Polymer/layered silicate nanocomposites: a review from preparation to processing

This critical review provides a processing-structure-property perspective on recent advances in cellulose nanoparticles and composites produced from them. It summarizes cellulose nanoparticles in terms of particle morphology, crystal structure, and properties. Also described are the self-assembly and rheological properties of cellulose nanoparticle suspensions. The methodology of composite processing and resulting properties are fully covered, with an emphasis on neat and high fraction cellulose composites. Additionally, advances in predictive modeling from molecular dynamic simulations of crystalline cellulose to the continuum modeling of composites made with such particles are reviewed (392 references).

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Cellulose nanomaterials review: structure, properties and nanocomposites

Polymer-based composites were heralded in the 1960s as a new paradigm for materials. By dispersing strong, highly stiff fibres in a polymer matrix, high-performance lightweight composites could be developed and tailored to individual applications. Today we stand at a similar threshold in the realm of polymer nanocomposites with the promise of strong, durable, multifunctional materials with low nanofiller content. However, the cost of nanoparticles, their availability and the challenges that remain to achieve good dispersion pose significant obstacles to these goals. Here, we report the creation of polymer nanocomposites with functionalized graphene sheets, which overcome these obstacles and provide superb polymer-particle interactions. An unprecedented shift in glass transition temperature of over 40 degrees C is obtained for poly(acrylonitrile) at 1 wt% functionalized graphene sheet, and with only 0.05 wt% functionalized graphene sheet in poly(methyl methacrylate) there is an improvement of nearly 30 degrees C. Modulus, ultimate strength and thermal stability follow a similar trend, with values for functionalized graphene sheet- poly(methyl methacrylate) rivaling those for single-walled carbon nanotube-poly(methyl methacrylate) composites.

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Functionalized graphene sheets for polymer nanocomposites

Background Since at least 400 C.E., when the Mayans first used layered clays to make dyes, people have been harnessing the properties of layered materials. This gradually developed into scientific research, leading to the elucidation of the laminar structure of layered materials, detailed understanding of their properties, and eventually experiments to exfoliate or delaminate them into individual, atomically thin nanosheets. This culminated in the discovery of graphene, resulting in a new explosion of interest in two-dimensional materials. Layered materials consist of two-dimensional platelets weakly stacked to form three-dimensional structures. The archetypal example is graphite, which consists of stacked graphene monolayers. However, there are many others: from MoS 2 and layered clays to more exotic examples such as MoO 3 , GaTe, and Bi 2 Se 3 . These materials display a wide range of electronic, optical, mechanical, and electrochemical properties. Over the past decade, a number of methods have been developed to exfoliate layered materials in order to produce monolayer nanosheets. Such exfoliation creates extremely high-aspect-ratio nanosheets with enormous surface area, which are ideal for applications that require surface activity. More importantly, however, the two-dimensional confinement of electrons upon exfoliation leads to unprecedented optical and electrical properties. Liquid exfoliation of layered crystals allows the production of suspensions of two-dimensional nanosheets, which can be formed into a range of structures. (A) MoS 2 powder. (B) WS 2 dispersed in surfactant solution. (C) An exfoliated MoS 2 nanosheet. (D) A hybrid material consisting of WS 2 nanosheets embedded in a network of carbon nanotubes. Advances An important advance has been the discovery that layered crystals can be exfoliated in liquids. There are a number of methods to do this that involve oxidation, ion intercalation/exchange, or surface passivation by solvents. However, all result in liquid dispersions containing large quantities of nanosheets. This brings considerable advantages: Liquid exfoliation allows the formation of thin films and composites, is potentially scaleable, and may facilitate processing by using standard technologies such as reel-to-reel manufacturing. Although much work has focused on liquid exfoliation of graphene, such processes have also been demonstrated for a host of other materials, including MoS 2 and related structures, layered oxides, and clays. The resultant liquid dispersions have been formed into films, hybrids, and composites for a range of applications. Outlook There is little doubt that the main advances are in the future. Multifunctional composites based on metal and polymer matrices will be developed that will result in enhanced mechanical, electrical, and barrier properties. Applications in energy generation and storage will abound, with layered materials appearing as electrodes or active elements in devices such as displays, solar cells, and batteries. Particularly important will be the use of MoS 2 for water splitting and metal oxides as hydrogen evolution catalysts. In addition, two-dimensional materials will find important roles in printed electronics as dielectrics, optoelectronic devices, and transistors. To achieve this, much needs to be done. Production rates need to be increased dramatically, the degree of exfoliation improved, and methods to control nanosheet properties developed. The range of layered materials that can be exfoliated must be expanded, even as methods for chemical modification must be developed. Success in these areas will lead to a family of materials that will dominate nanomaterials science in the 21st century.

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Liquid Exfoliation of Layered Materials

Recent advances in graphene based polymer composites

This review is designed to be a comprehensive source for polymer nanocomposite research, including fundamental structure/property relationships, manufacturing techniques, and applications of polymer nanocomposite materials. In addition to presenting the scientific framework for the advances in polymer nanocomposite research, this review focuses on the scientific principles and mechanisms in relation to the methods of processing and manufacturing with a discussion on commercial applications and health/safety concerns (a critical issue for production and scale-up). Hence, this review offers a comprehensive discussion on technology, modeling, characterization, processing, manufacturing, applications, and health/safety concerns for polymer nanocomposites.

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Review article: Polymer-matrix Nanocomposites, Processing, Manufacturing, and Application: An Overview

Understanding the structure−property relationship in polymer/layered silicate nanocomposites is of fundamental importance in designing materials with desired properties. To understand these relations in the case of poly(butylene succinate) (PBS)/organically modified layered silicate (OMLS) nanocomposites, we studied the rheological properties of these materials in detail, because the rheological behavior of polymer/OMLS nanocomposites is strongly influenced by their nanostructure and the interfacial characteristics. For this reason, a series of PBS/OMLS nanocomposites were prepared using a simple melt intercalation technique. Two different types of OMLS, montmorillonite (mmt) modified with octadecylammonium chloride and saponite (sap) modified with quaternary hexadecyl tri-n-butylphosphonium bromide, were used for the nanocomposite preparations. The structure of nanocomposites in the nanometer scale was characterized using wide-angle X-ray diffraction (WAXD) analyses and transmission electron microscopy (...

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Structure-Property Relationship in Biodegradable Poly(butylene succinate)/Layered Silicate Nanocomposites

New polylactide (PLA)/layered silicate nanocomposites have been prepared successfully by simple melt extrusion of PLA and organically modified montmorillonite. The d spacings of both the organically modified montmorillonite and intercalated nanocomposites were investigated by wide-angle X-ray diffraction (WAXD) analysis, and the morphology of these nanocomposites was examined by transmission electron microscopy (TEM). Using oligo(e-caprolactone) (o-PCL) as a compatibilizer, the effect of compatibilizer in nanocomposites was investigated by focusing on two major aspects:  morphological analysis and mechanical property measurements. The intercalated nanocomposites exhibited remarkable improvement of materials properties in both solid and melt states as compared to that of PLA matrices without clay.

New Polylactide/Layered Silicate Nanocomposites. 1. Preparation, Characterization, and Properties

https://www.toyota-ti.ac.jp/Lab/Zairyo/5z50/members2005/publications/032Polymer.pdf

Masami Okamoto

Papers

Polymer/layered silicate nanocomposites: a review from preparation to processing

Review article: Polymer-matrix Nanocomposites, Processing, Manufacturing, and Application: An Overview

Structure-Property Relationship in Biodegradable Poly(butylene succinate)/Layered Silicate Nanocomposites

New Polylactide/Layered Silicate Nanocomposites. 1. Preparation, Characterization, and Properties

New polylactide-layered silicate nanocomposites. 2. Concurrent improvements of material properties, biodegradability and melt rheology