Structure Of Carboxymethyl Cellulose Research Articles

Binder-enhanced reversible photochromic films by tungsten oxide hybrid composites for advanced applications

In this study, we developed binder-enhanced reversible photochromic tungsten oxide (WO3) films for advanced applications. Expanding on previous research, we used tungsten oxide hybrid composites as the base material and incorporated various binders, specifically polyethylene glycol (PEG), polysorbate 80 (PS 80), and carboxymethyl cellulose (CMC), to evaluate their effects on reversible photochromic reactions. Our experiments demonstrated that the inclusion of CMC significantly improved the photochromic properties and exhibited the fastest reversible reactions when compared to PEG and polysorbate 80. This enhancement is attributed to the high density of hydroxyl groups and the network structure of CMC, which facilitate efficient proton transfer and oxygen permeability, both crucial for the reoxidation process in WO3. Density functional theory (DFT) calculations supported these findings by indicating that CMC has a suitable bandgap and electron mobility, which enhance charge injection and transport. Additionally, the fabricated films showed consistent and stable performance under both heat treatment and natural ambient conditions. These results underscore the potential of CMC as an effective binder for developing high-performance, reversible photochromic films suitable for applications in smart windows, displays, and optoelectronic devices.

Modeling and investigation of swelling kinetics of sodium carboxymethyl cellulose/starch/citric acid superabsorbent polymer

Crosslinked hydrophilic polymers with high water absorption rates are known as superabsorbent polymers (SAPs). Most commercial superabsorbent polymers are made with acrylic acid, which is difficult to biodegrade. So, in this investigation, carboxymethyl cellulose (CMC) was utilized as a significant component in the synthesis of polysaccharide-based SAPs. Citric acid (CA) and starch were chosen as crosslinking agents because they are more eco-friendly, non-toxic, and biodegradable than traditional crosslinking agents. FTIR analysis revealed that the superabsorbent polymer product contains a crosslinked structure of CMC and starch with side chains that carry carboxylate functional groups. Superabsorbent weight loss and grafting data were satisfactorily studied using the TGA approach. Under optimum circumstances, the SAP2 water absorbency capacity in distilled water was 287.37 g.g−1 and SAP1 absorbency capacity in a solution containing 0.9 wt% NaCl was 52.18 g.g−1. Moreover, Schott's pseudo-second-order model was used to determine the kinetic swelling of the superabsorbent. The initial swelling rate of SAPs can be calculated using the Q∞ data acquired in the following order: SAP2 > SAP1 > SAP3 > SAP4 in distilled water and SAP1 > SAP2 > SAP3 > SAP4 in 0.9 wt% NaCl solution, respectively. The findings suggested that a small amount of citric acid introduced into the SAPs matrix could enhance the swelling rate of SAPs. The results of the cytotoxicity tests show that the extraction liquid of composite hydrogel fibers is less cytotoxic than the positive control. As well, SAP underwent in silico docking investigations on the DNA Gyrase enzyme. As the ligand is a monomer of SAP, it was a long chain of carbohydrate molecules with alcoholic groups, esters groups, and keto groups forms a strong binding interaction with DNA gyrase.

Flexible Au@AgNRs/CMC/qPCR film with enhanced sensitivity, homogeneity and stability for in-situ extraction and SERS detection of thiabendazole on fruits

In this study, a high-performance, stable and homogeneous Au@AgNRs/CMC/qPCR flexible film surface-enhanced Raman scattering (SERS) substrate was constructed by synergistically stabilizing and protecting bimetallic core–shell Au@Ag nanorods (Au@AgNRs) with carboxymethylcellulose (CMC) and fluorescent-quantitative-polymerase-chain-reaction (qPCR) film. The network structure of CMC immobilized and aligned Au@AgNRs through coordination of carboxyl groups with surface Ag atoms to provide intensive and stable ‘hot spots’, and the qPCR bilayer film performed as carrier and barrier to protect Au@AgNRs from oxidation, humidity and optical damage and improved the robustness and stability. The Au@AgNRs/CMC/qPCR film was used for in-situ extraction and SERS detection of thiabendazole on nectarine (0.24 ppm) and lemon (0.27 ppm) with low detection of limits. Furthermore, it retained 98.6% SERS performance after storage for 90 days under ambient conditions, revealing the great potential in promoting the commercialization of the SERS technique for sensitive contaminants sensing with simple fabrication procedures, homogeneity, reproducibility and long-term stability.

Application of Spectroscopy to Analyze the Degree of Substitution of Carboxymethyl Cellulose

In this study, the degree of substitution of CMC (carboxymethyl cellulose) was calculated through a titration method, and the data were compared with the measured value of the degree of substitution measured by EDS (energy dispersive X-ray spectroscopy) and the degree of substitution measured by IR (Infrared spectroscopy), and the correlation was analyzed to calculate the degree of substitution of CMC more conveniently. In addition, by identifying the chemical properties of CMC according to the degree of substitution, we tried to provide basic data for the application of CMC in the future. When the degree of substitution of CMC analyzed through EDS analysis was compared with the result of the degree of substitution by the titration method, it was confirmed to have relatively high accuracy, but expensive equipment and remaining NaCl may affect the result. So, it was judged that commercialization may be somewhat difficult. It was easier to analyze the degree of substitution through IR analysis, and more accurate results could be expected than analysis through EDS. Using the Savitzky-Golay algorithm and PCA (principal component analysis), it was possible to identify CMC’s chemical properties and analyze classification according to the degree of substitution. Therefore, it is believed that the application of IR when analyzing the degree of substitution of CMC will simplify the investigation of the relationship between the structure, physical properties, and applications of CMC in the future.

Carboxymethyl cellulose-polyvinyl alcohol based materials: A review

Carboxymethyl cellulose (CMC) - Polyvinyl alcohol (PVA) based materials have gained popularity over the years due to ease in synthesis and surface modifications coupled with diverse morphological features. CMC, a cellulose derivative, possesses high viscosity, film-forming ability, biodegradability and cytocompatibility and is a well-known biopolymer with wide abundance in nature. A remarkable improvement in the mechanical strength, thermal stability and flexibility of the polymeric structure of CMC is observed when it is cross-linked with hydrophilic biopolymer PVA. It is a synthetic polymer synthesized via partially or completely hydroxylating vinyl acetate. This review article evaluates various properties and applications of different types of CMC-PVA-based materials (hydrogels, beads, scaffolds, etc.) in agriculture, biomedical, environmental and food packaging.

Nacre-inspired composite film with mechanical robustness for highly efficient actuator powered by humidity gradients

Exploring and fabricating smart actuating materials that strike the perfect balance between humidity response and mechanical integrity (especially wet tensile strength) via reasonable structural design and simple yet low-cost preparation is critical for biomimetic devices, soft robotics, artificial muscles and generators, but it remains challenging. Herein, inspired by the structure of natural nacre, we demonstrated a robust yet highly sensitive composite film-based humidity actuator composed of carboxymethyl cellulose (CMC), MXene nanosheets, and multivalent aluminum ions (Al3+) via a facile evaporation-induced self-assembly method. The synergistic reinforcing effects of MXene nanosheets and Al3+ through hydrogen and ionic bonding as well as the densely hierarchical microstructure endow the composite film with both an ultrahigh mechanical strength (273.6 MPa), a desirable toughness (7.95 MJ/m3) and even an impressive wet tensile strength (154.2 MPa) at 97 % humidity. Interestingly, the unique laminated structure and water-induced swelling effect of CMC and MXene synergistically enable the composite film with large shape deformation, sensitive actuation (less than 2.3 s) and exceptional cycling stability (over 1500 cycles) upon exposure to humidity gradients. Based on the above merits, the composite film actuator can be well constructed to simulate a flying dragonfly, human finger, artificial muscle, and has also been preliminarily employed as a moist-electric generator, which provides new insight for designing comprehensive composite film-based actuators and reveals their extensive applications.

PLASTICIZED CMC-AMMONIUM ACETATE BASED SOLID BIOPOLYMER ELECTROLYTE: IONIC CONDUCTIVITY AND TRANSPORT STUDY

In this work, a plasticised carboxymethyl cellulose (CMC) solid biopolymer electrolytes (PSBEs) system was prepared via solution casting technique with ammonium acetate (NH4CH3COO), ethylene glycol (EG) as doping salt and plasticiser respectively. Upon addition of 35 wt.% of EG (PSBE 4), the ionic conductivity obtained is 1.81 × 10-5 Scm-1 which represents the optimum value for the system. The PSBE also tested at elevated temperatures and fitted to an Arrhenius equation. Fourier Transform Infrared Spectroscopy (FTIR) analysis found no significant changes to the molecular structure of CMC with addition of EG. Jonscher’s power law indicates that quantum tunnelling is the well-matched model to describe ionic conduction for PSBE 4 and it appears that it is also highly ionic with good transference number obtain from dc polarisation analysis technique.

Calcium Ion-Induced Structural Changes in Carboxymethylcellulose Solutions and Their Effects on Adsorption on Cellulose Surfaces.

The adsorption of carboxymethylcellulose (CMC) on cellulose surfaces is one of the most studied examples of the adsorption of an anionic polyelectrolyte on a like-charged surface. It has been suggested that divalent ions can act as a bridge between CMC chains and the surface of cellulose and enhance the CMC adsorption: they can, however, also alter the structure of CMCs in the solution. In previous investigations, the influence of cations on solution properties has been largely overlooked. This study investigates the effect of Ca2+ ions on the properties of CMC solutions as well as the influence on cellulose nanofibers (CNFs), which was studied by dynamic light scattering and correlated with the adsorption of CMC on a cellulose surface probed using QCM-D. The presence of Ca2+ facilitated the multichain association of CMC chains and increased the hydrodynamic diameter. This suggests that the adsorption of CMCs at high concentrations of CaCl2 is governed mainly by changes in solution properties rather than by changes in the cellulose surface. Furthermore, an entropy-driven mechanism has been suggested for the adsorption of CMC on cellulose. By comparing the adsorption of CMC from H2O and D2O, it was found that the release of water from the cellulose surface is driving the adsorption of CMC.

Strong influence of degree of substitution on carboxymethyl cellulose stabilized sulfidated nanoscale zero-valent iron

Carboxymethyl cellulose (CMC) has been widely adopted as stabilizer to enhance the subsurface mobility of nanoscale zerovalent iron (nZVI). However, CMC surface modification also cause severe decrease of the longevity and electron utilization efficiency (εe) of nZVI, which is still not well understood. In this study, we demonstrate the negative influence of CMC on the properties of sulfidated nZVI (S-nZVI) could be reversed by increasing the degree of substitution (D.S.) of CMC. Consistent with previous study, the sample CMC-S-nZVI prepared with commercial CMC with degree of substitution (D.S.) of 0.75 exhibited a considerable low longevity of 33 days with εe of 4.5%, much lower than that of sulfidated nZVI (S-nZVI, 113 days and 13%). In sharp contrast, the sample HCMC-S-nZVI synthesized with CMC with super high D.S. of 1.76 demonstrated significantly enhanced longevity of 139 days and εe of 20%. The enhancement was attributed to compatible molecular structure of CMC with super high D.S. Moreover, the HCMC-S-nZVI also exhibited higher mobility in porous media than CMC-S-nZVI. Our work provides a feasible way to prepare S-nZVI with desired properties including high subsurface transportability, high longevity and high εe.

Facile In Situ Cross-Linked Robust Three-Dimensional Binder for High-Performance SiOx Anodes in Lithium-Ion Batteries.

Silicon oxide (SiOx, 0 < x < 2) is considered one of the most promising anode materials for next-generation lithium-ion batteries due to its high theoretical capacity. However, its commercial application is limited by the non-negligible volume change during cycling. Herein, a three-dimensional (3D) structure of carboxymethyl cellulose (CMC) cross-linked with iminodiacetic (c-CMC-IDA150) was facilely formed through in situ thermal cross-linking of CMC and iminodiacetic acid (IDA) in the fabrication process of the electrode, which could construct a robust network to restrain the volume change of the SiOx anode and maintain the integrity of the electrode. In addition, the 3D cross-linked c-CMC-IDA150 provides sufficient contact sites to improve the adhesive strength. Thus, SiOx@c-CMC-IDA150 shows a prolonged cycle life, achieving a capacity of 1020 mAh g-1 after 100 cycles at a current density of 0.2 A g-1. With the increase in the current density to 1.0 A g-1, SiOx@c-CMC-IDA150 exhibits a reversible capacity of 899 mAh g-1 after 200 cycles with a capacity retention of 70.2%. This work provides a potential perspective to fabricate high-performance SiOx anodes and promote the stability of high-capacity Si-based anodes.

Corn starch reactive blending with latex from natural rubber using Na+ ions augmented carboxymethyl cellulose as a crosslinking agent

A mixture of corn starch and glycerol plasticizer (CSG) was blended with latex natural rubber (LNR) and carboxymethyl cellulose (CMC). The addition of 10 phr of CMC improved the Young’s modulus (6.7 MPa), tensile strength (8 MPa), and elongation at break (80%) of the CSG/LNR blend. The morphology of the CSG/LNR/CMC blends showed a uniform distribution of LNR particles (1–3 µm) in the CSG matrix. The addition of CMC enhanced the swelling ability and water droplet contact angle of the blends owing to the swelling properties, interfacial crosslinking, and amphiphilic structure of CMC. Fourier transform infrared spectroscopy confirmed the reaction between the C=C bond of LNR and the carboxyl groups (–COO−) of CMC, in which the Na+ ions in CMC acted as a catalyst. Notably, the mechanical properties of the CSG/LNR/CMC blend were improved owing to the miscibility of CSG/CMC and the CMC/LNR interfacial reaction. The CSG/LNR/CMC biodegradable polymer with high mechanical properties and interfacial tension can be used for packaging, agriculture, and medical applications.

Controllable preparation of carboxymethyl cellulose/LaF3:Eu3+ composites and its application in anti-counterfeiting

In this experiment, sodium carboxymethyl cellulose (CMC) was used as raw material, rare earth chloride was used as inorganic nano luminescent material to prepare a series of lanthanide rare earth ions-doped composite materials. The photoluminescent materials were prepared via in-situ chemical deposition of rare earth ions onto CMC surface with the help of carboxyl groups contained on the surface of CMC. The structure, fluorescence properties, surface morphology, surface elements, crystalline structure and thermal stability of CMC before and after surface modification were characterized by FT-IR spectra (FTIR), photoluminescence spectra (PL), field emission scanning electron microscope (FESEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and thermal gravimetric analyses (TGA), respectively. The results showed that CMC/LaF3:Eu3+ composites were successfully prepared, and the fluorescence intensity can be organically controlled by the reaction temperature, doping ratio and doping concentration of rare earth ions. The method has mild reaction conditions, facile process without expensive material equipment. Moreover, the as-prepared transparent anti-counterfeiting film possessed good fluorescence intensity, transparency and excellent mechanical properties, which can be used for large-scale functional packaging films.

Synthesis and structure of carboxymethylcellulose with a high degree of substitution derived from waste disposable paper cups

The cost of the cellulose derived from some raw materials was high. In addition, the dispersion of the cellulose with special shape and a low degree of substitution (DS) in water-soluble polymers was poor. To resolve this problem, cellulose was separated from waste disposable paper cups (WDPC) and then the carboxymethylcellulose (CMC) was synthesized by etherification. Under the optimized conditions (the etherification temperature of 70 ℃, the etherification time of 1.5 h, the monochloroacetic acid mass (C2H3ClO2) of 7 g), the DS of CMC was as high as 1.21. As-prepared CMC showed ribbon and rod-like shapes with a diameter of 25−50 μm. In addition, they exhibited an excellent thermal stability. Compared with other CMC, we could infer that as-prepared CMC in this paper will have potential applications in flexible composites and functional materials.

Exploring the properties of hemicellulose based carboxymethyl cellulose film as a potential green packaging

The performance of hemicellulose based carboxymethyl cellulose (H-CMC) films was investigated. Hemicellulose was extracted from oil palm empty fruit bunch (OPEFB) through alkali-ethanol extraction technique. Then the obtained hemicellulose was mixed with distilled water and embedded with carboxymethyl cellulose (CMC) at different hemicellulose loadings (20, 40, 60, and 80 wt %). Solution casting method was applied to produce H-CMC films within the thickness range (0.076–0.12 mm). The prepared films were characterized using tensile test, fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). Glass transition temperature (Tg) of H-CMC films has increased with hemicellulose content. According to mechanical properties, optimum performance has given by the film having 60 wt% of hemicellulose. FTIR spectroscopy confirms that the chemical structure of CMC has not been altered by the addition of hemicellulose. TGA and DSC curves represent that the thermal stability of pure CMC has increased with the added hemicellulose content. Surface morphology becomes rough when the hemicellulose loading is increased excessively (80 wt%). As per the overall result, 60 wt% of hemicellulose can be identified as the optimum loading into CMC as a potential material for green packaging applications. Further the research aimed to develop the film structure by incorporating functional materials for future intended applications such as electrically conductive and photocatalytic thin films.

Influence of wood pulp quality on the structure of carboxymethyl cellulose

ABSTRACTThe quality of carboxymethyl cellulose (CMC) prepared from different wood‐derived market pulps is examined. The pulps represent kraft and sulfite qualities with different levels of hemicellulose (1.5–22.8 wt %), intrinsic viscosity (391–780 mL g−1), and content of extractives (0.04–0.13 wt %). The pulps are carboxymethylated in aqueous medium at three different levels of sodium hydroxide concentration, resulting in three levels of degree of substitution (DS), 0.3, 0.7–0.8, and 1.3–1.4 (according to nuclear magnetic resonance spectroscopy and high‐performance liquid chromatography). CMC with DS 0.7–0.8 is found to be near the limit for water solubility and the resulting ranking for that solubility is shown to be correlated to DS. The DS is found to be impaired by a high content of impurities and high degree of Cellulose II in the pulp. The sulfite pulps yield CMC with the best solubility in water. A high level of extractives does not interfere with reactivity. Moreover, it is found that impurities, such as lignin and xylan, inhibit thickening behavior even at high DS, and that the ratio of substitution on Position 3 is a measure of the xylan content, which suggests that this position in xylan has extremely high reactivity. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47862.

Depolymerization of carboxymethyl cellulose using hydrodynamic cavitation combined with ultraviolet irradiation and potassium persulfate

In the present work, hydrodynamic cavitation (HC) has been used for the depolymerization of sodium salt of carboxymethyl cellulose (CMC) solution. Use of two different cavitating devices as slit and circular venturi has been investigated along with the combination of HC with potassium persulfate (KPS) and ultraviolet (UV) irradiation for understanding the process intensification benefits. The effect of operating parameters as inlet pressure (HC) and power dissipation (UV based treatment) on the degree of polymerization has been studied initially. The combined approaches of HC + UV, HC + KPS and HC + UV + KPS have been then investigated under optimized conditions of pressure and power dissipation. Depolymerization was favored in the case of slit venturi in HC and at higher power dissipation for UV based approach as well as at higher KPS loading for the combined approach of HC + KPS. For the combined approach of HC + UV + KPS, maximum viscosity reduction obtained was 75% under the optimized conditions (slit venturi, 3 bar as the pressure, 8 W as UV power and KPS loading of 0.4 g/L) in 180 min of treatment. The chemical structure of the native CMC and processed CMC using all approaches was analyzed using FTIR spectra and it was clearly established that any significant changes in the chemical structure are not observed.

Bead Gel sebagai Controlled Release Urea : Pengaruh Konsentrasi Crosslinker Glutaraldehid

The structure of carboxymethylcellulose (CMC)-carrageenan mixture was chemically modified using glutaraldehyde in order to prepare bead hydrogel form. The obtained beads gel were applied to control the urea release rate. The aim of this research was to compose mathematical model describing the mass transfer rate of urea release and determine the effect of concentration glutaraldehid on the bead gel endurance in water as medium release. The bead gels (CMC/carrageenan mass ratio =1 and 2) were physic crosslinked with CaCl 2 solution and then followed by chemically crosslinked with glutaraldehyde solution (4% & 1%) using immersion method and thermal curing at 110 o C for 25 minutes. After being washed and dried, the beads gel were immersed in urea solution. The rate release of urea from dried crosslinked beads gel in water was determined by measuring the concentration of urea in various time of immersion. The result showed that the mathematical model arranged could describe the mass transfer rate of urea release. The higher glutaraldehid concentration on beads gel, the higher beads gel endurance in water.

Gelation mechanism of organic additives with LiFePO4 in the water-based cathode slurries

Carboxymethyl cellulose (CMC) is a commonly used thickening agent for water-based lithium (Li) ion batteries. Addition of CMC improves the electrochemical properties of most electrodes but excessive amounts may cause the corresponding electrode slurries to gel, making it unfavorable for casting. This study investigates the gelation mechanism of CMC with the popular active cathode material lithium iron phosphate (LiFePO4) in a water-based slurry. Since there are two main types of functional groups, carboxyl (–COOH) and hydroxyl (–OH), in the chemical structure of CMC, it is essential to clarify which functional group determines the gelation of the slurry. On comparing the experimental results obtained by substituting CMC with poly(vinyl alcohol) that carries merely the –OH group and poly(acrylic acid) that carries merely the –COOH group, it is evident that the –OH rather than the –COOH group causes the cathode slurry to gel. In addition, the gelation between CMC and LiFePO4 is more significant when the surface carbon on the LiFePO4 particles has more chemical defects. Contrary to the thickening agent containing the –OH group, that containing the –COOH group helps in the dispersion of the cathode materials in the aqueous slurry. The electrochemical results show that the improved dispersion of electrode slurries leads to better cell performance of Li-ion batteries.

Synthesis and grafting of carboxymethyl cellulose from environmental pollutant cellulosic wastes of textile industry

Purpose This study aims to explore the use of knitted rag by synthesizing different grades of carboxymethyl cellulose (CMC) by applying multiple-step carboxymethylation techniques. Design/methodology/approach CMC was synthesized from knitted rag, a cellulosic waste of textile and garment industries, in aqueous ethanolic sodium hydroxide and subsequently mono-chloroacetic acid reaction medium. Low-substituted to high-substituted products were obtained from single-step to seven-step carboxymethylation of cellulose. In this way, it was possible to produce low-cost and different grades of substituted carboxymethylated cellulose. The synthesized CMC was characterized, and their physical properties were investigated. The structure of CMC and grafted CMC were investigated by Fourier transform infrared spectroscopy. Findings Solubility, CMC content, degree of substitution and molecular weight of CMC were increased gradually with the increase in the number of reaction steps, although fourth step attained the optimum. The cellulosic waste of knitted rag can easily be used to produce value-added products such as CMC and other cellulose derivatives, and that will ultimately reduce the pollution problems from this waste. Originality/value Grafting of prepared CMC film with methyl methacrylate monomer increased their strength, although decreased rigidity and moisture content because the incorporation of hydrophobic methyl methacrylate monomer was observed.

Thermal stability enhancement of modified carboxymethyl cellulose films using SnO2 nanoparticles

In this study, in-situ and ex-situ hydrothermal synthesis procedures were applied to synthesize novel CMC/porous SnO2 nanocomposites from rice husk extracted carboxymethyl cellulose (CMC) biopolymer. In addition, the effects of SnO2 nanoparticles on thermal stability of the prepared nanocomposite were specifically studied. Products were investigated in terms of morphology, particle size, chemical structure, crystallinity and thermal stability by using field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA), respectively. Presence of characteristic bands in the FTIR spectra of samples confirmed the successful formation of CMC and CMC/SnO2 nanocomposites. In addition, FESEM images revealed four different morphologies of porous SnO2 nanoparticles including nanospheres, microcubes, nanoflowers and olive-like nanoparticles with hollow cores which were formed on CMC. These nanoparticles possessed d-spacing values of 3.35ÿ. Thermal stability measurements revealed that introduction of SnO2 nanoparticles in the structure of CMC enhanced stability of CMC to 85%.