Hydroxyethyl Cellulose Research Articles

First insight into microplastic groundwater pollution in Latin America: the case of a coastal aquifer in Northwest Mexico

Microplastics have been studied on biota and other environmental domains, such as soils. Despite the importance of groundwater as a resource for millions of people worldwide as drinking water and personal hygiene, domestic, agricultural, mining, and industrial purposes, there are very few studies concerning microplastics in this domain around the world. We present the first study in Latin America addressing this topic. Six capped boreholes were analyzed in terms of abundance, concentration, and chemical characterization, at three different depths, from a coastal aquifer in Northwest Mexico. This aquifer is highly permeable and affected by anthropogenic activities. A total of 330 microplastics were found in the eighteen samples. In terms of concentration, the interval ranged from 10 to 34 particles/L, with an average of 18.3 particles/L. Four synthetic polymers were identified: isotactic polypropylene (iPP), hydroxyethylcellulose (HEC), carboxylated polyvinyl chloride (PVC), and low-density polyethylene (LDPE); with iPP being the most abundant (55.8%) in each borehole. Agriculture activities and septic outflows are considered the potential regional sources of these contaminants into the aquifer. Three possible transport pathways to the aquifer are suggested: (1) marine intrusion, (2) marsh intrusion, and (3) infiltration through the soil. More research about the occurrence, concentration, and distribution of the different kinds of microplastics in groundwater is needed to have a better understanding of the behavior and health risks to organisms, including human beings.

Polyphenylene carboxymethylene (PPCM), the active component of the topical contraceptive Yaso-GEL, exhibits potent antimicrobial activity against Neisseria gonorrhoeae in preclinical studies

IntroductionPolyphenylene carboxymethylene (PPCM) is a condensation polymer that has both contraceptive and antimicrobial activity against several sexually transmitted viruses including HIV, herpes simplex virus, Ebola virus and SARS-CoV-2 in preclinical...

Improvement of tribological properties of water‐based ZnO nanoparticles lubricant for zirconium alloy cold rolling by hydroxyethyl cellulose

AbstractCurrently, substantial adhesion wear frequently occurs in Zr alloy cold rolling, which not only affects the quality of product's surface, but shortens the mould's service life. In this paper, water‐based lubricant was prepared by using ZnO as additive and hydroxyethyl cellulose (HEC) as dispersant. The tribological test results showed the friction coefficient decreased by a maximum of 84.6%, and the friction surface was smooth and flat, with essentially no wear. By analysing the friction area, it was found after ZnO entered the friction interface, HEC carried a hydrated molecular layer to form a stable lubrication film at the interface. This film worked with nanoparticles to reduce friction and wear, and is expected to prolong the service life of rolling dies.

Effects of load level, dimensional effects and temperature conditions on the pressure sensitivity of short carbon fiber cementitious composites

Carbon fiber reinforced cementitious composites (CFRCC) are a kind of sensing materials in structural self-monitoring system. However, their performances still need to be enhanced. In this study, the effects of load level, dimensional effect, temperature and temperature cycles on the pressure sensitivity of CFRCC with hydroxyethyl cellulose (HEC) dispersant were systematically investigated. Simultaneously, the change rate of resistance was adopted to quantify the pressure and temperature sensitivity of CFRCC. It is found that the pressure sensitivity of CFRCC is stable as load level is below 50 per of the ultimate load. With the increasing size of the specimens, the compressive strength of CFRCC gradually declines whereas its change rate of resistance hikes quickly, both of which show obvious size effect. Furthermore, in the range of 5 °C to 80 °C, the resistivity of CFRCC demonstrates the effect of negative temperature coefficient (NTC), and the sensitivity coefficients of CFRCC tend to decrease with the increasing temperature. Compared with the sensitivity coefficient at 70 °C, the sensitivity coefficient of each specimen at 15 °C have increased by four times. In addition, the pressure sensitivity of CFRCC has significantly decreased after temperature cycles, and especially after 20 temperature cycles, CFRCC’s maximum change rate of resistance decreases by about 30% compared to the initial one. Therefore, CFRCC can be directly used in concrete structures to undertake the task of structural health self-monitoring.

SiO2 cryogel – cellulose composite thin layer

This study proposed the preparation of light, thin insulating composite layers from potential biocompatible components such as highly porous silica cryogels and cellulose fibers. One of the novelties in this work is the application of cellulose fibers as matrix, and the silica cryogel particles provide the reinforcing phase. The synthesis of silica cryogel was carried out by means of sol-gel chemistry and freeze drying process. The function of additives (NaOH, carbamide, hydroxyethyl cellulose) was to create connections between the components in the composites. The study extended to the investigation of chemical compositions, the time of treatment, as well as the measurements of the dust loss, thermal conductivity, and the adhesion of composites to the various substrates. The bond system of composites was controlled by FTIR, the morphology by SEM. The composites can be characterised by excellent thermal insulation properties (0.048 W/(m⋅K), very low dust loss (0.01 w/w%), and good adhesion to various surfaces.

Ionic conductive cellulose-based hydrogels for Al-air batteries: Influence of the charged-functional groups on the electrochemical properties

Gel electrolytes for aluminum-air (Al-air) primary batteries were prepared based on hydroxyethyl cellulose (HEC) and acrylate monomers bearing differently charged functional groups (i.e., -COOCH2CH2N+(CH3)3Cl−, -COO- and -COOCH2CF3). The acrylate monomers were grafted from HEC backbone and crosslinked using methylenebisacrylamide (MBA) to obtain hydrogels with tuned mechanical (15–75 kPa), morphological (pore size 35–125 μm) properties and varied swelling degrees at alkaline electrolyte (900–2500%). Electrochemical measurements were performed on Al-air cells assembled from Al anode, gel electrolytes (in 1 M NaOH) and carbon-based air-cathodes containing silver fine particles (Ag-FPs). Hydrogels with quaternary ammonium salt (HEC-AEtMACl) showed very long discharge time (6.5 h) compared to 1.8 h with the fluorinated hydrogels (HEC-TFEMA) and 1.1 h with carboxylated hydrogels (HEC-AA). Also, HEC-AEtMACl showed the highest current peak (3.9 μA at 1.4 V). Polarization curves proved that the anodic polarization behavior is dominant resulting from the anodic parasitic reaction. The Electrochemical Impedance Spectroscopy (EIS) evidenced that HEC-TFEMA has ionic conductivity (34.4 mScm−1) higher than that of HEC-AEtMACl. However, the highest specific capacity was observed to HEC- AEtMACl 0.928 mA h/cm2 compared to 0.26 and 0.15 mA h/cm2 for HEC-TFEMA and HEC-AA respectively.

Preparation of Porous Hydroxyethyl Cellulose Materials to Utilize Lactic Acid with Vacuum-Assisted Process.

For the first time, we succeeded in manufacturing a 2-hydroxyethyl cellulose (HEC)-based composite membrane with improved thermal stability, for use as a battery separator, coating a HEC polymer solution to a polypropylene (PP) support and using a vacuum-assisted process. A HEC polymer solution was prepared by utilizing HEC and lactic acid (LA) as a plasticizer. A vacuum-assisted process was used to move ethanol, which a mobile phase to permeate a plasticized region in the HEC polymer side for pore formation. The pores formed with uniform nano sizes, and areas in which some large pores formed were observed. The thermal stability of the composites was measured using TGA. The thermal decomposition temperatures were measured at about 250 °C for the neat HEC, about 210 °C for the HEC/LA film, and about 335 °C for the HEC/LA/PP membrane before the process. After the vacuum-assisted process, the first and second thermal decomposition were observed at about 360 °C and 450 °C, respectively. The HEC/LA/PP membrane after the process showed greater thermal stability than before the process. This means that the adhesion between the HEC polymer and the PP support was created through the rearrangement of the HEC chain, as LA escaped after the process, and it was seen indirectly that the mechanical strength was enhanced. In particular, the surface of the membrane was observed by SEM to investigate whether the HEC penetrated into the PP to block its pores, and whether the HEC region collapsed. Furthermore, the interaction of the HEC chain with the additives and the rearrangement of the HEC was confirmed using FT-IR. As a result, we demonstrated that the mechanical strength and thermal stability of the manufactured HEC/LA/PP membrane were enhanced.

Performance evaluation of guar gum and conventional binders based fire‐extinguishing aerosol‐forming composites

AbstractPyrotechnic‐based firefighting systems have been found to be effective in a wide variety of firefighting applications. Binders in pyrotechnic mixtures play a significant role as they consolidate the ingredients, provide excellent mechanical strength and increase the storage life. The rise in health and environmental safety concerns in recent years has directed our research towards natural binder systems of biological origins. Therefore, in this work, galactomannan, also called guar gum, was comparatively investigated against four different types of conventional binders, phenol–formaldehyde resin, ethyl cellulose, hydroxyethyl cellulose and carboxymethyl cellulose sodium salt, which are being used in aerosol‐forming pyrotechnic mixtures for firefighting application. It was found that the nature of the binder in an amount of 3% by weight significantly influences the combustion behaviour, fire suppression performance, mechanical and thermal characteristics of gallic acid–KNO3–KClO3 tertiary aerosol‐forming pyrotechnic mixture for fire fighting application. The safety and performance characteristics of these formulations were evaluated by conducting analyses specific to pyrotechnic formulations, that is, burn rate measurement, heat of combustion, TGA/DSC thermal analysis, hygroscopic study, compression test and n‐heptane pool fire suppression test. It can be inferred from the values obtained from these analyses that guar gum is a preferred binder to the other four‐binder systems for the gallic acid–KNO3–KClO3 pyrotechnic mixture.

Influence of pH on the release of a once daily formulation of ciprofloxacin tablets prepared with different polymers

Purpose: To study the release behaviour of ciprofloxacin hydrochloride tablet matrices prepared with different polymers in dissolution media of different pH. Methods: Different formulations of slow-release matrix tablets of ciprofloxacin hydrochloride were prepared with polymers, namely, ethyl cellulose (Etc), hydroxyethyl cellulose (Hec), hydroxypropyl methylcellulose (Hpc), and Eudragit® L-100 (Eud) using matrix embedding technique. The matrix tablets were characterized and studies of their dissolution profiles were studied in 0.1 N HCl (pH 1.2) and in simulated intestinal fluid (excluding enzymes) of pH 4.0, 6.0, and 7.4. Results: The tablets had the following characteristics: weight, 659.25 ± 7.96 to 661.65 ± 6.53 mg; hardness, 7.05 ± 0.21 to 9.60 ± 0.40 kgf; friability, 0.212 to 0.292 %; and drug content, 91.47 ± 0.53 to 112.50 ± 4.14 %. In batches prepared with ethyl cellulose, Eudragit L-100, and hydroxypropyl methylcellulose, drug release increased with a decrease in pH. However, matrix tablets prepared with hydroxyethyl cellulose displayed the highest drug release at pH 4.0 with Cmax of 108.75 % and T50% of 30.86 min; thereafter, drug release decreased with increase in pH. The pattern of drug release was Hec > Hpc > Eud > Etc in most media with more drug release in acidic than at alkaline pH. Conclusion: Release of ciprofloxacin from the formulated matrix tablets was pH-sensitive in vitro. This should be taken into consideration in designing sustained release oral form of ciprofloxacin.

Wet-spinnability and crosslinked Fiber properties of alginate/hydroxyethyl cellulose with varied proportion for potential use in tendon tissue engineering

Researchers have examined different bio-inspired materials in tissue engineering and regenerative medicine to fabricate scaffolds to address tendon regeneration requirements. We developed fibers based on alginate (Alg) and hydroxyethyl cellulose (HEC) by wet-spinning technique to mimic the fibrous sheath of ECM. Various proportions (25:75, 50:50, 75:25) of 1 % Alg and 4 % HEC were blended to this aim. Two steps of crosslinking with different concentrations of CaCl2 (2.5 and 5 %) and glutaraldehyde (2.5 %) were used to improve physical and mechanical properties. The fibers were characterized by FTIR, SEM, swelling, degradation, and tensile tests. The in vitro proliferation, viability, and migration of tenocytes on the fibers were also evaluated. Moreover, the biocompatibility of implanted fibers was investigated in an animal model. The results showed ionic and covalent molecular interactions between the components. In addition, by properly maintaining surface morphology, fiber alignment, and swelling, lower concentrations of HEC in the blending provided good degradability and mechanical features. The mechanical strength of fibers was in the range of collagenous fibers. Increasing the crosslinking led to significantly different mechanical behaviors in terms of tensile strength and elongation at break. Because of good in vitro and in vivo biocompatibility, tenocyte proliferation, and migration, the biological macromolecular fibers could serve as desirable tendon substitutes. This study provides more practical insight into tendon tissue engineering in translational medicine.

Two-Wavelength Dye-Doped Swellable Clad POF Humidity Sensor

Because humidity is an important indicator used in many fields, the development of technology for its measurement is of great significance. We investigated humidity sensors that use a swellable polymer as the cladding material of plastic optical fibers (POFs). A POF humidity sensor using hydroxyethyl cellulose (HEC) as the cladding material has a linear response at approximately 20% relative humidity (RH), but its sensitivity is low. The sensitivity can be improved by adding brilliant blue (BB) as a dye to cladding. However, this makes the detection range of the sensor too narrow for practical use. Therefore, we change the incident light from a single wavelength to two wavelengths and use the fact that the output waveform of the dye-doped sensor depends on the wavelength of the incident light. The results of experiments show that a humidity sensor with high sensitivity and an RH detection range of 10%–90% can be developed by combining the output waveforms of a two-wavelength sensor with a dye doping level of 0.8% in cladding.

Magnetic hydroxyethyl cellulose spheres with efficient congo red removal

Magnetic hydroxyethyl cellulose spheres with efficient congo red removal

Physical Stability of Binahong Leaf Extract (Anredera cordifolia (Ten.) Steenis) with Hydroxypropyl Methylcellulose and Hydroxyethyl Cellulose Gelling Agents

Second-degree burns have the highest prevalence and often occur in the household environment. The healing process can be accelerated by traditional medicine. One of the many plants known to have wound-healing abilities is the Binahong plant (Anredera cordifolia (Ten.) Steenis). The gel preparation is chosen because of the many benefits it can provide. The gelling agents used were Hydroxypropyl Methyl Cellulose and Hydroxyethyl Cellulose. The combination of these gelling agents was chosen because both agents are capable of producing gel preparations with good stability during storage. Therefore, the optimization was carried out to obtain the optimum formula that met the requirements. The observed responses were organoleptic, pH, spreadability, adhesion, viscosity, and homogeneity. The data obtained was optimized with the Simplex Lattice Design program in Design Expert software version 13.0.0. The results of the verification test were compared for their significance with the T-test with a 95% confidence level. The optimum gel stability of Binahong leaves (Anredera cordifolia (Ten.) Steenis) was tested using one-way ANOVA and post hoc. The results showed that the optimum formula for Binahong leaf extract gel (Anredera cordifolia (Ten.) Steenis) was obtained with a composition ratio of 0.5% HPMC and 4.5% HEC. The verification results obtained valid values for pH response, viscosity, and spreadability according to SLD predictions. The optimum formula for Binahong leaf extract gel (Anredera cordifolia (Ten.) Steenis) was stable during the cycling test.

Lubricating Performance of Polymer-Coated Liposomes

Dry mouth is a troublesome condition linked to lubrication failure and leads to other diseases such as fungal infections and wounds in the oral cavity. There are many commercial salivary substitutes in the market, but none with a long-lasting lubrication effect. Polymer-coated liposomes can be an interesting formulation strategy for retrieving the symptoms of dry mouth by mimicking the micelles of saliva. In the present study, polymer coated-liposomes were prepared by the conventional thin film method and subsequently coated with three different polymers with different charge densities; alginate, chitosan and hydrophobically modified ethyl hydroxyethyl cellulose (HM-EHEC). The prepared polymer-coated liposomes were studied concerning their lubricating properties using a ball-on-disc tribometer at 2 N load at 37 °C, and their flow behaviours were also measured. Solutions of the pure polymers and dispersions of the uncoated liposomes were also studied to investigate any contributions from the individual components. A commercial dry mouth product based on HEC (hydroxyethyl cellulose) and glycerol was also included. The formulations were measured as soon as possible after preparation and some of them after >4 weeks. Results demonstrated that all the positively-charged formulations (chitosan, positive liposomes and chitosan-coated liposomes) had superior lubricating properties with friction coefficients (μ < 0.1) at orally relevant speeds (50 mm/s) as compared to the neutral or negatively-charged systems. At boundary lubrication conditions (3 mm/s), the chitosan-coated liposomes obtained an even lower friction force than the individual components, thus indicating a synergistic effect between the polymer and the liposome.

Rapid, simple, and cost-effective plaque assay for murine norovirus using microcrystalline cellulose

Murine norovirus (MNV) is used widely as a practical alternative to human norovirus (HuNoV). Plaque-forming assays for MNV are important for developing therapeutic agents against HuNoV infections. Although agarose-overlay MNV assays have been reported, recent improvements in cellulose derivatives suggest that they could be optimized further, particularly with respect to improving the overlay material. To determine which overlay material is optimal for the MNV plaque assay, we compared four typical cellulose derivatives [microcrystalline cellulose (MCC), hydroxyethyl cellulose (HEC), hydroxypropyl methylcellulose (HPMC), and carboxymethyl cellulose (CMC)] with conventional agarose. We found that 3.5% (w/v) MCC-containing medium provided clear round-shaped plaques on RAW 264.7 cells 1 day after inoculation; the visibility of plaques was comparable with that of the original agarose-overlay assay. Removing residual MCC powder from the MCC-overlay assay before fixing was important for obtaining distinct plaques that are clearly countable. Finally, after calculating the plaque diameter as a percentage of well diameter, we found that 12- and 24-well plates were better than other plates for accurate plaque counting. The MCC-based MNV plaque assay is cost-effective and rapid, and produces plaques that are easy to count. Accurate virus quantification using this optimized plaque assay will enable reliable estimation of norovirus titers.

Preparation of Cellulose Hydrogels and Hydrogel Nanocomposites Reinforced by Crystalline Cellulose Nanofibers (CNFs) as a Water Reservoir for Agriculture Use

An effective strategy for the management of available water and fertilizers is imperative to improve agricultural production and food quality, including releasing them sustainably to the soil and plants. Polymeric hydrogels with three-dimensional (3D) networks can absorb ample water and soluble fertilizers without network dissolution. Subsequently, the absorbed water and fertilizers can be released to arid and semi-arid agricultural land to furnish enough moisture and nutrients for plant growth. In this study, carboxymethyl cellulose sodium salt (NaCMC)- and hydroxyethyl cellulose (HEC)-based hydrogels have been synthesized using citric acid (CA) as a crosslinker. The Fourier transform infrared (FTIR) spectroscopy study revealed the formation of hydrogels with porous structures depicted by field emission scanning electron microscopy images. The prepared hydrogels have shown a remarkable swelling ratio of ∼1070% for the hydrogel prepared using NaCMC/HEC: 2/1 and ∼840% for NaCMC/HEC: 3/1 and a reduction in the swelling ratio with increasing crosslinking density. Moreover, crystalline (shown by X-ray diffraction) cellulose nanofibers (CNFs: ∼600 nm), prepared by acid (H2SO4) hydrolysis of cotton fibers, have been used to prepare hydrogel nanocomposites. The evaluation of hydrogel nanocomposites’ mechanical properties (universal testing matching test) depicted an improved tensile strength (16.27 MPa using 0.7% CNFs) compared to that of the hydrogel without CNFs. The soil burial test for biodegradation study of prepared hydrogels revealed soil degradation of hydrogel, confirmed by FTIR analysis and visual appearance. The current study provides comprehensive data establishing the potential of hydrogels for agriculture applications.

Plasma-Activated Hydrogels for Microbial Disinfection.

A continuous risk from microbial infections poses a major environmental and public health challenge. As an emerging strategy for inhibiting bacterial infections, plasma-activated water (PAW) has proved to be highly effective, environmental-friendly, and non-drug resistant to a broad range of microorganisms. However, the relatively short lifetime of reactive oxygen and nitrogen species (RONS) and the high spreadability of liquid PAW inevitably limit its real-life applications. In this study, plasma-activated hydrogel (PAH) is developed to act as reactive species carrier that allow good storage and controlled slow-release of RONS to achieve long-term antibacterial effects. Three hydrogel materials, including hydroxyethyl cellulose (HEC), carbomer 940 (Carbomer), and acryloyldimethylammonium taurate/VP copolymer (AVC) are selected, and their antibacterial performances under different plasma activation conditions are investigated. It is shown that the composition of the gels plays the key role in determining their biochemical functions after the plasma activation. The antimicrobial performance of AVC is much better than that of PAW and the other two hydrogels, along with the excellent stability to maintain the antimicrobial activity for more than 14 days. The revealed mechanism of the antibacterial ability of the PAH identifies the unique combination of short-lived species (1 O2 , ∙OH, ONOO- and O2 - ) stored in hydrogels. Overall, this study demonstrates the efficacy and reveals the mechanisms of the PAH as an effective and long-term disinfectant capable of delivering and preserving antibacterial chemistries for biomedical applications.

Recoverable cellulose composite adsorbents for anionic/cationic dyes removal

GO/HEC/PGDE/Fe3O4 materials were successfully fabricated using environmentally-friendly hydroxyethyl cellulose (HEC), poly(ethylene glycol) diglycidyl ether (PGDE), graphene oxide (GO) and magnetic Fe3O4. Systematic investigations were completed to explore the influences of GO content in GO/HEC/PGDE/Fe3O4 and adsorption conditions on the adsorptions of cationic dyes (methylene blue (MB), crystal violet (CV)) and anionic dye acid blue 25 (AB-25). The increase of GO content can remarkably improve the adsorption capacity of GO/HEC/PGDE/Fe3O4 for the dyes. The three kinetic, four isothermic and three thermodynamic models were investigated to reveal the adsorption behaviors of the dyes. The formation of HEC/PGDE/Fe3O4 and adsorption mechanisms of the dyes by GO/HEC/PGDE/Fe3O4 were suggested. The GO/HEC/PGDE/Fe3O4 endowed with easy-fabrication, eco-friendly feature, efficient adsorption capacity of anionic/cationic dyes, convenient separation and reusability has potential applications in wastewater purification industry.

Morphology-controlled stabilised polyaniline nanoparticles and their electrorheological properties

Nanoparticles and sub-microparticles of the conducting polymers polyaniline (PANI), polyanisidine (PoANIS) and their copolymers were synthesised, deprotonated and dispersed in viscous media in order to study the influence of their synthetic conditions and of steric stabilisers (cellulose-based materials) on the physical, chemical and morphological characteristics of the polymers. Electrorheological (ER) measurements were performed and related to the polymer properties. The polymer particles had various loadings of stabilisers, depending on the polymer/stabiliser interactions and the stabiliser concentration. When stabilised with hydroxyethylcellulose (HEC), the PANI particles contained traces of HEC, while PoANIS, less stabilised by the electron-rich HEC molecules, did not. Stabilised PANI-HEC synthesised at 0°C readily formed small fibres that, when deprotonated, displayed a large electrorheological response (yield stress ca. 800 Pa at 3.2 kV.mm−1). PoANIS prepared under the same conditions yielded a polydisperse cenospheric material with no ER activity.

Liquid Plasticine-Based Electrokinetic Enrichment of Proteins.

Protein analysis is an important approach for disease diagnosis, in which sample pretreatment is an essential step since protein samples are often complex and many protein biomarkers are of low abundance. Here, given the good openness and light transmission of liquid plasticine (LP), which is a liquid entity formed by SiO2 nanoparticles and encapsulated aqueous solution, we developed a LP-based field-amplified sample stacking (FASS) system for protein enrichment. The system was composed of a LP container, a sample solution and a Tris-HCl solution containing hydroxyethyl cellulose (HEC). The system design, mechanism investigation, optimization of experimental parameters and characterization of LP-FASS performance for protein enrichment were well studied. Under the optimized experimental conditions of 1 % HEC, 100 mm Tris-HCl and 100 V in the LP-FASS system, a 40-80 times enrichment of proteins was obtained in 40 min using bovine hemoglobin (BHb) as the model protein using the constructed LP-FASS system. The simultaneous enrichment of multiple proteins (phycocyanin, BHb and cytochrome C) was also realized using the system. The LP-FASS system can serve as a new platform for protein enrichment which is easy to be combined with online and offline detections.