Current Search:  Composite materials--Biodegradation (x)

View All Items

  • CSV Spreadsheet
(1 - 3 of 3)
Evaluation of carbon fiber/polyetheretherketone composites exposed to marine microbial communities in laboratory media and natural seawater
Title
Evaluation of carbon fiber/polyetheretherketone composites exposed to marine microbial communities in laboratory media and natural seawater.
Creator
Sheetz, Andrew Douglas., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
This research proposed to characterize any microbial induced degradation of carbon fiber/polyetheretherketone (PEEK) composites from acid-producing bacteria (APB) and sulfate-reducing bacteria (SRB). Electrochemical impedance spectroscopy (EIS) was used to provide a measure of degradation of the composite system as a function of exposure time. In addition, mechanical testing and microscopic evaluation of the specimens were utilized to determine if changes in the EIS spectra as a function of...
Show moreThis research proposed to characterize any microbial induced degradation of carbon fiber/polyetheretherketone (PEEK) composites from acid-producing bacteria (APB) and sulfate-reducing bacteria (SRB). Electrochemical impedance spectroscopy (EIS) was used to provide a measure of degradation of the composite system as a function of exposure time. In addition, mechanical testing and microscopic evaluation of the specimens were utilized to determine if changes in the EIS spectra as a function of exposure time correlated to changes in the mechanical properties. Results from most EIS scans were consistent with a well-consolidated and undamaged composite system. Changes in the EIS response of specimens exposed to the SRB environment were not matched by a reduction in the flexural strength. Mechanical testing also indicated no reduction in the flexural strength in any of the other exposure environments. Environmental scanning electron microscopy (ESEM)/energy dispersive x-ray spectroscopy (EDS) were inconclusive, though changes in the EDS spectra were seen. No definitive degradation was seen to occur in this composite system.
Show less
Date Issued
1998
PURL
http://purl.flvc.org/fcla/dt/15531
Subject Headings
Corrosion and anti-corrosives, Composite materials--Biodegradation
Format
Document (PDF)
Chemical Method and Device to Detect Underwater Trace Explosives via Photo-Luminescence
Title
Chemical Method and Device to Detect Underwater Trace Explosives via Photo-Luminescence.
Creator
Langston, Tye A., Florida Atlantic University, Granata, Richard D., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
This research tests the use of sensitized lanthanide ions to determine if they can detect water-borne explosive traces and produces two designs for a field-deployable underwater explosive trace detector. 1,1 0-phenanthroline and thenoyltritluoroacetone are evaluated as sensitizing ligands to absorb energy and initiate the fluorescence process in europium ions. Different compounds obtained via ligand choice and mixing order are evaluated for their ability to produce a large fluorescence...
Show moreThis research tests the use of sensitized lanthanide ions to determine if they can detect water-borne explosive traces and produces two designs for a field-deployable underwater explosive trace detector. 1,1 0-phenanthroline and thenoyltritluoroacetone are evaluated as sensitizing ligands to absorb energy and initiate the fluorescence process in europium ions. Different compounds obtained via ligand choice and mixing order are evaluated for their ability to produce a large fluorescence differential between explosive-laden and explosive-absent solutions. Optimal excitation and emission wavelengths for several different compounds are determined, as well as practical wavelengths to be applied in the field. The effect of methanol as a solvent to deliver the reagents is evaluated and rough solubility limits are determined. The effects of seawater constituents on detection are investigated and explosive detection limits are determined. It was found that this method and device are viable for underwater explosive trace detection. A field-deployable device is designed, characterized, and proven.
Show less
Date Issued
2006
PURL
http://purl.flvc.org/fau/fd/FA00012600
Subject Headings
Silane compounds--Testing, Surface chemistry, Composite materials--Biodegradation, Carbon compounds--Testing
Format
Document (PDF)
Effects of POSS Fiber Sizing on the Mechanical and Thermal Properties of CarbonNinyl Ester Composites
Title
Effects of POSS Fiber Sizing on the Mechanical and Thermal Properties of CarbonNinyl Ester Composites.
Creator
Powell, Felicia M., Mahfuz, Hassan, Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
The degradation of polymer composites in moist environments is a limiting factor in the advancement of composite technology. The key to mitigate this degradation is to maintain the integrity of the fiber/matrix (F/M) interface. In this study, the F/M interface of carbon/vinyl ester composites has been modified by treating the carbon fiber with polyhedral oligomeric silsesquioxane (POSS). Two POSS systems, namely octaisobutyl and trisilanolphenyl, have been investigated. A set of chemical and...
Show moreThe degradation of polymer composites in moist environments is a limiting factor in the advancement of composite technology. The key to mitigate this degradation is to maintain the integrity of the fiber/matrix (F/M) interface. In this study, the F/M interface of carbon/vinyl ester composites has been modified by treating the carbon fiber with polyhedral oligomeric silsesquioxane (POSS). Two POSS systems, namely octaisobutyl and trisilanolphenyl, have been investigated. A set of chemical and mechanical procedures has been developed to coat carbon fibers with POSS, and fabricate layered composites using vinyl ester resin. lnterlaminar shear, transverse tension, and low velocity impact tests on composites have indicated around 10-38% improvement in mechanical properties with respect to control samples. Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA) tests have also shown significant improvement in glass transition temperature (T9). Hygrothermal tests, under various environments, have demonstrated that POSS reduces water absorption by 20-30%.
Show less
Date Issued
2009
PURL
http://purl.flvc.org/fau/fd/FA00012540
Subject Headings
Surface chemistry, Composite materials--Biodegradation, Carbon compounds--Testing, Thermodynamics, Fibrous compounds--Testing
Format
Document (PDF)