Resonant Multisensor System for High-Throughput Determinations of Solvent/Polymer Interactions

Abstract

Solvent-resistant polymers are important in numerous research, engineering, and consumer applications. To address the limitations of existing methods of evaluation of polymer solubility and solvent resistance, we developed and built a 6 x 4 array of resonant acoustic-wave sensors operating in the thickness shear mode (TSM). The application of this system makes possible analysis of nanogram quantities of polymers in small amounts of solvent and permits the simultaneous analysis of multiple samples, such as those produced in combinatorial polymerization reactions. These parallel determinations of polymer/solvent interactions eliminate errors associated with serial determinations. During the periodic exposure of the TSM crystals to polymer/solvent combinations, the mass increase of the crystal is determined, which is proportional to the amount of polymer dissolved and deposited onto the sensor from a polymer solution. We demonstrate our sensor system for reliable quantification of solubility of several types of polymers in various solvents. The high mass sensitivity of our resonant TSM sensors (10 ng), use of only a minute volume of a solvent (< 2 mL), and parallel operation (matching a layout of available 24 well plates) make this system a good fit with available polymer combinatorial synthesis equipment.