Open AccessJournal Article
XRD, TEM, and thermal analysis of Arizona Ca-montmorillonites modified with didodecyldimethylammonium bromide
TLDR
In this article, an Arizona SAz-2 Ca-montmorillonite was modified by a typical dialkyl cationic surfactant (didodecyldimethylammonium bromide, abbreviated to DDDMA) through direct ion exchange.Abstract:
An Arizona SAz-2 calcium montmorillonite was modified by a typical dialkyl cationic surfactant (didodecyldimethylammonium bromide, abbreviated to DDDMA) through direct ion exchange. The obtained organoclays were characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HR-TEM), high-resolution thermogravimetric analysis (HR-TG), and infrared emission spectroscopy (IES). The intercalation of surfactants greatly increased the basal spacing of the interlayers and the conformation arrangement of the loaded surfactant were assessed based on the XRD and TEM measurements. This work shows that the dialkyl surfactant can be directly intercalated into the montmorillonite without first undergoing Na(+) exchange. Moreover, the thermal stability of organoclays and the different arrangements of the surfactant molecules intercalated in the SAz-2 Ca-montmorillonite were determined by a combination of TG and IES techniques. The detailed conformational ordering of different intercalated surfactants under different conditions was also studied. The surfactant molecule DDDMA has proved to be thermally stable even at 400°C which indicates that the prepared organoclay is stable to significantly high temperatures. This study offers new insights into the structure and thermal stabilities of SAz-2 Ca-montmorillonite modified with DDDMA. The experimental results also confirm the potential applications of organic SAz-2 Ca-montmorillonites as adsorbents and polymer-clay nanocomposites.read more
Citations
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Removal of bisphenol A from wastewater by Ca-montmorillonite modified with selected surfactants
TL;DR: In this article, the structural properties of the prepared organoclays were characterized by XRD and BET instruments, and batch experiments were carried out on the adsorption of bisphenol A (BPA) under different experimental conditions of pH and temperature to determine the optimum BPA conditions.
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Enhanced removal of bisphenol A from aqueous solution by organo-montmorillonites modified with novel Gemini pyridinium surfactants containing long alkyl chain
TL;DR: In this article, the effect factors which played a significant role in removal of BPA from aqueous solution, such as the amount of modifier, alkyl chain length, contact time and solution pH were investigated in detail.
Journal ArticleDOI
A new ball milling method to produce organo-montmorillonite from anionic and nonionic surfactants
TL;DR: In this article, a ball milling method was used to prepare nonionic-organo-montmorillonite (NOMt) and anionic-nonionic organo-organononiononononomite (ANOMt), and the results showed that NOMt and ANOMt have better thermal stability than COMt.
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Facile synthesis of g-C3N4/montmorillonite composite with enhanced visible light photodegradation of rhodamine B and tetracycline
TL;DR: In this article, a novel g-C3N4/montmorillonite composite with enhanced visible light photocatalytic activity was synthesized via a facile two-step process including wet-chemical and calcination method.
Journal ArticleDOI
Removal characteristics of ammonium nitrogen from wastewater by modified Ca-bentonites
TL;DR: In this article, a modified inorganic bentonite (Na/Al) based on purified Ca-bentonite was prepared through exchanging Al and Na ions in the interlayer space of Ca bentonite.
References
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Journal ArticleDOI
Changes in the morphology of organoclays with HDTMA+ surfactant loading
Hongping He,Hongping He,Ray L. Frost,Thor E. Bostrom,Peng Yuan,Loc V. Duong,Dan Yang,Yunfei Xi,J. Theo Kloprogge +8 more
TL;DR: In this article, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and X-Ray Diffraction (XRD) were used to provide new insights into the interlayer structure and morphology of HDTMA+/montmorillonite organoclays.
Journal ArticleDOI
The dehydroxylation of the kaolinite clay minerals using infrared emission spectroscopy
Ray L. Frost,Anthony M. Vassallo +1 more
TL;DR: In this paper, the authors investigated the dehy- droxylation process of a series of kaolinite clay minerals, including halloysite and dickite, using Fourier transform in situ infrared emission spectroscopy over a temperature range of 100 to 800
Journal ArticleDOI
Modification of the surfaces of Wyoming montmorillonite by the cationic surfactants alkyl trimethyl, dialkyl dimethyl, and trialkyl methyl ammonium bromides.
TL;DR: A range of surfactant molecular environments within the surface-modified montmorillonite are proposed based upon their thermal decomposition.
Journal ArticleDOI
Modification of montmorillonite with cationic surfactants. Thermal and chemical analysis including CEC determination
TL;DR: In this article, the thermal stability of synthesized and commercial organically modified montmorillonites has been investigated using thermogravimetric analysis (TGA) using Fourier transform infrared spectroscopy (FTIR).
Journal ArticleDOI
'Rocky Mountain leather', sepiolite and attapulgite—an infrared emission spectroscopic study
TL;DR: In this article, infrared emission spectroscopy of the clay minerals attapulgite, sepiolite and ''Rocky Mountain leather'' has been used to characterise the thermal degradation over the temperature range of 100 to 700°C.