Barrier properties, of nanocomposite

Theoretical approaches on the barrier properties of nanocomposites beat fillers as impermeable nonoverlapping particles and assume no permeability changes in the polymer matrix. Effectively, this means that the permeability of the composite will be smaller than the permeability of the matrix (unfilled polymer) by a factor equal to path tortuosity in the composite (simply assuming that the penetrant path cannot cross any filler particles). This path tortuosity was calculated by Nielsen for completely aligned filler particles (aU fillers have then-larger surface parallel to the film surfaces, but there is no order in the filler center of mass), and its contribution to the composite permeability was derived to be... 

Mandal A, Chakrabarty D. Studies on the mechanical, thermal, morphological and barrier properties of nanocomposites based on poly(vinyl alcohol) and nanocellulose from sugarcane bagasse. J Ind Eng Chem 2014 20 462-73. 

Equation 3.1 clearly describes that the gas barrier property of nanocomposites depends primarily on two factors one is the dispersed layered silicate particles dimension and other is the dispersion of layered silicate in polymer matrix. When the degree of dispersion of layered silicate in the matrix is the same, barrier property directly depends on the dispersed layered silicate particles dimension, i.e. the aspect ratio. 

Swarmack C, Cox C, Hirt D, Liakos A, A 3D simulation study of barrier properties of nanocomposite films . Annual Technical Conference, Society of Plastics Engineers, 2003 610-2) 2100-4. 

The potentially high barrier properties of nanocomposites with the hierarchical strucmre of Fig. 3 are a primary motivation for this study [1,8,9]. Because polymer crystalhnity can irtfluence permeability, internal structrrre is characterized further using X-ray diffraction techniques. The corresponding oxygen permeation properties are reported for a few samples tested to date. 

In 2002, Lee et al. [51] reported the biodegradation of aliphatic polyester-based nanocomposites under compost. Figure 9.13(A, B) represent the clay content dependence of biodegradation of APES-based nanocomposites prepared with two different types of MMT clays. They assumed that the retardation of biodegradation was due to the improvement of the barrier properties of the aliphatic APSE after nanocomposite preparation with clay. However, there are no data about permeability. 

Park, H.W., Lee, W. K.,Park, C. Y.,Cho, W. J., Ha, C. S. (2003). Environmentally friendly polymer hybrids Parti. Meehanical, thermal, and barrier properties of thermoplastie stareh/elay nanocomposites. Journal of Materials Science, 38, 909-915. 

From a morphological point of view, there are four fundamental parameters that can be adjusted to maximize the barrier properties of clay nanocomposites. 

Messersmith, P.B. Giannelis, E.P. Synthesis and barrier properties of poly( -caprolactone)-layered silicate nanocomposites. J. Polym. Sci. Polym. Chem. 1995, 33 (7), 1047. 

The chemical-physical properties of nanocomposite and membrane finds unique place in sensor application due to combinational properties. The basic use of nanocomposite is to the products, which show many folds of improvement on the physical and mechanical properties or on the processing properties upon addition of very minute quantity of nanomaterials [99], Nanoscale particles not only enhance the mechanical properties but also have wide potential in the field of electronic, magnetic, optical, and chemical field. The polymer nanocomposites provide improvement over other known composites in thermal, mechanical, electrical, and even air barrier properties [64-70], Formulation of nanocomposite membranes with suitable polymer, suitable nanoparticles, and the processing technology of the nanocomposite are critical to success factor to dominate the gas sensor product in the market. 

Messersmith, P. B., Giannelis, E. R, Synthesis and barrier properties of poly(e-caprolactone)-layered silicate nanocomposites. loumal of Polymer Science Part A Polymer Chemistry. 7, 1047-1057 (1995), DOI 10.1002/pola.l995.080330707. 

M., Dubois, R, Vapor barrier properties of polycaprolactone montmo-rillonite nanocomposites Effect of clay dispersion. 2271-... 

---