磁性奈米氧化鐵與層狀黏土之插層及吸附

Abstract

利用有機黏土與鐵離子以共沈澱法製備磁性有機黏土複合材料，並探討氧化鐵粒子與有機黏土的機制及其在原油吸附上的應用。 一、將磁性氧化鐵粒子利用逐步插層法，插層於矽酸鹽層黏土中。鈉型蒙脫土經由一系列聚醚胺鹽插層改質（稱為有機黏土），可將層間距由12 Å最高提至91 Å。利用共沈澱法結合可在低溫下分散於水中的有機黏土及磁性氧化鐵，以製備有機黏土與磁性氧化鐵之複合材料，並探討磁性氧化鐵吸附或插層於有機黏土的機制。研究發現利用層間距最大之有機黏土D4000/MMT (91 Å)，因其較大的層間距可提供氧化鐵在黏土層間生成。由TEM觀察可知，氧化鐵粒子生成於黏土層間（層間距約47 Å）。 二、為了使此複合材料可作為磁性有機吸附劑，具有高的有機含量是必需的。D4000-MMT/Iron oxide複合材料由TGA測量得知，其有機含量可高達51 wt %，並可分散於甲苯中（1 wt %），進而將其應用於原油吸附。相對於複合材料的重量，最大原油吸附量可高達4倍，並維持其磁性，且氧化鐵含量僅17 wt %。 關鍵詞：磁性有機黏土、層狀矽酸鹽黏土、氧化鐵、原油、吸附、插層。

Magnetic and organic layered composite was prepared by the co-precipitation of organoclay with Fe(II)/Fe(Ⅲ) salts. Interaction mechanism of iron oxide particles into organoclay interlayer and their application for crude oil adsorption are studied. Part Ⅰ: The iron oxide particles were intercalated into the layered silicate clay by stepwise intercalation. The sodium montmorillonite (Na+–MMT) was modified by a series of poly(oxyalkylene)-amine salts to yield a spatially-expanded silicates (named as Organoclay) from the original 12 Å up to 91 Å. Combining the low-temperature-dispersible Organoclay with the iron-oxide particles ultimately produced a series of organoclay/iron oxide composite by the co-precipitation method. Two different mechanisms of adsorption and intercalation were found. The use of D4000 intercalated MMT at high d spacing (91 Å) allowed the incorporation of iron-oxide in the organoclay interlayer. As a result, the composite of Fe3O4/D4000/clay at 47 Å d spacing were obtained and observed the iron-oxide particles existed in the clay gallery by TEM. Part Ⅱ: In order to prepare a magnetic composite with functions for absorbing organics, high organic content in the clay layers is prepared. The TGA data of D4000-MMT/iron oxide composite showed the organic fraction up to 51 wt % and consequently dispersible in toluene (1 wt %). When applied for oil adsorption, the result of adsorption capacity at 4-fold of crude oil weight absorbed by the composites (by weight) was achieved. Due to the presence of iron-oxide particles (ca. 17 wt %), the oil-adsorbed Organoclay still retained the magnetic property and the compounds were movable by an applied magnetic field.

Keywords: magnetic organoclay, layered silicate, iron oxide, crude oil, adsorption, intercalation.