Carboxymethyl Starch Research Articles

Synergistic effect and mechanism of stabilization of Pickering emulsion by carboxymethyl starch and xanthan gum

Pickering emulsions were prepared using different proportions of carboxymethyl starch (CMS) and xanthan gum (XG) combined systems as emulsifying stabilizers (The mass ratios of CMS and XG were 10:0, 9:1, 7:1, 5:1, 3:1 and 1:1, respectively). The synergistic mechanism between CMS and XG was also explored. The results demonstrated that CMS particles were uniformly and densely embedded in the gel-like structure formed by XG, and the electrostatic repulsion between CMS and XG led to a reduction in droplet size (from 3370 nm to 482 nm), resulting in a more compact and orderly droplet distribution. Combined systems of CMS and XG at different proportions enhanced the hardness (3.05–8.36 g), adhesiveness (3.26–8.41 g), and chewiness (4.05–8.20 g) of the emulsion. AFM observed that the emulsion particles were finer and more evenly dispersed. After heat treatment at 25 °C, 60 °C and 80 °C, the emulsion showed no significant stratification phenomenon, and CMS/XG enhanced the heat stability of the emulsion. LF-NMR confirmed that the oil and water could be evenly distributed and the emulsification of the system was complete. Especially when the ratio of CMS and XG was 3:1 and 1:1, the emulsion with a stable and long storage period could be obtained.

Surface Molding Hydrogel Film Initiated by ZIF-8 with Ethylene Adsorption Performance for Preserving Perishable Fruits.

The quality deterioration of postharvest fruits is greatly influenced by ethylene, leading to food wastage worldwide. Therefore, it is urgent to develop an efficient packaging strategy to reduce ethylene concentration and prolong the shelf life of perishable fruits. In this work, a surface-molding hydrogel film was created using ZIF-8 in combination with carboxymethyl starch (CMS) and carboxymethyl chitosan (CMCS). Specifically, ZIF-8 is first anchored on CMS and then rapidly cross-linked in situ with CMCS, forming ZIF-8@CC on the fruit surface (within 10 s). The perfect tight-fitting effects of ZIF-8@CC were observed on various fruit surfaces with different roughness (Ra: ranges from 102 to 308 nm). ZIF-8@CC could absorb 57.3% endogenous ethylene from bananas, and the interaction mechanism between ethylene and ZIF-8 was studied by molecular dynamics simulations, providing insights into the ethylene adsorption capacity of ZIF-8@CC. Moreover, ZIF-8@CC presented excellent antibacterial properties and achieved satisfactory ultralong preservation effects on both nonclimatic and climatic fruits (12 days for strawberries and 14 days for bananas) at room temperature. Importantly, ZIF-8@CC is easily removed, washed, and degradable. These findings offer an efficient and potential food packing material with multifunctional properties for preserving perishable fruits.

Copper-amino acid/Carboxymethyl starch composite for controllable releasing of povidone-iodine

Povidone-iodine is identified as one of the widely applicable antiseptic reagents for treatment of skin infection and wound healing. Controllable releasing of povidone-iodine is extensively required for healing of chronic wounds. The release of povidone-iodine was systematically studied from the composites based on carboxymethyl starch (CMS). Currently, different ratios from copper precursor and L-aspartic acid (L-AA) were interacted with CMS to obtain Cu-L-AA@CMS composites. Increment the percentage of L-AA was reflected in clustering of dense masses from the desirable composite with highly crystalline/stable structural network. Regardless to pH conditions, Cu-L-AA(30%)@CMS composite showed the highest efficiency for controllable release of povidone-iodine, whereas, the release percentages were estimated to be 58%, 32% and 18% at pH 5, 7 and 9, respectively. The kinetic results revealed the impossibility of povidone-iodine releasing via diffusion/erosion for further support of the hypothesis of releasing via swelling process. Moreover, the release of povidone-iodine using column technique showed that the lowest release was estimated at using high rate of 6 mL/min. Besides the biocompatibility and biodegradability of the prepared Cu-L-AA@CMS composites, it showed the superiority for controllable release of povidone-iodine antiseptic reagent to regulate its beneficial effect in curing of the skin.

Folic acid functionalized Ag@MOF(Ag) decorated carboxymethyl starch nanoparticles as a new doxorubicin delivery system with inherent antibacterial activity

Considering the benefits of controlled drug delivery in cancer treatment, as well as the importance of biological macromolecules in this area, herein, the pre-synthesized carboxymethyl starch (CMS) was converted to CMS nanoparticles (CMS NPs) in one easy nanoprecipitation way. Thereafter, the Ag@MOF(Ag) was in situ synthesized in the presence of pre-prepared CMS NPs (CMS NPs/Ag@MOF(Ag)). Eventually, the functionalization with folic acid (FA) obtained the CMS NPs/Ag@MOF(Ag)-FA. The success of the accomplished process was approved by doing several techniques, including FT-IR, XRD, EDX, AFM, etc. The SEM analysis showed a combination of rod-like and spherical-like morphology for the fabricated bio-nanocomposite. The generated CMS NPs/Ag@MOF(Ag)-FA with a surface area of 10.595 m2/g displayed a pore size of 13.666 nm and 82.99 % of doxorubicin (DOX) loading efficiency (DOX@CMS NPs/Ag@MOF(Ag)-FA). The 38.46 % and 58.19 % of loaded DOX were released respectively within 240 h at pH 7.4 and pH 5.0, referring to the pH-responsivity of the constructed system. 27.25 % of inhibitory effects on HeLa cells were obtained for the drug-loaded bio-nanocomposite. The CMS NPs/Ag@MOF(Ag)-FA also displayed an inherent antibacterial activity towards two common gram-negative and gram-positive bacteria. All of these results can contribute to developing polysaccharide-based porous systems in controlled cancer therapy.

Roles of Nitrogen- and Sulphur-Containing Groups in Copper Ion Adsorption by a Modified Chitosan Carboxymethyl Starch Polymer

Owing to the toxicity and widespread use of copper, the pollution caused by copper ions has become a long-standing environmental and industrial challenge. In this study, a new adsorbent was developed to dispose of and remove copper ions from water. The modified chitosan–carboxymethyl starch (MCTS-CMS) polymer was characterised, and FTIR and SEM-EDS confirmed the successful graft modification of the receptor. The adsorption behaviour was investigated through various parameters, and the results showed that the optimal parameters were pH > 4.0, an adsorption time of 30 min, a reaction temperature of 293 K, and an initial concentration of 100–120 mg/L. The experimental data exhibited a good fit with pseudo-second-order models, and the Langmuir isotherm revealed that the polymer was found to be highly suitable for adsorption, with a maximum adsorption capacity of 321.16 mg/g. Thermodynamic analysis revealed that the adsorption process was exothermic and spontaneous. XRD and XPS confirmed the generation of posnjakite after the adsorption and the predominant roles of nitrogen- and sulphur-containing groups in the adsorption. Further analysis confirmed the existence of chemisorption and physical adsorption, with chemisorption mainly facilitating the Cu(II) absorption of the polymer. MCTS-CMS showed an excellent removal efficiency of 98% in acidic solutions. On the basis of these findings, the MCTS-CMS polymer demonstrates excellent performance and high selectivity in the removal of copper ions from industrial wastewater or polluted water bodies. This work recommends expanding the polymer’s practical applications to contribute to water purification efforts.

Molecular weight-mediated interaction changes for enhancing structural stability, release behavior and M cells-targeting transport efficacy of starch-based nanoparticles

Molecular weight (Mw) of ligand-mediated nanocarriers plays a pivotal role in their architecture and properties. In this study, self-assembled ovalbumin (OVA)-loaded nanoparticles were meticulously engineered by starch polyelectrolytes with different Mw. Results unveiled that, tailoring Mw of GRGDS pentapeptides-grafted carboxymethyl starch (G-CMS) displayed strong binding-affinity and transport efficiency through microfold cells (M cells) pathway in the simulated intestinal epithelial cell monolayer in which M cells were randomly located in the Caco-2 cells monolayer. Notably, nanoparticles assembled from G-CMS with relatively higher Mw exhibited more compact structures due to the stronger interactions between layers compared to that with relatively lower Mw, which rendered remarkably stable and only 19.01 % in vitro OVA leakage under conditions of the upper gastrointestinal tract. Subsequently, more intact nanoparticles reached M cells after in vitro digestion and exhibited higher transport efficiency through the M cells pathways (apparent permeability: 9.38 × 10−5 cm/s) than Caco-2 cells, attributing to specific- and non-specific binding affinity towards M cells. Therefore, optimal Mw tailoring of starch polyelectrolytes can mediate the molecular interactions among their assembled layers and the interactions with M cells to balance the structural compactness, release and transport efficacy of nanoparticles, holding promise for advancing M cells-targeting oral delivery technologies.

Novel Flowable Hemostatic Agent ActiClot: Efficacy and Safety Assessment in Rat and Porcine Models.

Background/Objectives: This study evaluated the hemostatic performance and safety of ActiClot (ATC), a new flowable hemostatic agent, through in vivo tests. Methods: ATC was compared with the commercially available FLOSEAL®. ATC consists of carboxymethyl starch, thrombin, and sorbitol powders in Syringe I, and a calcium chloride solution in Syringe II. In vivo evaluation used rat liver bleeding and porcine heart bleeding models. Safety was assessed using a rat subcutaneous implantation model. Results: ATC significantly reduced hemostasis time (70.00 ± 7.35 s) compared to gauze control (240.63 ± 32.31 s) in the rat liver model, showing a 70% reduction. There was no significant difference between ATC and FLOSEAL® (58.75 ± 13.42 s). In the porcine heart model, both agents achieved 100% hemostasis within 3 min, with no significant difference in success rates within 2 min (ATC 87.5%, FLOSEAL® 75%). The gauze control group failed in all tests. The rat subcutaneous implantation model showed no visual ATC observation after 48 h, indicating biocompatibility, with no inflammation observed. Conclusions: ATC demonstrated effective hemostatic performance similar to FLOSEAL® in two in vivo models, with faster hemostasis in the rat liver model. It also showed excellent safety and biocompatibility, indicating its potential for surgical and emergency bleeding control.

The Effect of Fibrillation, Semi-Dry Pressing, and Surface Treatment on the Barrier Properties of Water Molecules and Oxygen on Food Packaging Paper.

The characteristics of fiber morphology and paper structure are critical to the barrier properties of food packaging paper. Herein, this study aimed to use pulp fibrillation, paper semi-dry pressing and carboxymethyl starch (CMS) coating to flatten the fibers, which were formed on the paper surface with good barrier properties due to the tight bond between fibers. The results showed that the permeability of paper was reduced by 87.56%, from 81.44 μm/Pa·s to 10.13 μm/Pa·s after the pulp fibrillation treatment (60 °SR). Moreover, semi-dry pressing treatment contributed to decreasing the water vapor transmission coefficient (WVP) by 50.98% to 2.74 × 10-10 g/m·s·Pa, and the oxygen permeation coefficient (OP) decreased by 98.04% to 1.93 × 10-14 cm3·cm/cm2·s·Pa. After coating the paper surface with titanium dioxide (TiO2) and CMS, the WVP of the paper was further reduced to 1.55 × 10-10 g/m·s·Pa, and OP was reduced to 0.19 × 10-14 cm3·cm/cm2·s·Pa. These values were 72.27% and 99.8% lower than those of the original paper, respectively. Therefore, through pulp fibrillation, semi-dry pressing of paper, TiO2 filling, and surface coating with CMS, there is no need to use synthetic polymer surface film-forming agents to achieve the high barrier properties that are required for low water and oxygen molecules permeation in food packaging paper.

Controlled curcumin delivery via carboxymethyl starch‐modified gamma alumina nanoparticles in a polyethylene glycol‐based hydrogel

AbstractOne of the most prevalent cancers affecting women globally is breast cancer. Consequently, the development of cost‐effective and low‐risk treatment options remains a critical pursuit. This study describes the synthesis via water‐in‐oil‐in‐water (W/O/W) of a pH‐responsive nanocarrier for curcumin delivery, a promising anticancer drug. The nanocarrier comprises carboxymethyl starch (CMS), polyethylene glycol (PEG), and gamma alumina (γ‐Al2O3) nanoparticles. The molecular interactions between the nanocomposite components, its crystalline structure, surface morphology, size distribution, and surface charge were assessed via Fourier‐transformed infrared (FTIR) spectroscopy, field emission‐scanning electron microscopy (FE‐SEM), x‐ray diffraction (XRD), dynamic light scattering (DLS) and zeta potential, respectively. The nanocarrier showed a size ranging from 150 to 280 nm, zeta potential of +35.4 mV, drug loading of 47% and an encapsulation efficiency of 87%, which are among the maximum values reported to date for curcumin nanocarriers. A gradual drug release was observed, with 51% and 90% released after 72 h at pH 7.4 and 5.4, respectively, which corroborates the pH‐sensitivity of the nanocarrier. The cytotoxic effects of the curcumin‐loaded nanocomposite on MCF‐7 breast cancer cells and normal cells were investigated using methylthiazolyldiphenyl‐tetrazolium bromide (MTT) assay and flow cytometry. The results demonstrated that loading curcumin onto the hydrogel significantly enhances its penetration into MCF‐7 cells. Overall, this novel nanocomposite offers a promising approach for curcumin delivery in breast cancer treatment.

Joint use of sodium silicate and polysaccharides in the flotation of talcose copper-nickel ores

The paper considers the combined effect of polysaccharides (carboxymethyl cellulose and carboxymethyl starch) with sodium silicate in the f lotation of talcose copper-nickel ore. The analysis of the f lotation results and the assessment of hydrophobicity and surface charge of minerals showed that the composition of carboxymethylated polysaccharides and sodium silicate hydrophilizes the talc surface more effectively than each of the reagents separately. Moreover, sodium silicate alone hardly depresses the talc surface at all. The depression of f lotation-active silicates is effective when polysaccharide and sodium silicate are sequentially supplied. Under these conditions, sodium silicate makes a significant contribution to increasing the negative charge on the talc particles surface. The effect is more pronounced for compositions with starch, characterized by a lower degree of substitution compared to cellulose. It results in a significantly reduced recovery of f lotation-active magnesium-containing silicates and a slight decrease in sulfide recovery. To determine the features of the mechanism of talc and sulfide minerals depression in f lotation, we performed calculations using the extended DLVO theory based on the obtained values of the zeta potential and force of detachment. We established that sulfide minerals have no potential barrier preventing their interaction with an air bubble, regardless of the compositions of the studied depressants used. We propose the following interaction mechanism: when sodium silicate is supplied first, the talc basal surface is very insignificantly hydrophilized as SiO(OH)– ions are not easy to fix. On the contrary, when the carboxymethylated polysaccharide is supplied first, significant hydrophilization of the talc surface with carboxyl groups occurs due to the hydrophobic interaction between the corresponding regions of the macromolecule and the talc basal surface.

Studies on the adsorption of aqueous cadmium and the treatment of mine tailings using anionic Type-C starch

Adsorption-based water treatment technology is a sustainable strategy for health and environmental wellness, as well as mineral recovery and resource conservation. Extended studies on the Cd2+ adsorption characteristics of the cross-linked/phosphorylated carboxymethyl starch (SCCS) derivatives produced by treating a Type-C starch with anionic precursors, including sodium trimetaphosphate (STMP) and sodium monochloroacetate (SMCA) were carried out. The optimum product was subjected to surface area studies using the Brunauer–Emmett–Teller (BET) method, and then Fourier transformed infrared (FTIR), scanning electron microscopy (SEM), and energy dispersive X-ray (EDX) before and after adsorption of Cd2+. The BET results showed that the derivative is mesoporous (pore size: 3.5–6.4 m3/g), while the FTIR results indicated that the adsorption of Cd2+ can be attributed to interactions with the hydroxyl, carbonyl, and phosphoryl functional groups on the SCCS platform. Adsorption equilibrium, kinetics, isotherms, thermodynamics, and recovery/regeneration were extensively studied using various models and experimental conditions. The results showed that Cd2+ was efficiently adsorbed (≈ 99%) at equilibrium, and the data fitness for multiple models indicated that the adsorption process is based on a combination of physisorption and chemisorption processes that are thermodynamically feasible and reversible for economic utilization of the adsorbent. The adsorbent was used in the treatment of mine tailing, and the result showed that the removal of minerals from the tailings was very efficient (≈ 100%).

The preparation of edible water-soluble films comprising κ-carrageenan/carboxymethyl starch/gum ghatti and their application in instant coffee powder packaging

This study successfully prepared an edible packaging film that rapidly dissolves in water by utilizing a combination of κ-carrageenan, carboxymethyl starch, and gum ghatti. We investigated the influence of these three materials on the microstructure and physical properties of the film, as well as the impact of the film's dissolution on the stability of beverages. SEM, FTIR, and XRD analyses revealed that the κ-carrageenan, carboxymethyl starch, and gum ghatti primarily interacted through hydrogen bonding, resulting in a more uniform and dense film structure. Surface hydrophilicity and swelling tests indicated an increased presence of hydrophilic groups in the composite film. The inclusion of carboxymethyl starch and gum ghatti significantly improves the film's physical properties, resulting in a notable reduction in water solubility time, an increase in elongation at break from 19.5 % to 26.0 %, a rise in the contact angle from 49.1° to 67.0°, and a decrease in water vapor permeability from 7.5 × 10–10 to 6.2 × 10–10 g/m·s·Pa. Furthermore, coffee packaging bags made from this composite film dissolved entirely in hot water in just 40 s. Dissolving these bags significantly improved the stability of instant coffee, reducing centrifugal sedimentation from 3.8 % to 1.7 %. This study highlights the substantial potential of the κ-carrageenan/carboxymethyl starch/gum ghatti composite film as a packaging material for solid beverages.

Selective depression of biodegradable talc depressant sodium carboxymethyl starch on molybdenite flotation with sodium diethyldithiocarbamate

The selective separation of molybdenite and talc is still a challenging problem owing to its excellent inherent hydrophobicity. In this study, sodium carboxymethyl starch was evaluated for the first time as a cost-effective talc depressant to achieve the molybdenite-talc separation with sodium diethyldithiocarbamate, a collector widely used to float sulfide minerals. The single-mineral and multi-mineral flotation tests witness carboxymethyl starch has shown a selective depression on talc and has little effect on molybdenite recovery with sodium diethyldithiocarbamate as a collector, terpineol as a frother and pH = 8 ± 0.5 (at an industrially relevant pH). Furthermore, experimental comparison of FTIR, equilibrium adsorption and XPS analysis demonstrate that the adsorption of sodium carboxymethyl starch on the talc surface can be considered to be irreversible under these conditions, and the higher adsorption density of sodium diethyldithiocarbamate on molybdenite over talc has highlighted the importance of differential adsorption density in the predictions of the efficient separation of molybdenite and talc. The innovative method may be applied efficiently in industrial applications to improve the comprehensive utilization of resources.

Synthesis of carboxymethyl starch co (polyacrylamide/ polyacrylic acid) hydrogel for removing methylene blue dye from aqueous solution

Natural polysaccharides, notably starch, have garnered attention for their accessibility, cost-effectiveness, and biodegradability. Modifying starch to carboxymethyl starch enhances its solubility, swelling capacity, and adsorption efficiency. This research examines the synthesis of an effective hydrogel adsorbent based on carboxymethyl starch for the elimination of methylene blue from aqueous solutions. The hydrogel was synthesized using polyacrylamide and polyacrylic acid as monomers, ammonium persulfate as the initiator, and N,N′-methylenebisacrylamide as the cross-linker. Through FESEM, swelling morphology was evaluated in both distilled water and methylene blue dye. The adsorption data elucidated that the adsorption capacity of the hydrogel significantly depends on the dosage of the adsorbent, pH, and concentration of the MB dye. At a pH of 7 and a dye concentration of 250 mg/L, the hydrogel exhibited an impressive 95 % removal rate for methylene blue. The results indicate that the adsorption process follows pseudo-second-order kinetics and conforms well to the Langmuir adsorption isotherm, indicating a maximum adsorption capacity of 1700 mg/g. According to the pseudo-second-order kinetic model and FTIR analysis, methylene blue chemisorbs to the adsorbent material. Hydrogel absorbents regulate adsorption through both intra-particle diffusion and liquid film diffusion. These results highlight the potential of the new hydrogel absorber for water purification.

Facilitating safe and sustained submucosal lift through an endoscopically injectable shear-thinning carboxymethyl starch sodium hydrogel

Traditional submucosal filling materials frequently show insufficient lifting height and duration during clinical procedures. Here, the anionic polysaccharide polymer sodium carboxymethyl starch and cationic Laponite to prepare a hydrogel with excellent shear-thinning ability through physical cross-linking, so that it can achieve continuous improvement of the mucosal cushion through endoscopic injection. The results showed that the hydrogel (56.54 kPa) had a lower injection pressure compared to MucoUp (68.56 kPa). The height of submucosal lifting height produced by hydrogel was higher than MucoUp, and the height maintenance ability after 2 h was 3.20 times that of MucoUp. At the same time, the hydrogel also showed satisfactory degradability and biosafety, completely degrading within 200 h. The hemolysis rate is as low as 0.76 %, and the cell survival rate > 80 %. Subcutaneous implantation experiments confirmed that the hydrogel showed no obvious systemic toxicity. Animal experiments clearly demonstrated the in vivo feasibility of using hydrogels for submucosal uplift. Furthermore, successful endoscopic submucosal dissection was executed on a live pig stomach, affirming the capacity of hydrogel to safely and effectively facilitate submucosal dissection and mitigate adverse events, such as bleeding. These results indicate that shear-thinning hydrogels have a wide range applications as submucosal injection materials.

Comparative Study of the Performance of Underwater Concrete between Anionic and Nonionic Anti-Washout Admixtures

An investigation was carried out to study the influence of two types of anti-washout admixtures (AWAs) on the performance of underwater concrete, specifically, workability and washout resistance. The tested AWAs were hydroxypropyl methylcellulose (HPMC) and polyacrylamide (PAM) as nonionic AWAs and carboxymethyl starch (CMS) and polyanionic cellulose (PAC) as anionic AWAs. Rheological properties (slump and slump flow), washout resistance, and compressive strength were measured to evaluate the properties of the fresh and hardened concrete. The results indicate that anionic AWAs are more effective at improving workability and strength than nonionic AWAs in anti-washout underwater concrete. When the nonionic AWA dosage exceeded 0.3% (W/C = 0.45), the fluidity and air content were negatively impacted. Additionally, nonionic AWAs more readily alter the morphological structure of cement paste, affecting cement particle hydration and underwater concrete properties. Regarding the mechanical properties, compared with those of concrete without AWAs and with nonionic AWAs, the 28-day compressive strength of concrete with anionic AWAs reached 37 MPa, an increase of 151% and 131%, respectively. Compared with nonionic AWAs, concrete with anionic AWAs is more stable.

Nitrogen, fluorine and boron tri-doped flower-like porous carbon derived from sodium carboxymethyl starch for high-performance supercapacitors

In this work, nitrogen, fluorine, and boron tri-doped flower-like porous carbons were prepared from sodium carboxymethyl starch (CMS) by using potassium hydroxide (KOH) as an activator and ammonium borofluoride (NH4FB4) as a heteroatomic dopant. The specific surface area (SBET), total pore volume (Vt), pore size distribution (PSD), heteroatom content and electrochemical performance of the samples were directly determined by the KOH content. The optimized material (CMS-F/B/N-4) showed a flower-like porous structure with a large SBET (666 m2 g−1) and an appreciable amount of heteroatoms (oxygen: 8.01 at.%, nitrogen: 1.56 at.%, fluorine: 2.22 at.% and boron: 0.75 at.%). Owing to these merits, the supercapacitor based on CMS-F/B/N-4 displayed a maximum specific capacitance (Cg) of 219.2 F g−1 at 1 A g−1 and a high performance, with more than 72.5% of initial capacitance was retained when the current density was increased from 1 to 10 A g−1. In addition, a symmetric cell was assembled with a wide voltage range of 2.0 in 1 M Na2SO4 aqueous electrolyte, delivering a relatively high energy density of 26.47 Wh kg−1 at 500 W kg−1 and stable performance of ∼99% retention after 10,000 cycles. This study demonstrated the feasibility of fabricating porous carbon with specific morphology and heteroatom doping from natural polysaccharide polymers. The findings indicate an avenue toward practical applications of carbon-based supercapacitors.

Effects of carboxymethyl starch as a papermaking additive

Carboxymethyl starch (CMS) is a bio-based, anionic polymer that has potential as part of a dry-strength additive program for papermaking. Due to its negative charge, its effects can be expected to depend on its interactions with various cationic agents. In this work, the effects of CMS were observed following its sequential addition after one of three selected cationic strength agents at different dosage levels. In selected tests, the furnish was pretreated at the 1% level by a dispersant, sodium polyacrylate, which might represent a high level of anionic contaminants in a paper mill system. Laboratory tests were conducted to show the effects on dewatering, fine-particle retention, and flocculation. These tests were supplemented with measurements of charge demand, zeta potential, and handsheet properties. Sequential addition of cationic glyoxylated acrylamide copolymers (gPAM) and CMS were found to strongly promote dewatering. Two gPAM products and a poly(vinylamine) product in sequential addition with CMS were very effective for promoting fine-particle retention. These same sequential treatments of the stock contributed to moderate fiber flocculation, though severe flocculation was caused by further treatment of the furnish with colloidal silica. Handsheet strength results were mixed. In the default recycled copy paper furnish, the average breaking length for the sheets made with cationic additives followed by CMS was not greatly different from the blank condition. Superior strength resulted when the default furnish was treated with a dispersant alone. When the dispersant-contaminated furnish was treated with the same combinations of cationic additives and CMS, the strength returned to the baseline achieved in the absence of the dispersant. The results were discussed in terms of the charged character of the different additives and their interactions not only with the fiber surfaces but also with each other.

Improving the structural, optical, and electrical properties of carboxymethyl cellulose/starch/selenium oxide nanocomposites for flexible electronic devices

Nanocomposites based on biopolymers are interesting materials owing to their multifunctionality and ease of preparation. In this study, the solution casting method was used to mix selenium oxide nanoparticles (SeO2 NP) made by a solvothermal method into a bio-blend of carboxymethyl cellulose and starch (CMC/St). XRD analysis showed that SeO2 NP increased the amorphous portion inside the blend. HR-TEM revealed the spherical morphology of these NP with an average diameter of 16.88 nm. The FE-SEM indicated a satisfactory uniform distribution and homogeneity in the surface morphology of the films. FTIR confirmed the interaction between SeO2 and the blend functional groups. The films preserved good transmission after doping, and their direct and indirect band gaps decreased. The refractive index, absorption index, optical conductivity, and other dispersion parameters were improved after SeO2 loading. The DC conductivity of the blend is in the range of 3.8 × 10−7 to 5.6 × 10−4 S/m and improved after loading SeO2 NP. The IV characteristic curves in the temperature range of 300–415 K were studied to figure out the conduction mechanism in the CMC/St/SeO2 composites. Because the optical and electrical properties improved, these nanocomposites could be used for coatings and other things like waveguides, photovoltaic cells, and light-emitting diodes.

Fabrication and characterization of complex coacervates utilizing gelatin and carboxymethyl starch.

Modified polysaccharides have greatly expanded applications in comparison with native polysaccharides due to their improved compatibility and interactions with proteins and active compounds in food-related areas. Nonetheless, there is a noticeable dearth of research concerning the utilization of carboxymethyl starch (CMS) as a microcapsule wall material in food processing, despite its common use in pharmaceutical delivery. The development of an economical and safe embedding carrier using CMS and gelatin (GE) holds immense importance within the food-processing industry. In this work, the potential of innovative coacervates formed by the combination of GE and CMS as a reliable, stable, and biodegradable embedding carrier is evaluated by turbidity measurements, thermogravimetric analysis (TGA), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and rheological measurements. The results indicate that GE-CMS coacervates primarily resulted from electrostatic interactions and hydrogen bonding. The optimal coacervation was observed at pH 4.6 and with a GE/CMS blend ratio of 3:1 (w/w). However, the addition of NaCl reduced coacervation and made it less sensitive to temperature changes (35-55 °C). In comparison with individual GE or CMS, the coacervates exhibited higher thermal stability, as shown by TGA. X-ray diffraction analysis shows that the GE-CMS coacervates maintained an amorphous structure. Rheological testing reveals that the GE-CMS coacervates exhibited shear-thinning behavior and gel-like properties. Overall, attaining electroneutrality in the mixture boosts the formation of a denser structure and enhances rheological properties, leading to promising applications in food, biomaterials, cosmetics, and pharmaceutical products. © 2023 Society of Chemical Industry.