Optical trapping of nanomaterials and their application to the characterization of the onset of asphalthene precipitation in crude oils

• Grant number: 12/14895-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2012
• End date: January 31, 2013
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: René Alfonso Nome Silva
• Grantee: Gabriel Ferreira Setti
• Host Institution: Instituto de Química (IQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

This Undergraduate Research proposal entails the development of optical trapping instrumentation for the in situ characterization of asphaltenes inside high-pressure cells underflow. Initially, theoretical studies of optical trapping will be performed to understand the specific laser (intensity, wavelength, dynamic focusing) and system parameters (viscosity, turbidity, particle size) requirements. Uni-directional trapping will be implemented both in free space and through the use of optical fibers. The trapping efficiency in solution will be characterized by an emphasis on particles in suspension. Additional optical trapping schemes will be investigated with the goal of trapping nanoparticle-sized aggregates. Specific focus will be paid the characterization of the complex refractive index and how it affects trapping efficiency. Afterwards, the instrument will be adapted for micro-manipulation inside high-pressure cells. Initial tests will be performed with asphaltene suspensions, and, finally, crude oil samples. Experiments will be performed at a range of pressure, temperature, and chemical composition of the sample.(AU)