Hybrid Interface in Sepiolite Rubber Nanocomposites: Role of Self-Assembled Nanostructure in Controlling Dissipative Phenomena

Abstract

Sepiolite (Sep)–styrene butadiene rubber (SBR) nanocomposites were prepared by using nano-sized sepiolite (NS-SepS9) fibers, obtained by applying a controlled surface acid treatment, also in the presence of a silane coupling agent (NS-SilSepS9). Sep/SBR nanocomposites were used as a model to study the influence of the modified sepiolite filler on the formation of immobilized rubber at the clay-rubber interface and the role of a self-assembled nanostructure in tuning the mechanical properties. A detailed investigation at the macro and nanoscale of such self-assembled structures was performed in terms of the organization and networking of Sep fibers in the rubber matrix, the nature of both the filler–filler and filler–rubber interactions, and the impact of these features on the reduced dissipative phenomena. An integrated multi-technique approach, based on dynamic measurements, nuclear magnetic resonance analysis, and morphological investigation, assessed that the macroscopic mechanical properties of clay nanocomposites can be remarkably enhanced by self-assembled filler structures, whose formation can be favored by manipulating the chemistry at the hybrid interfaces between the clay particles and the polymers.

Hybrid Silica-Based Fillers in Nanocomposites: Influence of Isotropic/Isotropic and Isotropic/Anisotropic Fillers on Mechanical Properties of Styrene-Butadiene (SBR)-Based Rubber

“…As observed in the case of silica nanorods, the formation of oriented Sepiolite aggregates in the rubber matrix reinforce mechanical properties of composites [ 46 ]. However, a surface state modification (HCl treatment) of Sepiolites nanofibers is often performed in order to create more silanol surface reactive groups and to favour the filler/rubber interaction [ 47 ]. Another alternative to conventional fillers could be the use of hybrid fillers with identical or different morphologies [ 48 ].…”

Atomic force microscopy nanoindentation kinetics and subsurface visualization of soft inhomogeneous polymer

“…Rapid atomic force microscopy (AFM) nanoindentation measurements give tip‐sample interaction curve at each point of the investigated area with a good resolution. Analysis of these data, in addition to the surface topography, gives a contrast of adhesion, stiffness (elastic modulus) of inhomogeneous polymers (Bahrami et al, 2015; Dokukin & Sokolov, 2012; Kaimaki, Smith, & Durkan, 2018; Schön et al, 2011; Yang, Chen, Ding, Liao, & Hwang, 2020; Young et al, 2011), filled rubbers (Cobani et al, 2019; Ohashi, Sato, Nakajima, Junkong, & Ikeda, 2018; Qu et al, 2011; including the stretched state (Morozov, Izumov, & Garishin, 2018) and the vicinity of defects and cracks (Morozov, 2016)), biological objects (Alsteens, Müller, & Dufrêne, 2017; Krieg et al, 2019), coatings (Morozov, Kamenetskikh, Beliaev, Scherban, & Kiselkov, 2020; Wei et al, 2020), and many other materials.…”

Kinetics of atomic force microscope probe interaction with inhomogeneous polymer surface in fast nano-indentation regime

“…Речь, в первую очередь, идет о методиках быстрой наноиндентации, когда благодаря высокой скорости взаимодействия зонда с поверхностью, каждой точке исследуемой области соответствует своя кривая взаимодействия. Расшифровка этих данных, помимо рельефа поверхности, позволяет получить контраст адгезии, жесткости (модуля упругости) неоднородных полимеров [1][2][3][4][5][6], наполненных резин [7-9] (в том числе в растянутом состоянии [10], в окрестности дефектов и трещин [11]), биологических объектов [12,13], покрытий [14,15] и многих других материалов.…”