魔芋葡甘聚糖—碳纳米管气凝胶附着机理及应用研究

发布时间：2018-05-24 05:54

本文选题：魔芋 + 碳纳米管　；参考：《福建农林大学》2017年硕士论文

【摘要】：作为世界超级人口大国的中国,专家预计到本世纪2030年,人口数量将达到16亿,届时人均陆地面积将降为0.008平方公里,与世界人均0.3平方公里的水平相差甚远。且陆地上的各类资源,随着人口的增长、人为的开发和破坏,日渐匾乏,破坏状况令人担忧。为了满足十几亿人口对食物、淡水的日益增长的需求,在运用科学发展观和可持续发展的基础上,采用纳米吸附技术等现代高新技术,合理开发利用海洋资源和重复可循环利用治理污染水源,是未来海洋资源和污水开发、利用的必由之路。魔芋葡甘聚糖(KGM)是一种天然高分子多糖,在溶胶状态下,添入碱同时加热,可脱去乙酰基团,得到非常有弹性的凝胶,类似于橡胶。本文以魔芋粉、碳纳米管为实验对象,通过添加不同复配魔芋葡甘聚糖-碳纳米管气凝胶,并进行力学、物理学性质对比比较,最后采用吸附试验,探讨模拟研究魔芋葡甘聚糖-碳纳米管气凝胶的应用。本文的主要研究内容和结果如下:1、分别制备魔芋葡甘聚糖-单壁、双壁、多壁碳纳米管气凝胶的实验,对比不同魔芋葡甘聚糖-碳纳米管气凝胶品质的力学、物理学性质。实验结果表明添加了单壁、双壁、多壁碳纳米管后,脱乙酰KGM复合溶胶能够更好地支撑重于自己数倍重量的物体,且还原性较好。所有的KGM在溶胶中的剪切粘度与剪切速率偏离了线性关系,流动曲线符合Power Law模型σ=KYn。单壁和双壁复合体中,流体假塑性随着浓度的增加呈现增加的趋势,表观粘度增加。多壁复合体流体假塑性随着浓度的增加,表观粘度显著下降,流体假塑性减少。动态频率扫描表明,各个配比的复合溶胶的样品测试差异比较大,所有样品均具有较宽的线性炥弹区。在低频率下,KGM、脱乙酰KGM-单壁和双壁碳纳米管复合溶胶的损耗模量(G")均大于储能模量(G')。质构数据表明不同浓度的脱乙酰KGM-单壁和双壁碳纳米管复合凝胶的质构特性参数较为接近,脱乙酰KGM-多壁碳纳米管复合凝胶的压缩性几乎只有脱乙酰KGM--单壁和双壁碳纳米管复合凝胶压缩性的一半,但弹性、内聚性和回复性又比脱乙酰KGM--单壁和双壁碳纳米管凝胶的参数高出一倍。2、分别制备无添加、魔芋葡甘聚糖-羧基化、羟基化魔芋葡甘聚糖气凝胶的实验,对比添加不同基团的碳纳米管所形成的魔芋气凝胶的力学性质与物理性质。实验数据表明添加了羟基、羧基碳纳米管后,脱乙酰KGM复合溶胶能够更好地支撑重于自己数倍重量的物体,且还原性较好。所有的KGM在溶胶中的剪切粘度与剪切速率偏离了线性关系,流动曲线符合Power Law模型σ=KYn,溶胶均表现为假塑性流体。动态频率扫描表明,各个配比的复合溶胶的样品测试差异比较大,所有样品均具有较宽的线性炥弹区。在低频率下,KGM、脱乙酰KGM-羧基、羟基魔芋葡甘聚糖复合溶胶的损耗模量(G")均大于储能模量(G")。质构数据中可以看出无添加碳纳米管的KGM复合凝胶质构的各项指标均比添加了碳纳米管的KGM复合凝胶低。3、以羧基魔芋葡甘聚糖-碳纳米管气凝胶作为吸附剂,对甲基橙溶液进行吸附,通过标准曲线、pH值、离子强度、动力学、热力学等实验,研究魔芋葡甘聚糖-碳纳米管气凝胶对甲基橙的吸附能力,得出以下结论:(1)随着pH升高,吸附量从高逐渐降低,在pH=7时最低,之后随着pH值的升高逐渐缓慢上升。当pH=3时,吸附量最高,为18.18 mg/g;当pH=7时,达到吸附量最低值为0.25mg/g。(2)通过离子强度对吸附影响实验,发现Cacl2溶液对甲基橙吸附影响不大,而当NaCl浓度≤0.20mol/L,随着NaCl浓度增加,羟基化多壁魔芋葡甘聚糖-碳纳米管气凝胶对甲基橙吸附量均匀不变,为6mg/g的吸附量。当NaCl浓度0.20mol/L,吸附量迅速上升,达到12mg/g的吸附量。(3)在吸附时间和等温吸附试验中,发现吸附效率随时间先增大,在300min时达到最大值后稳定在较高值。整个吸附过程符合假二阶动力学方程和Freundlich等温吸附模型,且吸附行为主要是依靠物理吸附作用。
[Abstract]:As the world's superpopulous country, the population is expected to reach 1 billion 600 million of the population by 2030 of this century, and the land area per capita will fall to 0.008 square kilometers, which is far from 0.3 square kilometers per capita in the world. And all kinds of resources on land, with the growth of the population, human development and destruction, are increasingly lacking and destroyed. In order to meet the growing demand of more than a billion people on food and fresh water, on the basis of Scientific Outlook on Development and sustainable development, the modern high-tech technologies such as nano adsorption technology are adopted, and the rational exploitation and utilization of marine resources and the repeated recycling of polluted water are the future development of marine resources and sewage. The only way to use. Konjac glucomannan (KGM) is a natural macromolecule polysaccharide. Under the condition of the sol-gel, it is added to the alkali and can be heated simultaneously. It can remove the acetyl group and get the very elastic gel, similar to the rubber. In this paper, the konjac powder and carbon nanotubes were used as the experimental objects by adding different compound konjac glucomannan carbon nanotube aerogels. The main contents and results of this paper are as follows: 1, the experiment of preparing konjac glucomannan - single wall, double wall, multi wall carbon nanoscale aerogels, and the comparison of different konjac glucomannan - carbon nanoscale The mechanical and physical properties of the quality of the rice tube aerogel. The experimental results show that the addition of single wall, double wall, multi wall carbon nanotubes, the deacetylation KGM composite sol can better support the weight of several times the weight of the body, and the reducibility is better. The shear viscosity of all KGM in the sol and the shear rate deviate from the linear relationship, flow curve. In the Power Law model Sigma =KYn. single wall and double wall complex, the pseudoplasticity of the fluid increases with the increase of the concentration, and the apparent viscosity increases. The apparent viscosity decreases significantly and the fluid pseudoplasticity decreases with the increase of the concentration. The dynamic frequency scanning shows that the sample test of the composite sols of each ratio is poor. At low frequency, the loss modulus of KGM, KGM- single wall and double wall carbon nanotube composite sol (G ") is larger than the energy storage modulus (G') at low frequency. The compressibility of the acetyl KGM- multi walled carbon nanotube composite gel is almost only half of the gel compressibility of the deacetylation KGM-- single wall and double walled carbon nanotubes, but the elasticity, cohesion and resilience are twice as high as the parameters of the deacetylation KGM-- single wall and double wall carbon nanotube gels, and the separation preparation is not added, the konjac glucomannan carboxylation, hydroxyl group, and hydroxyl group are not added. The experiments of konjac glucomannan aerogel were conducted to compare the mechanical and physical properties of the konjac aerogels with different groups of carbon nanotubes. The experimental data showed that after the addition of hydroxyl group and carboxyl carbon nanotubes, the deacetylation KGM composite sol could better support objects weighing several times the weight of their own, and the reducibility was better. The shear viscosity of some KGM deviates from the shear rate linearly, the flow curve fits the Power Law model Sigma =KYn and the sol is pseudoplastic fluid. The dynamic frequency scanning shows that the sample test of the composite sol is different in different proportions, and all samples have a wide linear elastic zone. At low frequency, KGM, stripping. The loss modulus (G ") of the acetyl KGM- carboxyl, hydroxy konjac glucomannan composite sol (G") is greater than the energy storage modulus (G "). In texture data, it is found that all the indexes of the KGM composite gel without carbon nanotubes are lower than that of the KGM composite gel added with carbon nanotubes, and the carboxyl konjac glucomannan carbon nanotube aerogel is used as adsorption. By adsorption of methyl orange solution, the adsorption capacity of konjac glucomannan carbon nanotube aerogel to methyl orange was studied through the standard curve, pH value, ionic strength, kinetics, thermodynamics and other experiments. The following conclusion was drawn: (1) with the increase of pH, the adsorption amount decreased gradually, the lowest at pH=7, and then slowly along with the increase of the pH value. When pH=3, the adsorption amount is the highest, 18.18 mg/g; when pH=7, the lowest adsorption amount is 0.25mg/g. (2) through the ion strength to the adsorption experiment, it is found that Cacl2 solution has little influence on the adsorption of methyl orange, while NaCl concentration is less than 0.20mol/L, with the increase of NaCl concentration, the hydroxylation of multi wall konjac glucomannan carbon nanotube aerogel to methyl methylation The adsorption quantity of the orange is constant and the adsorption amount of 6mg/g. When the concentration of NaCl is 0.20mol/L, the adsorption amount rises rapidly to reach the adsorption quantity of 12mg/g. (3) the adsorption efficiency is first increased in the adsorption time and isothermal adsorption test, and the maximum value is stable at 300min when the maximum value is reached. The whole adsorption process is in accordance with the pseudo two order kinetic equation and Fre. Undlich isothermal adsorption model, and adsorption behavior mainly depends on physical adsorption.
【学位授予单位】：福建农林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O648.17;O647.3

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