- 學位論文
元素補償添加對水熱合成鋅膨潤石影響之研究
Study for compensation of elements on the hydrothermal synthesis of zinc-smectite
摘要
於水熱環境中，常因標準化學劑量配比的元素在水溶液中溶解度差異甚大，影響實際參與產物合成之元素配比，導致不易預期的雜相產生，因此本研究進行水熱合成實驗，探討溶液對各元素溶解情形，並做元素補償添加，以期提升鋅膨潤石的合成純度，並藉由陽離子交換、表面改質來證明元素補償可有效提升產物特性。 結果顯示，隨著元素補償增加，各元素於反應後水溶液中濃度逐漸上升且趨於飽和，其中又以鈉源所需補償最多，鋁源補償最少。當補償添加至第二次，鈉、鋅離子於水中溶解度逐漸往飽和狀態趨近，而矽、鋁離子則趨近於定值，故判定已達到反應水溶液中所需飽和濃度。由XRD分析得知，鋅膨潤石(001)繞射峰強度隨元素補償添加而增強，且鋅膨潤石(001)繞射強度與高嶺石雜相(001)繞射峰比值由1.67升到5.56，增加3.33倍，可有效去除高嶺石雜相。利用ICP分析經由醋酸鈉法所交換之鈉離子可知，隨著元素補償添加其陽離子交換能力可由82提升至131 meq/100g，大幅提升其應用特性。由FT-IR證明本研究產物可進行表面修飾，且其CH2及CH3鍵結隨著元素補償添加其吸收峰隨之增強。由眾多結果顯示，於水熱合成實驗中，考慮各元素在水溶液中溶解度並進行適當之補償添加，可有效減少高嶺石雜相，並增加鋅膨潤石之純度及結晶性，大幅提升其應用層面。
並列摘要
In the hydrothermal environment, the fact that an element in an aqueous solution usually has a solubility significantly different from that of another element may affect the molar ratio of the elements participating in a synthesis, resulting in the occurrence of impurity phase. Therefore, this study performed a hydrothermal synthesis to examine the influences of the solution on the dissolution of each element while elements of compensation were added in an attempt to enhance the purity of synthesized zinc smectite. Cation exchange and surface modification were further adopted to verify the ability of element compensation in effectively improving product characteristics. The results show that, as the added elements of compensation increased, the concentration of each element in the reaction solution rose gradually to approach saturation, and the source of sodium appeared to be in the greatest need of compensation while the source of aluminum the least need. When compensation was performed the second time, the solubility of sodium and zinc ions in solution moved slowly toward saturation while that of silicon and aluminum ions approached a fixed value, indicating that the reaction solution had reached the required saturation levels. As revealed by the results of XRD analysis, the zinc-smectite (001) diffraction peak sustained a greater intensity as the elements of compensation were added. Moreover, the ratio of the zinc-smectite (001) diffraction intensity to kaolinite impurity (001) diffraction peak rose 3.33 times from 1.67 to 5.56, suggesting that kaolinite impurity could be effectively removed. CEC was measured by the sodium acetate method, and with ICP analysis, it was known that as the added elements of compensation increased, cation exchange capacity ascended from 82 to 131 meq/100g to significantly improve the application characteristics of the compensated zinc smectite. The infrared spectra showed that the product of this study could be surface modified, and the absorption bands of the –CH at functional group reported an enhanced absorption as the elements of compensation were added. As demonstrated by the above results, in hydrothermal synthesis, taking into consideration of the aqueous solubility of each participating elements and adding appropriate elements of compensation can effectively reduce kaolinite impurity, increase the zinc-smectite purity and crystallinity, and significantly enhance its application level.