Grantee Research Project Results

Nanostructured Microemulsions as Alternative Solvents to VOCs in Cleaning Technologies and Vegetable Oil Extraction

EPA Grant Number: R830903
Title: Nanostructured Microemulsions as Alternative Solvents to VOCs in Cleaning Technologies and Vegetable Oil Extraction
Investigators: Sabatini, David A. , Harwell, Jeffrey H.
Current Investigators: Sabatini, David A. , Harwell, Jeffrey H. , Witthayapanyanon, Anuradee , Do, Linh
Institution: University of Oklahoma
EPA Project Officer: Aja, Hayley
Project Period: January 1, 2003 through December 31, 2005 (Extended to January 13, 2007)
Project Amount: $329,655
RFA: Environmental Futures Research in Nanoscale Science Engineering and Technology (2002) RFA Text | Recipients Lists
Research Category: Nanotechnology , Safer Chemicals

Objective:

The objective of this project is to develop and evaluate non-toxic, non-volatile, and biodegradable oil extraction. Specifically, we plan to formulate water continuous microemulsions to dissolve the oil in the hydrophobic core of swollen micelles (1-50 nm droplets). We will study the impact of novel microemulsion additives, called “linkers”, on the interfacial properties (interfacial tension, rigidity and curvature) and dynamic aspects of oil solubilization and displacement from porous and smooth surfaces under different shear conditions. Linkers are surfactant-like molecules that are wither too lipophilic or hydrophilic to self-assemble at the O/W interface, but in the presence of surfactant they self-assemble to produce microemulsions with improved performance for a variety of oils. We hypothesize that by introducing linkers we can formulate aqueous surfactant solutions that, upon contact with the oil to be removed, and under optimum flow conditions, will spontaneously from microemulsions that keep the oil in micelles. These surfactant solutions can therefore be used as alternatives to VOC solvents, such as hexane, in cleaning hard surfaces, textiles and vegetable oil extraction.

Approach:

The first phase of the project will focus on developing phase behavior diagrams for microemulsions with hexadecane and motor oil (model lubricant) and triolein (model for vegetable oil). We will use alkyl sulfosuccinates, lecithin, sorbitol esters and alkyl propoxy sulfonates as surfactants; fatty alcohols, and sorbitol esters as lipophilic linkers; and C6-C9 alkyl glucosides, and alkyl naphthalene sulfonates as hydrophilic linkers. The second phase of the project will focus on evaluating equilibrium solubilization, interfacial tension, interfacial rigidity and interfacial curvature. The third phase will involve dynamic solubilization/oil displacement studies from hard surfaces, textiles and ground seeds under different shear rates. We will model the influence of linkers and shear conditions on the interfacial phenomena based on mechanical and thermodynamic models used for biological membranes. Finally we will compare the solvent performance of the best systems with VOC solvents.

Expected Results:

In response to the solicitation, we propose to use the principles of nanoscale interfacial self-assembly phenomena in designing aqueous, non-volatile, non-toxic, biodegradable solvents for degreasers and vegetable oil extraction. With this technology we could reduce hexane emissions from vegetable oil recovery (close to 27 million pounds per year in the U.S.), as well as VOCs used as solvent degreasers (more than $10 billion market in the U.S.) and PCE in dry cleaning (used in >20,000 U.S. dry cleaners).

Publications and Presentations:

Publications have been submitted on this project: View all 11 publications for this project

Journal Articles:

Journal Articles have been submitted on this project: View all 2 journal articles for this project

Supplemental Keywords:

Nanotechnology, surfactants, microemulsions, membranes, fry cleaning, vegetable oil, degreaser, solvents, VOCs.
, Sustainable Industry/Business, RFA, Scientific Discipline, TREATMENT/CONTROL, INTERNATIONAL COOPERATION, POLLUTANTS/TOXICS, Technology for Sustainable Environment, pollution prevention, Sustainable Environment, Environmental Chemistry, Chemicals, Environmental Engineering, Technology, biodegradable materials, environmental sustainability, VOC removal, nanotechnology, vegetable oil extraction, alternative materials, clean technologies, cleaner production, Volatile Organic Compounds (VOCs), nanostructured microemulsions

Progress and Final Reports:

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.