Endüstriyel kompozit malzemelerde ara yüzey davranışının moleküler dinamik simülasyonları

Composite materials are widely used in aerospace, automotive, and defense industries due to their excellent strength, high stiffness-to-weight ratio and corrosion resistance. Beyond these sectors, two other important areas for composites are the construction industry and natural gas purification. In construction, cementitious composites that incorporate recycled rubber have emerged as a promising approach to enhance concrete performance while mitigating the environmental impact of waste rubber, with nearly one billion tires discarded annually. In gas purification, polymer-based composite membranes are typically fabricated by embedding porous nanoparticles into a polymer matrix, thereby improving the separation performance and durability of the membranes. In both industries, the performance of composite materials is strongly influenced by the compatibility between their constituent components. In rubber/concrete composites, the hydrophobic nature of rubber particles weakens their adhesion to the hydrophilic cement matrix, compromising the strength and durability of the composite. To overcome this limitation, improving the rubber-concrete interfacial bond is required to develop high-performance, sustainable construction materials. With this motivation, in the first part of the thesis, we build atomistic models of the rubber/Calcium Silicate Hydrate (CSH) interface and perform Molecular Dynamics (MD) simulations to investigate its structural properties using Radial Distribution Function (RDF) and by calculating the interfacial adhesion energy. We then evaluated several surface modification strategies to improve the bonding between rubber and cement. Specifically, we considered different polymers, including Polycarboxylate Ether (PCE), Carboxymethyl Cellulose (CMC) and Polyvinyl Alcohol (PVOH) between concrete and rubber. Among these, the rubber/concrete/PCE composite showed a 7.3% increase in interfacial adhesion energy of compared to the unmodified rubber-concrete composite. In addition, when comparing the binding performance of CMC and PVOH, the rubber/concrete/CMC composite exhibited a 17.08% higher interfacial adhesion energy than the rubber/concrete/PVOH system. In the second part of this thesis, we investigated the carbon dioxide (CO2) separation performance of composite materials used in the natural gas purification. We build atomistic models of Zeolitic Imidazolate Framework-8(ZIF-8)/Polymer of Intrinsic Microporosity-1 (PIM-1) interface. To assess gas separation behavior, we employed gas permeation models, including the classical Maxwell model and the modified Felske model, using adsorption and diffusion data obtained from Grand Canonical Monte Carlo (GCMC) and MD simulations. We studied both pristine PIM-1 and amine-functionalized PIM-1 (AF-PIM-1), each combined with either crystal ZIF-8 or ZIF-8 under pressure (aZIF-8@0.4GPa), to construct a variety of Mixed Matrix Membranes (MMMs). Our results showed that MMMs incorporating aZIF-8@0.4GPa with PIM-1 exhibit a modest (1.4%) increase in interfacial adhesion energy compared to those containing cryZIF-8 with PIM-1. Additionally, the modified Felske model provided more accurate predictions of MMM permeability, showing lower deviation from experimental results than the Maxwell model. By analyzing different material classes including ZIFs, polymers and concrete, this thesis demonstrates that targeted surface or filler modifications can enhance interfacial bonding. The findings contribute to both the recycling of waste tires in the construction sector and the development of advanced membranes for gas separation.