nano clay and its applications

Nano clay and itrsquos applications

ByThikra Kadhim Ibrahim

ClayClay is a naturally occurring material composedprimarily of fine grained minerals which showsplasticity through a variable range of watercontent and which can be hardened when driedor fired Clay deposits are mostly composed ofclay minerals (phyllosilicate minerals) andvariable amount of water trapped in the mineralClay materials have been investigated because oftheir importance in agriculture in ceramics inconstruction and other uses

GENERAL STRUCTURE OF CLAY

Figure -1- (a) Silica tetrahedron

Figure- 1- (b) Alumina octahedral

Figure -2- General structure of clay mineral

mineral

CLASSIFICATION OF CLAY

(b) 21 clay structure Figure -3- (a) 11 clay structure

There are four main groups of clays 1- Kaolinite2-Montmottilonite-smectitiethe essential nanoclayraw material a 2 to 1 layered smectite clay mineral with a platey structure 3-Illite 4- Chlorite

GROUPS OF CLAYS

Nano-clayNano clays are minerals which have a high aspect ratio

and with at least one dimension of the particle in thenanometer range The purity and cationexchange capacity of the nano-clay are also criticalcharacteristics The purity is important in achievingmaximum increases in mechanical properties andachieving optimum clarity for use in films Impuritiesact as stress concentrators resulting in poor impactand tensile properties The cation exchange capacityprovides the surface activity necessary for acceptanceof modifiers or surface treatments

Figure 4 Crystal lattice structure of montmorillonite nanoclay

The nanoclay used is a surfacemodified montmorillonite mineralThe general formula for class ofmontmorillonite is(NaCa)033(Al2yMgy)Si4O10(OH)2nH2OFigure 4 shows the crystal latticestructure of montmorillonitenanoclay

Nano-clay clay

PREPARATION OF NANOCLAY

Figure Schematic process diagram of nanoclay preparation

APPLICATION OF NANOCLAY

1Nanoclay is used in the ink formulation It helps toadjust the consistency of printing inks to the desiredvalue avoiding pigment sedimentation providinggood colour distribution obtaining desired filmthickness etc by incorporation of small amount oforganically modified layered silicate

2Thickening lubricating oils with nanoclays canproduce especially high temperature resistantlubricating greases

3The performance of cosmetics is enhancedby the use of nanoclays and they allow goodcolour retention and coverage for naillacquers lipsticks and eye shadows

Fields of application (paints inks greases and cosmetics)

4Waste water treatment

The use of nanoclays in wastewater treatment has becomecommon in industry today Nanoclays exhibit a synergisticeffect with many commonly utilized water treatment unitprocesses including granular-activated charcoal reverseosmosis and air strippers Granular-activated carbon isparticularly effective at removing a large range of organicmolecules from water however is very poor for removinglarge molecules such as humic acid and wastewaterscontaining emulsified oil and grease Nanoclays have provento be the technology of choice for treating oily wastewaters

5Nanoclay as drug vehicle nanoclays as drugvehicle for controlled release of drug is oneof the born age area in medicinalapplication nanoclays have great potentialas compared to polymer and carbonnanotubes for drug delivery

applications