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Effect of CMS dosage on removal rate 4. Conclusions Cross-linked carboxymethyl starch CMS was synthesized with cross-linked starch as raw material, sodium chloroacetate as etherification agent and sodium hydroxide as catalyst. The optimum synthesis conditions of CMS were m (CSt): m (MCA) = 5:3, NaOH dosage 12 ml, reaction temperature 55 o C, reaction time 3 h. When the concentration of copper ion in the simulated water sample was 25 mg/L and the dosage of CMS was 2 g/L, the removal rate of copper ion was 96.0%, and the adsorption capacity of CMS was 15.4 mg/g.
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Cross-linked carboxymethyl starch CMS was synthesized with cross-linked starch as raw material, sodium chloroacetate as etherification agent and sodium hydroxide as catalyst, and the structure of the product was characterized by FTIR, SEM and XRD. The optimum synthesis conditions of CMS were m (CSt): m (MCA) = 5:3, NaOH dosage 12 ml, reaction tempe...
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Citations
... Recently, the starch based graft copolymer flocculants has been widely utilized in water treatment industry [15][16][17][18][19]. Nonetheless, the application of these native starch graft copolymers for effluent treatment often brings forth some new problems related to their poor transparency and solubility (not cold water soluble, and need to be heated before use), including rising cost pressures and larger workload. One solution is to use carboxymethyl starch (CMS), an important water-soluble ether derivative of starch, as grafting skeleton for preparing the CMS grafted copolymers [20,21]. Therefore, the water solubility of etherified starch graft copolymer could be promoted greatly. ...
A novel inorganic–organic flocculant (CMS-g-PDMC/PAC) was synthesized by introducing quaternary ammonium and polyaluminum chloride (PAC) onto the backbone of carboxymethyl starch (CMS). The optimal preparation conditions were obtained through orthogonal experimental design. The success of the grafting was confirmed by SEC-MALS, FTIR, SEM, XRD and TGA characterization. The study of thermal properties showed that the grafting of poly(methacryloxyethyltrimethyl ammonium chloride) (PDMC) and PAC onto CMS has changed the thermal stability of CMS, the thermal effect per unit time increases with the increase of decomposition process. The kinetics of thermal analysis was measured using a TGA–DSC Thermal Analyzer and calculated by Kissinger equation. The results indicated that the activation energy for the thermolysis of CMS-g-PDMC/PAC was calculated to be 190.64 kJ/mol. Its flocculation abilities for oily wastewater were evaluated by oil removal efficiency and visible light transmittance. The effects of flocculation condition on removal efficiency and transmittance were also studied. The flocculant possessed the advantages of inorganic and organic polymers, and exhibited a good flocculation effect by charge neutralization, adsorption bridging and aggregation.
... In the study of Feng and Wen (2017), slight changes in peaks were observed, however, a disappearance of peak at 2900 to 3000 cm -1 were observed as a result of peak broadening in the region 3000 to 3600 cm -1 due to O-H stretching. Li et al. (2020) crosslinked carboxymethyl starch, wherein a slight difference in the intensities of O-H stretch was observed, whereas, the absorption peak at 1021 cm -1 was significantly enhanced. In this study, changes in the peak intensities and shifting of absorption frequency were observed as a result of crosslinking. ...
Context: The modification of starch from the grains of NSICRc222 rice variety may provide a new material with enhanced disintegrating functionality in compressed solid dosage forms. Aims: To synthesize hydroxypropylated crosslinked rice starch that may possess characteristics of a good disintegrant. Methods: Starch was isolated by the wet milling method. The crosslinking was performed using trisodium trimetaphosphate as crosslinking agent, and successively hydroxypropylated by using phosphorous oxychloride. The evidences of chemical modifications were determined by FTIR, TGA, and DSC. The application of modified rice starch as a disintegrant was evaluated by determining the dissolution profile, and was compared to the performance of commercially available disintegrants. The compatibility of modified rice starch was employed using FTIR, and the stability of the formulation was subjected to an accelerated stability study. Results: The changes in infrared spectra and thermogram confirmed successful chemical modification of rice starch. Allopurinol and modified starch mixture staged from 0 to 3 months showed no significant changes in the infrared spectra, which suggest compatibility of HCR with allopurinol. The dissolution rate of allopurinol tablets at pH 1.2, pH 4.5, and pH 6.8 with various superdisintegrants were comparable to the dissolution rate that utilized hydroxypropylated crosslinked rice starch as disintegrant. The accelerated stability study showed no significant changes from 0th to 3rd month, and no degradation products were detected in the HPLC analysis. Conclusions: The chemical modification of rice starch through crosslinking and hydroxypropylation yielded a novel material comparable to the commercially available superdisintegrants.
Objective:
To design and construct a hydrogel drug-controlled release system loaded with gentamicin on a titanium surface, and to evaluate the in vitro drug release behaviour and antibacterial properties and biocompatibility of the controlled release system.
Methods:
Titanium (Ti) surface was coated with poly dopamine (PDA) substrate, and then polyethylene glycol (PEG) was attached to PDA. The composite drug microsphere controlled release layer formed by gentamicin (GEN) and cross-linked starch (CSt) were subsequently covered with poly lactic⁃co⁃glycolic acid (PLGA) as a barrier to construct a Ti-GEN-Cst-PLGA anti-infective drug controlled release system.
Results:
The hydrogel drug release system was successfully constructed. The results of in vitro anti-staphylococcus aureus (SAU) assay, anti-staphylococcus epidermidis (SEP) assay and anti-Escherichia coli (ECO) assay showed that Ti-GEN-Cst-PLGA could effectively inhibit the growth of three bacteria. Assay in the New Zealand rabbit found that Ti-GEN-Cst-PLGA could promote wound healing at the 3rd week after implantation, and the pathology assay found that the Ti-GEN-Cst-PLGA group had less inflammatory reactions and significant tissue proliferation at the endophyte contact surface.
Conclusion:
Ti-GEN-Cst-PLGA can effectively inhibit the inflammatory response and promote wound healing, or may be a potential treatment for orthopaedic endophytes.
Starch xanthate was synthesized from corn starch and CS 2 under alkaline condition. The effects of catalyst dosage, CS 2 dosage and reaction temperature on sulfur content and copper ion removal rate were studied by single factor experiments, and the structure of the product was characterized by FTIR, SEM and XRD. The results showed that the optimum synthetic condition of ISX was NaOH dosage 16 mL, CS 2 dosage 2.5 mL, reaction temperature 35 °C and reaction time 2 h. The sulfur content of ISX synthesized under this condition was 7.54%, the removal rate of copper ion was 90.5%, and the adsorption capacity of ISX was 90.0 mg/g.
