed were assessed by XRF, ESI-MS, MALDI-MS, and NMR spectral analyses. Important modifications in color, contact angle, surface roughness, local mechanical properties, and thermal properties were found in the silicone material for maxillofacial prostheses after exposure to cigarettes smoke. The presence of lead, nicotine, and several other organic compounds adsorbed into the silicone material was emphasized. Slight decrease in hardness and increase in Young's modulus was found. The combined data show important impact of cigarette smoke on the silicone physical properties and could indicate chemical transformations by secondary cross-linking. To our knowledge, this is the first study making use of complementary physical methods to assess the effect of cigarette smoke on the aspect and integrity of silicone materials for maxillofacial prostheses.

Synthesis and Property Evaluations of a Bio‐Based Anticorrosive Urethane Composites Containing Bisphenol a as Extender

AbstractThis article reports the synthesis of an eco‐friendly polyurethane composite system, which was successfully prepared in a one‐pot synthetic pathway by combining castor seed oil (CSO), bisphenol A (BPA), isophorone diisocyanate (IPDI), and functional hybrid nanoparticles (prepared by modifying the peripheral surface of silica with 3‐aminopropyltrimethoxysilane (APTMS). The urethane composites were cast as thin films on tin foils and mild steel and cured under atmospheric moisture. Attenuated total reflectance Fourier transform infrared (ATR‐FTIR) spectroscopy was used to characterise the cured composite films, scanning electron microscopy (SEM), energy dispersive X‐ray (EDX), X‐ray diffraction (XRD), thermogravimetric analysis (TGA), corrosion resistance, antimicrobial analysis, salt spray test, and water contact angle measurements. Our evaluations showed improved thermal and hydrophobic properties of the composite coatings. Also, the electrochemical and antimicrobial analyses clearly show resistance to corrosion and test organisms as the percentage composition of APTMS‐SiO2 increases in the urethane system.