高校地质学报
高校地質學報
고교지질학보
GEOLOGICAL JOURNAL OF CHINA UNIVERSITIES
2014年
4期
537-548
,共12页
徐敏%盛玲%季峻峰%蔡进功
徐敏%盛玲%季峻峰%蔡進功
서민%성령%계준봉%채진공
蒙脱石%赖氨酸%壳聚糖%吸附%稳定性
矇脫石%賴氨痠%殼聚糖%吸附%穩定性
몽탈석%뢰안산%각취당%흡부%은정성
montmorillonite%L-lysine%chitosan%adsorption%stability
粘土矿物对有机质的吸附是自然界重要的过程之一。科学界对于有机质与粘土矿物的相互作用过程和机制研究仍处于一个比较薄弱的阶段。该文采用天然有机质赖氨酸(左旋)和壳聚糖与蒙脱石进行室内合成模拟实验,通过X射线衍射、化学分析和红外光谱分析的手段对反应产物进行系统研究。结果表明,蒙脱石对赖氨酸和壳聚糖的吸附均存在两种机制:阳离子交换和有机分子间的相互吸引。赖氨酸在蒙脱石层间的排布有三种构型,随着赖氨酸浓度的增加分别以倾斜式、垂直呈“之”字形排列,最后形成第二排并可能生成简单肽;氨基酸的净电荷是影响吸附过程的重要因素,主要与pH值相关。壳聚糖能在蒙脱石层间形成分层结构,溶液的pH值和无机盐的存在都会影响吸附过程。壳聚糖-蒙脱石复合体在常温常压下水溶液中能稳定存在,而相同条件下赖氨酸易从蒙脱石层间释放,这主要是由有机质本身的性质以及有机质和蒙脱石的结合方式决定的。
粘土礦物對有機質的吸附是自然界重要的過程之一。科學界對于有機質與粘土礦物的相互作用過程和機製研究仍處于一箇比較薄弱的階段。該文採用天然有機質賴氨痠(左鏇)和殼聚糖與矇脫石進行室內閤成模擬實驗,通過X射線衍射、化學分析和紅外光譜分析的手段對反應產物進行繫統研究。結果錶明,矇脫石對賴氨痠和殼聚糖的吸附均存在兩種機製:暘離子交換和有機分子間的相互吸引。賴氨痠在矇脫石層間的排佈有三種構型,隨著賴氨痠濃度的增加分彆以傾斜式、垂直呈“之”字形排列,最後形成第二排併可能生成簡單肽;氨基痠的淨電荷是影響吸附過程的重要因素,主要與pH值相關。殼聚糖能在矇脫石層間形成分層結構,溶液的pH值和無機鹽的存在都會影響吸附過程。殼聚糖-矇脫石複閤體在常溫常壓下水溶液中能穩定存在,而相同條件下賴氨痠易從矇脫石層間釋放,這主要是由有機質本身的性質以及有機質和矇脫石的結閤方式決定的。
점토광물대유궤질적흡부시자연계중요적과정지일。과학계대우유궤질여점토광물적상호작용과정화궤제연구잉처우일개비교박약적계단。해문채용천연유궤질뢰안산(좌선)화각취당여몽탈석진행실내합성모의실험,통과X사선연사、화학분석화홍외광보분석적수단대반응산물진행계통연구。결과표명,몽탈석대뢰안산화각취당적흡부균존재량충궤제:양리자교환화유궤분자간적상호흡인。뢰안산재몽탈석층간적배포유삼충구형,수착뢰안산농도적증가분별이경사식、수직정“지”자형배렬,최후형성제이배병가능생성간단태;안기산적정전하시영향흡부과정적중요인소,주요여pH치상관。각취당능재몽탈석층간형성분층결구,용액적pH치화무궤염적존재도회영향흡부과정。각취당-몽탈석복합체재상온상압하수용액중능은정존재,이상동조건하뢰안산역종몽탈석층간석방,저주요시유유궤질본신적성질이급유궤질화몽탈석적결합방식결정적。
Organic matter adsorbed onto the surface of clay minerals is one of an important process in the natural environment. However, the process and mechanism of the interaction between natural organic matter and clay minerals is highly debated due to its complexity. To solve this problem, natural organic matter of L-lysine and chitosan are intercalated in montmorillonite. Chemical analysis, infrared spectroscopy and X-ray diffraction have been employed in the characterization of the reaction products. Our data indicated that the adsorption of the L-lysine and chitosan is both firstly dominated by cation exchange and secondly by adsorption of electrically neutral forms. For L-lysine, three configurations seem to form. At low concentrations, L-lysine is inclined in the interlayer. As the concentration of L-lysine increases, the molecules orientate perpendicular to the montmorillonitelayers, maybe in a zig-zag arrangement. When the concentration is higher enough, the second row of L-lysine appears and peptides may formed in the interlayer by L-lysine polymerisation. The net charge of amino acids, which depends on the pH value in both the bulk solution and in the proximity of the clay layer or the interlayer space, is an important factor affecting the adsorption process. For chitosan, a layered structure can form in the interlayer of montmorillonite. The pH value of the solution and the presence of the inorganic salt will affect the adsorption process. Chitosan-montmor illonite complexes in aqueous solution at room temperature and atmospheric pressure is stable, but under the same condition, L-lysine is easily released from the interlayer space of montmorillonite, which is related to the nature of the organic matter itself and its form combined with montmorillonite.