本文關(guān)鍵詞： 蔗渣纖維素 核殼結(jié)構(gòu)乳液 疏水改性 纖維素基吸附劑 競爭吸附 吸附機(jī)理　出處：《廣西大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：21世紀(jì)隨著社會經(jīng)濟(jì)的高速發(fā)展,世界正面臨著環(huán)境、能源、材料等領(lǐng)域空前挑戰(zhàn)。植物纖維素是一種廉價(jià)、量廣、易降解、生物相容性好的天然高分子。但纖維素分子間和分子內(nèi)氫鍵和纖維素表面基團(tuán)過于單一,致使纖維素應(yīng)用受限,尤其在復(fù)合材料和廢水處理領(lǐng)域。目前控制工業(yè)廢水中重金屬排放法規(guī)越來越嚴(yán)厲,各種去除重金屬離子方法被大量使用,如化學(xué)沉淀、離子交換、吸附、納濾、超濾、反滲透、電化學(xué)、電滲析等方法。目前吸附是一種有效、經(jīng)濟(jì)的方法,由于簡單、有效、易操作和可重復(fù)使用等優(yōu)點(diǎn)而被廣泛研究。為提高植物纖維素對重金屬離子的吸附量,本文采用環(huán)氧氯丙烷、乙二胺、二硫化碳對纖維素進(jìn)行改性。將改性后的纖維素衍生物與羧甲基纖維素鈉(CMC-Na)溶于氫氧化鈉/硫脲體系后,用環(huán)氧氯丙烷進(jìn)行交聯(lián)得到纖維素基水凝膠吸附劑。討論了初始濃度、pH、離子強(qiáng)度、溫度對吸附劑吸附性能的影響。單組分吸附曲線表明Pb2+、Cu2+、Zn2+滿足Langmuir等溫吸附模型且最大吸附量分別是558.9、446.2、363.3 mg·g-1,吸附過程滿足擬二級吸附動力學(xué)且為自發(fā)放熱過程。在雙組分系統(tǒng)中采用Competitive Langmuir isotherm模型模擬數(shù)據(jù),結(jié)果顯示實(shí)驗(yàn)數(shù)據(jù)和模擬數(shù)據(jù)間的誤差均小于20%,表明該模型可對雙組份重金屬離子吸附進(jìn)行較準(zhǔn)確的預(yù)測。FTIR、SEM-EDAX、ICP-OES表明該吸附機(jī)理包括配位、離子交換、靜電吸附等作用。為解決纖維素與樹脂復(fù)合材料相界面“不相容”的問題。本文采用以苯乙烯(St)和己酸烯丙酯(AH)為核層共聚單體,丙烯酸丁酯(BA)、甲基丙烯酸丁酯(BMA)、甲基丙烯酸二甲氨乙酯(DMAEMA)為殼層共聚單體,以十六烷基三甲基氯化銨(CTAC)為乳化劑,2,2-偶氮二(2-甲基丙基咪)二鹽酸鹽(AIBA)為引發(fā)劑,二甲基丙烯酸乙二醇酯(EDGMA)為交聯(lián)劑制備出“硬核軟殼”的核殼型陽離子乳液。透射電鏡(TEM)、動態(tài)光散射多角度粒徑、Zeta電位分析儀測試結(jié)果表明制備的乳液粒徑分布較寬(PDI=0.314),平均粒徑84.95nm,Zeta電位32.8mv。在吸附過程中乳膠粒子分布較寬致使出現(xiàn)兩段吸附。第一段符合擬一級動力學(xué)吸附模型,第二段符合擬二級動力學(xué)吸附模型�；罨鼙砻魑竭^程先是物理吸附后是化學(xué)吸附。在高濃度下的活化能較高且吸附速率小于低濃度的吸附速率,表明了該過程受活化控制。在低濃度下活化能較小,吸附速率較大則為擴(kuò)散控制。當(dāng)額外補(bǔ)加乳化劑時(shí),低濃度下吸附率由60%增大到90%以上。通過紅外(FTIR)、掃描電鏡(SEM)、熱重(TGA)、比表面積儀(BET)、接觸角表明乳膠粒被成功的吸附在纖維素表面。在303 K時(shí)纖維素對乳膠粒的飽和吸附量520 mg·g-1。改性纖維素的接觸角隨吸附量的增加隨之增大。當(dāng)吸附量為196 mg.g-1時(shí)纖維素的接觸角為102°,表明疏水性纖維素制備成功。纖維素在吸附過程中以靜電吸附為主,共價(jià)和非共價(jià)作用(例如氫鍵、離子交換、電荷轉(zhuǎn)移、鏈的纏繞)為輔進(jìn)行吸附。
[Abstract]:In 21th century, with the rapid development of social economy, the world is facing unprecedented challenges in the fields of environment, energy and materials. Natural polymers with good biocompatibility. However, intermolecular and intramolecular hydrogen bonds and cellulose surface groups are too single, limiting the use of cellulose. Especially in the field of composite materials and wastewater treatment. At present, the regulations for controlling the discharge of heavy metals in industrial wastewater are becoming more and more stringent, and various methods of removing heavy metal ions are widely used, such as chemical precipitation, ion exchange, adsorption, nanofiltration, ultrafiltration, etc. Reverse osmosis, electrochemistry, electrodialysis, etc. At present, adsorption is an effective and economical method, which has been widely studied because of its advantages of simplicity, efficiency, ease of operation and reusability. Cellulose was modified with epichlorohydrin, ethylenediamine and carbon disulfide. The modified cellulose derivatives and CMC-Na were dissolved in the system of sodium hydroxide / thiourea. Cellulose based hydrogel adsorbent was prepared by crosslinking epichlorohydrin. The single component adsorption curve showed that Pb2 Cu2Zn2 satisfies the Langmuir isotherm model and the maximum adsorption capacity is 558.9% 446.2U 363.3 mg 路g-1.The adsorption process satisfies the pseudo-second-order adsorption kinetics and is a self-releasing heat process. The Competitive Langmuir isotherm model is used to simulate the data in the two-component system. The results show that the error between the experimental data and the simulated data is less than 20, which indicates that the model can accurately predict the adsorption of heavy metal ions in two components. FTIRN SEM-EDAXX ICP-OES indicates that the adsorption mechanism includes coordination and ion exchange. In order to solve the problem of "incompatibility" between cellulose and resin composites, the core layer copolymerization of styrene (St) and allyl hexanoate (AH) was studied. Butyl acrylate (BMA), butyl methacrylate (BMAA), dimethylaminoethyl methacrylate (DMAEMA) as shell copolymerization monomer and cetyltrimethylammonium chloride (CTAC) as emulsifier AIBA) were used as initiators. The core-shell cationic emulsion of "hard core soft shell" was prepared by using ethylene glycol dimethacrylate (EDGMA) as crosslinking agent. The particle size distribution of the prepared emulsion was determined by dynamic light scattering multi-angle particle size analyzer. The average particle size was 84.95 nm / m ~ (-1) and Zeta potential was 32.8mv. during the adsorption process, a wide distribution of latex particles resulted in two stages of adsorption. The first stage was in accordance with the pseudo-first-order kinetic adsorption model. The second stage accords with the pseudo-second-order kinetic adsorption model. The activation energy indicates that the adsorption process is first physically adsorbed and then chemisorbed. At high concentration, the activation energy is higher and the adsorption rate is lower than that of the low concentration adsorption rate. The results show that the process is controlled by activation. The activation energy is small and the adsorption rate is controlled by diffusion at low concentration. The adsorption rate increased from 60% to more than 90% at low concentration. The adsorption rate was increased from 60% to 90% by FTIR, SEM, TGA, TGA, BET. The contact angle indicated that the latex particles were successfully adsorbed on the cellulose surface. At 303K, cellulose saturated the latex particles. The contact angle of modified cellulose increased with the increase of adsorption capacity. When the adsorption amount was 196 mg.g-1, the contact angle of cellulose was 102 擄, which indicated that hydrophobic cellulose was successfully prepared. Covalent and non-covalent interactions (e. G. Hydrogen bonds, ion exchange, charge transfer, chain entanglement) are supplemented by adsorption.
【學(xué)位授予單位】：廣西大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TQ427.26;O647.3

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本文編號：1500831