Intercalated Clay Nanocomposites
Intercalated clay nanoparticles are dispersed in a continuous polymeric matrix. (RDC 7/23/2009) “Intercalation is the insertion of a molecule (or group) between two other molecules (or groups). For example, 2,4 dichlorophenoxyacetic acid or 2-(2,4 dichlorophenoxy-)propionic acid intercalates between layers of clays.” (Wikipedia 7/23/2009)
Nanoclays Exfoliation is a process where packets of nanoclay platelets separate from one another in a polymer matrix. During exfoliation, platelets at the outermost region of each packet cleave off, exposing more platelets for separation. Gallery is the space between parallel layers of clay platelets. The gallery spacing changes depending on the nature of the molecule or polymer occupying the space. Intercalant is any compound capable of entering the clay gallery and bonding to its surface. Intercalate is a clay-chemical complex where the clay gallery spacing has increased due to the process of surface modification. Under the proper conditions of temperature and shear, an intercalate is capable of exfoliating in a resin matrix. Inorganic nanoparticlate --- a layered inorganic material, e.g., clay, with one or more dimensions, such as length, width or thickness, in the nanometer size range and which is capable of undergoing ion exchange. Modified clay --- a clay material which has been treated with any inorganic or organic compound that is capable of undergoing ion exchange reactions with the cations present at the interlayer surfaces of the clay. Nanoclays can form chemical complexes with an intercalant that ionically bonds to surfaces in between the layers making up the clay particles. This results in a material which is compatible with many different kinds of host resins permitting uniform dispersion of the clay filler. Nanoparticulates are particles with diameters less than 1000 nm. Platelets are individual layers of the layered material. The inorganic nanoparticulate of the inorganic-organic nanocomposite can be natural or synthetic such as smectite clay, and should have certain ion exchange properties as in smectite clays, rectorite, vermiculite, illite, micas and their synthetic analogs, including laponite, synthetic mica-montmorillonite and tetrasilicic mica. (Williams, David A.,et al; US Patent 7,531,613; 5/12/2009)
Recent US Patents
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Recent Journal Articles
To get to the abstract or article, copy the citation and paste it into favorite search engine (ex. Google). The date is the date the entry was found. 7/10/2009 Processing of transmission electron microscope images for quantification of the layer dispersion degree in polymer-clay nanocomposites (p 531-542) Journal of Applied Polymer Science 114 #1 (2009)
Review Articles
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Editor's Notes
As the literature is reviewed, and items of interest concerning this topic are found. These may be added in an abbreviated form with the reference. Readers and contributors are invited to add their own notes. Contributors may add them directly and other readers can simply send their notes to the editor, Roger Corneliussen at rcorneliussen@4spe.org. He may edit and add them to this page at his discretion.