Influence of surface tension and concentration of a non-ionic surfactant on the barrier effectiveness of a microporous polypropylene fabric for pesticide protective clothing

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dc.contributor.authorPadki, Santosh Shankaren
dc.contributor.departmentClothing and Textilesen
dc.date.accessioned2014-03-14T21:43:16Zen
dc.date.adate2008-08-22en
dc.date.available2014-03-14T21:43:16Zen
dc.date.issued1997en
dc.date.rdate2008-08-22en
dc.date.sdate2008-08-22en
dc.description.abstractThis research evaluated the influence of concentration and surface tension (γ) of aqueous solutions of a non-ionic surfactant on the barrier effectiveness of a fabric containing microporous polypropylene (PP) film that may be used in pesticide protective clothing (PPC). Aqueous solutions of Triton® X-100, a non-ionic surfactant, at various concentrations were prepared, and the γ of each solution was determined. The immediate advancing contact angles (θ), made by a 5-<i>μ</i>L drop of each test liquid on the test fabric, were measured. Barrier effectiveness was evaluated from the capillary penetration, wicking, and wetting characteristics of the fabric using the surfactant solutions at various concentrations. Wetting characteristics were evaluated from the drop absorbency test, a modified Draves test, the spreading coefficient (S<sub>c</sub>) values and, by inference, from a Zisman plot. As surfactant concentration increased, γ decreased, and then remained relatively steady past the 0.0134 percent concentration level, the critical micelle concentration (CMC) of Triton® X-100. As Triton® X-100 concentration increased, θ decreased, even past the CMC. Results of the study indicate that, as surfactant concentration increases, the amount of capillary penetration and the wicking distance increase even past the CMC. The time for drop absorbency and the Draves wetting tests were very high (> 600 seconds) for all liquids below CMC. Beyond the CMC, drop absorbency times were significantly lower for solutions of 2.0 and 5.0 percent concentration, and the Draves wetting times were also significantly lower. The values of the cos θ and the γ were used to calculate the S<sub>c</sub> for each liquid. The calculated spreading coefficients indicate that the liquids at all concentrations did not spread (wet) on the micro-porous PP test fabric for the advancing θ measured within 10 seconds of placing the drop. Results of the statistical analysis showed that surfactant concentration was a significant factor in determining the barrier effectiveness of the fabric tested. Even though γ remained relatively unchanged beyond the CMC of the surfactant, the inability of the test fabric to serve as an effective barrier against liquid penetration by capillary action, wicking, and wetting increased significantly. Surface energy terms, that are normally used to explain liquid transport and wetting phenomena, may not in themselves be sufficient to determine the effectiveness of a fabric for PPC, especially since concentration of the surfactant, a pesticide adjuvant, is a significant factor in determining the barrier effectiveness of PPC. Consideration must be made for the fact that very high concentrations of surfactants are routinely used in pesticide application.en
dc.description.degreeMaster of Scienceen
dc.format.extentx, 151 leavesen
dc.format.mediumBTDen
dc.format.mimetypeapplication/pdfen
dc.identifier.otheretd-08222008-063707en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-08222008-063707/en
dc.identifier.urihttp://hdl.handle.net/10919/44355en
dc.language.isoenen
dc.publisherVirginia Techen
dc.relation.haspartLD5655.V855_1997.P335.pdfen
dc.relation.isformatofOCLC# 37744477en
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectsurfactantsen
dc.subjectsurface tensionen
dc.subjectwettingen
dc.subjectpesticide protective clothingen
dc.subjectmicroporous materialsen
dc.subjectbarrier effectivenessen
dc.subject.lccLD5655.V855 1997.P335en
dc.titleInfluence of surface tension and concentration of a non-ionic surfactant on the barrier effectiveness of a microporous polypropylene fabric for pesticide protective clothingen
dc.typeThesisen
dc.type.dcmitypeTexten
thesis.degree.disciplineClothing and Textilesen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Scienceen

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