Polymer nanotechnology: Nanocomposites

Abstract

a b s t r a c tIn the large field of nanotechnology, polymer matrix based nanocomposites have become a prominent area of current research and development. Exfoliated clay-based nanocomposites have dominated the polymer literature but there are a large number of other significant areas of current and emerging interest. This review will detail the technology involved with exfoliated clay-based nanocomposites and also include other important areas including barrier properties, flammability resistance, biomedical applications, electrical/electronic/optoelectronic applications and fuel cell interests. The important question of the ''nano-effect'' of nanoparticle or fiber inclusion relative to their larger scale counterparts is addressed relative to crystallization and glass transition behavior. Of course, other polymer (and composite)-based properties derive benefits from nanoscale filler or fiber addition and these are addressed.

Organically modified hydrotalcite for compounding and spinning of polyethylene nanocomposites

“…For instance the strain at break of plates decreased from about 1700% for HDPE plates to 380% for LDH-5. The decrease in both tensile strength and strain at break at high nanofiller content, particularly in LDH-5 plates and LDH-3 fiber, has been attributed to the presence of hydrotalcite aggregates, that may behave as defects, and could also reduce the interfacial adhesion between the matrix and the filler [5,47]. Some other indications on the fiber drawing can be evaluated from the mechanical draw ratio " MEC , or the maximum drawability that is defined according to Equation (4): (4) where # b is the strain at break expressed in percentage [13,21].…”

“…The main reason of this interest lies certainly in the properties of the nanoclay, like high stiffness, and high aspect ratio, that may induce enhancement of various polymer properties (thermal stability, mechanical properties, flame resistance and gas barrier) even with small amount of filler [3,4]. The nano composite materials can exhibit properties over those expected from continuum mechanics predictions, not achieved with larger scale reinforcement [5]. Moreover, nanocomposites can be processed more easily than microcomposites.…”

“…The commercially available nanoparticles consist of aggregates or stacks of platelets which are broken up by stress applied during melt mixing. With proper processing conditions, organically modified nanofiller can be melt-dispersed into polyolefins and exfoliated, while it is not very good as that observed in polyamides, polyurethanes, and some other polar polymers [5]. However, significant improvement of thermo-mechanical, flame retardant, barrier, rheological properties and frequently better thermoforming properties were observed in nanofilled polyethylene [6][7][8]12], polypropylene [10] and polybutene [11].…”

Geomaterials: their application to environmental remediation

“…At one end of this classification scheme are well-ordered and stacked multilayers [41,42]. These consist of polymer chains intercalated between the host layers.…”

Specific Bending and Compressive Strenght of Poly(Vinyl Alcohol)-CNT Composites

“…The field of nanotechnology is one of the most popular areas for current research and development in basically all technical disciplines [1]. Ajayan et al [2] reported the first polymernanocomposites using CNTs as a filler.…”