Chemical and Biological Engineering Department
PAPER SURFACE SCIENCE PROGRAM
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COMPLETED PROJECTS

MICRO-PROBE FOR PHYSICAL AND CHEMICAL SURFACE ANALYSIS
Objective: To measure local porosity and chemical variations.
Approach: Contact fluids on probe tip and measure force-time response.
student: Josh Mathews(MS)
adviser: D. Bousfield A. van Heiningen
RHEOLOGY-STRUCTURE-PROCESS RELATIONSHIPS IN COATINGS
Objective: To characterize the relationship between coating rheology and process conditions on final coating properties
Approach: Apply coatings with different rheological properties at different shear rates. Characterize the resulting coating layer
student: Basant Dimetry (MS)
advisor: D. Bousfield
ACOUSTIC SENSING OF COATING FORMULATIONS AND PRINTING INKS
 Objective: To probe microstructure of concentrated suspensions such as coating formulations and printing inks in real-time
Approach: A novel acoustic sensor is being developed using a quartz crystal resonator (QCR) directly exposed to test liquids, as a tool for studying suspension microstructure, viscoelasticity, or interfacial slip. It is expected that effects of inter-particle network dynamics on suspension microstructure arising from variations in colloid chemistry or imposed flow fields can be detected in real-time
student: Edgardo E. Schwiderke (Ph.D.)
advisor: H. P. Pendse
MECHANISMS OF PRINT GLOSS MOTTLE
 Objective: :To understand the mechanisms that cause print gloss mottle
Approach: Generate model substrates with know variation in porosity and surface roughness from point-to-point. Print in laboratory print tester and characterize gloss dynamics and its variation with high speed camera. Develop mathematical model of ink film leveling on porous and rough substrates.
student: Sung Jai Jeon (MS)
advisor: D. Bousfield
ELECTROACOUSTIC TITRATIONS FOR COATING COLOR CHARACTERIZATION
Objective: : To study modern instrumentation for Colloid Vibration Current (CVI) and Electrokinetic Signal Amplitude (ESA)
Approach:Two recent measurement techniques induced electrical signals associated with applied acoustic fields (CVI) and induced acoustic signals associated with applied electric fields (ESA) have been successfully used for electrokinetic characterization of high-solids aqueous suspensions of inorganic pigments. Further study is required to when complex suspensions involving two or more different types of pigments and dissolved polymers are involved. This project is aimed at identifying strengths and limitations of this two techniques for characterizing coating color under processing conditions
student: Jason Patton (MS)
advisor: H. P. Pendse
PREPARATION, CHARACTERISATION, AND INK PENETRATION IN COATINS PREPARED WITH SURFACE MODIFIED PIGMENTS
Objective: To characterize the role of surface chemistry on ink setting rate
Approach: Modify surface chemistry of pigments with CVD. Generate paper coatings using bare and surface modified pigments. Use Raman to measure differences, if any, of the pigment/binder ratio in coatings generated using surface modified pigments. Compare absorption rates of fluids and inks on coatings made with both bare and surface treated pigments. Characterize location of ink species within coating layer
student: Shivashanker Bitla(MS)
advisors: D. Bousfield , Carl Tripp , Bill DeSisto
INFLUENCE OF INTERFACIAL CHEMISTRY ON SURFACE MECHANICAL PROPERTIES
 Objective: To characterize the role of chemistry on solid-liquid interfacial forces.
Approach: Use nano-indentor to measure the work of adhesion and mechanical response of model coating surfaces in liquid environments
Student: Srinivasa Koduri
advisors: D. Bousfield , Bill Unertl
FIBER AND COATING PICKING DURING PRINTING
Objective: To predict picking and linting during printing operations.
Approach:Characterize surface strengths and extensional behavior of inks. Model ink transfer event to predict work of adhesion. Compare theory and experiments
Scientist: Jong Tae Youn
advisor: D. Bousfield
VISCOELASTIC COATING FLOWS
Objective: : To understand the high shear rate response of fluids in coating geometries
Approach: Measure pressure pulse in nip for model fluids at high speeds. Characterize rheological behavior with standard and novel methods. Compare with model predictions
student: Mitch Johnson (PhD)
advisor: D. Bousfield
INK PROPERTIES THAT INFLUENCE INK SETTING RATE
 Objective: To understand the key parameters in an ink that influence the setting rate
Approach: : Measure ink setting rates on model coating layers of inks with different pigment sizes, resin content, and other additives. Compare with new equation for ink setting rates.
student: Matthieu Gros (visiting MS student)
advisor: D. Bousfield
LOCAL VARIATION OF INK TACK AND ITS DEPENDENCE ON THE PHYSICO-CHEMICAL PROPERTIES OF COATED PAPERS
Objective: To measure local ink tack variation and relate to the physico-chemical properties of coated papers
Approach:Develop a method to measure the tack buildup of ink on a small scale. Measure papers with different degrees of mottle. Characterize these papers in terms of physical and chemical properties.
Investigator: Yang Xiang with D.Bousfield

THE EFFECT OFPAPER PROPERTIES, PROCESS CONDITIONS, AND COATING PROPERTIES ON COATING UNIFORMITIES
Objective: To understand the important paper and process conditions that influence the uniformity of coating properties
Approach: On actual and model papers, apply coatings of different compositions. Characterize the uniformity of the properties such as gloss, porosity, and ink setting
Investigator: Seongnam Ahn with D.Bousfield

PRESSURE DISTRIBUTION IN ROLLING NIPS WITH VISCOELASTIC FLUIDS
 Objective: To characterize the flow fields and pressure distribution during coating and printing flows.
Approach:Using commercial software, calculate the flow fields for fluids with rheological properties that may apply to coatings and inks. Compare with experiments
Investigator: Janne Poranen with D.Bousfield

MICRO-SCALE TENSILE TESTING OF TREATED PAPERS
 Objective: :The characterize the strain field of papers and treated papers on the micron length scale.
Approach:Record paper tensile test in ESEM. Quantify strain field
Investigator: Yasushi Ozaki with D.Bousfield, Dr. Steve Shaler

EMULSIFIED INK – COATING INTERACTIONS
Objective: : To characterize how fountain solution modifies the ink-substrate interactions. local ink tack variation and relate to the physico-chemical properties of coated papers
Approach:Contact emulsified ink with dry and wetted surfaces with probe
Investigator: Yang Xiang with D.Bousfield

MICRO-PROBE FOR PAPER SURFACE ANALYSIS
Objective: To characterize variations in the paper surface at a fine lengthscale
Approach: Contact fluids on a fine probe tip and measure force-time response. Relate to variations in printing properties
student: Yingfeng Shen (MS)
advisors: D. Bousfield , A. van Heiningen
THE INFLUENCE OF WATER UPTAKE RATE OF FIBERS ON DEWATERING OF COATING SOLUTIONS
 Objective: To clarify the role of the water uptake rate of fibers on the total fluid uptake rate of paper.
Approach: Measure the fluid uptake rate of model papers that contain fibers of different water retention values. The water uptake rate will be determined with the Bristow wheel setup for handsheets made from carboxymethylated fibers, which have different degrees of substitution (DS) and thus different water retention values. The handsheets will also be tested for other properties such as roughness, Hg-porosimetry, void fraction (silicon oil), air permeability and coating qualities when they are coated
Student: Sedef Aklini (MS)
advisors: D. Bousfield , A. van Heiningen
NANO-SCALE SURFACE PROBE
 Objective: To characterize surfaces both mechanically and chemically on a small length scale.
Approach: Do micro-indentation tests with probes. Measure deformation response and pull-off force.
student: Manish Giri (PhD)
advisors: B. Unertl , D. Bousfield
POLYELECTROLYTE/SURFACTANT INTERACTIONS WITH OXIDE SURFACES
Objective: : To study the interactions of polyelectrolytes and surfactants with pigment surfaces
Approach: The adsorption dynamics, competitive dynamics, and molecular orientation will be characterized using Infrared Spectroscopic techniques such as Attenuated Total Reflectance. Thin layers of model compounds will be deposited on top of Si or ZnSe crystals. The influence of pH, ionic strength, and temperature will be characterized.
student: Brian Ninness
advisors: D. Bousfield, Carl Tripp
OXIDE PARTICULATE/POLYMER INTERACTIONS
 Objective: :To develop a new tool to study the molecular interactions between particles and polymers in aqueous environment.
Approach: Raman Spectroscopy will be used to characterize the molecular structure in aqueous media of polymers and oxide particles. A novel dynamic settling cell will link Raman measurements with colloidal stability.
student: Pei He (MS)
adviser: Carl Tripp
MECHANICAL PROPERTIES OF PIGMENTED COATINGS
Objective: To establish relationships between the mechanical properties and the structure and composition of pigmented coatings and to develop predictive models.
Approach: A two-prong approach is being considered, building on work currently in progress in the PSSP group, using both macroscopic- and microscopic-scale stress-strain measurements. Develop a model of a coated paper from composite theories.
student: Katharina Prall (PhD)
adviser: Dr. Steve Shaler
RHEOLOGICAL PREDICTIONS WITH PARTICLE MOTION ANALYSIS
Objective: To model the rheological properties of coating suspensions
Approach: Include polymer-particle force interactions in model.
Investigator: Fabio Barbesta (STFI) with M. Rigdahl and Dr. D. Bousfield
FILAMENT SIZE DISTRIBUTION IN ROLLING NIPS
Objective: To relate the filament size distribution formed at the exit of a nip with process conditions and rheological properties.
Approach: Record filamentation at the exit of a nip. Measure the filament size distribution. Relate to model predictions.
student: Saybil Ercan (PhD)
adviser: D. Bousfield
DROP IMPACT, PENETRATION, AND SPREADING ON A POROUS
Objective: To model and measure the relative spreading verses penetration of a drop on a porous surface.
Approach: Flow flow modeling accounting for liquid penetration into the support surface. Experiments use high-speed video camera to record the impact event.
student: Martine Bouchon (MS)
adviser: D. Bousfield
INK SETTING AND LEVELING DYNAMICS
Objective: To characterize the role of coating structure and properties and of ink rheology on ink setting and leveling dynamics.
Approach:A novel rheological test will determine the rate of ink setting after contact with substrate. Gloss dynamics on different substrates will characterize the ability of ink to flow after contact with the substrate.
student: Daphné Desjumaux (PhD)
adviser: D. Bousfield
MOTION OF DISK SHAPED PARTICLES IN COMPLEX FlOWS
Objective: To model the motion of particles in coating flow geometries.
Approach: Use Stokesian dynamics techniques to calculate particle trajectories. Compare with experimental results.
student: Aldo Ramangoli (MS)
adviser: D. Bousfield
EFFECT OF POROUS SUBSTRATES ON DOUBLE COATING STRUCTURE
Objective: To characterize the influence of porous substrates on the top coating structure.
Approach: Base coatings on plastic films will be characterized. The properties of the second layers will be measured in terms of pore volume, opacity, and gloss.
visting scientist:Byeong-Soo Kim and D. Bousfield
WETTING AND SPREADING OF LATEX ON PAPER SURFACES
 Objective: To investigate the processes leading to the formation of bonds between latex and paper surfaces.
Approach: Use atomic force microscopy and other techniques to follow the deformation of latex particles on model cellulosic surfaces.
Student: Dan Woodland (PhD).
Advisor:W. Unertl
EVOLUTION OF THE SURFACE CHEMISTRY OF PIGMENTED COATINGS DURING DRYING
 Objective: To investigate the evolution of the structure and of the chemical composition of the surface of pigmented coatings during consolidation and drying of the coating.
Approach: Prepare model coatings of various compositions. Quench at various stages of drying. Characterize surface structure, chemical composition, and surface energy. Examine influence of intense drying at various stages of consolidation, and of substrate absorbency. Relate surface chemistry and chemical composition to performance.
Student: Hamad Al-Turaif (PhD).
Advisor: P. LePoutre.
EFFECT OF COATING VISCOELASTICITY ON THE EVOLUTION OF COATING STRUCTUR
 Objective: To establish the relationship between viscoelastic properties of a coating and the final coating structure.
Approach: Measure rheology and structure of various model coatings. Compare results with different drying conditions
Investigator: Hideaki Nisogi with D. Bousfield and P. LePoutre.
INFLUENCE OF FIBER PROPERTIES ON PAPER ROUGHENING
 Objective: Characterize the influence of wood species on roughening.
Approach: Examine the dimensional changes of papers of various composition after exposure to water using the ESEM and other techniques.
Investigator: T. Hallamaa, visiting scientist from KCL, with P. LePoutre.
RHEOLOGY OF NON-NEWTONIAN SUSPENSIONS
 Objective: Model the rheology of suspensions containing dissolved polymers and verify experimentally.
Approach: Modify previous computer model simulating particle motion in a Newtonian fluid to include the shear-thinning effects that soluble binders or polymeric additives contribute to pigment suspensions.
Student: Robert Bilodeau (PhD).
Advisor: D. Bousfield.
ADHESION IN COATED PAPERS
 Objective:To investigate the role of mechanical interlocking in the adhesion between pigmented coatings and paper.
Approach:Surface-treat handsheets of different structures with a fluorocarbon polymer to suppress physico-chemical interactions. Examine influence of coating composition. Measure adhesion by peel test and other methods. Characterize failure.
Student:Robert Dickson (PhD).
Advisor:P. LePoutre.
MICROMECHANICAL BEHAVIOR OF COATED PAPERS
Objective: To investigate and model the micro-mechanical behavior of pigmented paper coatings.
Approach: Consider coated paper as a three-layer laminate comprised of the paper, the coating and an interphase where coating and fibers interpenetrate. Map micro-strain field under tension in the ESEM using Digital Image Correlation techniques. Use Finite Element Modeling to predict mechanical performance.
Student: Kamala Raman (MS).
Advisors: S. Shaler and D. Bousfield.
WEB RELEASE IN ROLLING NIPS
 Objective: To characterize the role of fluid rheology and substrate properties on the separation of a fluid layer from a web.
Approach: Measure force versus time in separating two paralell discs separated by a fluid, in the Instron mechanical tester. Look for evidence of cavitation and filamentation, using different substrates. Develop model of pressure profile during plate separation.
Student: Brian Ninness (MS).
Advisor: D. Bousfield.
EFFECT OF SIZE AND SHAPE DISTRIBUTION OF PIGMENTS ON MECHANICAL PROPERTIES OF COATINGS.
Objective: To investigate the effect of pigment size and shape distribution on the mechanical properties of coatings.
Approach: Prepare model coatings using monodisperse clay and calcium carbonate pigments alone and in blends. Characterize structure. Perform tensile and z-direction tests.
Investigator: Koji Okomori, visiting scientist from Nippon Paper Industries, with P. LePoutre.
COATING-PAPER INTERACTIONS
Objective: To examine the influence of basestock compressibility, absorbency and sheet formation on coating mass distribution and coated paper quality, using model experiments.
Approach: Coat on CLC model handsheets of varying roughness, compresibility, sheet formation and absorbency, measure coat weight uniformity and uniformity in print density and gloss.
Student: Ting Huang (PhD).
Advisor: P.LePoutre.
SETTING OF WATER-BASED SYSTEMS ON PAPER
Objective: To predict the setting of water-based systems on paper.
Approach: Develop a model for the setting of water-based solutions or suspensions into a porous network under dehydration conditions. Perform experiments on various substrates to identify contributions to setting and to verify model.
Student: Rajan Iyer (PhD).
Adviser: D. Bousfield.
INK SETTING AND PRINT GLOSS
Objective: To investigate the setting of inks on pigment-coated surfaces and its effect on print gloss, and to propose a model for the ink setting process.
Approach: Prepare well characterized (topography, porosity, chemistry) coating structures. Print and follow gloss development. Model the effect of setting, considering both capillary and diffusion processes, as slowing down leveling of the ink film.
Student: Travis Glatter (MS).
Adviser: D. Bousfield.
EFFECT OF INTERNAL STRESSES ON PAPER ROUGHENING
Objective: To relate surface roughening, which occurs when paper is exposed to water, to the level of internal stresses witin paper.
Approach: Prepare sheets with varying stress level (beating, pressing, drying). Estimate internal stress by Kubat's method. Relate roughening after contact with water to extent of stress relaxation.
Student: Don Additon (MS).
Adviser: P. LePoutre.
CONSOLIDATION OF COATING STRUCTURE
Objective: To investigate the development of the structure of pigmented coatings and the effect of pigment, binder and basestock properties on coating structure development.
Approach: Quench the structure with liquid nitrogen as it consolidates; freeze-dry and characterize quenched structure.
Student: Anna Stanislawska (PhD).
Adviser: P. LePoutre.
WETTING AND SPREADING OF LATEX ON PIGMENT SURFACES
Objective: To investigate the processes leading to the formation of bonds between latex and pigment surfaces.
Approach: Use atomic force microscopy and other techniques to follow the deformation of latex particles on pigment surfaces.
Student: Yiren Luo (PhD).
Adviser: W. Unertl.
GLOSS OF PIGMENTED COATINGS Objective: To relate the gloss of pigmented coatings to structural aspects of the surface and to pigment morphology.
Approach: Prepare coatings based on well characterized, unisized pigments of different shape. Relate goniophotometric measurements to profilometry and SEM observation.
Student: Fabien Pesenti (MS) .
Advisers: P. LePoutre and J. Hassler.
BLADE FORCES DURING COATING
Objective: To measure blade displacement on CLC and compare to calculated values.
Approach: Measure blade displacement on CLC during coating and compare to prediction from hydrodynamic model .
Student: E. Guler (MS) .
Adviser: D. Bousfield.
MODELING OF COATING STRUCTURE DEVELOPMENT
Objective: To develop a three-dimensional model of coating structure development based on pigment and latex shape and size distributions.
Approach: Construct model to place particles into a structure resulting from the dewatering process by considering hydrodynamic forces on each particle as they move and interact with each other.
Student: Guner Eksi (MS).
Adviser: D. Bousfield.
MODELING PENETRATION OF MOLTEN POLYMER
Objective: To model the penetration of molten polymers in paper or board during extrusion coating or glueing with hot-melts.
Approach: Develop model of forced penetration of a fluid into a pore under non isothermal conditions.
Student: Nasser Omari (PhD).
Adviser: D. Bousfield.

SURFACE ROUGHENING BY WATER:
1. EFFECT OF CALENDERING MODE
Objective: To investigate the influence of calendering conditions on the surface roughening in coating and printing.
Approach: Calender LWC and wood-free basestocks using supercalendering and soft calendering: Measure stress relaxation and roughening by water.
Post-Doctorate Fellow: Toshiharu Enomae.
2. GLOSS RELAXATION PROCESSES
Objective: To understand the mechanism of surface roughening by water.
Approach: Build apparatus for continuously measuring gloss as relative humidity is varied. Compare to bulk stress relaxation measurements.
Post-Doctorate Fellow: Toshiharu Enomae.
MODELING OF PIGMENT MOTION
Objective: Computer simulation of the motion of pigment particles in flow fields encountered in the surface treatment of paper.
Approach: Stokesian Dynamics calculations extended to include non-spherical particles in simple shear flows. Compare with experimental viscosities.
Student: Kevin Hase (MS) .
Adviser: D. Bousfield.
IMPACT OF DROPS ON SURFACES
Objective: To examine and model the spreading of liquid drops impacting a surface.
Approach: Video images to characterize the spreading of liquid drops with different rheological properties. Compare with model predictions.
Student: Brian Scheller (PhD) .
Adviser: D. Bousfield.
SURFACE CHEMISTRY OF PAPER COATINGS
 Objective: To establish relationships between the surface chemistry and the surface energy of paper coatings, and their effect on the transfer of fluids.
Approach: Prepare films from water-based polymers with increasing pigmentation level. Relate surface energy to chemical composition and morphology. Examine effect of surface chemistry/energy on the transfer of inks and water-based pigmented systems.
Student: Hamad Al-Turaif (MS) .
Adviser: P. LePoutre.
MOTION OF DISK SHAPED PARTICLES IN COMPLEX FlOWS
Objective: To model the motion of particles in coating flow geometries.
Approach: Use Stokesian dynamics techniques to calculate particle trajectories. Compare with experimental results.
student: Aldo Ramangoli (MS)
adviser: D. Bousfield
INK SETTING AND LEVELING DYNAMICS
Objective: To characterize the role of coating structure and properties and of ink rheology on ink setting and leveling dynamics.
Approach:A novel rheological test will determine the rate of ink setting after contact with substrate. Gloss dynamics on different substrates will characterize the ability of ink to flow after contact with the substrate.
student: Daphné Desjumaux (PhD)
adviser: D. Bousfield
EFFECT OF POROUS SUBSTRATES ON DOUBLE COATING STRUCTURE
Objective: To characterize the influence of porous substrates on the top coating structure.
Approach: Base coatings on plastic films will be characterized. The properties of the second layers will be measured in terms of pore volume, opacity, and gloss.
visting scientist: Byeong-Soo Kim and D. Bousfield


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Updated MARCH,2001