竹纳米纤维素晶须的制备及其生物复合材料运用
发布时间：2019-04-07 20:20
【摘要】：纳米纤维素晶须是通过强酸水解或其他方法将纤维素中的无定形区降解，剩下纤维素微晶部分，其直径约为1-100nm，长度约为10-1000nm，我们习惯上把它称为纳米纤维素晶须。通常利用硫酸水解纤维素的方法可以快速、高效制备出纳米纤维素晶须。纳米纤维素晶须具有纳米级尺寸、大的长径比、大的比表面积、高强度、良好的生物相容性、可降解性、低成本等优势使其在生物医学材料、光学材料及复合材料的增强相等方面得到广泛运用。我国是竹子的生产大国，竹纤维具有生长周期短、成本低、可再生等特点使其成为纤维素的主要来源之一。 本课题利用硫酸水解竹纤维的方法制备竹纳米纤维素晶须，通过控制硫酸浓度、硫酸水解时间、水浴温度等工艺参数制备长径比相对较大的竹纳米纤维素晶须，研究了纳米纤维素晶须的结构与性能以期其能够作为生物复合材料的增强相。研究显示随着水解时间的延长其长径比、结晶度逐步提高，在水解时间20min时竹纳米纤维素的长径比最大、结晶度最高、热稳定性最好之后又开始降低。同时研究了纳米纤维晶须悬乳液的液晶现象，研究显示随着纳米纤维素悬乳液浓度达到临界浓度时开始形成液晶，其螺距随着浓度的增加而逐渐减小；在相同浓度下，随着时间的延长其螺距也会逐渐变小。通过层层自组装技术构建纳米纤维素晶须/壳聚糖/丝素生物复合材料，研究了复合材料的结构与性能；研究显示经过自组装后复合材料随着自组装层数的增加孔隙率逐渐减小，力学性能逐步提高，以其作为生物支架材料得到广泛运用。
[Abstract]:Nano-cellulose whisker is the degradation of amorphous region in cellulose by strong acid hydrolysis or other methods, leaving the microcrystalline part of cellulose, its diameter is about 100 nm, its length is about 10 脳 1000 nm, we used to call it nano-cellulose whisker. Nano-cellulose whiskers can be prepared rapidly and efficiently by hydrolysis of cellulose with sulfuric acid. Nano-cellulose whiskers have the advantages of nanometer size, large aspect ratio, large specific surface area, high strength, good biocompatibility, biodegradability and low cost. Optical materials and composite materials have been widely used in strengthening phase. Bamboo fiber is one of the main sources of cellulose because of its short growth cycle, low cost, renewable and so on. In this paper, bamboo nanocellulose whiskers were prepared by hydrolysis of bamboo fibers with sulfuric acid. By controlling the concentration of sulfuric acid, the hydrolysis time of sulfuric acid and the temperature of water bath, the bamboo nanocellulose whiskers with relatively large ratio of length to diameter were prepared. The structure and properties of nano-cellulose whiskers were studied in order to be used as the reinforcing phase of bio-composites. The results show that with the increase of hydrolysis time, the crystallinity of bamboo nano-cellulose increases gradually. When the hydrolysis time is 20min, the ratio of length to diameter of bamboo nano-cellulose is the largest, the crystallinity is the highest, and the thermal stability is the best. At the same time, the liquid crystal phenomenon of nano-fiber whisker suspension emulsion was studied. The results showed that the liquid crystal began to form when the concentration of nano-cellulose suspension emulsion reached the critical concentration, and the pitch decreased gradually with the increase of the concentration. At the same concentration, the pitch will gradually decrease with the prolongation of time. Nano-cellulose whisker / chitosan / silk fibroin bio-composites were constructed by layer-by-layer self-assembly technique, and the structure and properties of the composites were studied. The results show that with the increase of the number of self-assembled layers, the porosity and mechanical properties of the composites decrease and the mechanical properties are gradually improved. The composites are widely used as biomaterials.
【学位授予单位】：中原工学院
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R318.08
本文编号：2454392
[Abstract]:Nano-cellulose whisker is the degradation of amorphous region in cellulose by strong acid hydrolysis or other methods, leaving the microcrystalline part of cellulose, its diameter is about 100 nm, its length is about 10 脳 1000 nm, we used to call it nano-cellulose whisker. Nano-cellulose whiskers can be prepared rapidly and efficiently by hydrolysis of cellulose with sulfuric acid. Nano-cellulose whiskers have the advantages of nanometer size, large aspect ratio, large specific surface area, high strength, good biocompatibility, biodegradability and low cost. Optical materials and composite materials have been widely used in strengthening phase. Bamboo fiber is one of the main sources of cellulose because of its short growth cycle, low cost, renewable and so on. In this paper, bamboo nanocellulose whiskers were prepared by hydrolysis of bamboo fibers with sulfuric acid. By controlling the concentration of sulfuric acid, the hydrolysis time of sulfuric acid and the temperature of water bath, the bamboo nanocellulose whiskers with relatively large ratio of length to diameter were prepared. The structure and properties of nano-cellulose whiskers were studied in order to be used as the reinforcing phase of bio-composites. The results show that with the increase of hydrolysis time, the crystallinity of bamboo nano-cellulose increases gradually. When the hydrolysis time is 20min, the ratio of length to diameter of bamboo nano-cellulose is the largest, the crystallinity is the highest, and the thermal stability is the best. At the same time, the liquid crystal phenomenon of nano-fiber whisker suspension emulsion was studied. The results showed that the liquid crystal began to form when the concentration of nano-cellulose suspension emulsion reached the critical concentration, and the pitch decreased gradually with the increase of the concentration. At the same concentration, the pitch will gradually decrease with the prolongation of time. Nano-cellulose whisker / chitosan / silk fibroin bio-composites were constructed by layer-by-layer self-assembly technique, and the structure and properties of the composites were studied. The results show that with the increase of the number of self-assembled layers, the porosity and mechanical properties of the composites decrease and the mechanical properties are gradually improved. The composites are widely used as biomaterials.
【学位授予单位】：中原工学院
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R318.08
【引证文献】
相关期刊论文 前1条
1 王雪;刘志明;冯丽;张亚翠;王宇颂;;NCC增强聚氨酯泡沫的制备进展[J];广东化工;2013年16期
，本文编号：2454392
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