Relevant Degree Programs
Edward R. Grant is Professor of Chemistry at the University of British Columbia. He joined the faculty in 2005, moving from Purdue University. While at Purdue, he served as Chairman and Chief Executive Officer of SpectraCode, Inc., a West Lafayette maker of instruments for spectrochemical analysis. At UBC, he was Department Head from 2005-10. He began his academic career at Cornell University, where from 1977 to 1986, he was first Assistant and then Associate Professor of Chemistry.
Grant has held visiting positions as Professor of Physics at the University of Crete and Foundation for Research and Technology, Hellas in 1988, and as Professor of Chemistry at the Institut für Physikalische und Theoretische Chemie of the Technischen Universität München from 1992 to 1993. In 1999, he served as Directeur de Recherche Associe (5 ème échelon) CNRS Laboratoire Aimé Cotton, Université de Paris Sud, and Professeur Invité in 2011. In 2000, he was Visiting Professor of Chemical Physics and Visiting Fellow of the Joint Institute for Laboratory Astrophysics at the University of Colorado, Boulder.
Grant's accomplishments in research and education have been recognized by national and international awards, including, a Fulbright Senior Fellowship, an Alexander von Humboldt Research Award for Senior U.S. Scientists and a Nobel Laureate Signature Award for Graduate Education in Chemistry. He has won an R&D 100 Award, a Tibbetts Award, and a Henry Ford Technology Award. He has twice earned the Arthur E. Kelly Award for Excellence in Undergraduate Teaching, and has been recognized as One of the Ten Best Teachers in the School of Science of Purdue University. He has been elected a Fellow of the American Physical Society.
Grant has co-authored 210 papers and has presented more than 200 invited talks on his work. Since 1977, he has overseen the research of 32 PhD graduates, 23 postdoctoral fellows and senior visitors, and 38 undergraduate research students. 10 of his former students now hold tenured academic positions at major research universities.
He has organized and chaired eight international conferences including the 1996 Gordon Conference on Multiphoton Processes and the 2012 Gordon Conference on Electronic Spectroscopy and Dynamics.
Graduate Student Supervision
Doctoral Student Supervision (Jan 2008 - May 2019)
Vibrational spectroscopy has received significant interest in last decades as a robust,rapid, and cost-effective alternative to the traditional wet-chemical methods employed by various industries. The spectra of complex materials may contain some components with a low concentration, whose information is buried within a major peak of another component. These small hidden peaks contain critical information in some analysis. This thesis aims to develop novel data mining methods to improve the quality of data, select its essential features, and finally build prediction models.The pulp industry offers one example in which spectroscopy offers attractive advantages as an on-line method for optimizing manufacturing. While spectroscopic techniques are inherently sensitive to many of properties of interest to the pulp industry, they are potentially sensitive to provide features uncorrelated with physical properties of pulp; which could hinder the development of robust prediction models. To overcome this challenge, we introduced Template Oriented GeneticAlgorithm (TOGA). TOGA is aimed to establish significant features to assign predictors according to a template determined to minimize prediction variance in a calibration space. It was found that TOGA significantly improved the prediction accuracy of certain pulp properties compared to those without undergoing these data processing techniques.Near Infrared (NIR) is the most well-known spectroscopy technique which has been successfully applied to pulp industry. However, broad overtone NIR absorption band makes discerning of signature features a difficult process. We showed that a combination of DWT and Orthogonal Signal Correction improved accuracy of prediction models built based on pulp NIR spectra.In the second part of this thesis, a combined technique of interferometric scattering microscopy (iSCAT) and Raman spectroscopy was used to study the dynamics of gold-nanoparticle cellular uptake in cancer and normal cells model. Images derived from the study of these complex samples are heterogeneous which poses a challenge on true quantification and identification of the structure and components of a cell. To address this challenge, we used DWT to remove the out-of-focus and uncorrelated features from the original iSCAT images. This would make a true 3D volume of a cell and a precise track of AuNP internalizing a cell.
The conditions aforded by a skimmed free-jet expansion intersected by two laser pulses, driving resonant transitions in nitric oxide, determine the phase-space volume of a dense molecular Rydberg ensemble. Spontaneous avalanche to plasma within this system leads to the development of two macroscopic domains. These domains are clearly distinguished by their polarizability as well as their locality within the plasma. The first domain appears at the system core, is polarized by fields exceeding 500 mV/cm and displays an ambipolar expansion character suggestive of initial electron temperatures exceeding 150 Kelvin. The second domain travels with the velocity of the supersonic beam and is robust to the application of several hundred V/cm pulses. It is further distinguished through the apparent arrest of relaxation channels, annealing the domain over a millisecond or more in a state far from thermal equilibrium. Both domains are linked via the spontaneous breaking of ellipsoidal symmetry to form bifurcating arrested volumes.
The research work focuses on developing novel methods for determining small molecules in food matrices using molecularly imprinted polymers (MIPs) and surface enhanced Raman spectroscopy (SERS). MIPs are synthesized as artificial antibodies towards target molecules utilizing interactions between templates and functional monomers to impress complementary binding sites on polymers. MIPs selectively isolate templates from food extracts. SERS technique provides rapid and sensitive detection of MIPs-separated molecules. Statistical analysis including unsupervised principal component analysis (PCA), supervised simple linear regression and partial least square regression (PLSR) is employed to analyze SERS spectra. Chloramphenicol in milk and honey was determined using MIPs-packed solid phase extraction cartridge to isolate chloramphenicol from food matrices and dendritic silver to acquire SERS spectra of the eluted chloramphenicol. These spectra obtained from different spiked contents (0, 0.1, 0.5, 1, 5 ppm) of chloramphenicol in milk and honey were analyzed by PCA and PLSR (R > 0.9). MIPs particles were spread onto a thin layer chromatography (TLC) plate to determine Sudan I in paprika powder. Separation of Sudan I from paprika extract by an MIPs-TLC plate takes 30-40 s. SERS spectra obtained from Sudan I spot on the plate can be acquired within 1 s with gold colloid serving as SERS active substrate. A PLSR (R² = 0.978) model was constructed based on spiking levels (5, 10, 40, 70 and 100 ppm) of Sudan I in paprika powder. Histamine level in canned tuna was investigated using MIPs-polyvinyl chloride (PVC)-SERS method. MIPs-PVC films (recognition element) selectively extracted histamine from tuna extract. A gold colloid solution served as an eluting solvent to extract histamine from MIPs-PVC film and conducted a SERS detection of histamine. A PLSR model (R² = 0.947, RMSECV = 3.526) was built on SERS spectra of histamine with different spiking levels (3, 30 and 90 ppm) in canned tuna. The spectral results suggest the powerful separation of MIPs and sensitive detection of SERS. With statistical analysis, we have confirmed that SERS signals obtained by this MIPs-SERS approach rapidly and accurately quantify chloramphenicol in milk and honey, Sudan I in paprika powder and histamine in canned tuna.
Ultracold molecular plasmas represent a new frontier of plasma physics. They offer an easy and accessible laboratory for the study of strongly coupled Coulomb systems. Strong Coulomb coupling can give rise to exotic materials such as Wigner crystals and liquid like plasmas. In this thesis, I present a set of experiments and theoretical models that explore the properties of ultracold plasma in great detail. A supersonic beam of nitric oxide in helium creates a cold ensemble of ground state molecules. Upon two-color excitation, a Rydberg gas of nitric oxide evolves on a time scale of nanoseconds to form an ultracold plasma. The excited volume is imaged using a multichannel plate detector mounted on a movable grid. By moving the detector back and forth, we can observe the expansion dynamics of the plasma and its decay. Selective field ionization captures the relaxation of the Rydberg states to a plasma. We use a very reliable coupled-rate-equation model to understand the decay dynamics and evolution of Rydberg gas to a plasma by accounting for all the major processes that happen during the avalanche process. We find that a plasma evolved from an ultracold Rydberg gas expands very slowly, exhibits long relaxation time, and shows evidence suggesting the development of spatial order.
Raman and infrared spectroscopy offer characteristic molecular vibrational information that enables a rapid quantitative and qualitative analysis of many types of samples. Easy to operate and requiring little sample preparation, these techniques offer great potential for the classification and quantification of complex materials. The research described in this thesis has sought to apply vibrational spectroscopy and multivariate data analysis to tackle a variety of challenging analytical problems.In vitro fertilization has relied purely on embryo morphological appearance to select viable embryos. We explore the potential of Raman spectroscopy to profile embryo metabolism. By analyzing blank culture media, patient samples and bacteria spent media, we establish that Raman spectroscopy does not offer sufficient sensitivity to differentiate used culture media from control. Even using liquid core Teflon-AF 2400 fibre to enhance the Raman signal of aqueous solution, analytical information still lies beneath the sensitivity limit. Turning to a classification problem relative to variance on a larger scale, we investigate olive oil as a complex biomaterial. The adulteration of extra virgin olive oil with cheaper vegetable oils presents a serious food integrity problem. We demonstrate Raman spectroscopy can detect corn, canola, grape seed and walnut oil in extra virgin olive oils from various countries and cultivars, but only at levels greater than 20%. This contrasts with conclusions of many limited studies, suggesting Raman spectroscopy reliably detects a 5% adulterant. Our analysis shows that such high sensitivity relies on olive oils limited to a specific geographic region or cultivar.Bleached kraft pulps represent important economic resources. By referring to wet chemistry, we apply infrared spectroscopy to study alkaline treated bleached eucalyptus kraft pulp. Infrared spectroscopy shows how alkaline treatment modifies hardwood pulp structure. It also classifies bleached hardwood pulps based on species. Despite the natural biological variance presented by this material, we establish that spectroscopic analysis can accurately quantify the contents of hemicelluloses in a large variety of bleached kraft pulps (softwood, hardwood and their mixture) in industry.
Ultracold neutral plasmas (UNPs) are highly correlated, charged-particle systems studiedin standard atomic-molecular optical physics laboratories. Advances in ultracold physics techniques haveled to the development of magneto-optical traps that permit the localization of micro-Kelvintemperature atomic samples (10⁸ - 10¹⁰ cm -³ that can be photoionizedwith a defined excess laser energy. Magneto-optical trapping of molecules proves difficult, and to date, lags in reaching conditionsattainable for atoms. Molecules possess additional degrees of freedomwhere energy can flow during laser trapping and cooling. Alternatively, elastic collisions withinert gases offer another route to low temperatures.Super-sonic expansions of target molecules seeded in a noble gas can reduced the translationaltemperature to values as low as 0.1 K. Here I report on the formation of a molecular ultracold plasma in a molecular beam of nitric oxide seeded in an inert gas. Our method does not directly forma plasma, but instead, I create a Rydberg gas that spontaneously evolves to a plasma. I have verified the transition to a collective plasma state by applying pulsed-fields to the field-free flight region, and observea signal that persists well beyond classical field amplitudes required to ionize individual Rydberg states. Electricfield screening is a collective effect occurring over a characteristic distance, quantified by the Debye length, λ_D. Molecular ultracold plasmas described here exhibit Debye lengths smaller than the overall size, λ_D
Master's Student Supervision (2010 - 2018)
Thiabendazole is a systemic fungicide frequently used to treat vegetables and fruits during the post-harvest process, leading to potential detriment to consumers. This work has combined molecularly imprinted polymers (MIPs) with surface enhanced Raman spectroscopy (SERS) to afford a novel MISPE-SERS chemosensor to determine trace amount of thiabendazole in orange juice. MIPs were synthesized via precipitation polymerization. Kinetic and static adsorption tests validated the efficient separation and enrichment of thiabendazole by using MIPs. Synthesized MIPs were packed into solid phase extraction (SPE) cartridge to work as tailor-made sorbents for the separation of thiabendazole in orange juice. Silver colloid functioned as SERS-active substrate to quantify eluted thiabendazole by MISPE-SERS chemosensor. The whole process only took 23 min with limit of detection of 4 ppm for thiabendazole. In sum, this MISPE-SERS chemosensor can be considered as a promising method for fast and high-throughput detection of trace amount of thiabendazole in agri-food products.
Xerographic photoreceptors play a large role in the printing process and advancements in photoreceptor robustness and efficiency will have a positive impact on both the economy and environment. During the printing process, the photoreceptor is exposed to plasma which causes degradation leading to a loss of print quality over time and eventual replace- ment of the part. To this end, we utilize a combination of static SIMS, ATR-FTIR, and AFM to characterise both chemical and physical changes on the photoreceptor surface after the photoreceptor had been brought to an end of life state. We also attempt to correlate changes in the photoreceptor to visible print defects in printed test pages. Our results point to evidence of binding polymer degradation at two speciﬁc locations in the molecule with water from the environment playing a large role in this process. Photorecep- tor stressing leads to deep regular undulations in the photoreceptor surface which can be seen via AFM. However, we did not ﬁnd any signiﬁcant observable differences in printed test pages. Although we obtained evidence and clues on the general mechanism of photore- ceptor degradation, more work is required to properly identify degradation pathways and products. Further work is also required to properly determine the way in which chemical degradation manifests itself onto printed pages.