Behavior of Particles As Tunable Emulsion Stabilizers

     Behavior of Particles as Tunable Emulsion Stabilizers

Institute: City College of New York

Topic: Fuels, Petrochemicals, and Energy

Student's Name: Jannatul Ferdaous

Mentor's Name: Ilona Kretzschmar

PhD Candidate's Name: Sepideh Razavi

Abstract

                Emulsions exist in our daily lives as natural and manufactured systems. Emulsion stability or instability is a huge concern for the industrial branched of pharmaceuticals, personal care, and oil recovery. It is expected for every pharmaceutical and food emulsion to aspire utmost stability which will help maintain the product's quality and conduct over a certain period of time. Adjusting the stability of emulsions can contribute immensely in development of new materials, regulating chemical reactions and new separation mechanism.

            Our primary goal of this research is to investigate the effect of modified particles on emulsion stability, and how their role differentiates from that of a simple surfactant in an emulsion. One of our main objectives of this research is to prove our hypothesis that unmodified and modified particles are capable of increasing the stability of emulsions.

            This past summer, a PhD candidate, Sepideh Razavi, and I worked on understanding the characteristics of oil-in-water emulsions. We used hexadecane and dilute aqueous KNO3 solution (10-4 M) to make emulsions, which we then centrifuged to increase the speed of coalescence and separation of oil and water phases. The longer time and the stronger centrifugal force a sample of emulsion requires to separate, the more stable the emulsion is. We tried to produce the most stable emulsions possible without the addition of particles by varying one of the many parameters in each experiment. After a number of experimental trials, we have settled on a 1:1 of oil and water mixture and an emulsification time of 60s to produce the most stable emulsion possible without particles.

            Eventually we progressed to experimenting with unmodified silica (SiO2) particles. We have worked with three different sizes (250nm, 500nm, and 1um) of particles to compare the effect they have on emulsion stability. As we proposed in our hypothesis, the particles did enforce a greater stability on the emulsion which enabled us to separate the process of coalescence from creaming. This leads us to the conclusion that particles can be used to produce stable emulsion, which can be very beneficial for pharmaceuticals and personal care industries.