The present study was carried out on the effect of acid leaching on the modification and structure alteration of montmorillonite. A nanostructured, activated material was prepared by selective leaching of pure smectite clay with different concentrations of sulfuric acid (1 10 N/L) at 85 ̊C for 120 min using a solid/liquid ratio of 1:20 and a reflux system. The Fourier transform infrared (FTIR), ...

Clay mineral studies in the U.S.S.R., mainly since 1960, are summarized. Electron diffraction techniques especially have been developed and used extensively. Methods have been developed for simultaneous recording of DTA curves and other properties. Polytypism of phyllosilicates has been studied intensively by Zvyagin and others. Mucfi new information on the structure and morphology of halloysit...

Isolated patches of white clay occurring in the terminal moraine of Long Island, Staten fsland, and southern New Jersey have been mentioned in a number of geologic descriptions. Such an occurrence was recently encountered during excavation for a building site and samples were submitted to the mineralogical laboratory of Columbia University for identification by Messrs. Schoonmaker and Kirkman. ...

B. B. Basak, Sharmistha Pal and S. C. Datta* Division of Soil Science and Agricultural Chemistry, Indian Agricultural Research Institute, New Delhi 110 012, India Present address: Directorate of Medicinal and Aromatic Plant Research, Boriavi, Anand 387 310, India Present address: Central Soil and Water Conservation Research and Training Institute, Research Centre, Madhya Marg, Chandigarh 160 01...

The Soil Series It is frequently possible to encounter, in a very limited area, almost the whole range of every soil property: from soil reaction values of pH 3.5 to pH 9.0, from structureless to very strongly structured, from sands to clays, from impermeable to excessively permeable materials etc. It has been one of the main objectives of the pedologist to classify this seemingly incomprehensi...

Clays have been used in southern Africa as photoprotectants by the indigenous people. Typically, two types of clay are used: one white in colour and the other red. In this work, the two clays were identified and characterized, and their in vitro SPF values measured. The clays afford a low SPF but offer broad-spectrum protection. No cutaneous side effects from the use of these clays are known. F...

The demand for robust hydrogels in pharmaceutical, biomedical, and industrial applications has motivated intense research efforts in these wet polymeric materials. Recent advances have resulted in different strategies for creating highly stretchable polymeric hydrogels, including sliding-ring gels (SR gels), nanocomposite gels (NC gels), doublenetwork gels (DN gels), macromolecular microsphere ...

Scaling relationships are identified between NMR longitudinal relaxation times and clay dispersion quality in polymer-paramagnetic clay nanocomposites. Derived from a previously published analytical relationship developed from a lamella-based model, the scaling relationships are based on the enhancement of NMR relaxation rates with increasing exfoliation and dispersion homogeneity. The paramagn...

To address the high salinity of flow-back water during hydraulic fracturing, we have studied the equilibrium partitioning of NaCl and water between the bulk phase and clay pores. In shale rocks, such a partitioning can occur between fractures with a bulk-like phase and clay pores. We use an advanced Grand Canonical Monte Carlo (GCMC) technique based on fractional exchanges of dissolved ions and...

-A method of clay mineral sample preparation for electron microprobe analysis has been developed in which a film of clay plus 10-12 wt. % colloidal graphite is deposited on a porous ceramic disc using a specially designed suction device. Correction procedures are used to obtain quantitative elemental analyses representing the average chemical composition of the prepared sample. A statistical te...