title: Thin films of block copolymer blends for enhanced performance of acoustic wave-based chemical sensors.
abstract: The performance of quartz crystal oscillator-based volatile organic compound (VOC) sensors has been enhanced by using coatings made from poly(styrene-block-ethylene-co-butylene-block-styrene) block copolymers blended with resins and homopolymers. Enhanced performance is characterized by a wider operational temperature range (-10 to +50 degrees C) over which the sensors displayed, concurrently, an analyte sensitivity of >0.2 Hz/ppm toluene, minimal energy loss (resistance <120 ohms), and response times of <20 min (time required to reach 90% of full response). Atomic force microscopy images are consistent with a process in which the additive associates with the polystyrene portions of the microphase-separated block copolymer. This association reinforces the rigidity of the polystyrene network while allowing the rapid uptake of VOCs by the softer polyethylene/butylene phase.
authors.affiliation: Microanalytical Instrumentation Center, Department of Chemistry, and Ames Laboratory-USDOE, Iowa State University, Ames, Iowa 50011, USA. blipert@porter1.ameslab.gov
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Lipert
authors.forename: Ruth
authors.initials: R
authors.lastname: Shinar
authors.forename: Bikas
authors.initials: B
authors.lastname: Vaidya
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Pris
authors.forename: Marc D
authors.initials: MD
authors.lastname: Porter
authors.forename: Guojun
authors.initials: G
authors.lastname: Liu
authors.forename: Ted D
authors.initials: TD
authors.lastname: Grabau
authors.forename: John P
authors.initials: JP
authors.lastname: Dilger
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D004784:Environmental Monitoring / Q000295:instrumentation*; D018625:Microscopy, Atomic Force; D011090:Polyenes / Q000737:chemistry; D020959:Polyethylene / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D011137:Polystyrenes / Q000737:chemistry; D011791:Quartz; D013696:Temperature; D014050:Toluene / Q000032:analysis* / Q000737:chemistry
chemical_list: D000393:Air Pollutants; D011090:Polyenes; D011108:Polymers; D011137:Polystyrenes; D011791:Quartz; D014050:Toluene; D020959:Polyethylene; C008967:polyisobutylene; C008952:polybutene