浙江大学学报（农业与生命科学版）
浙江大學學報（農業與生命科學版）
절강대학학보（농업여생명과학판）
JOURNAL OF ZHEJIANG UNIVERSITY(AGRICULTURE & LIFE SCIENCES)
2014年
3期
297-302
,共6页
朱青%施元旭%范冬梅%于翠平%孙志明%王校常
硃青%施元旭%範鼕梅%于翠平%孫誌明%王校常
주청%시원욱%범동매%우취평%손지명%왕교상
端羟基%超支化聚合物%茶多酚%吸附%解吸
耑羥基%超支化聚閤物%茶多酚%吸附%解吸
단간기%초지화취합물%다다분%흡부%해흡
hydroxyl-terminated%hyperbranched polymer%tea polyphenol%adsorption%desorption
采用一步法,通过控制 AB2单体和三羟甲基丙烷的摩尔量,利用 Michael 加成反应制备得到一种端羟基超支化聚(胺酯)[Hyperbranched poly(amine-ester),HPAE],在此基础上研究了 HPAE 对茶多酚(tea polyphenols, TPs)的吸附特性及其反应时间和不同 pH 对该吸附行为的影响.结果表明：在298 K 条件下,pH 7,m(TPs)∶m (HPAE)=14∶1时,吸附量随时间的增加而增大,吸附6 h 后达到平衡,其实验所得平衡吸附量 Qe(experiment, Exp)为279.69 mg/g.吸附动力学模拟结果显示其准一级动力学模型、准二级动力学模型和 Weber-Morris 颗粒内扩散模型的 R 2分别为0.6148,0.9977,0.7445.准二级动力学模型拟合计算所得平衡吸附量 Qe,2(calculation, Cal)为302.11 mg/g,与 Qe(Exp)更为接近,因此该吸附过程符合准二级动力学方程,并且可能是物理吸附为主. HPAE 对茶多酚的吸附量主要受介质 pH 影响.在298 K 条件下,m(TPs)∶m(HPAE)=5∶1时吸附量随 pH 升高而增加,当 pH=4时,平衡吸附量 Qe 为72.56 mg/g；当 pH=7时,平衡吸附量 Qe 为194.90 mg/g.利用 pH 对吸附的效应特性,可通过调节 pH 方法方便洗脱吸附茶多酚.结果也显示该吸附剂对茶多酚的吸附能力远远大于相同吸附条件下大孔树脂的吸附能力.
採用一步法,通過控製 AB2單體和三羥甲基丙烷的摩爾量,利用 Michael 加成反應製備得到一種耑羥基超支化聚(胺酯)[Hyperbranched poly(amine-ester),HPAE],在此基礎上研究瞭 HPAE 對茶多酚(tea polyphenols, TPs)的吸附特性及其反應時間和不同 pH 對該吸附行為的影響.結果錶明：在298 K 條件下,pH 7,m(TPs)∶m (HPAE)=14∶1時,吸附量隨時間的增加而增大,吸附6 h 後達到平衡,其實驗所得平衡吸附量 Qe(experiment, Exp)為279.69 mg/g.吸附動力學模擬結果顯示其準一級動力學模型、準二級動力學模型和 Weber-Morris 顆粒內擴散模型的 R 2分彆為0.6148,0.9977,0.7445.準二級動力學模型擬閤計算所得平衡吸附量 Qe,2(calculation, Cal)為302.11 mg/g,與 Qe(Exp)更為接近,因此該吸附過程符閤準二級動力學方程,併且可能是物理吸附為主. HPAE 對茶多酚的吸附量主要受介質 pH 影響.在298 K 條件下,m(TPs)∶m(HPAE)=5∶1時吸附量隨 pH 升高而增加,噹 pH=4時,平衡吸附量 Qe 為72.56 mg/g；噹 pH=7時,平衡吸附量 Qe 為194.90 mg/g.利用 pH 對吸附的效應特性,可通過調節 pH 方法方便洗脫吸附茶多酚.結果也顯示該吸附劑對茶多酚的吸附能力遠遠大于相同吸附條件下大孔樹脂的吸附能力.
채용일보법,통과공제 AB2단체화삼간갑기병완적마이량,이용 Michael 가성반응제비득도일충단간기초지화취(알지)[Hyperbranched poly(amine-ester),HPAE],재차기출상연구료 HPAE 대다다분(tea polyphenols, TPs)적흡부특성급기반응시간화불동 pH 대해흡부행위적영향.결과표명：재298 K 조건하,pH 7,m(TPs)∶m (HPAE)=14∶1시,흡부량수시간적증가이증대,흡부6 h 후체도평형,기실험소득평형흡부량 Qe(experiment, Exp)위279.69 mg/g.흡부동역학모의결과현시기준일급동역학모형、준이급동역학모형화 Weber-Morris 과립내확산모형적 R 2분별위0.6148,0.9977,0.7445.준이급동역학모형의합계산소득평형흡부량 Qe,2(calculation, Cal)위302.11 mg/g,여 Qe(Exp)경위접근,인차해흡부과정부합준이급동역학방정,병차가능시물리흡부위주. HPAE 대다다분적흡부량주요수개질 pH 영향.재298 K 조건하,m(TPs)∶m(HPAE)=5∶1시흡부량수 pH 승고이증가,당 pH=4시,평형흡부량 Qe 위72.56 mg/g；당 pH=7시,평형흡부량 Qe 위194.90 mg/g.이용 pH 대흡부적효응특성,가통과조절 pH 방법방편세탈흡부다다분.결과야현시해흡부제대다다분적흡부능력원원대우상동흡부조건하대공수지적흡부능력.
Summary Tea polyphenols (TPs),as one kind of effective components in tea,are composed of catechins, anthocyanins,flavonoids,etc.Catechins take up 70% 80% of TPs.The epigallocatechin gallate (EGCG) is the most abundant and important bioactivity among TPs.Various studies have demonstrated that EGCG possesses a higher efficient bioactivity compared with other components of tea polyphenols, especially in inhibiting carcinogenesis and preventing metastasis in established tumors.Therefore,it was studied widely to develop new methods or techniques to enhance the efficiency of extraction and purification of TPs (including EGCG). <br> Now column chromatography is the main method in purification industry of TPs.However,this technique involves of organic solvents and complex operational processes,which leads to an environmental pollution and increases the additional costs virtually.The demand for an environment-friendly and cheaper technique in TPs industry is growing rapidly while more people become to pay attention to ambient bio-environment,so seeking for some new methods or new materials is of great significance.The hyperbranched poly (amine-ester)(HPAE) is a new sort of materials,having internal cellular structure and a large amount of hydroxyl terminals.HPAE has been widely used as surface modifiers,drug carriers and adsorbents for heavy metal ions on account of its high adsorption properties and complex ability.To date,there is no research on the adsorption of tea polyphenols by HPAE.The objective of this study is to investigate the characteristics of HPAE as a new environment-friendly and low-energy adsorbent for the adsorption of tea polyphenols from aqueous solutions. <br> The adsorbent HPAE was prepared by one step method with 1-(bis(2-hydroxyethyl)amino) pentan-3-one(as a AB2 monomer) and 2-ethyl-2-(hydroxymethyl)-1,3-propanediol (as a core molecule) in our laboratory.The kinetic experiments of adsorption were done with 10 mL HPAE(1%,w/w)and 40 mL 98% TPs solution(3.5 g/L) under the condition of 298 K and pH 7.0.The TPs contents in supernatant were determined by HPLC methods. The experiments about effects of different pH values (from 4.0 to 8.0) on adsorption also were done with similar steps with 40 mL TPs solution (1.25 g/L).Finally,the comparison of the adsorption capacity was made among HPAE and 1 6 kinds of traditional macroporous resins under the same condition of 298 K,pH=7. <br> The results indicated that the adsorption of tea polyphenols by HPAE increased with time and reached equilibrium time in six hours of contact.The experimental value of the equilibrium adsorption capacity Q e(Exp)was 279.69 mg/g.The R 2 values were 0.614 8,0.997 7 and 0.744 5 for the pseudo-first-order kinetic model,pseudo-second-order kinetic model and intraparticle diffusion kinetic model,respectively.The pseudo-second-order kinetic model due to its higher R 2 value and closest Q e,2(Cal),was considered to be the best choice to describe the adsorption behavior of tea polyphenols by HPAE,suggesting that the adsorption mechanism might be a physical adsorption process. The increase in pH from 4 to 8 resulted in the increase in the TPs adsorption capacity,indicating that pH had an obvious effect on the TPs adsorption capacity onto HPAE and adsorbed tea polyphenols could be desorbed by controlling pH value in acid medium.The maximum adsorption capacity of HPAE was 194.90 mg/g at the present experiment condition,and far greater than the adsorption capacity of macroporous resins studied widely in TPs industry,such as LSA-8,LSA-20, XDA-1,HPD600,NKA,AB-8,D3520,D4020,PVPP and PA,etc. <br> In conclusion,the new adsorbent HPAE has excellent adsorption and desorption properties for tea polyphenols. Its adsorption capacity could achieve 1 94.90 mg/g,and adsorption of TPs could be desorbed easily by adjusting pH instead of using organic solvents.HPAE shows a great potential as an environment-friendly and high efficiency substitute materials for tea comprehensive processing.
