Resume

• 2002

  B.Eng.

  Chemical Engineering

  Plasma Engineering

  Advanced Process Dynamics and Control

  Chemical Reaction Engineering

  Advanced Heat and Mass Transfer

• 2000

  English

  French

• 1995

  D.E.S.

  High School/Secondary Diplomas and Certificates

  Séminaire Sainte-Trinité

• Process Engineering

  Spectroscopy

  Matlab

  Plasma Processing

  Engineering

  Powder X-ray Diffraction

  Energy Recovery

  Photochemistry

  Chemical Engineering

  Surface Chemistry

  Materials

  Surface

  Nanotechnology

  Materials Science

  AFM

  Nanomaterials

  Nanoparticles

  Nanofabrication

  Characterization

  Research

  Ultrasonication of spray- and freeze-dried cellulose nanocrystals in water

  Marie-Claude Heuzey

  (first author is Q. Beuguel)\nThe structural and rheological properties of aqueous suspensions of spray-dried cellulose nanocrystals (CNCs) were investigated and compared to those of freeze-dried. The cellulose nanocrystals were obtained from sulfuric acid hydrolysis of wood pulp. Ultrasonication was used to disperse cellulose nanocrystals in Milli-Q water and the power applied during ultrasonication was shown to be the controlling parameter for their dispersion

  more than total energy. Dynamic light scattering measurements showed a decrease of the average hydrodynamic diameter down to the same limiting value

  i.e. ∼ 75 nm

  for both spray and freeze-dried cellulose nanocrystals. Since the same maximum dispersion state was reached for both CNC types

  it indicated that the spray drying process did not limit dispersion

  provided that sufficient ultrasonication was provided. Moreover

  no desulfation occurred during ultrasonication at ambient temperature. Strong ultrasonication also caused a decrease of intrinsic viscosity

  along with an increase in maximum packing concentration. These properties were correlated to agglomerates break-up

  which released both ions and water in suspension. The ionic strength increase may lead to a thinner electrostatic double layer surrounding the cellulose nanocrystals

  reducing their apparent concentration.

  Ultrasonication of spray- and freeze-dried cellulose nanocrystals in water

  Wendell Raphael

  (first author is F. Sabri)\nSolid-stabilized Pickering emulsions have attracted a lot of attention recently due to their surfactant-free character

  and exceptional stability. At the moment

  how the viscosities of the liquid phases impact the processing of Pickering emulsions remain to be clearly understood – it is however an important parameter to consider when developing chemical engineering processes employing these multiphase liquids. Our first assumption was that the amount of emulsified dispersed phase would drastically decrease as viscosity increases.\nIn this work

  we demonstrate that double water-in-oil-in-water (W/O/W) Pickering emulsions are obtained in a single processing step when using very high viscosity silicone oils (≥10

  000 cSt) and a single type of sub-μm silica particles modified with two grafted silanes and sodium alginate. The formation of water sub-inclusions proceeds via a phase-inversion mechanism. These sub-inclusions are subsequently stabilized and retained in the oil phase due to its viscosity

  limiting sub-inclusions mobility

  and the presence of adsorbed particles forming dense layers at oil-water interfaces

  acting as barriers. The process we present is simple

  requires a minimum number of components

  and allows the preparation of multiple emulsions which could then be used to efficiently protect and/or transport a variety of sensitive encapsulated compounds.

  One-step processing of highly viscous multiple Pickering emulsions

  (special issue \"Quid Novi

  Quo Vadis?\")\nStudents at Polytechnique Montreal have demonstrated the ability to tackle large-scale

  complex calculations through their integrative projects. However

  high quality engineers must not only master calculations

  but the underlying fundamental concepts as well − this level of retention allows them to transfer their knowledge to the new challenges they will face. To ensure this

  accreditation criteria for engineering programs in Canada require the evaluation of multiple attributes

  the first of which is “a knowledge base for engineering”. While most universities opt to evaluate this attribute through in-class grades

  we choose to adapt a pedagogical tool (a concept inventory) to formulate an evaluation of our students. Our students are examined using a subset of questions from more than 800 chemical engineering questions

  split into 10 subcategories. Data amassed over four years is presented

  showing the impact of various improvements to this tool

  as well as its use for instructor feedback and curriculum improvement. Key improvements include question revisions and targeted revisions of muddy concepts in the affected courses.

  A Concept Inventory for Knowledge Base Evaluation and Continuous Curriculum Improvement

  (H. Nasri and D. Farhanian share first authorship)\nDuring our studies on surface engineering

  we photopolymerize syngas onto silicon surfaces. XPS and TOF-SIMS analyses show that the syngas-derived oligomer covalently bonds to free silanol sites. Iron atoms appear in the coating

  despite the fact that no iron was (intentionally) added to the system. GC–MS analysis reveals low concentrations of iron pentacarbonyl (IPC) are generated within the carbon monoxide cylinder. Its presence plays a determinant photocatalytic role in the reaction.

  Shedding light on iron pentacarbonyl photochemistry through a CVD case study

  Gérald Chouinard

  Simon Knoch

  (first author is A. Mukherjee)\nThe use of exclusion netting as an Integrated Pest Management technique is likely to become increasingly important as a means to increasing crop yields whilst minimising pesticide use. However

  the increasing use of these nets will also lead to a rise in greenhouse gas emissions in the agricultural sector and pose problems related to their end-of-life disposal. Employing biopolymers made from low-carbon and renewable biomass feedstock to fabricate exclusion nets can potentially resolve these issues by merging the benefits of the two emerging technologies. Despite this

  there has only been limited work on the use of biopolymer netting in agriculture. By looking at the challenges needed to be overcome for biopolymers to be widely used as a netting material

  this review aims to bridge the gaps between the two fields of research. To do so

  the past work done on agricultural netting is discussed

  with a focus on the implemented materials and their desired properties. After this

  potential candidate biopolymers for manufacturing agricultural nets are pointed out

  emphasising their sustainability with respect to widely used Life Cycle Analysis (LCA) parameters

  including the end-of-life treatment.

  Use of bio-based polymers in agricultural exclusion nets: A perspective

  Marie-Claude Heuzey

  (first author is C. Bruel)\nThe Teas graph of wood-based sulphuric acid-hydrolyzed cellulose nanocrystals (CNCs) was plotted based on sedimentation tests in a set of 25 common solvents. Comparisons with those of sucrose and dextran

  taken as equivalents for cellobiose (the cellulose repeating unit) and amorphous cellulose respectively

  highlighted the amphiphilic nature of CNCs. In the absence of any chemical arguments

  the hydrophobic behaviour displayed is thought to be caused by the exposure of (200) lattice planes at the CNC surface. This apparent struc- tural hydrophobicity can be taken advantage of to achieve CNC dispersion in mildly non-polar matrices such as poly(ethylene glycol) and poly(lactic acid). The Teas graph is a useful tool for predicting CNC dispersibility potential and selecting a proper solvent for nanocomposite preparation.

  Apparent structural hydrophobicity of cellulose nanocrystals

  Gérald Chouinard

  (first author is S. Knoch)\nThe dip-dip-dry method is a novel surface treatment that can tune the wetting properties of polylactic acid (PLA). This fast

  solvent-induced method yields water contact angles up to 150°

  resulting from hierarchical microstructure growth at the surface. This ˜100% increase in static contact angle is achieved by successively dipping the solid PLA samples in solvent and coagulant baths

  the choice of which allows us to tune the surface properties

  producing wetting states approaching « lotus » or « petal » effects. SEM imaging

  XRD and contact angle measurements have been deployed to characterize treated substrates

  demonstrating stable properties

  with only a gradual loss of the residual solvent to evidence the passage of time. Polymer crystallinity largely influenced the extent of surface modification - unless surface texturation (sanding) was applied

  solvents only had a minor effect on wettability on crystalized substrates.

  Dip-dip-dry: solvent-induced tuning of polylactic acid surface properties

  (first author is F. Sabri)\nIn this article

  we demonstrate that submicrometer particles with surface-grafted sodium alginate (SA) display enhanced and reversible aggregation/disaggregation properties in aqueous solution. 300 nm silica particles were first functionalized with an aminosilane coupling agent

  followed by the grafting of pH-sensitive SA

  as confirmed by zeta potential

  XPS and FTIR analyses. The SA-modified particles show enhanced aggregation properties at acidic pH compared to unmodified silica

  with a 10 times increase in average aggregate diameter. The process is reversible

  as the aggregates can be broken and dispersed again when the pH is increased back to 7.0. As a result

  the sedimentation rate of SA-modified particles at pH 3.0 is both significantly faster and complete compared to the unmodified particles. This enhanced aggregation is most likely due to the formation of intermolecular hydrogen bonds between neighboring SA-modified particles. This work illustrates how surface-grafted macromolecules of natural origins can be used to tune interparticle interactions

  in order to improve separation processes.

  Sodium alginate-grafted submicrometer particles display enhanced reversible aggregation/disaggregation properties

  Marie-Claude Heuzey

  Bernard Riedl

  (first author is D. Khandal)\nThe present paper reports the surface modification of commercially available cellulose nanocrystals (CNCs) using polyethyleneimine (PEI) by means of non-covalent electrostatic interaction between the negatively charged sulfate groups of CNCs and positively charged amine functionalities of PEI. The modification

  carried out in an aqueous medium

  results in a stable CNC-PEI suspension with no phase separation that exhibit interesting rheological behavior due to bridging-type inter-particle interactions. The Newtonian 3% (w/w) CNC suspension evolves into a non-Newtonian gel system after modification with PEI with a consequent increase of almost three decades in complex viscosity. Pre-shearing of the 3% (w/w) CNC-PEI suspension resulted in the loss of the linear viscoelastic properties with increasing shear rate

  as would be expected from the breaking of the inter-particle network. However

  the system gradually re-established the inter-particle network in less than an hour to give the original rheological parameters. The effect of PEI on the rheological properties was attributed to the physical adsorption of PEI chains on the CNC particles

  examined by dynamic light scattering (DLS)

  zeta potential

  X-ray photoelectron spectroscopy (XPS)

  elemental analyses

  and isothermal adsorption studies. The modified CNC-PEI particles did not show any significant change in the particle morphology compared to the unmodified CNCs

  as observed from transmission electron microscope (TEM) images.

  Tailoring Cellulose Nanocrystals Rheological Behavior In Aqueous Suspensions Through Surface Functionalization With Polyethyleneimine

  Marie-Claude Heuzey

  (C. Bruel is first author)\nCellulose nanocrystals (CNCs)

  usually considered as isotropically polar nanoparticles

  are sheet-like crystalline assemblies of cellulose chains. Here

  we link the anisotropy of the CNC structure to an amphiphilic behavior in suspension. The Hansen solubility parameters (HSP: δD;δP;δH) of wood-based H2SO4-hydrolyzed CNCs were measured from sedimentation tests in a wide set of 59 solvents and binary mixtures. Two sets of cohesion parameters corresponding to a polar surface (18.1; 20.4; 15.3) ± (0.5; 0.5; 0.4) MPa1/2 and to a mildly non-polar one (17.4; 4.8; 6.5) ± (0.3; 0.5; 0.6) MPa^1/2 were determined

  with respective solubility radii of 7.8 and 2.1 MPa^1/2. The polar sphere is thought to correspond to the (110)&(1\n0) surfaces of cellulose Iβ nanocrystals

  while the smaller non-polar sphere is coherent with the exposure of (200) surfaces. The HSP graph provides new insights on the amphiphilic nature of CNCs and a mapping of their chemical affinity for solvents and polymer matrices.

  The structural amphiphilicity of cellulose nanocrystals characterized from their cohesion parameters

  Nathalie Faucheux

  (first author is E. Hosseininasab)\nSingle-wall carbon nanotubes (SWCNTs) have various remarkable properties

  which make them a promising candidate for many applications. However

  their inherent hydrophobicity have limited their commercial use in optical

  biological

  and electrical applications. Photo-initiated chemical vapor deposition (PICVD) using syngas is proposed as a novel

  affordable

  and versatile method to tailor SWCNT wettability through the addition of oxygen-containing functional groups. Following PICVD surface treatment

  X-ray photoelectron spectroscopy

  water contact angle measurements (CA)

  thermogravimetric analysis

  Raman spectroscopy and transmission electron microscopy confirm controlled oxygenation of the SWCNT surface. Indeed

  this novel approach allows to reproducibly make SWCNT having surfaces properties ranging from superhydrophilic (CA<5°) to superhydrophobic (CA>150°)

  including any intermediate values

  by simply varying operational parameters such as molar ratio of the syngas precursor

  photo-polymerization time and reactor pressure (about normal conditions).

  Full Range of Wettability through Surface Modification of Single-Wall Carbon Nanotubes by Syngas Photo-Initiated Chemical Vapor Deposition

  (O. Gazil

  M. Gosselin and F. Tanguay-Rioux share first authorship)\nStudents identified a lack of practical applications for the theoretical concepts taught as a key weakness for some classes in our chemical engineering undergraduate program. We have thus implemented a new simulation tool to help overcome these weaknesses: A dynamic process simulator based on a carbon dioxide capture plant. Aspen Simulation Workbook

  a recent tool developed by AspenTech© is used in a novel approach to implement a user‐friendly interface based on Microsoft Excel. Exercises incorporating the use of the simulator were developed to cover the main concepts taught in chemical engineering. Longitudinal implementation of the simulator within the curriculum recently began and should be completed over the coming semesters. Student and instructor feedback was collected by means of surveys. Based on the information collected

  using the simulator improves comprehension of key concepts taught throughout the curriculum. Feedback analysis also helped identifiy needs for future exercises and avenues for improvement.

  Simulating dynamically: A longitudinal and practical simulation approach for students

  Theron Darlow

  (first author is C. Bruel)(special series on Experimental Methods)\nThe contact angle (CA) formed at equilibrium at the three-phase line of contact between a liquid

  a solid

  and a gas may be expressed as a function of both the interfacial and surface tensions. Young first derived this thermodynamic relationship in 1805. In practice

  multiple CA values are observed due to kinetic phenomena induced by evaporation

  vapour adsorption

  or swelling

  and thermodynamic ones induced by roughness and surface chemical heterogeneities

  even at molecular-scale. These non-ideal conditions result into an hysteresis

  i.e.

  a difference between wetting and dewetting behaviours

  and Young’s equation rarely applies. Three measuring methods stand out for their applicability and reliability. In the sessile drop method

  a syringe deposits a liquid drop on a flat surface and the contact angle is measured through optical means based on the drop shape. In the Wilhelmy balance method

  the force required to immerse a solid plate in a bath of liquid is indirectly related to the contact angle. In the Washburn capillary rise method

  the contact angle is derived from the rate at which a liquid rises by capillarity through a packed bed of powder. Employing probe liquids of various polarities

  the free surface energy of the solid may be estimated. Over the last two years

  ∼8600 published articles mentioned “contact angle” in their topic. Their main focus was either to develop the fundamental understanding of wetting science

  or to assess the success of surface modification methods for the production of novel surfaces

  composites

  and membranes with enhanced wetting

  adhesive

  and filtration properties.

  Experimental Methods in Chemical Engineering: Contact Angles

  Nathalie Faucheux

  (First author is S. Hosseininasab)\nPhoto-initiated chemical vapor deposition (PICVD) is a solvent-free process that can be used to produce thin films on a variety of substrates

  with applications in fields ranging from biomedicine to optics and\r\nmicroelectronics. This study presents a kinetic analysis for this process using syngas (CO + H2) as a precursor for the surface treatment of single-walled carbon nanotubes\r\n(SWCNT) with average dimensions of 1.5 × 100 nm (diameter × length)

  and addresses the role of iron pentacarbonyl (Fe(CO)5)

  a photo-active contaminant found in CO. This work builds upon previously developed reaction schemes for PICVD

  based mainly on surface characterizations

  by coupling these analyses with gas-phase monitoring. This allows us to propose two separate reaction schemes for the gas and surface phase reactions and consider temperature effects. Online FTIR

  offline GC-MS

  and online GC characterized the gas phase

  while for surface characterizations

  XPS and\r\nTGA were used. Characterizations showed that a coating with a general formula of CnO3nFen was deposited

  corresponding to 0.29 ± 0.04 mg carbon and 0.49 ± 0.03 mg\r\niron on the SWCNT substrate over the course of treatment. The Fe(CO)5 was identified as the key reactant in syngas/PICVD reactions and was nearly completely consumed (94%). Mass balances derived from the gas phase characterization showed that Fe(CO)5 inputted to the plug flow reactor could potentially contribute all the amount of 0.49 ± 0.03 mg of Fe and 0.29 ± 0.04 mg of C to the coating on the SWCNT

  indicating that syngas/PICVD can be optimized in the future to decrease gas throughput. Temperature did not show a significant effect in the case of PICVD. However

  in the absence of ultraviolet light

  \r\nits role becomes determinant

  with rising temperatures causing more Fe deposition.

  Reaction kinetics and temperature effects in syngas photo-initiated chemical vapor deposition on single-walled carbon nanotubes

  (first author is E. Kasparek)\nPhotoinitiated chemical vapor deposition (PICVD) has become attractive for selective and specific surface functionalization

  because it relies on a single energy source

  the photons

  to carry out (photo-) chemistry. In the present wavelength (λ)-dependent study

  thiol (SH)-terminated thin film deposits have been prepared from gas mixtures of acetylene (C2H2) and hydrogen sulfide (H2S) via PICVD using four different vacuum-ultraviolet (VUV) sources

  namely

  KrL (λpeak = 123.6 nm)

  XeL (λpeak = 147.0 nm)

  XeE (λpeak = 172.0 nm)

  and Hg (λ = 184.9 nm) lamps. Different λ influence the deposition kinetics and film composition

  reflecting that photolytic reactions are governed by the gases’ absorption coefficients

  k(λ). Thiol concentrations

  [SH]

  up to ∼7.7%

  were obtained with the XeL source

  the highest reported in the literature so far. Furthermore

  all films showed islandlike surface morphology

  regardless of λ.

  VUV Photodeposition of Thiol-Terminated Films: A Wavelength-Dependent Study

  Rony Snyders

  Damien Thiry

  (first author is E. Kasparek)\nThiol (SH)‐terminated surfaces have gained interest over the past years due to their potential applications

  especially in the biomedical field. In this work

  SH‐terminated films have been prepared by “co‐polymerizing” gas mixtures of acetylene (C2H2) and hydrogen sulfide (H2S) using low‐pressure r.f. plasma‐enhanced chemical vapor deposition. R.f. power greatly influences the deposition rate

  sulfur content

  [S]

  and thiol concentration

  [SH]

  of the films

  as confirmed by XPS (both before and after chemical derivatization)

  FTIR

  and mass spectrometry measurements. These data are compared with those obtained in a similar discharge by using a single molecule precursor

  propanethiol. Among other differences

  it is demonstrated that [SH] is higher when using binary gas mixtures compared to the single molecule precursor.

  Growth mechanisms of sulfur‐rich plasma polymers: Binary gas mixtures versus single precursor

  Marie-Claude Heuzey

  (first author is Q. Beuguel)\nThe rheological behavior of cellulose nanocrystals (CNCs) in polar media based on polyethylene glycol (PEG) was investigated from aqueous suspensions to nanocomposites. The aim of this work is to improve our knowledge on the CNC behavior in polymer media and develop rheological indices to characterize the dispersion of nanoparticles in polymer matrices. CNCs were obtained from sulfuric acid hydrolysis of wood pulp and supplied after a spray- or freeze-drying process. Ultrasonication was used to break agglomerates and disperse CNCs in aqueous suspensions before mixing with an aqueous PEG solution at room temperature. The samples were subsequently dried and compression molded. From capillary and oscillatory shear rheology

  no adsorption of PEG chains on CNCs could be detected

  as many had previously hypothesized. The increase of PEG concentration in aqueous suspension favored the gelation by depletion effect and suggested CNC orientation. Viscoelastic properties and transmission electronic images of PEG/CNC nanocomposites highlighted the formation of a percolated network of CNCs for low concentrations ≥ 0.15 vol. %. From the model of Shih et al.

  a fractal dimension of 2 was obtained for these percolated nanocomposites

  suggesting a 2D network of CNCs in the PEG matrix.\n

  Rheological behavior of cellulose nanocrystal suspensions in polyethylene glycol

  (first author is D. Farhanian)\nPhoto-initiated chemical vapor deposition (PICVD) has been adapted for use in a jet-assisted fluidized bed configuration

  allowing for the encapsulation of magnetic iron oxide nanoparticles on a larger scale than ever reported (5 g). This new methodology leads to a functional coating with a thickness of 1.4–10 nm

  confirmed by HRTEM and TGA. XPS and TOF-SIMS characterization confirm that the coating is composed of both aliphatic and polymerized carbon chains

  with incorporated organometallic bonds and oxygen-containing moieties. UV-Vis absorbance spectra show that the coating improved dispersion in non-polar solvents

  such as n-dodecane. This process represents a first step towards the large-scale

  solvent-free post-synthesis processing of nanoparticles to impart a functional coating.

  Large-Scale Encapsulation of Magnetic Iron Oxide Nanoparticles via Syngas Photo-Initiated Chemical Vapor Deposition

  Bernard Riedl

  (B. Zakeri and D. Khandal share first authorship)\nCellulose nanocrystals (CNCs) are bio-derived

  natively hydrophilic nanomaterials that disperse well in water according to their surface chemistry upon extraction. However

  to be suspended in non-polar

  hydrophobic media such as most polymers [1]

  the CNCs are chemically modified by reactions that are environmentally unfriendly and not cost-effective for the industry. The present work reports the preliminary findings of the non-covalent surface modification of CNCs using polyethyleneimine (PEI)

  a common additive used in the paper industry [2]

  through a low-cost process and without any use of organic solvents. The successful surface modification was confirmed through different techniques

  including Fourier transform infrared (FTIR) spectroscopy

  X-ray Photoelectron Spectroscopy (XPS)

  Dynamic Light Scattering (DLS) and Zeta Potential (ζ-potential) measurements. The CNC agglomerates formed in aqueous suspensions as a result of the modification showed improved dispersion in toluene and were found to precipitate in deionized water. The turbidity measurements of the water suspensions of pristine and modified CNCs (mCNCs) were performed using UV-Visible (UV-Vis) transmission spectroscopy.

  Non-covalent surface modification of cellulose nanocrystals by polyethyleneimine

  Changsheng Wang

  (F. Sabri is first author)\nWe demonstrate that the separation and recovery of solid-stabilized (Pickering) emulsion constituents are significantly improved via a simple filtration approach – without any additional chemical agent – by initially grafting sodium alginate (SA)

  a natural polysaccharide

  onto silane-modified sub-micrometer silica particles. The combination of surface-grafted trimethoxy(propyl)silane (TMPS) and (3-aminopropyl) trimethoxysilane (APTMS) controls particle wettability

  verified via zeta potential and contact angle measurements. Rheometry and filtration experiments reveal that further grafting of SA via APTMS enhances particle–particle and droplet–droplet interactions. This work provides an approach towards the design of environmentally friendly Pickering emulsion based chemical engineering processes with easy- to-separate and reusable particles

  allowing waste reduction and reduced toxicity advantages.

  Tuning particle–particle interactions to control Pickering emulsions constituents separation

  Polytechnique Montreal

  PyroGenesis Canada

  In a fossil fuel waste incineration or plasma gasification process

  waste heat generated by combustion of waste is captured by a heat transfer fluid and conveyed to an Organic Rankine Cycle (ORC) for energy recovery. In the case of a fossil fuel-fired waste incineration system

  the heat transfer fluid captures waste heat from a double-walled combustion chamber

  a heat exchanger being used to cool the hot process exhaust (gas cooler). In the case of a plasma waste gasification system

  the heat transfer fluid captures waste heat from a plasma torch

  a gasification chamber and combustion chamber cooling jackets as well as any other high-temperature components requiring cooling

  and then a heat exchanger used to cool the hot process exhaust (gas cooler). The heat exchanger may take on several configurations

  including plate or shell and tube configurations.\nhttp://patentscope.wipo.int/search/en/WO2012122631

  Method to maximize energy recovery in waste-to-energy processes

  US9447705 B2

  PCT/CA2012/000233

  PyroGenesis Canada

  A method and reactor for in-situ synthesis

  stabilization and dispersion of nanoparticles in a organic host fluid

  and nanofluids containing nanoparticles that are coated in-situ with a surface layer compatible with the organic host fluid.

  Organic nanofluids

  method and reactor for synthesis thereof

  McGill University

  Sylvain Coulombe

  Member (MCIC)

  Chemical Institute of Canada

  http://www.polymtl.ca/crepec/

  Member

  CREPEC

  http://www.plasmaquebec.ca

  Associate member

  Plasma-Québec

  Engineer (ing.)

  OIQ - Ordre des ingénieurs du Québec

  Member

  Sigma Xi Research Society