【作者】 何雪梅；

【导师】 谢孔良；

【作者基本信息】 东华大学 ， 纺织化学与染整工程， 2014， 博士

【摘要】 壳聚糖,甲壳素的脱乙酰化产物,是自然界唯一生物可降解的聚阳离子多糖,具有分子链柔顺,容易成膜,可加工性好,价廉及便于分子设计等特点。但是,尽管壳聚糖容易成膜,但也存在纯壳聚糖膜在水中易溶胀,不耐酸、强度低、制膜过程中结构不易控制等基本问题。本论文采用高碘酸钠氧化、酰化反应、季铵化、希夫碱化等手段改性壳聚糖材料,以硅偶联剂为交联剂,制备了改性壳聚糖基含硅杂化膜材料,以及以天然高分子及其衍生物为原料制备了壳聚糖/羧甲基纤维素/硅,壳聚糖/双醛淀粉/硅杂化膜材料,并对所得材料的结构、性能以及对印染废水中染料、重金属离子的分离与吸附进行应用研究。另外,以棉纤维为基材,分别通过轧-烘-焙工艺及超声沉积法制备了氧化双醛壳聚糖杂化材料表面修饰的棉织物、壳聚糖季铵盐/硅以及壳聚糖酰化衍生物/多壁碳纳米管(MWCNT)杂化体系修饰的棉织物,并研究修饰后纤维结构和性能的变化。(1)采用纳米Si02为原料,以壳聚糖为基体,乙烯基硅氧烷为前驱体,采用共混法制得壳聚糖/改性Si02纳米杂化膜,并用于吸附溶液中直接染料。通过红外、SEM、热分析等对手段对该杂化膜的结构、表面形态进行表征。结果表明：Si02纳米粒子在壳聚糖相内均匀分散,无机相与有机相交界处,会出现空隙。与纯壳聚糖相比,杂化膜的溶胀性能降低,在NaCl、NaOH水溶液中溶胀率较小。机械强度有所增强,透光率下降,表面润湿性能下降。此外,对染料的吸附实验表明该纳米杂化膜具有较好的吸附直接染料性能。当染料浓度在60mg/L,吸附温度为55℃,pH为8,吸附4.5小时,杂化膜对直接桃红12B和直接耐晒蓝B2RL具有较高的吸附量。在实验研究范围内杂化膜对直接桃红12B和直接耐晒蓝B2RL等温吸附过程可以分别用Langmuir和Freundlich等温式来描述。(2)以壳聚糖(CS)和羧甲基纤维素(CMC)共混作为有机基体,用硅偶联剂γ-缩水甘油醚氧丙基三甲氧基硅烷(KH560)作为交联剂,通过溶液共混法制备出有机-无机壳聚糖/羧甲基纤维素/硅复合杂化膜。通过红外光谱(FTIR)、热重分析(TGA)、扫描电镜(SEM)等方法对纯壳聚糖膜及壳聚糖/羧甲基纤维素/硅杂化膜的形态结构进行表征和分析,并测试不同膜的溶胀性能、耐酸性能及吸附染料和重铬酸根离子的性能。研究结果表明壳聚糖/羧甲基纤维素/硅杂化膜内引入了-COOH和-NH2官能团,具有两性离子的特征。由于硅偶联剂KH560的交联作用,使杂化膜溶胀性能降低,吸附染料性能提高。壳聚糖/羧甲基纤维素/硅杂化膜的耐酸性能较纯壳聚糖膜的有所提高。研究浓度、温度、pH和时间对复合膜吸附染料及重铬酸根离子性能的影响。实验结果表明：当KH560的用量为1%时,壳聚糖/羧甲基纤维素/硅杂化膜吸附染料效果最好。当吸附条件为30℃,染料浓度为120mg/L,pH分别为3.97,3.90时,杂化膜对弱酸性蓝RAW、酸性黑ATT的吸附性较好。当吸附条件为30℃,浓度为120mg/L,吸附时间50min, pH为3.83时,壳聚糖/羧甲基纤维素/硅复合膜对重铬酸根离子的吸附较好。(3)淀粉是生物高分子材料,无毒,环保,生物降解性好。通过高碘酸钠选择性氧化的方法,制备了淀粉双醛氧化物。利用醛基官能团与氨基官能团希夫碱反应,在壳聚糖酸溶液中交联制得壳聚糖/双醛淀粉杂化膜以及使用硅偶联剂氨丙基三乙氧基硅烷为交联剂,制备了壳聚糖/双醛淀粉/硅杂化膜；并将这两类膜用于吸附溶液中的直接染料,对壳聚糖/双醛淀粉膜以及壳聚糖/双醛淀粉/硅杂化膜吸附染料的作用机理进行了探讨。研究表明,在双醛淀粉还原交联的作用下,壳聚糖的某些特征吸收峰的强度和波数有明显的改变,从SEM照片可看出,壳聚糖/双醛淀粉杂化膜表面比较致密,各组分之间没有产生明显的相分离,而在壳聚糖/双醛淀粉/硅杂化膜内表面粗糙,有一些孔结构。并且壳聚糖/双醛淀粉与壳聚糖/双醛淀粉/硅杂化膜的热学性能与溶胀性能明显不同。双醛淀粉交联的壳聚糖硅杂化膜对直接染料的吸附性能要好于壳聚糖/双醛淀粉膜。而两种膜对直接染料蓝B2RL和桃红12B的吸附行为皆属于准二级动力学模型。(4)选择性氧化壳聚糖,获得双醛氧化壳聚糖。通过采用氨丙基三乙氧基硅烷(KH550)和乙二胺协同双醛壳聚糖,分别对棉织物进行表面修饰,获得双醛壳聚糖杂化材料修饰的棉织物。用红外、热分析、扫描电镜对双醛壳聚糖杂化材料修饰的棉织物进行结构表征,并对其物理机械性能以及抗紫外性能、吸附性能进行研究。探讨不同方法修饰后棉织物对直接桃红12B的吸附动力学。结果表明：用氨丙基三乙氧基硅烷(KH550)和乙二胺(EDA)协同双醛氧化壳聚糖修饰后棉织物的物理机械性能都比未处理样得到了改善,染料吸附性能,防紫外线指数UPF和抗皱性能均有明显增加。不同温度下的染色动力学数据表明,直接桃红12B在两种双醛壳聚糖杂化材料修饰的棉上的吸附符合准二级动力学模型。(5)制备了2,3-环氧丙基十二烷基二甲基壳聚糖氯化铵衍生物,利用所制备的壳聚糖季铵盐为阳离子化试剂,通过溶胶-凝胶法,硅偶联剂的水解缩合,在棉纤维表面上原位自发构筑壳聚糖季铵盐/硅杂化膜。SEM, EDS结果证实了壳聚糖季铵盐/硅杂化膜存在于纤维表面上。经壳聚糖季铵盐/硅杂化膜修饰后的棉纤维表面润湿性能、吸附性能均发生了显著的变化。随着沉积时间延长,纤维表面的疏水性能以及抗紫外性能增强。(6)碳纳米管具有显著的电学、力学、热学等性能,是目前最有发展前景用于制备复合材料的纳米填充剂。利用所制备的N-邻苯二甲酰-O-琥珀酰化壳聚糖(PHCSSA),在超声作用下分散多壁碳纳米管(MWCNT),获得PHCSSA/MWCNT杂化溶液。利用获得的PHCSSA/MWCNT杂化溶液对棉织物进行浸渍沉积处理。用IR、SEM等手段对PHCSSA/MWCNT杂化膜沉积修饰的棉织物进行结构表征。研究了PHCSSA浓度、MWCNT用量、处理温度和处理时间等因素对改性棉织物表面性能,如抗紫外及吸附亚甲基蓝染料性能的影响。结果表明：N-邻苯二甲酰-O-琥珀酰化壳聚糖(PHCSSA)能够均匀分散多壁碳纳米管,棉织物经PHCSSA/MWCNT复合膜的沉积处理后,棉织物的防紫外性能得到了明显的提高,对亚甲基蓝染料的吸附性能也得到了改善。PHCSSA浓度为2g/L, MWCNT用量为7.5ng/mL,温度为50℃,超声处理30min,可使修饰后棉织物对亚甲基蓝染料具有较好的吸附性能和抗紫外性能。更多还原

【Abstract】 Chitosan (CS), N-deacetylated form of chitin, is the second abundant renewable biopolymer. It has many unique properties such as soft molecular long chain, excellent forming film characteristics, ease of molecular design (synthesis, blending modification, grafting etc.). However, pure chitosan membrane is highly swollen in water, and has low mechanical strength and poor acid resistance property, in addition, membrane structure is difficult to control during the membrane process, the adsorption and separation mechanism of membranes need to be explored further. In this dissertation, chitosan was used as raw materials to prepare hybrid materials. Firstly, chitosan were premodificated by carboxylation, acylation reaction and shiff base reaction. After that, chitosan/silica hybrid membrane and chitosan/natural polymer/silica hybrid membrane material were prepared respectively with silicon coupling agent as crosslinking agent. The structure and performance of the obtained hybrid membranes were studied. In addition to, chitosan oxidation hybrid material, chitosan quaternary derivatives/silica, chitosan acylated derivatives/MWCNT hybrid systems were prepared respectively on the cotton fiber by dip-pad-cure propcesses and ultrasonic deposition method. The effect of these types of hybrid systems on structure, and performance of cotton fabrics were studied. These results are shown as follows:Chitosan/silica hybrid membrane was prepared by using chitosan and nano-SiO2modified in presence of coupling agent triethoxyvinylsilane. The distribution of SiO2on the surface of chitosan/silica hybrid membrane was investigated by SEM. The adsorption behaviors of direct dyes from aqueous solution onto chitosan/silica hybrid membrane were studied under various experimental conditions such as time, temperature, pH etc. The results showed that the nano-SiO2particles distributed enenly in the chitosan phase and there were interspaces between inorganic and organic phase in the hybrid membrane. Experimental results indicated that the adsorption capacity of hybrid membranes for the both direct dyes was higher when the concentration of Direct Pink12B and Direct blue B2RL were60mg/L, and adsorbed at55℃, pH8for4.5h. Adsorption equilibrium studies showed that adsorption of Direct Pink12B on hybrid membranes more followed Langmuir isotherm model while adsorption of Direct blue B2RL on hybrid membranes more followed Freundlich isotherm model.Novel chitosan/carboxylmethyl cellulose/silica hybrid membranes (CS/CMC/Silica) were prepared by combining chitosan with carboxyl methyl cellulose as the functional reagent and using3-glycidoxypropyltrimethoxysilane (GPTMS) as crosslinking agent. The hybrid membrane materials were characterized by FT-IR spectroscopy, scanning electron microscopy (SEM) and thermolgravimetry (TG) analysis and used to adsorb Blue RAW, Black ATT and Cr2O72-iron in textile wastewater. The influence of dyes and metal ion concentration, solution temperature, pH and adsorption time on adsorption performance of hybrid membrane was investigated. Compared with chitosan itself, the hybrid membranes showed significant changes in the molecular constitutions and thermal properties, which were more stable in acid solution and had the lower swelling properties. Adsorption capacity increased with the increase of initial dyes, Cr2O72-concentration and absorbing time, and decreased with the increase of biosorbent dosage and temperature. Adsorption equilibriums of Cr2O72-ion, Black ATT and Blue RAW were reached in about60min,90min and160min, respectively, and the kinetic data conformed better to the pseudo-second order equation.Oxidized starch crosslinked chitosan membrane (CS/OSR) and chitosan/Oxidized starch/silica hybrid membrane (CS/OSR/Silica) were prepared respectively by combination chitosan and oxidized starch as the functional reagent and using3-aminopropyltriethoxysilane as crosslinking agent. Both of the hybrid membrane materials were characterized by FT-IR spectroscopy, scanning electron microscopy and TG thermal analysis methods, which were used to adsorb direct blue B2RL and pink12B in textile dyes from aqueous solutions. The influences of types of membrane, temperature, and pH and adsorption time on adsorption performance of hybrid membranes were studied. Compared with chitosan itself, hybrid membranes showed significant changes in the molecular constitutions and thermal properties. It was more stable in acid solutions. Adsorption capacity was found to increase with pH value and time. When pH was9.82, at60℃, adsorption equilibrium of blue B2RL and Pink12B was achieved in about90min and60min, respectively. The kinetic data conformed better to the pseudo-second order equation.Modified cotton fabrics were prepared by pad-dry-cure technique from the aldehyde chitosan solution containing3-aminopropyltriethoxysilane (KH550) and1,2-Ethanediamine (EDA) respectively. The structural characterization of the modified cotton fabrics was performed by attenuated total reflection ATR, scanning electron microscopy (SEM) and thermogravimetry (TG) analysis and physical mechanical properties were measured. The adsorption kinetics of modified cotton fabrics were also investigated by using the pseudo first-order and pseudo second-order kinetic model. The dyeing rate constant k1, k2and half adsorption time t1/2were calculated, respectively. The results showed that the mechanical properties of different modified cotton fabrics have been improved, and the surface color depth values of K/S, UV index UPF and anti-wrinkle properties were better than those of untreated cotton. Dyeing kinetics data at different temperatures indicated that Direct Pink12B up-take on the modified cotton fabrics fitted to pseudo second-order kinetic model.Using2,3-epoxy-propyl dodecyl dimethyl ammonium chloride as cationic chitosan reagent, by deposition, chitosan quaternary ammonium salt/silica hybrid sol hybrid film were constructed on cotton fiber. SEM and EDS anylysis results confirmed the quaternary ammonium salt/silica hybrid film was deposited on the surface of cotton fiber. After deposition modification, surface properties of modified cotton such as wetting ablity, adsorption properties produced significant changes. With the assembly of deposition time increased and anti-UV properties increased.MWCNT were evenly dispersed in N-phthaloyl-O-succinyl chitosan DMF solvent under ultrasound condition. Cotton fabrics were impregnated in N-phthaloyl-O-succinyl chitosan/MWCNT DMF solution. Structure of modified cotton fabric was characterized by using infrared spectroscopy (FT-IR), scanning electron microscopy (SEM). The effect of PHCSSA concentration, MWCNT dosage, temperature and time on the surface properties (such as UV, hydrophobic properties and adsorption on methylene blue etc.) of modified cotton fabric was studied. The results showed that:N-phthaloyl-O-succinylated chitosan/MWCNT hybrid materials can be uniformly dispersed on the surface of cotton fabrics, UV performance, and adsorption performance on methylene blue dye of modified cotton fabrics have been significantly improved. When PHCSSA concentration of2g/L, MWCNT amount of7.5mg/L, bath ratio of1:100, the temperature is50℃, ultrasonic treatment30min, modified cotton fabrics had the higher UPF values and better adsorption on methylene blue.更多还原