Open Positions for Summer Research

Below you find some research topics. If you are interested in contributing to any of these, send your C.V. to Prof. Rosa M. Espinosa-Marzal via e-mail.

1) Influence of Additives on Stabilization and Mineralization Pathway of Colloidal Amorphous Calcium Carbonate (ACC) Nanoparticles

Amorphous calcium carbonate (ACC) has been recognized to be a precursor of other crystalline calcium carbonate phases that are more energetically stable. Counterintuitively, ACC has been shown to be stored for long time for the subsequent formation of new tissues and even to be the final phase in various organisms. It has been shown that the presence of organic additives can change the fate of ACC in solution, either inhibit the agglomeration and thereby stabilize ACC, or promote crystallization. We in SIEN lab are currently investigating the influence of organic additives (aspartic acid, glutamic acid, glucose) on the mineralization pathway of ACC nanoparticles inside of a globule matrix formed by macromolecules. This endeavor will contribute to the understanding of the mechanism dictating the fate of ACC in the context of biomineralization.

The project will be an excellent opportunity for a student looking for experience in surface science and nanotechnology, through the operation of UV-Vis, dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), Atomic Force Microscopy (AFM). Direct guidance of laboratory activities and data analysis will be provided by a PhD student, Yijue Diao, which prepares the student capable of independent research and critical thinking in future.

The student will be involved in:

  • Preparing ACC nanoparticle solutions with different concentrations of additives;
  • Measuring the growth of ACC nanoparticles in solution with DLS and UV-Vis;
  • Characterizing the properties of the ACC nanoparticles with the help of FTIR and TGA;
  • Analyzing experimental data.

Preferred background:

  • Students with a past experience in chemistry lab are preferred.
  • Experience in UV-Vis, DLS, FTIR, TGA and QCM will be an added advantage but not necessary.
  • A responsible and motivated personality is required.
  • Grades will be taken into account.

2) Design of a Model Cell Membrane for Interfacial Studies

Lipid bilayer, which is the basic structure of a cell membrane, is vital for maintaining cellular activities and providing an effective protection for the cell components. Membrane proteins are an integral part of cell membranes and perform a variety of functions which include catalyzing reactions, responding to stimuli, and transporting molecules, to name a few. Hence, protein-membrane interactions are studied to understand the general phenomenon of membrane proteins behavior and function. The project aims at functionalizing a model cell membrane surface with membrane proteins. The model cell membrane consists of a polymeric support upon which a lipid bilayer is assembled. Protein functionalization is carried out via a biotin-avidin linkage.

The main techniques used for this project are Quartz Crystal Microbalance (QCM) and Transmission Interference Adsorption Sensor (TInAS). Students will gain hands on experience on fabricating hydrogels and assembling lipid bilayers on soft supports along with a thorough knowledge of QCM and TInAS. Complimentary techniques such as Fourier Transform Infrared Spectroscopy (FTIR) and Fluorescence microscopy will also be occasionally employed.

The project is a great opportunity for students aspiring to do research in surface science, polymers and biomaterials.

3) Biomineralization as a route to tailor host matrix properties

Many marine organisms have mechanisms, referred to as biomineralization, to produce controlled and highly tunable crystalline or amorphous precipitates within soft organic matrices. A plethora of studies investigating the morphology, composition and structure of precipitated minerals in solvated (biological and synthetic) polymer matrices exist, yet, the possibility of tuning the structure and mechanical response of the polymeric matrices by mineralization has not been explored. This project involves studying behavior of the host matrix as a potential route to create new biomimetic soft composites with “designer” properties, where the mineral is the dispersed hard constituent and the soft polymer matrix adapts to the process of mineralization.

Students will get trained on fabrication of physically crosslinked hydrogels and their subsequent mineralization. Furthermore, they will work on developing a protocol to extract and test pore solutions of hydrogels.

Fourier Transform Infrared Spectroscopy (FTIR), Optical Microscopy and Dynamic Light Scattering (DLS) will be employed as the main techniques to characterize the hydrogels as well as their pore solutions.

4) Estimating Surface Adsorption Kinetics of surfactants

At SIEN, we study novel additives (surface-adsorbing molecules) that will be employed in lubricant formulation to reduce friction and wear between the moving parts in an Engine. Such additives will assist in improving the efficiency of an automobile and as well reduce the amount of poisonous exhaust emissions into the environment. These additives, however, should display two important characteristics for them to be considered as good candidates for formulation: (1) high surface interaction with engine material such as stainless steel, for example (2) high solubility in the base-oil. The specific aims of the project are to estimate the solubility of the additives in the base-oil and further estimate the surface adsorption kinetics of the additives in base oil with the help of Quartz Crystal Microbalance (QCM). This project is an excellent opportunity in gaining experience with working in a lab dedicated to surface science and nanotechnology research. A Postdoc will directly supervise the student, although, student’s ability to be self-directed and independent is crucial.

The student will be involved in:
– Preparing solutions/formulations with different concentrations of additives and estimate the solubility of the solutions.
– Operating Quartz Crystal Microbalance to estimate adsorption behavior of additive molecules.
– Analysis of experimental data.

Preferred background:
– Preferable for students with a past experience in wet-lab chemistry. Experience in Quartz Crystal Microbalance will be an added advantage but not necessary. Grades will be taken into account.