BIO

Dr. Aleena Alex is an ADAGIO post-doctoral fellow in the University of the Basque Country, in the Molecular Spectroscopy Group headed by Dr. Hegoi Manzano. Aleena is a computational material scientist from a Civil Engineering background, and possesses a wealth of expertise in material science, programming, classical mechanics, multi-scale modelling, computational chemistry, molecular dynamics, kinetic Monte Carlo, and nano mechanics. Beginning her research journey at CSIR-SERC, India, she pursued her Masters utilizing Molecular Dynamics (MD) to model cementitious systems. At IIT Madras, India, her PhD centered on developing a multiscale mechanical model for hydrating cement, employing computational and experimental techniques.

In May 2021, Aleena joined as a post-doctoral research associate (PDRA) at Newcastle University under the EPSRC project Engineering Microbial Induced Carbonate Precipitation (e-MICP), co-developing a novel bio-chemo-mechanical simulator handling mineral dissolution-precipitation and bacterial processes. Her research was showcased as a keynote lecture at the DMMF mini symposium (CFRAC conference). From February to August 2023, Aleena contributed to an Impact Acceleration project at Newcastle University, collaborating with Northumbria Water to explore bacterial spores' long-term activity in cement mortar. During her post-doctoral tenure, Aleena actively cultivated independent research networks and pursued grant opportunities. She participated in the Innovators training program by Northern Accelerator, focusing on research commercialization, and secured £28K seed-funding alongside fellow ECR, Dr. Xin Liu, through the Dispersed Industrial Decarbonization sandpit organized by C-DICE.

Project

Atomistic and molecular simulations have greatly aided material research. However, their implementation in cementitious materials started only in the early 2010s. This was fueled by a need to understand the chemistry, structure property relationships and transport properties of these minerals in fundamental scale and the advent of high-performance computing. After a decade of rigorous research, we currently have reliable atomistic models and forcefields for most of the cementitious minerals. We can perform reactive simulations and even accelerated dynamics on these models. Nevertheless, the timescales that can be achieved with atomistic scale investigations remain in nanoseconds. Although these investigations can provide valuable insights, they cannot directly aid or inform models or experiments at higher scales. Kinetic Monte Carlo (KMC) simulations overcome these drawbacks. Aleena will use the KMC technique to produce reliable discrete nanoparticle based molecular scale models for the dissolution and precipitation of major minerals such as C-S-H (Calcium silicate hydrate), M-S-H (Magnesium silicate hydrate), and CaCO3 (Calcium carbonate) and thus explore the carbonation of new greener concretes.

This method of modelling reactions and morphology formation in minerals has lots of advantages:

1. It works at a higher length scale compared to atomistic simulations, each discretized particle representing a molecule. The simulation box sizes can go from nanometer to sub micrometer depending on the computation capacity.

2. KMC can sample larger timescales. In KMC time is calculated as inverse of cumulative rate. Thus, depending on the likelihood of dissolution and precipitation, these simulations can sample larger timescales.

3. Coarse graining the discrete particle models to higher scales (sub-micrometer) is relatively simple and straightforward.