{"title":"分子动力学模拟研究不同壳聚糖基接枝聚合物单体类型对其絮凝行为的影响","authors":"Fengyang Liu, Wenjie Zou, Ting Xiao, Wentao Hu, Ming Zhang, Zhijun Zhang, Fang Zhou","doi":"10.1007/s00396-025-05399-3","DOIUrl":null,"url":null,"abstract":"<div><p>The selection of the grafting monomer plays a pivotal role in determining the flocculation performance of chitosan-based grafted copolymers. In this work, the flocculation behavior and mechanism of chitosan-based graft copolymers with different grafting monomers (i.e. carboxymethyl chitosan-grafted polyacrylamide (CMCP), carboxymethyl chitosan-graft-poly (acrylamide-dimethyl diallyl ammonium chloride) (CMCPD), and chitosan-graft-poly (acrylamide-dimethyl diallyl ammonium chloride) (CPD)) on the kaolinite (001) surface were investigated using molecular dynamics simulations, flocculation experiments and flocs size measurement. The interaction energy calculations revealed that the copolymers exhibited the following order: CPD (− 943.105 kcal/mol) > CMCPD (− 522.812 kcal/mol) > CMCP (− 340.026 kcal/mol). The calculated solvent-accessible surface area (SASA) showed that amphoteric CMCPD exhibited complete extension and unrestricted diffusion in solution, surpassing the capabilities of both CMCP and CPD. The diffusion coefficients of CMCPD, CPD, and CMCP, were determined to be 5.17 × 10<sup>–10</sup> m<sup>2</sup>/s, 2.68 × 10<sup>–10</sup> m<sup>2</sup>/s and 4.25 × 10<sup>–10</sup> m<sup>2</sup>/s, respectively. It can be inferred that the bridging ability of the CMCPD flocculant in solution is directly proportional to its higher diffusion coefficient. However, excessive adsorption of CPD onto kaolinite resulted in a reduction in the bridging capacity of CPD. The simulation results were validated by conducting flocculation experiments, and it was observed that CMCPD, possessing the strongest bridging capability, exhibited a significantly higher settling rate (19.47 m/h) compared to CPD (12.56 m/h) and CMCP (9.81 m/h). The analysis of flocs particle size further confirmed the superior bridging ability of CMCPD, as evidenced by its largest flocs particle size, thereby facilitating rapid settling. This study provides valuable insights for the design and development of chitosan-based flocculants.</p><h3>Graphical abstract</h3>\n<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":520,"journal":{"name":"Colloid and Polymer Science","volume":"303 6","pages":"1071 - 1080"},"PeriodicalIF":2.2000,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Molecular dynamics simulations investigating the influence of different chitosan-based graft polymer monomer types on their flocculation behavior\",\"authors\":\"Fengyang Liu, Wenjie Zou, Ting Xiao, Wentao Hu, Ming Zhang, Zhijun Zhang, Fang Zhou\",\"doi\":\"10.1007/s00396-025-05399-3\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>The selection of the grafting monomer plays a pivotal role in determining the flocculation performance of chitosan-based grafted copolymers. In this work, the flocculation behavior and mechanism of chitosan-based graft copolymers with different grafting monomers (i.e. carboxymethyl chitosan-grafted polyacrylamide (CMCP), carboxymethyl chitosan-graft-poly (acrylamide-dimethyl diallyl ammonium chloride) (CMCPD), and chitosan-graft-poly (acrylamide-dimethyl diallyl ammonium chloride) (CPD)) on the kaolinite (001) surface were investigated using molecular dynamics simulations, flocculation experiments and flocs size measurement. The interaction energy calculations revealed that the copolymers exhibited the following order: CPD (− 943.105 kcal/mol) > CMCPD (− 522.812 kcal/mol) > CMCP (− 340.026 kcal/mol). The calculated solvent-accessible surface area (SASA) showed that amphoteric CMCPD exhibited complete extension and unrestricted diffusion in solution, surpassing the capabilities of both CMCP and CPD. The diffusion coefficients of CMCPD, CPD, and CMCP, were determined to be 5.17 × 10<sup>–10</sup> m<sup>2</sup>/s, 2.68 × 10<sup>–10</sup> m<sup>2</sup>/s and 4.25 × 10<sup>–10</sup> m<sup>2</sup>/s, respectively. It can be inferred that the bridging ability of the CMCPD flocculant in solution is directly proportional to its higher diffusion coefficient. However, excessive adsorption of CPD onto kaolinite resulted in a reduction in the bridging capacity of CPD. The simulation results were validated by conducting flocculation experiments, and it was observed that CMCPD, possessing the strongest bridging capability, exhibited a significantly higher settling rate (19.47 m/h) compared to CPD (12.56 m/h) and CMCP (9.81 m/h). The analysis of flocs particle size further confirmed the superior bridging ability of CMCPD, as evidenced by its largest flocs particle size, thereby facilitating rapid settling. This study provides valuable insights for the design and development of chitosan-based flocculants.</p><h3>Graphical abstract</h3>\\n<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>\",\"PeriodicalId\":520,\"journal\":{\"name\":\"Colloid and Polymer Science\",\"volume\":\"303 6\",\"pages\":\"1071 - 1080\"},\"PeriodicalIF\":2.2000,\"publicationDate\":\"2025-03-14\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Colloid and Polymer Science\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://link.springer.com/article/10.1007/s00396-025-05399-3\",\"RegionNum\":4,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"CHEMISTRY, PHYSICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Colloid and Polymer Science","FirstCategoryId":"92","ListUrlMain":"https://link.springer.com/article/10.1007/s00396-025-05399-3","RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
Molecular dynamics simulations investigating the influence of different chitosan-based graft polymer monomer types on their flocculation behavior
The selection of the grafting monomer plays a pivotal role in determining the flocculation performance of chitosan-based grafted copolymers. In this work, the flocculation behavior and mechanism of chitosan-based graft copolymers with different grafting monomers (i.e. carboxymethyl chitosan-grafted polyacrylamide (CMCP), carboxymethyl chitosan-graft-poly (acrylamide-dimethyl diallyl ammonium chloride) (CMCPD), and chitosan-graft-poly (acrylamide-dimethyl diallyl ammonium chloride) (CPD)) on the kaolinite (001) surface were investigated using molecular dynamics simulations, flocculation experiments and flocs size measurement. The interaction energy calculations revealed that the copolymers exhibited the following order: CPD (− 943.105 kcal/mol) > CMCPD (− 522.812 kcal/mol) > CMCP (− 340.026 kcal/mol). The calculated solvent-accessible surface area (SASA) showed that amphoteric CMCPD exhibited complete extension and unrestricted diffusion in solution, surpassing the capabilities of both CMCP and CPD. The diffusion coefficients of CMCPD, CPD, and CMCP, were determined to be 5.17 × 10–10 m2/s, 2.68 × 10–10 m2/s and 4.25 × 10–10 m2/s, respectively. It can be inferred that the bridging ability of the CMCPD flocculant in solution is directly proportional to its higher diffusion coefficient. However, excessive adsorption of CPD onto kaolinite resulted in a reduction in the bridging capacity of CPD. The simulation results were validated by conducting flocculation experiments, and it was observed that CMCPD, possessing the strongest bridging capability, exhibited a significantly higher settling rate (19.47 m/h) compared to CPD (12.56 m/h) and CMCP (9.81 m/h). The analysis of flocs particle size further confirmed the superior bridging ability of CMCPD, as evidenced by its largest flocs particle size, thereby facilitating rapid settling. This study provides valuable insights for the design and development of chitosan-based flocculants.
期刊介绍:
Colloid and Polymer Science - a leading international journal of longstanding tradition - is devoted to colloid and polymer science and its interdisciplinary interactions. As such, it responds to a demand which has lost none of its actuality as revealed in the trends of contemporary materials science.