Srinivas Manne

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• Manne, S., Johns, K. A., Milsom, J. A., Prather, E. E., & Wallace, C. S. (2021). Students taught by a first-time instructor using active learning teaching strategies outperform students taught by a highly-regarded traditional instructor. Journal of College Science Teaching, 50(4), 48-57.
• Manne, S., Murdaugh, A. E., & Manne, S. -. (2009). Friction dependence on growth conditions in epitaxial films. Langmuir : the ACS journal of surfaces and colloids, 25(17).
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  In investigating the growth kinetics of epitaxial films in situ by force microscopy, we have observed several instances where the lateral force contrast on the growing monolayer exhibits a strong dependence on the driving force for growth (i.e., solute concentration). We present results for three epitaxial growth systems in aqueous solutions: CaSO(3) on CaCO(3), PbSO(4) on BaSO(4), and BaSO(3) on BaSO(4). In each system, material grown at higher solute concentrations exhibits a friction higher than that of material grown at lower concentrations. These observations suggest a link between defect density and friction contrast in growing epitaxial films. An additional time-dependent behavior is observed in the CaSO(3)/CaCO(3) system, indicating an annealing process.
• Murdaugh, A. E., & Manne, S. (2009). Friction dependence on growth conditions in epitaxial films. Langmuir, 25(17), 9792-9796.
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  PMID: 19663430;Abstract: In investigating the growth kinetics of epitaxial films in situ by force microscopy, we have observed several instances where the lateral force contrast on the growing monolayer exhibits a strong dependence on the driving force for growth (i.e., solute concentration). We present results for three epitaxial growth systems in aqueous solutions: CaSO3 on CaCO3, PbSO4 on BaSO4, and BaSO3 on BaSO4. In each system, material grown at higher solute concentrations exhibits a friction higher than that of material grown at lower concentrations. These observations suggest a link between defect density and friction contrast in growing epitaxial films. An additional time-dependent behavior is observed in the CaSO3/CaCO3 system, indicating an annealing process. © 2009 American Chemical Society.
• Ulrich, E. S., Limbach, C. M., & Manne, S. (2008). Imaging microflows and nanopore structures using hydrodynamic force microscopy. Applied Physics Letters, 93(24).
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  Abstract: We report the three-dimensional profilometry of gas microflows and the two-dimensional mapping of fluid permeability through nanoporous substrates using hydrodynamic force microscopy (HFM). Using fluid drag from external flows as a contrast mechanism, HFM has mapped Poiseuille flow through ∼100 nm pores and has identified subsurface fouling unresolvable by conventional force microscopy. HFM demonstrates nanoscale spatial resolution and flow velocity resolution on the order of 1 cms, making it an attractive investigative tool for applications in separation science, microfluidics, and nanoporous materials. © 2008 American Institute of Physics.
• Manne, S., Murdaugh, A. E., Liddelow, M., Schmidt, A. M., & Manne, S. -. (2007). Two-dimensional crystal growth from undersaturated solutions. Langmuir : the ACS journal of surfaces and colloids, 23(11).
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  The solubility of a substance is commonly understood as the minimum concentration necessary for the condensation of a solid phase from solution. Here we report the nucleation and growth of ionic compounds from aqueous concentrations on the order of 0.1 times the solubility. The condensation is catalyzed by a foreign substrate, and the new phase grows as a crystalline monolayer. Undersaturated growth is observed only in cases where the dissolved compound is isomorphic with the substrate and the interaction strength between a dissolved-ion/substrate-ion pair exceeds that between the two dissolved ions. These results are consistent with a simple model in which favorable ion-surface interactions lead to ion enrichment and supersaturation in the two-dimensional interfacial zone.
• Murdaugh, A. E., Liddelow, M., Schmidt, A. M., & Manne, S. (2007). Two-dimensional crystal growth from undersaturated solutions. Langmuir, 23(11), 5852-5856.
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  PMID: 17455964;Abstract: The solubility of a substance is commonly understood as the minimum concentration necessary for the condensation of a solid phase from solution. Here we report the nucleation and growth of ionic compounds from aqueous concentrations on the order of 0.1 times the solubility. The condensation is catalyzed by a foreign substrate, and the new phase grows as a crystalline monolayer. Undersaturated growth is observed only in cases where the dissolved compound is isomorphic with the substrate and the interaction strength between a dissolved-ion/substrate-ion pair exceeds that between the two dissolved ions. These results are consistent with a simple model in which favorable ion-surface interactions lead to ion enrichment and supersaturation in the two-dimensional interfacial zone. © 2007 American Chemical Society.
• Manne, S., Workman, R. K., & Manne, S. -. (2004). Molecular transfer and transport in noncovalent microcontact printing. Langmuir : the ACS journal of surfaces and colloids, 20(3).
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  Microcontact printing is commonly used to create patterned films of molecules covalently bonded to substrates (e.g., thiols on gold). Here we describe microcontact printing of several types of noncovalently bonding molecules on mica. Due to the weaker interaction of the molecules with the substrate, environmental factors such as temperature and relative humidity play an important role. The vapor pressure of the inks also had a large impact on the fidelity of the stamped patterns. Fingering instabilities were observed for monolayers of octadecanol, docosanol, stearylamine, and stearic acid stamped at moderate relative humidity. The fidelity of the stamped pattern generally increased with the headgroup-surface interaction strength. These stamped monolayer films shed light on molecular transfer and two-dimensional spreading mechanisms.
• Workman, R. K., & Manne, S. (2004). Molecular transfer and transport in noncovalent microcontact printing. Langmuir, 20(3), 805-815.
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  PMID: 15773108;Abstract: Microcontact printing is commonly used to create patterned films of molecules covalently bonded to substrates (e.g., thiols on gold). Here we describe microcontact printing of several types of noncovalently bonding molecules on mica. Due to the weaker interaction of the molecules with the substrate, environmental factors such as temperature and relative humidity play an important role. The vapor pressure of the inks also had a large impact on the fidelity of the stamped patterns. Fingering instabilities were observed for monolayers of octadecanol, docosanol, stearylamine, and stearic acid stamped at moderate relative humidity. The fidelity of the stamped pattern generally increased with the headgroup-surface interaction strength. These stamped monolayer films shed light on molecular transfer and two-dimensional spreading mechanisms.
• Hay, M. B., Workman, R. K., & Manne, S. (2003). Mechanisms of metal ion sorption on calcite: Composition mapping by lateral force microscopy. Langmuir, 19(9), 3727-3740.
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  Abstract: We show that lateral force microscopy (also known as frictional force microscopy) can differentiate between substrate and overlayer phases during an inorganic surface reaction. A calcite substrate is imaged in situ, while immersed in aqueous solutions of pH ∼ 6 9 containing metal ions (Cd2+, Sr2-, and La3+) at concentrations of 10-5 to 10-3 M. Cd2+ and Sr2- passivate surface steps, initiating overgrowth only in solutions already supersaturated relative to their respective carbonates. In contrast, La3+ initiates overgrowth even in undersaturated conditions and carries the reaction to completion by scavenging carbonate anions directly from the dissolving calcite surface. Monomolecular surface steps play a central role, serving as both dissolution sites for the substrate and nucleation sites for the overgrowth.
• Hay, M. B., Workman, R. K., & Manne, S. (2003). Two-dimensional condensed phases from particles with tunable interactions. Physical Review E - Statistical, Nonlinear, and Soft Matter Physics, 67(1 1), 124011-124014.
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  Abstract: An experimental model was presented for condensed phases, consisting of an ensemble of identical magnetic dipoles on a vibrating bed. The model combined tunable and accurately known pair potentials, lattice structure, equilibrium times of seconds and dynamics visible to the naked eye. Fundamental ensemble properties were directly observed and quantitatively linked to the underlying pair potential.
• Manne, S., Hay, M. B., Workman, R. K., & Manne, S. -. (2003). Two-dimensional condensed phases from particles with tunable interactions. Physical review. E, Statistical, nonlinear, and soft matter physics, 67(1 Pt 1).
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  We present a conceptually simple experimental model for condensed phases, consisting of an ensemble of identical magnetic dipoles on a vibrating bed. The model combines tunable and accurately known pair potentials, equilibration times of seconds, and lattice structure and dynamics visible to the naked eye. Fundamental ensemble properties--specifically phonon propagation, edge relaxation, and binary condensation--are directly observed and quantitatively linked to the underlying pair potential.
• Workman, R. K., Schmidt, A. M., & Manne, S. (2003). Detection of a diffusive two-dimensional gas of amphiphiles by lateral force microscopy. Langmuir, 19(8), 3248-3253.
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  Abstract: Sparsely adsorbed amphiphiles with high surface mobility play a central role in surfactant spreading and in the nucleation and growth of self-assembled monolayers. Here we show that lateral force microscopy can directly visualize a gas phase of adsorbed long-chain alcohols and fatty acids. The two-dimensional (2D) gas originates from the edge evaporation of dense monolayer domains, transferred to a mica surface by microcontact printing. Monolayer corrals act as 2D containers, eventually saturating the enclosed area with the trapped gas phase. Scratching a small hole in the corral allows the gas to leak out of its container, and monitoring this transport process provides a rough estimate of the surface diffusion constant. Our results suggest that friction measurement and mapping can detect amphiphile densities down to 1% of a monolayer, making this technique useful in studying the early stages of monolayer formation.
• Workman, R. K., & Manne, S. (2002). Patterned thin water films on mica. Langmuir, 18(3), 661-666.
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  Abstract: Patterned water films were formed on the surface of mica by contact with clean, patterned poly(dimethylsiloxane) stamps in ambient humidity. Capillary condensation of ambient atmospheric water in the stamp channels allowed transport of potassium from the mica surface to the stamp, which locally modified the wetability of the mica surface. The resulting mica surface was imaged with contact-mode atomic force microscopy, revealing 3 Å-tall patterns. The pattern disappeared as the relative humidity was decreased (
• Wolgemuth, J. L., Workman, R. K., & Manne, S. (2000). Surfactant aggregates at a flat, isotropic hydrophobic surface. Langmuir, 16(7), 3077-3081.
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  Abstract: We report results of surfactant aggregate morphologies at an amorphous hydrophobic surface whose roughness is small compared to the size of a micelle. Direct imaging by atomic force microscopy shows that single-chain ionic, nonionic, and zwitterionic surfactants, which form spherical micelles in solution, form globular aggregates consistent with half-micelles at an amorphous hydrophobic surface. This result is consistent with the expected isotropy of chain-surface interactions.
• Workman, R. K., & Manne, S. (2000). Variable temperature fluid stage for atomic force microscopy. Review of Scientific Instruments, 71(2 I), 431-436.
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  Abstract: The design of a simple, variable temperature fluid cell for an atomic force microscope is presented. The stage is based on a thermoelectric heating/cooling element, which allows control of sample and fluid temperature from -5 to 130°C. The stage is stable enough to image at molecular resolution almost throughout the range of accessible temperature and can be used for imaging in either gas or liquids. This allows the molecular scale investigation of surface phase transitions and chemical kinetics at solid/liquid interfaces by varying the temperature. As an example, we present results of temperature-induced phase transitions in self-assembled surfactant aggregates at solid/liquid interfaces. © 2000 American Institute of Physics.
• Manne, S., & Warr, G. G. (1999). Supramolecular structure of surfactants confined to interfaces. ACS Symposium Series, 736, 2-23.
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  Abstract: The mounting evidence for the existence of surfactant aggregates at solid/solution interfaces prompts a re-examination of common experimental techniques for studying surfactant adsorption. The simple models of a surfactant monolayer or bilayer, while reasonable in the face of older experimental data, are now seen to be inadequate to describe the rich range of order seen by atomic force microscopy and other techniques. In this manuscript we review the results of atomic force microscopy which demonstrate the existence of surface micelles, look again at the experimental results which pointed towards surface aggregates, and also look ahead at how the existence of surface micelles requires us to revise the interpretation of other experimental studies and our entire picture of adsorbed films.
• Patrick, H. N., Warr, G. G., Manne, S., & Aksay, I. A. (1999). Surface micellization patterns of quaternary ammonium surfactants on mica. Langmuir, 15(5), 1685-1692.
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  Abstract: The microscopic equilibrium structures of adsorbed films of quaternary ammonium surfactants on mica have been investigated by noncontact atomic force microscopy imaging as a function of alkyl chain length and headgroup structure. Spherical and cylindrical surface micelles were observed; these were found to be related to bulk solution self-assembly and the surfactant packing parameter, v/aolc. Shape transitions in the surface aggregates were observed on changing the counterion between chloride, bromide, and salicylate. © 1999 American Chemical Society.
• Jaschke, M., Butt, H. -., Gaub, H. E., & Manne, S. (1997). Surfactant aggregates at a metal surface. Langmuir, 13(6), 1381-1384.
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  Abstract: Surfactant adsorption on metals has been used in the past to limit the activity of electrode surfaces and to stabilize colloidal clusters in solution, but the adsorption and aggregation morphology of these surfactants has not been known. We present direct images of ionic surfactant aggregates at a gold surface in aqueous solution using atomic force microscopy. These images are generally striped in appearance as viewed from the top, indicating linear aggregates (cylindrical or half-cylindrical) lying on the substrate plane. The orientation of these aggregates is controlled either by monatomic steps on the gold surface or by the gold lattice itself, depending on the surfactant counterion.
• Manne, S. (1997). Visualizing self-assembly: Force microscopy of ionic surfactant aggregates at solid-liquid interfaces. Progress in Colloid and Polymer Science, 103, 226-233.
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  Abstract: The adsorption of surfactants from micellar solutions onto solid surfaces plays a crucial role in applications such as surface wetting, particulate detergency, and colloidal stabilization. Recent work (see below) has shown that the shape, size, and lateral organization of ionic surfactant aggregates at solid-liquid interfaces can be determined directly by atomic force microscopy (AFM). Imaging is performed using repulsive stabilization forces between surfactant layers adsorbed to both the tip and sample, and aggregate structures are determined by comparing AFM images with previous adsorption measurements. The observed interfacial structures for ionic surfactants result from a tradeoff between intermolecular interactions (i.e. geometric packing considerations) and molecule-surface interactions (i.e. the density, type, and crystalline order of adsorption sites). The hydrophobic, crystalline cleavage planes of graphite and MoS2 adsorb and orient single-tail surfactants along the substrate symmetry axes, and this horizontal adsorption serves as a template for half-cylindrical aggregates. The hydrophilic, anionic surfaces of mica and silica interact with cationic headgroups, giving rise to spherical, cylindrical, or planar aggregates depending on the surfactants geometry and density of electrostatic binding sites.
• Manne, S., & Aksay, I. A. (1997). Thin films and nanolaminates incorporating organic/inorganic interfaces. Current Opinion in Solid State and Materials Science, 2(3), 358-364.
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  Abstract: Recent research on the solution-based fabrication of inorganic thin films and organic/inorganic nanolaminates has ranged from fundamental studies of biomineralization to the synthesis of novel materials and devices. Highlights include the elucidation of how biogenics and model organic nucleants affect the form of the biomineral; synthesis of mesoscale nanocomposite films by surfactant templating at interfaces; and fabrication of heterostructures with enhanced electronic and mechanical properties. © 1997 Current Chemistry Ltd.
• Manne, S., Schäffet, T., Huo, Q., Hansma, P. K., Morse, D. E., Stucky, G. D., & Aksayt, I. A. (1997). Gemini surfactants at solid-liquid interfaces: Control of interfacial aggregate geometry. Langmuir, 13(24), 6382-6387.
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  Abstract: Recent work has shown that conventional surfactants form ordered aggregates of well-defined shape and size at solid-liquid interfaces.1,2 Here we report interfacial aggregate structures as a function of surfactant geometry by using gemini surfactants with varying tail and spacer lengths. On the anionic cleavage plane of mica, aggregates tend to favor a lower curvature than in solution but follow the same general variation with surfactant geometry (i.e., with larger headgroup areas resulting in greater curvature). These morphologies on mica correlate well with those observed in surfactant-silicate mesophases, where electrostatic binding of headgroups also plays a dominant role. In addition, interfacial sphere-to-rod transitions are induced on mica (as in free solution) by binding with a headgroup-specific counterion. In contrast to mica, the hydrophobic cleavage plane of graphite interacts with surfactant tailgroups, giving rise to interfacial aggregates that are surface-controlled and relatively independent of surfactant geometry. This interaction is used to heterogeneously nucleate a surfactant-silicate mesophase which is interfacially controlled and differs from the bulk phase.
• Patrick, H. N., Warr, G. G., Manne, S., & Aksay, I. A. (1997). Self-assembly structures of nonionic surfactants at graphite/solution interfaces. Langmuir, 13(16), 4349-4356.
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  Abstract: The interfacial self-assembly structures of a series of poly(oxyethylene) n-dodecyl ether (C12En) nonionic surfactants on graphite has been imaged by atomic force microscopy using only the steric stabilization force as the contrast mechanism. Aggregates are arranged in parallel stripes perpendicular to the underlying graphite symmetry axes for C12E5-C12E10. These are interpreted as hemicylindrical micelles, consistent with previous studies of ionic surfactants adsorbed on graphite. C12E23 shows a featureless layer and C12E3 forms an anchored lamellar phase growing normal to the graphite surface. We relate the interfacial structures to those formed in bulk solution and show that the initially adsorbed molecules template the interfacial aggregates, modifying their self-assembly behavior.
• Aksay, I. A., Trau, M., Manne, S., Honma, I., Yao, N., Zhou, L., Fenter, P., Eisenberger, P. M., & Gruner, S. M. (1996). Biomimetic pathways for assembling inorganic thin films. Science, 273(5277), 892-898.
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  Abstract: Living organisms construct various forms of laminated nanocomposites through directed nucleation and growth of inorganics at self-assembled organic templates at temperatures below 100°C and in aqueous solutions. Recent research has focused on the use of functionalized organic surfaces to form continuous thin films of single-phase ceramics. Continuous thin films of mesostructured silicates have also been formed on hydrophobic and hydrophilic surfaces through a two-step mechanism. First, under acidic conditions, surfactant micellar structures are self-assembled at the solid/liquid interface, and second, inorganic precursors condense to form an inorganic- organic nanocomposite. Epitaxial coordination of adsorbed surfactant tubules is observed on mica and graphite substrates, whereas a random arrangement is observed on amorphous silica. The ability to process ceramic-organic nanocomposite films by these methods provides new technological opportunities.
• Jaschke, M., Butt, H., Manne, S., Gaub, H. E., Hasemann, O., Krimphove, F., & Wolff, E. K. (1996). The atomic force microscope as a tool to study and manipulate local surface properties. Biosensors and Bioelectronics, 11(6-7), 601-612.
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  Abstract: The atomic force microscope (AFM), a prominent member of the new class of scanning near-field microscopes, has become a standard instrument to image the topography of surfaces with high resolution. In addition, the AFM is more and more used to study other local surface properties, like the local surface charge density, the surface energy, or viscoelastic properties. Beside its analytical capabilities, surfaces can be modified with the AFM tip. Examples of all three applications are given and future possibilities are discussed.
• Bezanilla, M., Manne, S., Laney, D. E., Lyubchenko, Y. L., & Hansma, H. G. (1995). Adsorption of DNA to mica, silylated mica, and minerals. Characterization by atomic force microscopy. Langmuir, 11(2), 655-659.
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  Abstract: The nature of DNA adsorption to various substrates has been investigated by atomic force microscopy. The substrate used were mica, silylated mica, calcite, fluorite, and barite. The presence of a divalent cation, either in solution or accessible to the DNA on the substrate, greatly improves DNA adsorption. A comparison of DNA adsorption from different buffers onto mica and silylated mica shows that buffer composition is much less important for DNA adsorption to silylated mica and also suggests that for good adsorption DNA must be electrostically adsorbed to the surface.
• Manne, S., & Gaubt, H. E. (1995). Molecular organization of surfactants at solid-liauid interfaces. Science, 270(5241), 1480-1482.
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  Abstract: Interactions between surfactant solutions and solid surfaces play a key role in technologically important processes such as colloidal stabilization, ore flotation, and soil removal; however, the interfacial aggregation of surfactant molecules is not yet well understood. Direct images of surfactant aggregates at solid surfaces in aqueous solutions were obtained with atomic force microscopy. The resulting structures for quaternary ammonium surfactants (above the critical micelle concentration) are consistent with half-cylinders on crystalline hydrophobic substrates, full cylinders on mica, and spheres on amorphous silica. These structures - surprisingly different from earlier models - appear to result from a compromise between the natural free curvature as defined by intermolecular interactions and the constraints imposed by specific surfactant-surface interactions. Such interfacial aggregates can potentially be used to pattern surfaces at nanometer-length scales.
• Manne, S., Cleveland, J. P., Gaub, H. E., Stucky, G. D., & Hansma, P. K. (1994). Direct visualization of surfactant hemimicelles by force microscopy of the electrical double layer. Langmuir, 10(12), 4409-4413.
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  Abstract: The morphology of ionic surfactant molecules adsorbed from aqueous solution onto hydrophobic substrates has been determined by atomic force microscopy. Near the critical micelle concentration (cmc), noncontact imaging using double-layer repulsion between the tip and sample shows parallel, epitaxially oriented stripes spaced apart by about twice the surfactant length. This represents the first direct imaging of 'hemimicelles', liquid-crystalline aggregates of amphiphilic molecules (analogous to bulk micelles) which form at interfaces. The striped pattern is indicative of hemicylindrical hemimicelles, which is further corroborated by images of the monolayer adsorbate (in contact mode) below the cmc. Our results suggest that the hemimicelle structure is templated by the epitaxially bound monolayer in contrast with previous interpretations of the adsorption mechanism.
• Cleveland, J. P., Manne, S., Bocek, D., & Hansma, P. K. (1993). Nondestructive method for determining the spring constant of cantilevers for scanning force microscopy. Review of Scientific Instruments, 64(2), 403-405.
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  Abstract: The spring constant of microfabricated cantilevers used in scanning force microscopy (SFM) can be determined by measuring their resonant frequencies before and after adding small end masses. These masses adhere naturally and can be easily removed before using the cantilever for SFM, making the method nondestructive. The observed variability in spring constant - almost an order of magnitude for a single type of cantilever - necessitates calibration of individual cantilevers in work where precise knowledge of forces is required. Measurements also revealed that the spring constant scales with the cube of the unloaded resonant frequency, providing a simple way to estimate the spring constant for less precise work.
• Giles, R., Cleveland, J. P., Manne, S., Hansma, P. K., Drake, B., Maivald, P., Boles, C., Gurley, J., & Elings, V. (1993). Noncontact force microscopy in liquids. Applied Physics Letters, 63(5), 617-618.
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  Abstract: Force microscopy in liquids offers many advantages including the mitigation of capillary forces and the simulation of real environments for biological and technological processes. Noncontact force microscopy in liquids adds the advantage of probing electrical and magnetic fields above surfaces. Here we demonstrate magnetic force imaging of recorded bits on a computer hard disk in air and in liquid. A method of noncontact force microscopy (patent pending, Digital Instruments) is used in which the tip is first scanned in contact to image topography and then rescanned above the surface to image long-range forces.
• Hillner, P. E., Manne, S., Hansma, P. K., & Gratz, A. J. (1993). Atomic force microscope: A new tool for imaging crystal growth processes. Faraday Discussions, 95, 191-197.
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  Abstract: We present real-time and in situ atomic force microscope (AFM) observations of solution growth on the cleavage plane of two minerals, calcite and fluorite. Different growth behaviours are exhibited: the calcite surface grows via a layer-spiral mechanism, while the fluorite surface grows via the formation of sharp asperities. The differences in behaviour of the two minerals may be linked to the lack of local charge neutrality on the fluorite surface. The growth mechanisms observed on calcite and fluorite provide insight into the expected behaviour of a wide range of salts important in nature and industry.
• Manne, S., Cleveland, J. P., Stucky, G. D., & Hansma, P. K. (1993). Lattice resolution and solution kinetics on surfaces of amino acid crystals: an atomic force microscope study. Journal of Crystal Growth, 130(1-2), 333-340.
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  Abstract: We report atomic force microscopy (AFM) results on six amino acid crystal surfaces: glycine, L-aspartic acid, L-valine, L-isoleucine, L-leucine, and L-phenylalanine. Samples were grown by slow evaporation of concentrated aqueous solutions. All samples contained crystalline areas where the AFM showed extended molecularly flat sheets (up to hundreds of nm in size) separated by steps a single molecule thick. The ordered lattice of each amino acid could be imaged on the sheets. Images revealed periodicities corresponding to bulk terminations in most cases, as well as other periodicities which probably correspond to molecular structure within the unit cell. Step motion kinetics were also imaged in situ during dissolution of L-leucine in flowing propanol. Steps oriented along the 〈010〉 direction traveled with speeds that were independent of both interstep distance and solvent flow rate for flow rates above 20 μl/s, indicating a reaction rate limited process. Orthogonal bends along the 〈001〉 direction moved at speeds one to ten times that of steps, with narrow bends moving faster than wide. We speculate that these speed differences were caused by anisotropy in reaction kinetics coupled with partially saturated boundary layers near wide bends. © 1993.
• Gratz, A. J., Hillner, P. E., Manne, S., & Hansma, P. K. (1992). Dynamic studies of crystal growth using the AFM. Proceedings of SPIE - The International Society for Optical Engineering, 1639, 182-185.
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  Abstract: Recent advances in AFM technology allow direct observation of solution growth and dissolution (etching) processes important in industry and nature, and direct tests of crystal growth models. We present results of studies of calcite and quartz, including real-time, in situ observations. While both crystals experience layer growth/dissolution, calcite grows by direct addition of material to growth steps without an important contribution from surface diffusion; quartz surfaces are consistent with more traditional, BCF-type growth models. Dynamic AFM observations of growth processes may allow optimization of industrial systems.
• Hillner, P. E., Gratz, A. J., Manne, S., & Hansma, P. K. (1992). Atomic-scale imaging of calcite growth and dissolution in real time. Geology, 20(4), 359-362.
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  Abstract: We present a new experimental technique for real-time observation of aqueous mineral growth and dissolution at the atomic scale using an atomic-force microscope (AFM) equipped with a flow-through fluid cell. We applied this technique to observe changes in surface topography on the (101̄4) cleavage plane of calcite during alternating episodes of growth and dissolution. -from Authors
• Hillner, P. E., Manne, S., Gratz, A. J., & Hansma, P. K. (1992). AFM images of dissolution and growth on a calcite crystal. Ultramicroscopy, 42-44(Part B), 1387-1393.
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  Abstract: We present atomic-force-microscope (AFM) images of aqueous dissolution and growth of monolayers on the cleavage plane of calcite. These processes were observed in real time and in situ. Dissolution in 0.015N NaOH occurred primarily by faceting and expansion of pre-existing surface pits and by removal of islands. No new dissolution sites were observed to nucleate during this process. We also observed a simple growth sequence wherein CaCO3 monolayers were deposited on the calcite surface by uniformly advancing steps. Atomic resolution was readily obtained, even at larger-scale features such as steps and etch pits. This shows the potential of the AFM to study deposition and removal of individual molecules on a crystal surface in solution.
• Gratz, A. J., Manne, S., & Hansma, P. K. (1991). Atomic force microscopy of atomic-scale ledges and etch pits formed during dissolution of quartz. Science, 251(4999), 1343-1346.
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  PMID: 17816189;Abstract: The processes involved in the dissolution and growth of crystals are closely related. Atomic force microscopy (AFM) of faceted pits (called negative crystals) formed during quartz dissolution reveals subtle details of these underlying physical mechanisms for silicates. In imaging these surfaces, the AFM detected ledges
• Manne, S., Hansma, P. K., Massie, J., Elings, V. B., & Gewirth, A. A. (1991). Atomic-resolution electrochemistry with the atomic force microscope: Copper deposition on gold. Science, 251(4990), 183-186.
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  PMID: 17836948;Abstract: The atomic force microscope (AFM) was used to image an electrode surface at atomic resolution while the electrode was under potential control in a fluid electrolyte. A new level of subtlety was observed for each step of a complete electrochemical cycle that started with an Au(111) surface onto which bulk Cu was electrodeposited. The Cu was stripped down to an underpotential-deposited monolayer and finally returned to a bare Au(111) surface. The images revealed that the underpotenrial-deposited monolayer Has different structures in different electrolytes. Specifically, for a perchloric acid electrolyte the Cu atoms are in a close-packed lattice with a spacing of 0.29 ± 0.02 nanometer (nm). For a sulfate electrolyte they are in a more open lattice with a spacing of 0.49 ± 0.02 nm. As the deposited Cu layer grew thicker, the Cu atoms converged to a (111)-oriented layer with a lattice spacing of 0.26 ± 0.02 nm for both electrolytes. A terrace pattern was observed during dissolution of bulk Cu. Images were obtained of an atomically resolved Cu monolayer in one region and an atomically resolved Au substrate in another in which a 30° rotation of the Cu monolayer lattice from the Au lattice is clearly visible.
• Gould, S. A., Drake, B., Prater, C. B., Weisenhorn, A. L., Manne, S., Kelderman, G. L., Butt, H. -., Hansma, H., Hansma, P. K., Magonov, S., & Cantow, H. J. (1990). The atomic force microscope: A tool for science and industry. Ultramicroscopy, 33(2), 93-98.
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  Abstract: Images of graphite and RuCl3 show that the atomic force microscope (AFM) is capable of imaging rigid samples with atomic resolution. Images of photographic film showing the emulsion demonstrate the potential of the microscope for industrial quality control. An image of a stoma on a leaf shows that the microscope is gentle enough not to damage surfaces, even of soft biological samples.
• Hartman, H., Sposito, G., Yang, A., Manne, S., Gould, S. A., & Hansma, P. K. (1990). Molecular-scale imaging of clay mineral surfaces with the atomic force microscope. Clays & Clay Minerals, 38(4), 337-342.
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  Abstract: Specimen samples of Crook County montmorillonite and Silver Hill illite, purified and prepared in the Na-form, were imaged under 80% relative humidity using an atomic force microscope. The direct images showed clearly the hexagonal array of hexagonal rings of oxygen ions expected for the basal planes of 2:1 phyllosilicates. Fourier transformation of the digital information obtained by the microscope scanning tip led to an estimate of 5.1 ± 0.3 Å for the nearest-neighbor separation, in agreement with the ideal nearest-neighbor spacing of 5.4 Å for hexagonal rings as derived from X-ray powder diffraction data. The atomic force microscope should prove to be a useful tool for the molecular-scale resolution of clay mineral surfaces that contain adsorbed macromolecules. -Authors
• Manne, S., Butt, H. J., Gould, S. A., & Hansma, P. K. (1990). Imaging metal atoms in air and water using the atomic force microscope. Applied Physics Letters, 56(18), 1758-1759.
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  Abstract: Gold atoms in an epitaxial film on mica are clearly visible in images obtained with an atomic force microscope (AFM). The measured lattice spacing of 3.0±0.3 Å is consistent with previous scanning tunneling microscope images obtained in air and vacuum. Atoms are visible even if the sample surface, tip, and cantilever are submerged in water in a closed cell. Electrochemical studies of metal electrodes at atomic resolution may now be possible with the AFM.