Hydroxyethyl Cellulose Research Articles

Deposition of Nanometric Polymer-Surfactant Complexes Formed by Cationic Dextran: A Path to Sustainable Formulations.

The home and personal care industry is evolving toward more sustainable and environmentally friendly ingredients. Rinse-off personal care products rely on formation of polymer-surfactant complexes to drive deposition of benefit agents (e.g., conditioning oils, fragrances, etc.) onto the skin or hair. The most used natural polymers for this purpose are cationic guar (catGuar) and cationic hydroxyethyl cellulose (catHEC), and the complexation of these polymers with surfactants has been rigorously characterized. Various gaps still exist with these polymers, specifically low biodegradation and undesirable aquatic toxicity profiles. Modified dextran offers an exciting solution as a biodegradable polysaccharide with a high natural origin content. This paper aims to compare the morphology of polymer-surfactant complexes formed between a cationic dextran (catDex) polymer with mixtures of sodium lauryl ether sulfate (SLES) and cocamidopropyl betaine (CapB) to the morphologies of complexes formed between catGuar or catHEC and the same surfactants. Solutions were designed to mimic industrially relevant shampoos. Through a suite of complementary techniques, unique nanometric sized complexes were observed to form between catDex-SLES/CapB compared to the widely reported micrometer-sized coacervates (liquid-liquid phase separation) or precipitates (liquid-solid) formed in catHEC or catGuar-SLES systems. Using a quartz crystal microbalance with dissipation, the adsorption behavior of the catDex-SLES/CapB is characterized on a silica-coated sensor. The results show deposition throughout the dilution regime for catDex-SLES/CapB where the highest deposition is recorded with the undiluted rinsing formulation. This contrasts with catHEC-SLES/CapB and catGuar-SLES/CapB where the highest deposition is recorded in phase-separated regimes. This result was extended to performance testing on hair, confirming that the unique complexes formed by catDex can drive remarkably high levels of silicone deposition from rinse-off personal care products. This innovative approach of utilizing catDex-SLES/CapB complexes could enable design of more sustainable formulations that rely on polycation-surfactant nanocarriers.

Effect of additives on the microstructure and properties of pulsed electrodeposited copper foils

ABSTRACT A low-roughness ultra-thin copper foil was prepared by pulsed electrodeposition with a duty cycle 60%, pulse frequency of 600 Hz on titanium. The influence of sodium 3,3'-dithiodipropane sulphonate (SPS), hydroxyethyl cellulose (HEC), gelatin and collagen additives on the microstructure, mechanical properties and electrochemical behaviour of electrolytic copper foil was explored. Furthermore, the reaction mechanism of SPS and collagen additives on electrodeposited copper were discussed. The results showed that at 0.08 g L−1 collagen concentration, the lowest thickness, the highest microhardness and the optimal surface roughness were achieved (5.12 μm, 279.63 HV and 1.885 μm, respectively). X-ray diffraction results confirmed that electrolytic copper foils prepared when SPS was introduced into the blank solution had a preferred orientation of (220) texture, which benefitted from the synergistic effect of copper ions and additives. The intermediates formed by the additive and Cu+ occupied the active sites on the cathode surface that increased the nucleation sites for deposition. In addition, the formed complexes can act as a barrier to narrow ion deposition channels and inhibit the growth of Cu ions.

In Vivo Evaluation of Demineralized Bone Matrix with Cancellous Bone Putty Formed Using Hydroxyethyl Cellulose as an Allograft Material in a Canine Tibial Defect Model.

Demineralized bone matrix (DBM) is a widely used allograft material for bone repair, but its handling properties and retention at defect sites can be challenging. Hydroxyethyl cellulose (HEC) has shown promise as a biocompatible carrier for bone graft materials. This study aimed to evaluate the efficacy of DBM combined with cancellous bone putty formed using HEC as an allograft material for bone regeneration in a canine tibial defect model. Experiments were conducted using dogs with proximal tibial defects. Four groups were compared: empty (control group), DBM + HEC (DH), DBM + cancellous bone + HEC (DCH), and DBM + cancellous bone + calcium phosphate + HEC (DCCH). Radiographic, micro-computed tomography (CT), and histomorphometric evaluations were performed 4 and 8 weeks postoperatively to assess bone regeneration. The Empty group consistently exhibited the lowest levels of bone regeneration throughout the study period, indicating that DBM and cancellous bone with HEC significantly enhanced bone regeneration. At week 4, the DCCH group showed the fastest bone regeneration on radiography and micro-computed tomography. By week 8, the DCH group showed the highest area ratio of new bone among all experimental areas, followed by the DH and DCCH groups. This study demonstrated that HEC significantly enhances the handling, mechanical properties, and osteogenic potential of DBM and cancellous bone grafts, making it a promising carrier for clinical applications in canine allograft models. When mixed with allograft cancellous bone, which has high porosity and mechanical strength, it becomes a promising material offering a more effective and reliable option for bone repair and regeneration.

Effect of Magnetic Field on the Structure and Sorption Properties of Films Based on Hydroxyethyl Cellulose and Carbon Nanotubes

Effect of Magnetic Field on the Structure and Sorption Properties of Films Based on Hydroxyethyl Cellulose and Carbon Nanotubes

Recombinant Fibrous Protein Gels as Rheological Modifiers in Skin Ointments.

Rheological modifiers are an important component in the development of skin cream (SC) chassis for personal skin care products (PSCPs). The viscous behavior of a PSCP is critical to its effectiveness where its uniformity and material strength impact its processing, storage, and delivery of active ingredients. Due to the mildly acidic environment of the skin, PSCPs require a SC that will assist in maintaining their material strength at low pHs. We have investigated a coiled-coil protein hydrogel system for the ability to possess pH-responsiveness, where physical cross-linking and material strength is controlled by pH relative to the isoelectric point (pI) of the protein. We recently designed a coiled-coil protein hydrogel variant, Q5, which possesses a relatively low pI that we hypothesized to have improved supramolecular assembly into a hydrogel at acidic conditions. We demonstrate that Q5 can retain a partial solution-to-gel transition at pH 6.0 and acts as a soft hydrogel by rheology. We further tested Q5 to act as a rheological modifier in a standard SC at pH 6.0 and pH 8.0 to test conditions mediated by pH changes in the skin environment. Q5 reveals the ability to uniquely increase material strength at low pH in comparison to a standard rheological modifier like hydroxyethyl cellulose (HEC), suggesting modular protein-based coiled-coil rheological modifiers can be used in PSCPs.

Gelatin-based hydrogels with tunable network structure and mechanical property for promoting osteogenic differentiation

Osteoarthritis (OA) is a joint disease involving all joint components, including cartilage, calcified cartilage, and subchondral bone. The repair of osteochondral defects remains a significant challenge in orthopedics. Development of new strategies is essential for effective osteochondral injury repair. In this study, gelatin (Gel), polyethylene glycol diglycidyl ether (PEGDGE), hydroxyethyl cellulose (HEC) and chitosan (CS) were used to prepare semi-IPNs and IPNs hydrogels. Mechanical properties of Gel based hydrogels significantly improved with the semi-IPN and IPN structures. Tensile strength ranges from 238.7 KPa to 479.5 KPa, and its compressive strength ranges from 35.6 KPa to 112.7 KPa. Additionally, the stress relaxation rate increased with higher CS concentrations, ranging from 25 % to 35 %. The network structure of Gel-based hydrogels was a key factor in regulating stress relaxation. Viscoelasticity was adjusted by its network structures. Swelling and degradation behaviors of Gel based hydrogels were systematically investigated. Gel based hydrogels had good cytocompatibility. Both semi-IPN and IPN structures Gel based hydrogels could promote cell spreading and osteogenic differentiation. G10HEC1 and G10CS1 hydrogels show promise as candidates for osteochondral tissue regeneration, offering a new strategy for osteochondral tissue engineering.

Ionic liquids-assisted integration of biobased materials for sustainable elaboration of nanocomposites using hydroxyethyl cellulose and interlayered clay for efficient separation of Co(II) from multi-component mixtures

This study focuses on the development of eco-friendly biobased adsorbents through a sustainable hydrothermal and freeze-drying synthesis process, utilizing cost-effective bio-sourced materials to minimize energy consumption and waste. The biobased adsorbents were elaborated using hydroxyethyl cellulose-ionic liquids and bentonite clay. The elaborated biocomposites were characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy/attenuated total reflection (FTIR/ATR), thermogravimetric analysis (TGA), and electron microscopy-energy dispersive X-ray (SEM–EDX), Brunauer–Emmett–Teller (BET) and zeta potential (ZP). Structural analysis confirms the intercalation and incorporation of HEC-ILs polymeric chains into Be-Na matrix and the formation of biocomposites. The [HEC-ILs/Be-Na] composite was subsequently employed for solid-phase extraction of Co(II) by investigating the effect of pH, initial Co(II) concentrations, time, temperature, and the presence of co-existing ions (Na(I), Li(I), Mn(II), Ni(II), and Al(III)). The adsorption kinetics of Co(II) metal ions were suitably characterized using the pseudo-second-order model (with R2 > 0.99). Furthermore, the adsorption isotherms conformed to the Langmuir model (with R2 > 0.97), suggesting a chemisorption process with an adsorption capacity of 69.8 mg/g. The thermodynamic study reveals that the adsorption process exhibits characteristics of spontaneity and endothermicity (ΔH° = 74.197 kJ mol−1, ΔG° < 0 kJ mol−1). The proposed mechanism for Co(II) adsorption on the developed biocomposite involves electrostatic interactions, ion exchange, and anion-π interactions. The biobased composite exhibited remarkable selectivity for Co(II) and demonstrated great potential as an adsorbent for industrial applications.Graphical abstract

Biodegradable, stretchable, and high-performance triboelectric nanogenerators through interfacial polarization in bilayer structure

The increasing demand for wearable electronics has led to the development of triboelectric nanogenerators (TENGs) as a promising energy harvesting and sensing technology. However, conventional TENGs often utilize non-biodegradable materials, contributing to environmental pollution. In this work, we present a stretchable and biodegradable TENG based on hydroxyethyl cellulose (HEC) and gelatin (HG-TENG). The HG-TENG features a bilayered structure, where the large difference in their relative permittivity between HEC and gelatin induces interfacial polarization, effectively mitigating charge recombination and enhancing triboelectric performance. The optimized HG-TENG achieves an open-circuit voltage (Voc) of 93 V, a maximum power density of 57.8 µW/cm2, and can power 38 blue light-emitting diodes. The device exhibits a stretchability of 150 % and biodegrades within 3 hours in phosphate-buffered saline. Furthermore, we demonstrate the application of the HG-TENG as a wearable sensor by modifying it with trichloro(1H, 1H, 2H, 2H-perfluorooctyl)silane (FOTS) (FHG-TENG). The FHG-TENG-based smart glove, integrated with machine learning algorithms, enables real-time monitoring of blood pressure waveforms and finger motions, showcasing its potential for human-machine interfaces. The smart glove, equipped with five FHG-TENGs on the proximal interphalangeal joints of each finger, detects diverse finger gestures and generates voltage signals that control a robotic hand in real-time, demonstrating effective human-machine interaction through synchronized motion. Moreover, the smart glove achieves a high recognition accuracy of 96.15 % for 10 different hand sign languages.

Polyvinyl acetate wood adhesive stabilized with hydroxyethyl cellulose: synthesis and characterizations

Specifically, the conventional wood adhesive uses polyvinyl alcohol (PVA) as colloid to stabilise the polyvinyl acetate (PVAc) emulsion. Green materials are being used as a result of recent study on chemicals and alternative sources. This factor has made the substitution of sustainable biopolymers for petrochemicals considerably more important. An emulsifier, sodium lauryl sulphate (SLS), was used during the addition polymerization process to produce a hydroxyethyl cellulose-grafted-poly (vinyl acetate) (HEC-g-P(VAc)) emulsion from HEC and VAc. The purpose of the study was to increase the content of renewable materials in the emulsion. The adhesive films glass transition temperatures (Tg) have been identified via Differential Scanning Calorimetry (DSC). The performance of the PVAc emulsion-based adhesive in accordance with EN 204 and EN 205 standards was evaluated by measuring the tensile shear strength of wood joints under both dry and wet conditions. The viscosity of the adhesives significantly increased along with the addition of HEC. The application of HEC led to an increase in PVAc film hardness, which was confirmed by the film’s glass transition temperature. In an environment that was wet, after 24 h, the tensile strength of the sample containing HEC increased by 54% compared to a pristine sample, as per EN 204 and EN 205. Water resistance significantly increased in sample with HEC, as was found by measuring the water contact angle which is in line with wet strength. The overall study conclusion emphasises the superior water resistance and increased adhesion capabilities of PVAc emulsion-based wood adhesives stabilised by HEC.

Design of nature-inspired patterns on knitted fabrics for directional transportation of sweat and study of their performances

The human body in a hot environment or during intense training will sweat a lot. Traditional cotton fabrics are soft and breathable, but they tend to absorb moisture easily and evaporate it slowly, which makes people feel cold and wet. Sweat staying on fabrics for a long time could also cause bacteria to grow. Thus, it is necessary to transport the excessive sweat from the gathering section to the collection points along the surface paths in time to minimize such problems. The mechanism of directional water transport of desert beetles, cacti, nepenthes, and river meanders was referenced in this paper. The paths in dot, tree, V-shape, and river meander patterns were designed and manufactured from the inspiration of these natural architectures. The paths were coated on the surfaces of selected knitted fabrics with different structures through a one-step coating process. The optimal recipe of hydrophobic solution was determined when 0.1 g hydroxyethyl-cellulose (HEC) was added into MS-S002 solution. The results showed that sweat movement is mainly influenced by FL, FWD, FG, and knitted structure. The continuous and enclosed paths such as tree and river contribute to a better sweat moving track than those of dot and V-shape ones. Terry structure is more suitable for surface sweat transport than plain and pique. The highest movement speed of the terry structure with a tree pattern reaches 0.43 cm/s, followed by that of the terry structure with river pattern 0.35 cm/s. The coated fabrics also have ideal moisture and air permeability for wearing.

Ionic Conductivity Studies on Proton Conducting Solid Biopolymer Electrolyte based on 2-Hydroxyethyl Cellulose (2HEC) Doped with Ammonium Chloride (NH4CL)

Solution casting techniques have been used to create a solid biopolymer electrolyte (SBEs) based on 2-hydroxyethyl cellulose (2HEC) doped with varying amounts of ammonium chloride (NH4Cl) to investigate the potential of NH4Cl in enhancing the ionic conductivity of SBE. Electrical impedance spectroscopy (EIS) was used to measure the impedance of the electrolytes between 50 Hz and 1 MHz in frequency. At room temperature, ionic conductivity was at its highest for 16% weight percent of NH4Cl which was 1.74 x 10-3 Scm-1. The temperature dependence data of 2HEC-NH4Cl SBEs abides Arrhenius behaviour. Complex electrical modulus and complex permittivity were used to assess the dielectric data for the sample at various temperatures.

Encapsulation of Bacillus subtilis in Electrospun Poly(3-hydroxybutyrate) Fibers Coated with Cellulose Derivatives for Sustainable Agricultural Applications.

One of the latest trends in sustainable agriculture is the use of beneficial microorganisms to stimulate plant growth and biologically control phytopathogens. Bacillus subtilis, a Gram-positive soil bacterium, is recognized for its valuable properties in various biotechnological and agricultural applications. This study presents, for the first time, the successful encapsulation of B. subtilis within electrospun poly(3-hydroxybutyrate) (PHB) fibers, which are dip-coated with cellulose derivatives. In that way, the obtained fibrous biohybrid materials actively ensure the viability of the encapsulated biocontrol agent during storage and promote its normal growth when exposed to moisture. Aqueous solutions of the cellulose derivatives-sodium carboxymethyl cellulose and 2-hydroxyethyl cellulose, were used to dip-coat the electrospun PHB fibers. The study examined the effects of the type and molecular weight of these cellulose derivatives on film formation, mechanical properties, bacterial encapsulation, and growth. Scanning electron microscopy (SEM) was utilized to observe the morphology of the biohybrid materials and the encapsulated B. subtilis. Additionally, ATR-FTIR spectroscopy confirmed the surface chemical composition of the biohybrid materials and verified the successful coating of PHB fibers. Mechanical testing revealed that the coating enhanced the mechanical properties of the fibrous materials and depends on the molecular weight of the used cellulose derivatives. Viability tests demonstrated that the encapsulated B. subtilis exhibited normal growth from the prepared materials. These findings suggest that the developed fibrous biohybrid materials hold significant promise as biocontrol formulations for plant protection and growth promotion in sustainable agriculture.

The Wound-Healing Effect of a Novel Fibroblasts-Impregnated Hydroxyethylcellulose Gel in a Rat Full-Thickness Burn Model: A Preclinical Study.

Background/Objectives: The objective of this study was to assess the efficacy of a cell-containing wound dressing based on fibroblasts in hydroxyethylcellulose (HEC) gel for the local treatment of deep partial-thickness and/or full-thickness skin burns in an animal model. Methods: The rats (male Wistar, n = 100) were subjected to a full-thickness thermal burn (16 cm2). Radical necrectomy was performed one day after the burn. Three days later, the rats were randomly assigned to one of four groups: group 1 (no treatment), group 2 (chloramphenicol and methyluracil ointment, a routine clinical treatment), group 3 (a gel without cells, mock treatment), and group 4 (a dermal fibroblast-impregnated HEC gel). The treatment lasted for five days. The wound-healing process was evaluated by planimetric, cytologic, histologic, and immunohistochemical methods. Results: The differences in the rate of wound healing and the characteristics of wound cytology were identified. In the group 4, a regenerative type of cytogram was revealed, characterized by a significantly increased number of fibroblastic cells in comparison to samples from non-treated and mock-treated animals. Biopsy samples of burn wounds from animals in the group 4l demonstrated the presence of mature granulation tissue and a large number of microvessels. The repair process was stimulated, as evidenced by the increased thickness of newly formed granulation tissue and epidermis in the wound zone, elevated cellularity, and enhanced re-epithelialization activity. The number of Ki-67-positive proliferating cells was significantly higher in group 4 than in the control groups). A small number of non-proliferating donor fibroblasts was observed in the wound area 3 days after the end of treatment. Conclusions: The cell product is an effective agent for promoting wound healing during the regenerative phase. The experiments demonstrated that a gel populated by dermal fibroblasts can stimulate reparative regeneration processes in deep partial- and full-thickness burn wounds.

Cross-reactivity to Hydroxypropyl Methylcellulose and Hydroxyethyl Cellulose in a Patient Allergic to Carboxymethylcellulose: A Case Report.

Cross-reactivity to Hydroxypropyl Methylcellulose and Hydroxyethyl Cellulose in a Patient Allergic to Carboxymethylcellulose: A Case Report.

Antimicrobial Hydroxyethyl-Cellulose-Based Composite Films with Zinc Oxide and Mesoporous Silica Loaded with Cinnamon Essential Oil.

Background: Cellulose derivatives are gaining much attention in medical research due to their excellent properties such as biocompatibility, hydrophilicity, non-toxicity, sustainability, and low cost. Unfortunately, cellulose does not exhibit antimicrobial activity. However, derivatives like hydroxyethyl cellulose represent a proper matrix to incorporate antimicrobial agents with beneficial therapeutic effects. Methods: Combining more antimicrobial agents into a single composite material can induce stronger antibacterial activity by synergism. Results: Therefore, we have obtained a hydroxyethyl-cellulose-based material loaded with zinc oxide nanoparticles and cinnamon essential oil as the antimicrobial agents. The cinnamon essential oil was loaded in mesoporous silica particles to control its release. Conclusions: The composite films demonstrated high antibacterial activity against Staphylococcus aureus and Escherichia coli strains, impairing the bacterial cells' viability and biofilm development. Such antimicrobial films can be used in various biomedical applications such as topical dressings or as packaging for the food industry.

In Vitro Study of Cyano-Phycocyanin Release from Hydrogels and Ex Vivo Study of Skin Penetration.

This study explored the most suitable materials for incorporating cyano-phycocyanin (C-PC) into hydrogels, focusing on maintaining the C-PC's long-term structural integrity and stabilityNext, the release of C-PC from the hydrogels and its skin penetration were investigated. A series of 1% (w/w) C-PC hydrogels was prepared using various gelling agents and preservatives. Spectrophotometric measurements compared the amount of C-PC in the hydrogels to the initially added amount. After selecting the most suitable gelling agent and preservative, two C-PC hydrogels, with and without propylene glycol (PG) (Sigma-Aldrich, St. Louis, MO, USA), were produced for further testing. In vitro release studies utilized modified Franz-type diffusion cells, while ex vivo skin-permeation studies employed Bronaugh-type cells and human skin. Confocal laser scanning microscopy analyzed C-PC accumulation in the skin. The findings demonstrated that sodium alginate (Sigma-Aldrich, St. Louis, MO, USA), hydroxyethyl cellulose (HEC) (Sigma-Aldrich, St. Louis, MO, USA), and SoligelTM (Givaudan, Vernier, Switzerland) are effective biopolymers for formulating hydrogels while maintaining C-PC stability. After 6 h, C-PC release from the hydrogel containing PG was approximately 10% or 728.07 (±19.35) μg/cm2, significantly higher than the nearly 7% or 531.44 (±26.81) μg/cm2 release from the hydrogel without PG (p < 0.05). The ex vivo qualitative skin-permeation study indicated that PG enhances C-PC penetration into the outermost skin layer. PG's ability to enhance the release of C-PC from the hydrogel, coupled with its capacity to modify the skin barrier ex vivo, facilitates the penetration of C-PC into the stratum corneum.

Pyrene carbaldehyde derived carbon dots for detecting water in alcohol and security printing

This study focuses on preparing Carbon dots (CDs) from Pyrene-1-carbaldehyde (PCA) using a solvothermal method and further purification using column chromatography. The aggregation-induced emission (AIE) of CDs was systematically investigated in a THF/water medium. The CDs showed red shifts in their photoluminescence (PL) spectra upon increase in water content. Scanning electron microscopic (SEM) images revealed the formation of aggregates, while X-ray diffraction (XRD) confirmed that the d-spacing values remains unchanged. The NMR spectrum of the CDs displayed peaks corresponding to aromatic carbon, which disappeared upon addition of water due to π-π stacking, indicating aggregate formation. Based on the aggregation-induced fluorescence emission mechanism, detection of water content in alcohol is demonstrated. Moreover, the synthesized CDs were used as fluorescent colorant in screen inks along with polyvinyl alcohol (PVA) and hydroxyethyl cellulose (HEC) as binders. The print proofs obtained on UV-dull paper using PVA-based screen ink exhibited fluorescence emission at longer wavelengths and showcased desirable photostability under prolonged UV exposure compared to the prints obtained using HEC-based ink. Moreover, though the PVA based print appeared blue or cyan fluorescent, the actual yellow emissions from the CDs can be visualised using UV block filter. Such features, masked to the forger, but known to the user can be utilised in checking the authenticity of the print.

Development of dual drug loaded-hydrogel scaffold combining microfluidics and coaxial 3D-printing for intravitreal implantation

Treating diabetic retinopathy (DR) effectively is challenging, aiming for high efficacy with minimal discomfort. While intravitreal injection is the current standard, it has several disadvantages. Implantable systems offer an alternative, less invasive, with long-lasting effects drug delivery system (DDS). The current study aims to develop a soft, minimally invasive, biodegradable, and bioadhesive material-based hydrogel scaffold to prevent common issues with implants. A grid-shaped scaffold was created using coaxial 3D printing (3DP) to extrude two bioinks in a single filament. The scaffold comprises an inner core of curcumin-loaded liposomes (CUR-LPs) that prepared by microfluidics (MFs) embedded in a hydrogel of hydroxyethyl cellulose (HEC), and an outer layer of hyaluronic acid-chitosan matrix with free resveratrol (RSV), delivering two Sirt1 agonists synergistically activating Sirt1 downregulated in DR. Optimized liposomes, prepared via MFs, exhibit suitable properties for retinal delivery in terms of size (<200 nm), polydispersity index (PDI) (<0.3), neutral zeta potential (ZP), encapsulation efficiency (∼97 %), and stability up to 4 weeks. Mechanical studies confirm scaffold elasticity for easy implantation. The release profiles show sustained release of both molecules, with different patterns related to different localization of the molecules. RSV released initially after 30 min with a total release more than 90 % at 336 h. CUR release starts after 24 h with only 4.78 % of CUR released before and gradually released thanks to its internal localization in the scaffold. Liposomes and hydrogels can generate dual drug-loaded 3D structures with sustained release. Microscopic analysis confirms optimal distribution of liposomes within the hydrogel scaffold. The latter resulted compatible in vitro with human retinal microvascular endothelial cells up to 72 h of exposition. The hydrogel scaffold, composed of hyaluronic acid and chitosan, shows promise for prolonged treatment and minimally invasive surgery.

Performance Properties and Finite Element Modelling of Forest-Based Bionanomaterials/Activated Carbon Composite Film for Sustainable Future

Thanks to its highly crystalline structure and excellent thermal, optical, electrical and mechanical properties, carbon and its derivatives are considered the preferred reinforcement material in composites used in many industrial applications, especially in the forest and forest products sector, including oil, gas and aviation. Since hydroxyethyl cellulose (HEC) is a biopolymer, it has poor mechanical and thermal properties. These properties need to be strengthened with various additives. This study aims to improve the thermal and mechanical properties of hydroxyethyl cellulose by preparing hydroxyethyl cellulose/activated carbon (HEC/AC) composite materials. With this study, composites were obtained for the first time and their mechanical properties were examined using a 3D numerical modeling technique. The thermal stability of the prepared composite materials was investigated via thermal gravimetric analysis (TGA). The samples were heated from 30 °C to 750 °C with a heating rate of 10 °C/min under a nitrogen atmosphere and their masses were measured subsequently. The mechanical properties of the composites were investigated via the tensile test. The viscoelastic properties of the composite films were determined with dynamic mechanical thermal analyses (DMTA) and their morphologies were examined with scanning electron microscopy (SEM) images. According to the results, the best F3 sample (films containing 3 wt.% activated carbon) had an elastic modulus of 168.3 MPa, a thermal conductivity value of 0.068 W/mK, the maximum mass loss was at 328.20 °C and the initial storage modulus at 30 °C was 206.13 MPa. It was determined that the hydroxyethyl cellulose composite films containing 3 wt.% activated carbon revealed the optimum results in terms of both thermal conductivity and viscoelastic response and showed that the obtained composite films could be used in industrial applications where thermal conductivity was required.

Reduction in Olfactory Discomfort in Inhabited Premises from Areas with Mofettas through Cellulosic Derivative-Polypropylene Hollow Fiber Composite Membranes.

Hydrogen sulfide is present in active or extinct volcanic areas (mofettas). The habitable premises in these areas are affected by the presence of hydrogen sulfide, which, even in low concentrations, gives off a bad to unbearable smell. If the living spaces considered are closed enclosures, then a system can be designed to reduce the concentration of hydrogen sulfide. This paper presents a membrane-based way to reduce the hydrogen sulfide concentration to acceptable limits using a cellulosic derivative-propylene hollow fiber-based composite membrane module. The cellulosic derivatives considered were: carboxymethyl-cellulose (NaCMC), P1; cellulose acetate (CA), P2; methyl 2-hydroxyethyl-cellulose (MHEC), P3; and hydroxyethyl-cellulose (HEC), P4. In the permeation module, hydrogen sulfide is captured with a solution of cadmium that forms cadmium sulfide, usable as a luminescent substance. The composite membranes were characterized by SEM, EDAX, FTIR, FTIR 2D maps, thermal analysis (TG and DSC), and from the perspective of hydrogen sulfide air removal performance. To determine the process performances, the variables were as follows: the nature of the cellulosic derivative-polypropylene hollow fiber composite membrane, the concentration of hydrogen sulfide in the polluted air, the flow rate of polluted air, and the pH of the cadmium nitrate solution. The pertraction efficiency was highest for the sodium carboxymethyl-cellulose (NaCMC)-polypropylene hollow fiber membrane, with a hydrogen sulfide concentration in the polluted air of 20 ppm, a polluted air flow rate (QH2S) of 50 L/min, and a pH of 2 and 4. The hydrogen sulfide flux rates, for membrane P1, fall between 0.25 × 10-7 mol·m2·s-1 for the values of QH2S = 150 L/min, CH2S = 20 ppm, and pH = 2 and 0.67 × 10-7 mol·m-2·s-1 for the values of QH2S = 50 L/min, CH2S = 60 ppm, and pH = 2. The paper proposes a simple air purification system containing hydrogen sulfide, using a module with composite cellulosic derivative-polypropylene hollow fiber membranes.