Edward Grant
Relevant Thesis-Based Degree Programs
Biography
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
Dissertations completed in 2010 or later are listed below. Please note that there is a 6-12 month delay to add the latest dissertations.
The core of an ellipsoidal Rydberg gas of nitric oxide undergoes spontaneous avalanche, leadingto the formation of plasma. Ambipolar expansion quenches electron temperature as it radially accelerate NO⁺ ions in the core. Ballistic ions enter the wings of the ellipsoid where they engage in long-range, resonant charge transfer with frozen Rydberg molecules, equalizing the ion-Rydberg molecule relative velocity. This sequence of process gives rise to a remarkable process of self assembly, where the kinetic energy of the initially generated hot electrons and ions drives the separation of plasma volumes. These dynamics effectively store energy in a reservoir of mass transport, initiating a process that facilitates the annealing of the separating volumes into a seemingly glass like state consisting of strongly coupled ions and electrons. Experimental evidence for complete ionization is provided through short-time electron spectroscopy. Notably, the long lifetime and stability of this system, with respect to recombination and neutral dissociation, suggest that this transformation yields a resilient state of arrested relaxation, significantly deviating from thermal equilibrium. This thesis, provided direct evidence for these processes observed in the absorption spectrum of transitions to states within the selected Rydberg series, which persist as a long-lived signal even after travelling for 400 μs to reach an imaging detector. Plasma images elucidate kinetic processes that occur within the Rydberg volume, leading to the formation of a long-lived plasma that undergoes an initial density dependent bifurcation. Spectroscopic results shed light on how the initial electron density, resulting from prompt Penning ionization and varying with the chosen initial principal quantum number and Rydberg gas density, play a crucial role in determining plasma stability. This Penning-regulated ion-Rydberg equilibrium appears to be play an essential role in extending plasma lifetime, thereby enabling the detection of spectral features after significant time delays. Studies of bifurcation velocity as a function of initial Rydberg gas principal quantum number and density map patterns in plasma energy disposal and long term stability notably show that, irrespective of the initial conditions, this final bifurcated state exhibits a constant density.
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In many-body systems out-of-equilibrium, strong coupling triggers emergent propertiesthat can act to limit the natural dissipation of energy and matter. The physicsof strong coupling plays an important but incompletely understood role in thedynamics of natural plasmas over a wide range of length scales. Particularlyremarkable signs of hindered transport appear under laboratory conditions in theself-organized avalanche, bifurcation, and quench of the nitric oxide molecularultracold plasma.Here, a UV-UV double-resonant excitation of nitric oxide, cooled to 500 mKin a skimmed supersonic molecular beam prepares an ellipsoidal Rydberg gasof known initial density in a single selected state of principal quantum number,n₀. Penning ionization, followed by an avalanche of electron-Rydberg collisions,forms a plasma of NO⁺ ions and weakly bound electrons, in which a residualpopulation of n₀ Rydberg molecules evolves to a state of high orbital angularmomentum, ℓ.A 60 MHz radio frequency pulse with a peak-to-peak amplitude as low as 400mV/cm, applied to a plasma in a state of arrested relaxation, depletes the residualRydberg signal. Similarly, mm-wave fields in the range from 70 to 100 GHz tunedto resonance with n₀f (2)→(n₀ ±1)d(2) transitions deplete the plasma signal toan amplitude near zero. We associate both effects with Rydberg electronic orbitalangular momentum redistribution.New theoretical work has developed a primitive picture of this system usinga Lindblad master equation to describe the Markovian dynamics that arise whena closed quantum system of disordered, randomly interacting molecular dipolescouples to a thermal continuum of free atoms.
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Leaps forward in technology now yield volumes of data so immense they surpass the capacity of humans to interpret. At the core of data science, automated algorithms reliably transform enormous sums of raw data into meaningful information. A diversity of data in the form of vibrational spectra, microscope images and electrocardiograms (ECGs) appear very different at face value, however the algorithms used to process these data structures share many common threads.This first part of this thesis presents the progress made on the development of a novel microscope integrating collinear Raman and interferometric scattering (iSCAT) microscopies. iSCAT directly images sub-diffraction limited nanoscopic particles without the need for extraneous labelling. This overcomes one of the main drawbacks of fluorescence microscopy, however iSCAT fails to provide any chemical specificity. The integration of Raman microscopy overcomes this hurdle by probing the vibrational energy structure of the target analyte.The second part of this thesis presents the progress made on the development of a novel, non-invasive, and inexpensive diagnostic methodology for risk of sudden cardiac death (SCD). Despite the prevalence of heart disease as the leading cause of death worldwide, over half of SCD incidents remain unexplained. Brugada Syndrome (BrS) is an inherited arrhythmic cardiomyopathy which often lies dormant until manifests for the first time as SCD. In some parts of the world a physician can administer a sodium blocker challenge to reveal the signature of BrS in an ECG, however its use may cause life-threatening proarrhythmic effects. In collaboration with the IRCCS Policlinico San Donato, we have introduced a novel non-invasive methodology to diagnose BrS from the analysis of an ECG using a deep neural network.
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Not long after metastable xenon was photoionized in a magneto-optical trap, groups in Europe and North America found that similar states of ionized gas evolved spontaneously from state-selected Rydberg gases of high principal quantum number. Studies of atomic xenon and molecular nitric oxide entrained in a supersonically cooled molecular beam subsequently showed much the same final state evolved from a sequence of prompt Penning ionization and electron impact avalanche to plasma, well-described by coupled rate-equation simulations. However, measured over longer times, the molecular ultracold plasma (UCP) was found to exhibit an anomalous combination of very long lifetime and very low apparent electron temperature. In this thesis I summarize early developments in the study of UCP formed by atomic and molecular Rydberg gases, and then I detail observations as they combine to characterize properties of the nitric oxide molecular UCP that appear to call for an explanation beyond the realm of conventional plasma physics. I also explain how I leveraged a radio frequency electric field to understand the causes of classically-unexplainable behavior of our molecular system.
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The pulp and paper industry stands to benefit immensely from the development of automated process control technologies that provide real-time feedback about the quality of in-process product. Current methods are destructive and labor-intensive wet-chemical assays, which cannot be implemented in an on-line setting. Rapid on-line alternatives to these methods hold great promise for improving efficiency and reducing costs, as well as providing the opportunity to make product quality guarantees based on data collected from in-process samples.This thesis presents the progress made on the development of two such automated methods. The first, principal method couples Raman spectroscopy with chemometric analysis to model and predict value-critical properties of pulp products, with a focus on strength properties. The second method implements machine vision in the detection of contaminants in in-process pulp, the presence of which have a deleterious effect on product strength - and therefore value. In both cases, we have taken these techniques from academic proofs-of-concept to industrial trials, one in a pilot plant, and the other in a pulp mill. This is a significant milestone in any academic-industrial collaboration.The first two chapters provide overviews of the nature of pulp and the current state of analytics in the industry, followed by a theoretical discussion of the methods used in this project. Following this are three chapters documenting the progress made towards the development of the Raman probe system, and a chapter presenting machine vision system, used to detect pulp contaminants. Finally, there is a discussion of some of the ongoing challenges, as well as future steps that will be undertaken to bring these technologies to full-scale on-line implementation in a working pulp mill.
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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.
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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.
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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.
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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.
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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.
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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
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Master's Student Supervision
Theses completed in 2010 or later are listed below. Please note that there is a 6-12 month delay to add the latest theses.
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.
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The use of online spectroscopic analysis to predict final properties of in-process pulp has the capacity to revolutionize the paper industry saving time and money in process control and quality assurance. Water has a very low Raman scattering cross section, which makes this spectroscopic probe ideal for classification typical pulps with high and varying water content. Work described in this thesis aims to develop new methods to predict pulp end product properties from the Raman spectra of in process pulps. We predict breaking length of wet and dry pulps from their Raman spectra using a laboratory Raman probe. Pulp samples were refined to five levels of refining energy by Canfor Pulp Ltd. We determined that to accurately predict breaking length, pulp spectra must first, before modelling, be sorted into groups based on refining energy. Dry pulps yield better prediction models then wet pulps. Breaking length can be determined within 10% error after discrete wavelet transform (DWT) and template oriented genetic algorithm (TOGA) preprocessing, however, industry standard is 5%. Principal component analysis (PCA) suggests that Raman measurements made on the side edge of a pulp sheet are similar to those made on the top surface. We designed and built a Raman probe set-up for the investigation of industry-standard brightness pads in a modified PulpEye sample chamber to mimic online monitoring. We fashioned a 5-axis stage, from optical positioning components, to hold an INNO spectrometer for easy alignment through a small sapphire widow in the sample holder. Spectra acquired with the INNO-PulpEye set-up predict breaking length with an accuracy similar to the spectra taken with the laboratory set-up. Utilizing DWT for background suppression and noise reduction as well as TOGA for feature selection we were able to predict breaking lengths with 6-10% error using both the lab and PulpEye sample chamber Raman probe systems. We have also investigated the possibility of predicting pulp viscosity from its Raman spectrum. We were able to predict viscosity over the full range with errors below 6% and 1% for pulps with viscosities between 500-560 mL/g.
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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.
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