
Siavash SoltanahmadiUniversity of Leeds · Institute of Functional Surfaces
Siavash Soltanahmadi
PhD
About
16
Publications
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194
Citations
Citations since 2017
Introduction
Additional affiliations
October 2013 - April 2017
Publications
Publications (16)
Investigation of lubrication behaviour of phase change materials (PCM) can be challenging in applications involving relative motion, e.g. sport (ice skating), food (chocolates), energy (thermal storage), apparel (textiles with PCM), etc. In oral tribology, a phase change often occurs in a sequence of dynamic interactions between the ingested PCM an...
Polysaccharides are often used as rheology modifiers in multiphasic protein-rich food systems. Recently, proteinaceous microgels have garnered research attention as promising lubricating agents. However, whether proteinaceous microgels can be used to replace polysaccharides in a tribological context remains poorly understood. In this study we compa...
Poroelastic materials are commonly found in biological systems, such as articulating cartilage, and the ability to predict their biphasic behaviour is a key step in the understanding of joint health and the development of biomimetic devices. Here, a fully coupled three dimensional finite element study is presented to demonstrate the permeability de...
The ability to replicate the load-bearing properties of articular cartilage is attractive for many engineering applications, particularly bearings where low friction, low wear, and high durability are required. Hydrogels are widely used materials spanning many diverse applications owing to their lubricity and unique mechanical/chemical properties....
Food oral processing research has attracted a great deal of attention in the last few decades owing to its paramount importance in governing sensory appreciation and pleasurable experience of consuming foods and beverages and eventually regulating nutrient intake. A range of physiologically-controlled unit operations from first bite, to particle si...
The ability to create super-lubricious aqueous lubricant is important for various biological and technological applications. Here, a non-lipid bio-lubricant with strikingly-low friction coefficients is fabricated (patented) by reinforcing a fluid-like hydrogel composed of biopolymeric nanofibrils with proteinaceous microgels, which synergistically...
The mechanisms of friction in natural joints are still relatively unknown and attempts at modelling cartilage-cartilage interfaces are rare despite the huge promise they offer in understanding bio-friction. This article derives a model combining finite strain, porous and thin film flow theories to describe the lubrication of cartilage-on-cartilage...
In wind turbine gearboxes, (near-)surface initiated fatigue is attributed to be the primary failure mechanism. In this work, the surface fatigue of a hydrogenated tungsten carbide/amorphous carbon (WC/aC:H) thin-film was tested under severe cyclic tribo-contact using PolyAlphaOlefin (PAO) and PAO + Zinc DialkylDithioPhosphate (ZDDP) lubricants. The...
A newly developed in-situ technique has been employed to investigate the effect of lubricant additives and water contamination in oil on hydrogen intrusion into the steel. Hydrogen in oil-lubricated contacts is generated as a result of tribochemical reactions. The hydrogen uptake measurement results indicated that tribofilm formation can impede hyd...
Surface reactive additives are crucial in the lubrication of surfaces experiencing cyclic contact. The combination of additives in the lubricant, on the material surface and the complex tribo-contact conditions hinders the design of additive packages which can simultaneously protect steel surfaces from wear and fatigue. Amine-based Organic Friction...
This work focuses on the proposed mechanisms for the lubrication of synovial joints and applies them to an idealised bearing geometry considering a porohyperelastic material (cartilage) rotating against a stationary rigid impermeable surface. The model captures the behaviour of all lubrication regimes including fluid film formation and boundary con...
Corrosion is a major oilfield flow assurance problem with coatings being commonly used by industry as a barrier to electrochemically active species. In recent years, studies on sol-gel materials have drawn an increased interest, gaining more recognition as an alternative to conventional coatings due to many promising properties including hardness,...
Zinc Dialkyl DithioPhosphate (ZDDP) as a well-known anti-wear additive enhances the performance of the lubricant beyond its wear-protection action, through its anti-oxidant and Extreme Pressure (EP) functionality. In spite of over thirty years of research attempting to reveal the mechanism of action of ZDDP, there are still some uncertainties aroun...
Water ingress into the lubricant as a contaminant affects performance leading to an alteration in wear, corrosion and fatigue behaviour of the tribological components especially in the rolling element bearings. The current study addresses the tribochemical phenomena involved in micropitting in tribocorrosion systems where different levels of dissol...
The effect of N-Tallow-1,3-DiaminoPropane (TDP) on friction, rolling wear and micropitting has been investigated with the ultimate objective of developing lubricants with no or minimal environmental impact. A Mini Traction Machine (MTM-SLIM) has been utilised in order to generate tribofilms and observe the effect of TDP on anti-wear tribofilm forma...
Projects
Projects (2)
I am the Principal Investigator of the European Research Council (ERC) funded research project LubSat. LubSat will run for 5 years (2017-22) with a value of €1.5 million to understand the role of oral lubricity on satisfaction, satiation and satiety. In particular, our quantitative multi-scale understanding of lubrication of the human salivary film when exposed to stimuli from food biomolecules, which in turn can have significant appetite suppression consequences, remains poorly understood. The key limitation to accurately measure oral lubrication is the lack of availability of tribo-contact surfaces that effectively emulate the oral surfaces (i.e. the soft, slippery mucous-coated human tongue and the upper palate). This project will apply classical theories from Physics and tools from Mechanical Engineering to design novel soft lubricious elastomeric surfaces emulating our saliva-coated human tongue with mimicked material properties. This will be then used to create fundamental understanding of how food molecules and model food structure (complex gels, microgels, phase separated systems) lubricate the oral surfaces and the implications this have on the satisfaction of the food and perceived satiety.
Follow us on https://sarkar.leeds.ac.uk/erc-project-lubsat/ to receive updates on the project outcomes and the new articles!!