Structure and nanomechanics of nanoreinforced polymeric materials

Joint research project

Project leaders: Clara Silvestre, Rumiana Kotsilkova Kirilova
Agreement: BULGARIA - BAS - Bulgarian Academy of Sciences
Call: CNR/BAS 2013-2015
Department: Molecular Design
Thematic area: Chemical sciences and materials technology
Status of the project: New

Research proposal

Nanoscience and nanotechnology are broad domains of research and innovation; therefore they necessitate special research techniques and methodologies for fine analysis. The concept of nanofiller reinforcement of polymers, resulting in multifunctional or metamaterials is attracting a great deal of technological and scientific interest owing to dramatic enhancements in physical and mechanical properties of the polymers with minimal increase in density due to the low nanofiller loading required. A thorough understanding of the changes to the structure and properties at the nanoscale by the processing conditions imposed is essential to tailor nanocomposite for specific applications. It has been known that materials and structures with nanoscale dimensions do not behave in the same manner as their macro-scale counterparts. Unfortunately, most of our knowledge is based on macro scale material behavour, which many times fails to describe material response in small scale dimensions because of the dominance of surface and interface effects, number of grains in a given structure and etc.
In general, mechanics of nanomaterials are essential elements in all of the transcendent technologies, however new measurement tools integrating high-resolution imaging instruments, are necessary in order to make further advances in the field. There are several important modern developments in nanomechanical characterization tools and methods. Recently, the nanoindentation method has widely been adopted and used in the characterization of mechanical behaviour of materials at small scales. The method was well established for elastic-plastic materials, but it also offers a favorable means for the investigation of the mechanical behavior of thin films and coatings, which is important for many technical applications, e.g. for microelectronic devices and protective coatings. Atomic force microscopy is increasingly being used as a nanoindentation tool to measure local elastic properties of surfaces, as well as it is one of the foremost tools for imaging, measuring, and manipulating matter at nanoscale.
Meanwhile, polymer nanocomposites incorporating gold (Au) nanoparticles as well as clay nanolayers have already found a range of new applications in electronics and other engineering fields. However, for developing efficient and economically viable technology for those applications, a well developed understanding of nanodispersions, nanoscale structure and nanomechanics of materials are required. Many issues concerning the control of nanocomposite dispersion structure and understanding the structure-property relationships in order to ensure desired property enhancement needs of further developments. Therefore, in the last few years, the emphasis of nanocomposite research has been on the understanding of the structure–property relationships of those nanomaterials. The extremely large surface area available for interactions with a polymeric matrix is largely responsible for the properties enhancement. Moreover, establishing the morphological hierarchy in polymer/clay nanocomposites seems to be the key factor in developing and understanding the structure–property relationships in these systems. However, many issues concerning the control of nanocomposite dispersion structure and understanding the structure-property relationships in order to ensure desired mechanical property enhancement are unsolved, which strongly limit the industrial applications of those nanocomposites. It is increasingly important to assess the quality of the interface between the nanoreinforcement and the matrix, which facilitates improvements to composite predictive models. These week problems will be studied in more details in our project, which define the importance and the actuality of the proposed project topics.
The proposed project seeks to understand deeply the nanoreinforcement effects of nanofillers in polymers, as related to the structure and the interfaces at the nanoscale. To reach the goal, the project will study in details the structure, morphology, micro- and nanomechanical properties of epoxy and polypropylene based nanocomposites incorporating gold nanoparticles and clay nanolayers.

Research goals

The significance of the proposed joint project will be in obtaining new knowledge for the design and fabrication of nanocomposites with controlled structure and desired mechanical properties. The study will include advanced methods for nanoscale characterization of both bulk nanocomposite materials and thin films, thus to tailor nanocomposites for specific applications in electronics and engineering (e.g. packaging materials).
Objectives are:
(1) to elaborate appropriate process technology for fabrication of polymer nanocomposites under investigation, both bulk and coating samples;
(2) to control the Au nanoparticle dispersion and clay exfoliation in the polymer matrix using rheological approaches;
(3) to verify the effects of gold nanoparticles and clay nanolayers on the structure of the matrix polymer (epoxy resin and polypropylene) by characterization of the structure and morphology at the nanoscale;
(4) to understand better the nanofiller reinforcement and interfacial effects in polymer nanocomposites by using the experimental methods of micro and nanomechanics.
(5) fundamental understanding of the relations between nanoscale structure and nanomechanical properties of nanocomposites, as a basis for designing new materials.
In addition to these scientific objectives, there are other general objectives, such as to help both teams in submitting other research projects in this field, which will attract further national or international support; and to contribute to integrating young scientists in nanocomposite research and to give them opportunities to create new scientific contacts.
Novel aspects of the research program will be: (i) clarifying the role of surfaces and interfacial effects of nanofillers on the polymer structure and the final nanocomposite properties; (ii) application of rheological approaches for control on the process technology; (iii) application of nanomechanics as a method for investigation the of nanoreinforcement; (iv) fundamental study on the relations of structure and properties at the nanoscale.
The project will estimate how competitive are the polymer nanocomposite systems in comparison with conventional composites for application in electronics and engineering.

Last update: 08/06/2025