analytical chemistry division - usna.edu · electroanalytical chemistry • current major project:...
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Analytical Chemistry• Not JUST titrations!
From
the Am
erican
Che
mical Society (A
CS)
“Analytical chemistry is the art and science of determining what matter is and how much of it exists.In 2012 (salary survey data), analytical chemistry was the most popular field of work for ACS chemists.”
“Analytical chemists use their knowledge of chemistry, instrumentation, computers, and statistics to solve problems in almost all areas of chemistry and for all kinds of industries.”
Analytical Chemistry• Not JUST titrations!• We’re doing research in topics as diverse as better batteries, labs‐on‐chips, forensics, explosives detection and degradation, biofuels analysis, and creating new materials.
• We use almost every instrument you’ve seen plus some.
• Two of the departments’ scanning probe instruments are in the Analytical Division.
Analytical Chemistry Members
• Professor Graham Cheek
• Professor Christine Copper
• Professor Dianne Luning Prak
• Professor Maria Schroeder
• Associate Professor Ron Siefert
• CDR Julie Spencer
• Professor Paul Trulove
RESEARCH INTERESTSProf. Graham Cheek
Mi 144 36625 [email protected]
Electrochemistry of organic compounds1. Bio‐electrochemistry of amino acids
Cyclic and Square‐Wave VoltammetrySpectroscopic Techniques (NMR, MALDI)
2. Effect of Lewis acids on reaction pathwaysKetone Systems
Solvents : Water, non‐aqueous solvents, ionic liquidsN
+CF3 SO3 -
Forensic Applications1. Soil Characterization : X‐Ray Fluorescence2. Paper / Ink Characterization : Raman Spectroscopy
cysteine tryptophan
RESEARCH INTERESTS Prof. Graham Cheek
SolventspH 5, 7 aqueous buffersNonaqueous solventsIonic liquids
Use of NMR, MALDI ?
Bio‐electrochemistry of amino acids
Effect of metal ions ( Zn2+ ) on electrochemical behavior, especially for “zinc fingers” !
RESEARCH INTERESTS Prof. Graham CheekBio‐electrochemistry of amino acids
Wikipedia, “Zinc Fingers,” accessed 11 February 2018
Interaction of Zn2+ and possibly other ionswith cysteine and histidine side groups in proteins
CHEEK, Graham T., Professor, and WOROSZ, Matthew A., MIDN, “Electrochemical Studies of L‐Cysteine,”ECS Trans., 2016, 72(27), pp. 1‐8. doi:10.1149/07227.0001ecst
Prof Christine [email protected] 265
project will also include collaboration with scientists at George Washington University, Washington, D.C.
Development of Separation and Detection Methods for Forensic Analysis
Capillary Electrophoresis (CE)
*Separation is achieved based on different rates of migration of charged species in an applied electric field.
Capillary
Lamp
Inlet Buffer/Sample Injection Outlet Buffer
Data Collection/Storage
vi = uapp E
High Voltage Power +-
DetectorDetector
Electrophoresis
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• CE was first used in the early 1980’s.• Reasonably high sensitivity (ppm or ppb)• Short separation time (<5 min)• Small Sample Volume (nanoliters)• Can be done on a microchip device instead
of in a column
Instrumentation
This automated instrument can run samples when you are not there!
CE instrument is in MI 264.
Capillary Electrophoresis can be used to detect…
• Explosives in seawater, sand, and soil• Poisons in beverages• Ozone in submarine atmospheres• Nerve agents in atmospheres• Polyaromatic hydrocarbons in environmental samples• Carbon monoxide poisoning in blood• Illicit drugs in urine• Current students (Erbach, McDonough, Wieman and
Barrow) are working on analyzing pen inks (document authentication) and lipsticks (residue at a crime scene)
http://greenfleet.dodlive.mil/energy/great‐green‐fleet
Fuel certification program/Office of Naval Research
Prof. Dianne Luning Prak ([email protected])
January 2016Navy launched Carrier Strike Group out of San Diego powered by mixtures of petroleum‐based and bio‐based fuel.
Sept 2016Successful test flight of EA-18G Growleron 100% CHCJ fuel at Naval Air StationPatuxent River, MD (Lt. Cmdr. BradleyFairfax, project officer & test pilot)
http://www.navy.mil/submit/display.asp?story_id=96702
Fuel certification program/Office of Naval Research Chemical composition, physical properties & combustion of bio‐based and petroleum‐based fuels
Goal: How does chemical structure impact the physical and chemical properties of fuels?
∙ density ∙ viscosity ∙ enthalpy of combustion∙ speed of sound ∙ bulk modulus ∙ flash point∙ surface tension ∙ flash point ∙ distillation behavior∙ enthalpy of vaporization ∙ combustion in diesel engines
Prof. Dianne Luning Prak ([email protected])
Example student publicationsLuning Prak, D. J.; Ye, S.; McLaughlin, M.; Trulove, P. C.; Cowart, J. S., 2018. Bio‐based Diesel Fuel Analysis and Formulation and Testing of Surrogate Fuel Mixtures, Ind. Eng. Chem. Res., 57,600‐610.
Luning Prak, D. J., Ye, S., McLaughlin, M., Cowart, J. S., Trulove, P., 2017. Density, Viscosity, Speed of Sound, Bulk Modulus, Surface Tension, and Flash Point of Selected Ternary Mixtures of Butylcyclohexane + a Linear Alkane (Hexadcane or Dodecane) + an Aromatic Compound (Toluene, n‐Butylbenzene, or n‐Hexylbenzene), J. Chem. Engin. Data, 62, 3452–3472.
Sahara GraftTed Johnson
Prof. Dianne Luning Prak ([email protected])
Program review: U.C. Davis
Department of Energy Videohttps://betterbuildingssolutioncenter.energy.gov/swap/season-2, Technical video:Energy Research, Start at 1:17 of video
Professor Schroeder’s Research Interests
Harold Edgerton, photographer
‐ Improved Polymer Coatings for:‐ Military Transport (Humvees)‐ Body Armor‐ Hazardous Material Transport‐ Transparent Armor
‐ Education Research/Laboratory Development‐ Analyzing Plebe Chemistry Curriculum
Changes‐ Experiments in support of Chemistry
of Cooking course or IL
Projectile hitting elastomer at > 500 mph
Motivation for Coatings Research• To understand the mechanisms of impact protection of polymer‐coated surfaces
projectiles hittingelastomers at high speed
protection no protection
• To understand temp effects (Tg)• To improve armor protection
Polymer synthesis, characterization, processing
Engineering, physical and mechanical testing
Materials Science Ballistic testing
Basic research with military applicationsPast Research Student
John Chamberlain, ’15Research Collaboration:
Naval Research Laboratory (NRL)
Another Research AreaLaboratory Development for IL
Midn 1/C Lizzie Lee
• Determining the Heavy Metal Uptake in Hyperaccumulator Plants by X‐Ray Fluorescence (XRF)
• XRF specific to metals, simultaneous analysis, direct analysis of solids, nondestructive
• Plants grown in spiked Agar• Would this make an interesting IL experiment?
Rascio, Nicoletta. Plant Science, 2011, 180, 169‐181 http://www.horiba.com/scientific
Ron SiefertAssociate Professor
3‐6336 (office), Mi‐243 (office), Mi‐240 (lab)
Iron in Marine Aerosols
Vehicle NH3 Emissions
Agricultural NH3 Emissions
2016-2017 Project – Nanotubes & Their Applications
Deposition of Nutrients to Surface Waters
Novel Sorbents (periodic mesoporous organisilicas) • For Analysis of Nitroenergetics (i.e, explosives)• For Analysis of Perchlorates (used as propellants)• As a substrate for catalysts to destroy contaminants
Past
Pro
ject
s
Chesapeake Bay Ammonia & Nitrate Measurements
OBJECTIVE: Investigate the ability of nanotubes to encapsulate and stabilize biomacromolecules. Possible applications include: drug delivery, and as a method to protect biomacromolecules from thermal and chemical stresses.
Nanotubes & Their ApplicationsOBJECTIVE: Investigate the ability of nanotubes to encapsulate and stabilize biomacromolecules. Possible applications include: drug delivery, and as a method to protect biomacromoleculesfrom thermal and chemical stresses.
APPROACH: Use model systems to study the ability of the nanotubes to protect and stabilize biomacromolecules.‐ Method development: Choosing enzymes & substrates
‐ Encapsulation of enzymes in nanotubes‐ Protein assays‐ Substrates that result in products that fluoresce at appropriate
wavelengths
‐ Performing studies investigating the stability of encapsulated enzymes to thermal and chemical stresses
Current studies using lithocholic acid (LCA) nanotubes & chymotrypsin.
Analysis of Explosives ‐ Capillary Electrophoresis• Micellar electrokinetic chromatography (MEKC) – allows for
separation of neutral molecules in an electric field by adding surfactant micelles to the separation buffer.
• Simultaneous analysis of hydrophilic and hydrophobic analytes
• On‐line pre‐concentration to improve detection limits
10 15 20 25 30 35 40TIme (Minutes)
100 mAU
EOF Marker
1,3,5‐TNB
TNT 2,4‐DNT
2‐Am‐4,6‐DNT
Figure 4. Separation of 4 nitroaromatic compounds. Background electrolyte is 20 mM Tris, 200 mM Sodium Cholate, 10% v/v MeOH, pH 10.0. Sample matrix is 180 mM NaCl. From bottom to top, sample plug lengths are 1.6 cm, 2.4 cm, 4.0 cm, and 6.5 cm. Separation voltage of 15 kV with and operating current of 43 µAmps. Capillary is 50 micron i.d., 60 length (50 cm effective length).
Electroanalytical Chemistry and Surface Science
CDR Julie Spencer, USN, Ph.D.Mi‐230, 3‐6605
Electroanalytical chemistry• Corrosion is a major challenge for Naval Aviation and in general – Ongoing research to develop new coatings for better protection and to replace coatings that contain Cr(VI), a carcinogen
Electroanalytical chemistry
• Current major project:– Further development of a rapid screening technique for new anti‐corrosion coatings for Naval Aviation using scanning electrochemical microscopy (SECM).
– Work will move into screening of additive materials (AM) since they are showing differences from the same alloys when forged.
Scanning Electrochemical Microscope (SECM)Experimental Visualization
Coating
5‐20 µm
Aluminum Substrate
Fc+
Fc
0.1V
0.5V to 3.0V
FcMeOHSolution
SECM Tip
Substrate
Soluble oxide? Ferrocene?
Sample 1.0V 1.5V 1.8V 2.5V
non-chromated primer on anodized Al 0.28 0.28 3.50 10.00
waterborne primer on alodine pretreated Al
0.25 0.25 1.60
chromated primer on alodine pretreated Al
0.28 0.18 0.18
Tip current (nA) at indicated substrate
potential vs. Ag/AgCl
TABLE I
‘Screening of Novel Anti‐Corrosion Coatings by Scanning Electrochemical Microscopy’, Lee, C., Dorriety, W., Hanrahan, R., Calhoun, R., ECS Transactions, 2015 66(30): 65‐71
Future Work• Continue previous work on coatings• Begin evaluation of coatings on samples made by additive manufacturing
• Use surface science tools to characterize the coatings – before and after SECM treatment– Scanning Electron Microscope (SEM)– X‐ray Photoelectron Spectroscopy (XPS)
• Look at aspects of corrosion from several different angles
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http://www.ammrf.org.au/myscope/sem/background/
Scanning Electron Microscope (SEM): Images and Energy Dispersive Spectroscopy (EDS)
Images
Elemental Composition via EDS (X-
rays)
hν
BE
KE
1s
2s2p
Vacuum Level
hν
EjectedPhotoelectron
54°
Hemispherical Analyzer
Detector
X-ray Source
Lens
(+)
(‐)
Sample EjectedPhotoelectron
BE = hν - KE
X‐ray Photoelectron Spectroscopy (XPS): Obtaining Chemical Composition from the Surface (~10 nm)
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Rosenberg et. al., Physical Chemistry Chemical Physics 15.11 (2013): 4002-4015. Wnuk, Joshua. "Electron Beam Induced Deposition: A Surface Science Approach." Order No. 3381524, The Johns Hopkins University,
2009. Ann Arbor: ProQuest. Web. 5 Aug. 2016.
KE = hν - BE
WO3
W(CO)6
What would a research student do?• Learn to use the Scanning Electrochemical Microscope (SECM) and conduct electrochemical experiments
• Learn to use the Scanning Electron Microscope (SEM) and image corrosion samples
• Possibly travel to Johns Hopkins and observe XPS experiments
• Possibly visit NAVAIR • Possibly attend a meeting: American Chemical Society, Electrochemical Society…
If this sounds interesting….Contact me or stop by to discuss!
CDR Julie Spencer, USN, Ph.D.Mi‐230, 3‐6605
Department of ChemistryQ
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Natural PolymersNatural polymers are renewable materials that have many attractive properties. Some natural silks have strength and toughness comparable to the best synthetic polymers.The ability to modify and tailor the shape and properties of natural polymers is limited.
Ionic Liquids SolventsWe have shown that ionic liquids are powerful solvents for the dissolution and processing of a wide variety of natural polymers.The solvating ability of ionic liquids provides a powerful tool for the modification and processing of natural polymers.
N N
R'
R R''
+
CH3COO−
Develop multi-functional natural materials and coatings with unique electronic, catalytic, optical, and sensing properties for Air Force and DoD relevant applications in areas such as ballistic protection, energy storage, microelectronics, stealth, laser eye protection, optical computing, chem./bio sensing, in-situ medical applications
Producing natural materials with dramatically enhanced mechanical propertiesEnabling tuneable natural material properties with high spatial resolution Facilitating the integration of functional solid materials with electrical, magnetic and optical properties into natural fibermatrices
MAIN ACHIEVEMENTSInvestigated the nature of the ionic welding solvent and the impacts of co-solvent & biopolymer contentEvaluated the impact of tension on fiber weldingPrepared nanoscale bimetallic catalysts in natural polymer materials and welded them to natural materials to prepare catalytic assembliesStudied the fiber welding of silane modified nanocellulose into natural polymer materialsInvestigating the application of fiber welding to produce novel hair-karatin composite structuresDeveloped welded antimicrobial coatings on cellulose substrates
Fe3O4 Particles in Linen Yarn
Department of Chemistry
Biopolymer Properties
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Fiber Elongation at Failure
(%)
Modulus (GPa)
Strength (GPa)
Density (g/cm3)
Energy to Break (J/g)
Dragline Spider Silk (Nephila clavipes)
10-40 1-30 0.3-1.8 1.35 30-125
Silkworm Cocoon Silk (Bombyx mori)
15-35 5 0.6 1.45 70
Nylon 66 18 5 0.88 1.14 80Cotton 6-7 6-11 0.3-0.7 1.50 5-15Kevlar 49 2.5 124 2.8 1.44 15Steel 8 200 2 13.0 2
D.L. Kaplan, S.J. Lombardi, W. Muller, S. Fossey, in Biomaterials: Novel Materials from Biological Sources (Ed: Byrom D.), Stockton Press, New York 1991.
Department of Chemistry
“Natural Fiber Welding”
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Heated 60 min
Natural Fibers Welded Fibers
add Ionic
Liquid
remove Ionic
Liquid
Controlled Application of ILs Opens Up the Fiber
Structure to Enable Physical and Chemical
Modification L. M. Haverhals, H C. De Long, W. M Reichert, P. C. Trulove, “Natural Fiber Welding,” US patent 8,202,379; L. M. Haverhals, et al, Cellulose, 19, 13 – 22 (2012).; L. M. Haverhals, et al, Macromolecular Materials & Engineering, 295 (5), 425 – 430 (2010)
Department of Chemistry
Applications of NFW• Improve Natural Material Properties• Controlled Fabrication of Novel Composites
Integrate Small MoleculesMerge Functional Polymers Entrap Functional Solids
Department of Chemistry35
Use of Ionic Liquids to Fabricate Biopolymer Composite Materials
Knitted Electrochemical Capacitors for Smart Textiles*
*Collaboration with Drexel University
Bamboo (0.54 mg/cm)
Department of Chemistry
+ + +
Yarn Separator
Yarn Electrode
Yarn Electrode
Knitted Linen/Bamboo/Viscose Capacitors!
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Department of Chemistry37
Printing and Welding of Ag & Au Nanoparticles
MIDN Saok Park
20 μm
Linen Fiber
50 μm
Linen + Nanoparticles
Dimatix DMP-2800
Department of Chemistry
MIDN Robert Chung
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Fluorescence Microscopy Evaluation of Welding
Control (untreated) treated 60 min.