林产化学与工业
林產化學與工業
림산화학여공업
Chemistry and Industry of Forest Products
2015年
5期
45-52
,共8页
郝汉%陈保莹%陈维韬%郭鑫宇%刘文君%吴学民
郝漢%陳保瑩%陳維韜%郭鑫宇%劉文君%吳學民
학한%진보형%진유도%곽흠우%류문군%오학민
阿维菌素%羧甲基化木质素%吸附%动力学%热力学
阿維菌素%羧甲基化木質素%吸附%動力學%熱力學
아유균소%최갑기화목질소%흡부%동역학%열역학
avennectins%carboxymethylated lignin%adsorption%kinetic%thermodynamics
通过凝胶渗透色谱、红外光谱和官能团含量测定表明经过羧甲基化改性后的碱木质素的分子质量增加,多分散性降低;分子中酚羟基含量减少,羧基含量增加。在此基础上采用振荡吸附实验研究了羧甲基化木质素( CML)在阿维菌素颗粒表面的吸附等温线、动力学和热力学。结果表明,吸附等温线符合Langmuir模型,饱和吸附量和吸附常数均随温度升高而降低,最大饱和吸附量为9.569 mg/g,0<RL <1表明该吸附易于进行;吸附动力学符合准二级动力学方程,吸附速率常数随温度升高而增加,吸附平衡时间约为60 min;吸附热力学结果表明:ΔGad <0、ΔHad <0、ΔSad >0,表明该吸附为自发、放热、熵增过程;由ΔHad为-5.18 kJ/mol, Ea 为14.23 kJ/mol可知该吸附过程属于物理吸附,主要作用力为范德华力。 SEM分析表明,阿维菌素颗粒表面光滑无孔型结构,吸附CML后可有效阻止阿维菌素团聚,增加其悬浮剂物理稳定性。由此可知,CML能够在阿维菌素颗粒表面形成稳定吸附,适合作为分散剂用于阿维菌素水悬浮剂。
通過凝膠滲透色譜、紅外光譜和官能糰含量測定錶明經過羧甲基化改性後的堿木質素的分子質量增加,多分散性降低;分子中酚羥基含量減少,羧基含量增加。在此基礎上採用振盪吸附實驗研究瞭羧甲基化木質素( CML)在阿維菌素顆粒錶麵的吸附等溫線、動力學和熱力學。結果錶明,吸附等溫線符閤Langmuir模型,飽和吸附量和吸附常數均隨溫度升高而降低,最大飽和吸附量為9.569 mg/g,0<RL <1錶明該吸附易于進行;吸附動力學符閤準二級動力學方程,吸附速率常數隨溫度升高而增加,吸附平衡時間約為60 min;吸附熱力學結果錶明:ΔGad <0、ΔHad <0、ΔSad >0,錶明該吸附為自髮、放熱、熵增過程;由ΔHad為-5.18 kJ/mol, Ea 為14.23 kJ/mol可知該吸附過程屬于物理吸附,主要作用力為範德華力。 SEM分析錶明,阿維菌素顆粒錶麵光滑無孔型結構,吸附CML後可有效阻止阿維菌素糰聚,增加其懸浮劑物理穩定性。由此可知,CML能夠在阿維菌素顆粒錶麵形成穩定吸附,適閤作為分散劑用于阿維菌素水懸浮劑。
통과응효삼투색보、홍외광보화관능단함량측정표명경과최갑기화개성후적감목질소적분자질량증가,다분산성강저;분자중분간기함량감소,최기함량증가。재차기출상채용진탕흡부실험연구료최갑기화목질소( CML)재아유균소과립표면적흡부등온선、동역학화열역학。결과표명,흡부등온선부합Langmuir모형,포화흡부량화흡부상수균수온도승고이강저,최대포화흡부량위9.569 mg/g,0<RL <1표명해흡부역우진행;흡부동역학부합준이급동역학방정,흡부속솔상수수온도승고이증가,흡부평형시간약위60 min;흡부열역학결과표명:ΔGad <0、ΔHad <0、ΔSad >0,표명해흡부위자발、방열、적증과정;유ΔHad위-5.18 kJ/mol, Ea 위14.23 kJ/mol가지해흡부과정속우물리흡부,주요작용력위범덕화력。 SEM분석표명,아유균소과립표면광활무공형결구,흡부CML후가유효조지아유균소단취,증가기현부제물리은정성。유차가지,CML능구재아유균소과립표면형성은정흡부,괄합작위분산제용우아유균소수현부제。
The analysis by FT-IR, GPC and functional groups content tests indicated that carboxymethylated lignin ( CML) had higher molecular weight, lower polydispersity, less phenolic hydroxyl and more carboxyl content than those of alkali lignin ( AL) . In order to investigate the feasibility of using CML to disperse avennectins particles in aqueous suspension, the adsorption isotherm, kinetics and thermodynamics of CML on avennectins particles surfaces were studied by batch equilibrium experiments. The results showed that the adsorption of CML was fitted to Langmuir isotherm equation, and the saturated adsorption amounts and Langmuir constants decreased with temperature increasing. The maximum saturated adsorption amount was 9. 569 mg/g, and 0<RL <1 indicated that the adsorption process was feasibility. The adsorption process followed the pseudo-second-order kinetic model with the entire adsorption, and the adsorption rate constants increased with temperature increasing. The equilibrium adsorption time was approximately 60 min. The thermodynamic parameters were obtained asΔGad <0,ΔHad <0 andΔSad >0. This indicated that the adsorption was a spontaneous, exothermic and entropy process. Theoretically, high temperature was not beneficial to the adsorption process. The values ofΔHad = -5. 18 kJ/mol implied that Van der Waals forces were responsible for the binding of CML with avennectins. The values of Ea =14. 23 kJ/mol indicated that the adsorption process was physical adsorption. The SEM showed that abamectin particle surface was smooth without hole structure. Abamectin particles adsorbed by CML could prevent particle from aggregation effectively, and increase physical stability of abamectin SC. The adsorption characteristics study demonstrated that CML was able to form stable adsorption on avermectin particles surfaces, and eligible to be used as a suspending agent in avermectin suspension.