Poly（vinyl alcohol）/collagen （PVA/COL） micro-nanofibers were successfully prepared by electrospinning process. Water, green, and non-toxic was used as the solvent. The electrospun mats consisted of micro-nanoscale...Poly（vinyl alcohol）/collagen （PVA/COL） micro-nanofibers were successfully prepared by electrospinning process. Water, green, and non-toxic was used as the solvent. The electrospun mats consisted of micro-nanoscale fibers with mean diameter ranging from approximately 363 nm to 179 nm. It was observed that the mean diameters of PVA/COL electrospun fibers decreased with increasing collagen content. The effects of PVA/COL blending ratio on the rheological behavior of PVA/COL blended solutions were investigated by rotate rheometer. It was found that PVA/COL blended solutions behaved as Non-Newtonian fluids. With increasing collagen content, the Non-Newtonian index （n） of PVA/COL blended solutions decreased. Meanwhile, a linear relationship was found between the Non-Newtonian index （n） and the mean diameters of the PVA/COL micro- nanofibers. The chemical structures of PVA/COL electrospun fibers were also characterized by FTIR.展开更多
Composites of montmorillonite clay and sawdust were prepared with the desired result being having new materials which burn longer than unmodified sawdust. The three forms of clay used for preparation of composites wer...Composites of montmorillonite clay and sawdust were prepared with the desired result being having new materials which burn longer than unmodified sawdust. The three forms of clay used for preparation of composites were unmodified montmorillonite, mono-ionic montmorillonite and organically modified montmorillonite. Montmorillonite clay was converted to mono-ionic clay by ion exchange with sodium using a sodium chloride solution. The mono-ionic clay was organically modified with an organic surfactant, methyl triphenyl phosphonium bromide. Nanocomposites were then prepared by combining the modified and raw forms of the clay with sawdust. The solution blending method was used to make the nanocomposites. The samples were analysed using thermogravimetric analysis and cone calorimetry. The studies showed that the nanocomposite which was made from sawdust and 1% organically modified clay had the most improved results in terms of burning time and thermal stability, as well as giving a calorific value closest to unmodified sawdust and the least amount of residue.展开更多
Medical devices-related infections pose a great threat to patients and cause an increased morbidity and mortality. Herein, we prepare an antibacterial composite(TPU-x) through blending medical grade thermoplastic poly...Medical devices-related infections pose a great threat to patients and cause an increased morbidity and mortality. Herein, we prepare an antibacterial composite(TPU-x) through blending medical grade thermoplastic polyurethane(TPU) and the complex(PL-DOSS) of ε-polylysine(ε-PL) and docusate sodium(DOSS). >99% reduction of colony forming unit(CFU) can be obtained in TPU-x composite films even at relatively low content of PL-DOSS, e.g. 0.13% for Methicillin resistant S. aureus(MRSA) and 0.5% for E. coli. The excellent antibacterial activity is mainly attributed to the formation of PL-DOSS nanoparticles that are uniformly dispersed in the TPU matrix with a size of ~100 nm. TPU-x composite films exhibit long-term stability in saline and good biocompatibility, and retain mechanical properties of TPU.展开更多
基金Funded by the National Natural Science Foundation of China(Nos.21076199,51373158)the Department of Science and Technology of Henan Province(No.124300510)
文摘Poly（vinyl alcohol）/collagen （PVA/COL） micro-nanofibers were successfully prepared by electrospinning process. Water, green, and non-toxic was used as the solvent. The electrospun mats consisted of micro-nanoscale fibers with mean diameter ranging from approximately 363 nm to 179 nm. It was observed that the mean diameters of PVA/COL electrospun fibers decreased with increasing collagen content. The effects of PVA/COL blending ratio on the rheological behavior of PVA/COL blended solutions were investigated by rotate rheometer. It was found that PVA/COL blended solutions behaved as Non-Newtonian fluids. With increasing collagen content, the Non-Newtonian index （n） of PVA/COL blended solutions decreased. Meanwhile, a linear relationship was found between the Non-Newtonian index （n） and the mean diameters of the PVA/COL micro- nanofibers. The chemical structures of PVA/COL electrospun fibers were also characterized by FTIR.
文摘Composites of montmorillonite clay and sawdust were prepared with the desired result being having new materials which burn longer than unmodified sawdust. The three forms of clay used for preparation of composites were unmodified montmorillonite, mono-ionic montmorillonite and organically modified montmorillonite. Montmorillonite clay was converted to mono-ionic clay by ion exchange with sodium using a sodium chloride solution. The mono-ionic clay was organically modified with an organic surfactant, methyl triphenyl phosphonium bromide. Nanocomposites were then prepared by combining the modified and raw forms of the clay with sawdust. The solution blending method was used to make the nanocomposites. The samples were analysed using thermogravimetric analysis and cone calorimetry. The studies showed that the nanocomposite which was made from sawdust and 1% organically modified clay had the most improved results in terms of burning time and thermal stability, as well as giving a calorific value closest to unmodified sawdust and the least amount of residue.
基金the National Natural Science Foundation of China(Nos.51773201 and 51973212)the Bureau of Science and Technology of Changchun(No.19SS005)+1 种基金the Department of Science and Technology of Jilin Province(No.20200301017RQ)the Joint Program of CAS-Jilin Province(No.2019SYHZ0002).
文摘Medical devices-related infections pose a great threat to patients and cause an increased morbidity and mortality. Herein, we prepare an antibacterial composite(TPU-x) through blending medical grade thermoplastic polyurethane(TPU) and the complex(PL-DOSS) of ε-polylysine(ε-PL) and docusate sodium(DOSS). >99% reduction of colony forming unit(CFU) can be obtained in TPU-x composite films even at relatively low content of PL-DOSS, e.g. 0.13% for Methicillin resistant S. aureus(MRSA) and 0.5% for E. coli. The excellent antibacterial activity is mainly attributed to the formation of PL-DOSS nanoparticles that are uniformly dispersed in the TPU matrix with a size of ~100 nm. TPU-x composite films exhibit long-term stability in saline and good biocompatibility, and retain mechanical properties of TPU.
