1
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Xu X, Stellacci F. Amino Acids and Their Biological Derivatives Modulate Protein-Protein Interactions in an Additive Way. J Phys Chem Lett 2024; 15:7154-7160. [PMID: 38967372 PMCID: PMC11261602 DOI: 10.1021/acs.jpclett.4c01175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Revised: 06/21/2024] [Accepted: 07/02/2024] [Indexed: 07/06/2024]
Abstract
Protein-protein interactions (PPIs) differ when measured in test tubes and cells due to the complexity of the intracellular environment. Free amino acids (AAs) and their derivatives constitute a significant fraction of the intracellular volume and mass. Recently, we have found that AAs have a generic property of rendering protein dispersions more stable by reducing the net attractive part of PPIs. Here, we study the effects on PPIs of different AA derivatives, AA mixtures, and short peptides. We find that all the tested AA derivatives modulate PPIs in solution as effectively as AAs. Furthermore, we show that the modulation effect is additive when AAs form mixtures or are bound into short peptides. Therefore, this study demonstrates the additive effects of a class of small molecules (i.e., AAs and their biological derivatives) on PPIs and provides insights into rationally designing biocompatible molecules for stabilizing protein interactions and consequently tuning protein functions.
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Affiliation(s)
- Xufeng Xu
- Institute
of Materials, Ecole Polytechnique Fédérale
de Lausanne (EPFL), Lausanne 1015, Switzerland
| | - Francesco Stellacci
- Institute
of Materials, Ecole Polytechnique Fédérale
de Lausanne (EPFL), Lausanne 1015, Switzerland
- Bioengineering
Institute, Ecole Polytechnique Fédérale
de Lausanne (EPFL), Lausanne 1015, Switzerland
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2
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Ong Q, Xufeng X, Stellacci F. Versatile Capillary Cells for Handling Concentrated Samples in Analytical Ultracentrifugation. Anal Chem 2024; 96:2567-2573. [PMID: 38301115 PMCID: PMC10867799 DOI: 10.1021/acs.analchem.3c05006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 12/18/2023] [Accepted: 12/20/2023] [Indexed: 02/03/2024]
Abstract
In concentrated macromolecular dispersions, far-from-ideal intermolecular interactions determine the dispersion behaviors including phase transition, crystallization, and liquid-liquid phase separation. Here, we present a novel versatile capillary-cell design for analytical ultracentrifugation-sedimentation equilibrium (AUC-SE), ideal for studying samples at high concentrations. Current setups for such studies are difficult and unreliable to handle, leading to a low experimental success rate. The design presented here is easy to use, robust, and reusable for samples in both aqueous and organic solvents while requiring no special tools or chemical modification of AUC cells. The key and unique feature is the fabrication of liquid reservoirs directly on the bottom window of AUC cells, which can be easily realized by laser ablation or mechanical drilling. The channel length and optical path length are therefore tunable. The success rate for assembling this new cell is close to 100%. We demonstrate the practicality of this cell by studying: (1) the equation of state and second virial coefficients of concentrated gold nanoparticle dispersions in water and bovine serum albumin (BSA) as well as lysozyme solution in aqueous buffers, (2) the gelation phase transition of DNA and BSA solutions, and (3) liquid-liquid phase separation of concentrated BSA/polyethylene glycol (PEG) droplets.
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Affiliation(s)
- Quy Ong
- Laboratory Of Supramolecular
Nanomaterials And Interfaces, Ecole Polytechnique
Fédérale de Lausanne (EPFL), Station 12, 1015 Lausanne, Switzerland
| | - Xu Xufeng
- Laboratory Of Supramolecular
Nanomaterials And Interfaces, Ecole Polytechnique
Fédérale de Lausanne (EPFL), Station 12, 1015 Lausanne, Switzerland
| | - Francesco Stellacci
- Laboratory Of Supramolecular
Nanomaterials And Interfaces, Ecole Polytechnique
Fédérale de Lausanne (EPFL), Station 12, 1015 Lausanne, Switzerland
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3
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Chowdhury P, Bhandary D. Evolution, Stability, and Applicability of Surfactant Aggregates in Targeted Delivery. J Phys Chem B 2023; 127:3001-3009. [PMID: 36971543 DOI: 10.1021/acs.jpcb.2c08625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
Abstract
Self-assembly/self-aggregation of surfactant molecules in bulk and the vicinity of a surface has been a topic of interest for decades because of its utilization in numerous modern technical applications. In this article, the results of molecular dynamics simulations are reported to investigate the self-aggregation of sodium dodecyl sulfate (SDS) at an interface of mica and water. SDS molecules starting from lower to higher surface concentrations tend to create distinct aggregated structures in the vicinity of a mica surface. The structural properties, such as density profiles, radial distribution functions, and thermodynamic properties like excess entropy and second virial coefficient, are calculated to address the bits and pieces of the self-aggregation. The change in the free energy for aggregates of varied sizes approaching the surface from the bulk aqueous solution, along with the change in their shapes during the process in terms of change in the radius of gyration and its components, is reported respectively to model a generic pathway for a surfactant-based targeted delivery system.
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4
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Okoli U, Rishi K, Beaucage G, Kammler HK, McGlasson A, Chauby M, Narayanan V, Grammens J, Kuppa VK. Dispersion of modified fumed silica in elastomeric nanocomposites. POLYMER 2023. [DOI: 10.1016/j.polymer.2022.125407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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5
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Ofosu CK, Kang J, Truskett TM, Milliron DJ. Effective Hard-Sphere Repulsions between Oleate-Capped Colloidal Metal Oxide Nanocrystals. J Phys Chem Lett 2022; 13:11323-11329. [PMID: 36453921 DOI: 10.1021/acs.jpclett.2c02627] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Nanocrystal interactions in solvent influence colloidal stability and dictate self-assembly outcomes. Small-angle X-ray scattering is used to study how dilute oleate-capped In2O3 nanocrystals with 7-19 nm core diameters interact when dispersed in a series of nonpolar solvents. Osmotic second virial coefficient analysis finds toluene-dispersed nanocrystals in this size range interact like effective hard spheres with diameters comprising the inorganic core and a ligand-solvent corona with a core-size independent thickness. Hard-sphere-like structure factors are similarly observed for nanocrystals with a 9.7 nm core diameter dispersed in all the solvents investigated. Nanocrystal hydrodynamic diameters from dynamic light scattering measurements correlate with thermodynamic diameters obtained from the osmotic second virial coefficient analysis for all samples. The ability to prepare nanoscale building blocks of different sizes, and dispersed in a variety of solvents, with effective hard-sphere repulsions provides a foundation for assembly, where secondary linking or depletant molecules can be deliberately added to customize interactions to form superstructures such as gel networks or superlattices.
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Affiliation(s)
- Charles K Ofosu
- Department of Chemistry, University of Texas at Austin, Austin, Texas78712, United States
| | - Jiho Kang
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas78712, United States
| | - Thomas M Truskett
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas78712, United States
- Department of Physics, University of Texas at Austin, Austin, Texas78712, United States
| | - Delia J Milliron
- Department of Chemistry, University of Texas at Austin, Austin, Texas78712, United States
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas78712, United States
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6
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Xu X, de With G, Cölfen H. Self-association and gel formation during sedimentation of like-charged colloids. MATERIALS HORIZONS 2022; 9:1216-1221. [PMID: 35113101 DOI: 10.1039/d1mh01854j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Formation of superstructures from colloidal dispersion involves a continuous increase in particle concentration, resulting in increasingly more complicated interparticle interaction. At high particle concentration, the presence of the super-crowding effect, strong non-ideality in addition to significant light absorption and scattering makes particle analysis very difficult. Here we report quantitative molecular, microscopic and macroscopic experimental results on like-charged colloids with concentration up to 60 vol%, close to the densest possible packing of spheres. It is achieved by conducting sedimentation-diffusion-equilibrium analytical ultracentrifugation (SE-AUC) on a concentrated dispersion of colloidal silica nanoparticles in a refractive-index-matching solvent. Surprisingly, we observed the self-association and even colloidal gel formation of like-charged colloids at very high concentration. Further experiments indicate that the attraction force may be counter-ion mediated. These results represent an important step forward in understanding complicated interparticle interaction in extremely high concentration, which is vital for the controlled fabrication of colloidal superstructures.
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Affiliation(s)
- Xufeng Xu
- Laboratory of Physical Chemistry, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Het Kranenveld 14, PO Box 513, 5600MB, Eindhoven, The Netherlands.
| | - Gijsbertus de With
- Laboratory of Physical Chemistry, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Het Kranenveld 14, PO Box 513, 5600MB, Eindhoven, The Netherlands.
| | - Helmut Cölfen
- Physical Chemistry, University of Konstanz, Universitätsstrasse 10, Box 714, 78457, Konstanz, Germany.
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7
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Based on the Second Virial Coefficient (A2) to Study Effect of the Synergistic Action of Solvent and External Electric Field on the Solution Behavior and Film’s Condensed State Structure. CHINESE JOURNAL OF POLYMER SCIENCE 2022. [DOI: 10.1007/s10118-022-2687-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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8
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Ong Q, Mao T, Iranpour Anaraki N, Richter Ł, Malinverni C, Xu X, Olgiati F, Silva PHJ, Murello A, Neels A, Demurtas D, Shimizu S, Stellacci F. Cryogenic electron tomography to determine thermodynamic quantities for nanoparticle dispersions. MATERIALS HORIZONS 2022; 9:303-311. [PMID: 34739025 PMCID: PMC8725794 DOI: 10.1039/d1mh01461g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 10/15/2021] [Indexed: 05/24/2023]
Abstract
Here we present a method to extract thermodynamic quantities for nanoparticle dispersions in solvents. The method is based on the study of tomograms obtained from cryogenic electron tomography (cryoET). The approach is demonstrated for gold nanoparticles (diameter < 5 nm). Tomograms are reconstructed from tilt-series 2D images. Once the three-dimensional (3D) coordinates for the centres of mass of all of the particles in the sample are determined, we calculate the pair distribution function g(r) and the potential of mean force U(r) without any assumption. Importantly, we show that further quantitative information from 3D tomograms is readily available as the spatial fluctuation in the particles' position can be efficiently determined. This in turn allows for the prompt derivation of the Kirkwood-Buff integrals with all their associated quantities such as the second virial coefficient. Finally, the structure factor and the agglomeration states of the particles are evaluated directly. These thermodynamic quantities provide key insights into the dispersion properties of the particles. The method works well both for dispersed systems containing isolated particles and for systems with varying degrees of agglomerations.
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Affiliation(s)
- Quy Ong
- Institute of Materials, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
| | - Ting Mao
- Institute of Materials, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
| | - Neda Iranpour Anaraki
- Center for X-ray Analytics, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, St. Gallen, 9014, Switzerland
- Laboratory of Particles-Biology Interactions, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, St. Gallen, 9014, Switzerland
- Department of Chemistry, University of Fribourg, Chemin du Musée 9, Fribourg, 1700, Switzerland
| | - Łukasz Richter
- Institute of Materials, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
| | - Carla Malinverni
- Institute of Materials, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
| | - Xufeng Xu
- Institute of Materials, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
| | - Francesca Olgiati
- Institute of Materials, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
| | | | - Anna Murello
- Institute of Materials, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
| | - Antonia Neels
- Center for X-ray Analytics, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, St. Gallen, 9014, Switzerland
- Department of Chemistry, University of Fribourg, Chemin du Musée 9, Fribourg, 1700, Switzerland
| | - Davide Demurtas
- Interdisciplinary Centre for Electron Microscopy (CIME), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Seishi Shimizu
- York Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, York YO10 5DD, UK
| | - Francesco Stellacci
- Institute of Materials, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
- Bioengineering Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
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9
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Pathak JA, Nugent S, Bender MF, Roberts CJ, Curtis RJ, Douglas JF. Comparison of Huggins Coefficients and Osmotic Second Virial Coefficients of Buffered Solutions of Monoclonal Antibodies. Polymers (Basel) 2021; 13:601. [PMID: 33671342 PMCID: PMC7922252 DOI: 10.3390/polym13040601] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 02/12/2021] [Accepted: 02/14/2021] [Indexed: 01/08/2023] Open
Abstract
The Huggins coefficient kH is a well-known metric for quantifying the increase in solution viscosity arising from intermolecular interactions in relatively dilute macromolecular solutions, and there has been much interest in this solution property in connection with developing improved antibody therapeutics. While numerous kH measurements have been reported for select monoclonal antibodies (mAbs) solutions, there has been limited study of kH in terms of the fundamental molecular interactions that determine this property. In this paper, we compare measurements of the osmotic second virial coefficient B22, a common metric of intermolecular and interparticle interaction strength, to measurements of kH for model antibody solutions. This comparison is motivated by the seminal work of Russel for hard sphere particles having a short-range "sticky" interparticle interaction, and we also compare our data with known results for uncharged flexible polymers having variable excluded volume interactions because proteins are polypeptide chains. Our observations indicate that neither the adhesive hard sphere model, a common colloidal model of globular proteins, nor the familiar uncharged flexible polymer model, an excellent model of intrinsically disordered proteins, describes the dependence of kH of these antibodies on B22. Clearly, an improved understanding of protein and ion solvation by water as well as dipole-dipole and charge-dipole effects is required to understand the significance of kH from the standpoint of fundamental protein-protein interactions. Despite shortcomings in our theoretical understanding of kH for antibody solutions, this quantity provides a useful practical measure of the strength of interprotein interactions at elevated protein concentrations that is of direct significance for the development of antibody formulations that minimize the solution viscosity.
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Affiliation(s)
- Jai A. Pathak
- Vaccine Production Program (VPP), Vaccine Research Center (VRC), Formulation and Stabilization Sciences Department, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), 9 W. Watkins Mill Rd., Gaithersburg, MD 20878, USA; (J.A.P.); (S.N.); (M.B.)
| | - Sean Nugent
- Vaccine Production Program (VPP), Vaccine Research Center (VRC), Formulation and Stabilization Sciences Department, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), 9 W. Watkins Mill Rd., Gaithersburg, MD 20878, USA; (J.A.P.); (S.N.); (M.B.)
| | - Michael F. Bender
- Vaccine Production Program (VPP), Vaccine Research Center (VRC), Formulation and Stabilization Sciences Department, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), 9 W. Watkins Mill Rd., Gaithersburg, MD 20878, USA; (J.A.P.); (S.N.); (M.B.)
| | - Christopher J. Roberts
- Colburn Laboratory, Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE 19716, USA;
| | - Robin J. Curtis
- Department of Chemical Engineering and Analytical Science, University of Manchester, Oxford Road, Manchester M13 9PL, UK;
| | - Jack F. Douglas
- Materials Science and Engineering Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899-8544, USA
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10
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The quantum second virial coefficient as a predictor of formation of small spin-polarized tritium (T↓) clusters. Chem Phys Lett 2018. [DOI: 10.1016/j.cplett.2018.05.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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11
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Mulderig A, Beaucage G, Vogtt K, Jiang H, Jin Y, Clapp L, Henderson DC. Structural Emergence in Particle Dispersions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:14029-14037. [PMID: 29144144 DOI: 10.1021/acs.langmuir.7b03033] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Particle dispersions, such as pigment-based inks, comprise weakly bound, milled nanoparticles. The properties of these pigments depend on both their chemical composition and a rather complex structural hierarchy which emerges from these dispersions. The emergence of structure under semidilute conditions is related to the structure of the dilute particles, the particle spacing (mesh size), processing history, and the interaction potential. Kinetic simulations could predict such emergence using these input parameters. In this paper, organic pigments are studied as an example of the importance of emergent structure to predict properties such as brilliance and opacity. Organic pigments are used to impart color to commercial inks, plastics, coatings, and cosmetics. In many cases, dilute pigments are mass fractal structures consisting of aggregated nanoparticles held together by weak van der Waals forces. In water, surfactant is added to create a pigment dispersion (an ink). The final properties of a pigment emerge from a complex interplay between aggregation and dispersion of aggregates as a function of concentration. Samples of the organic pigment yellow 14, PY14, were milled to four primary particle sizes to study the effect on structural emergence. The interaction between surfactant-stabilized PY14 aggregates in an aqueous medium was quantified by the second virial coefficient, A2, which reflects long-range interactions. The degree of aggregation is associated with short-range attractive interactions between primary particles. In this series of pigments, the degree of aggregation increases dramatically with reduction in primary particle size. Concurrently, the second-order virial coefficient, A2, increases reflecting stronger long-range repulsive interactions with particle size. Structural emergence can be understood through the percolation concentration and the filler mesh size. A2 is translated into a repulsive interaction potential for use in dissipative particle dynamics simulations to enable predictive modeling. This description of the interactions between dispersed pigment aggregates allows for a more scientific and predictive approach to understand structural emergence.
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Affiliation(s)
- Andrew Mulderig
- Department of Materials Science, University of Cincinnati , Cincinnati, Ohio 45221, United States
| | - Gregory Beaucage
- Department of Materials Science, University of Cincinnati , Cincinnati, Ohio 45221, United States
| | - Karsten Vogtt
- Department of Materials Science, University of Cincinnati , Cincinnati, Ohio 45221, United States
| | - Hanqiu Jiang
- Department of Materials Science, University of Cincinnati , Cincinnati, Ohio 45221, United States
| | - Yan Jin
- Department of Materials Science, University of Cincinnati , Cincinnati, Ohio 45221, United States
| | - Lisa Clapp
- Colors Group, Sun Chemical Corporation , Cincinnati, Ohio 45232, United States
| | - Donald C Henderson
- Colors Group, Sun Chemical Corporation , Cincinnati, Ohio 45232, United States
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12
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Baranov D, Hill RJ, Ryu J, Park SD, Huerta-Viga A, Carollo AR, Jonas DM. Interferometrically stable, enclosed, spinning sample cell for spectroscopic experiments on air-sensitive samples. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2017; 88:014101. [PMID: 28147656 DOI: 10.1063/1.4973666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
In experiments with high photon flux, it is necessary to rapidly remove the sample from the beam and to delay re-excitation until the sample has returned to equilibrium. Rapid and complete sample exchange has been a challenge for air-sensitive samples and for vibration-sensitive experiments. Here, a compact spinning sample cell for air and moisture sensitive liquid and thin film samples is described. The principal parts of the cell are a copper gasket sealed enclosure, a 2.5 in. hard disk drive motor, and a reusable, chemically inert glass sandwich cell. The enclosure provides an oxygen and water free environment at the 1 ppm level, as demonstrated by multi-day tests with sodium benzophenone ketyl radical. Inside the enclosure, the glass sandwich cell spins at ≈70 Hz to generate tangential speeds of 7-12 m/s that enable complete sample exchange at 100 kHz repetition rates. The spinning cell is acoustically silent and compatible with a ±1 nm rms displacement stability interferometer. In order to enable the use of the spinning cell, we discuss centrifugation and how to prevent it, introduce the cycle-averaged resampling rate to characterize repetitive excitation, and develop a figure of merit for a long-lived photoproduct buildup.
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Affiliation(s)
- Dmitry Baranov
- Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, USA
| | - Robert J Hill
- Department of Physics, University of Colorado Boulder, Boulder, Colorado 80309, USA
| | - Jisu Ryu
- Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, USA
| | - Samuel D Park
- Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, USA
| | - Adriana Huerta-Viga
- Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, USA
| | - Alexa R Carollo
- Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, USA
| | - David M Jonas
- Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, USA
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13
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Philipse AP, Kuipers BWM, Vrij A. A thermodynamic gauge for mobile counter-ions from colloids and nanoparticles. Faraday Discuss 2015; 181:103-21. [PMID: 25924773 DOI: 10.1039/c4fd00261j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A thermodynamic equilibrium sensor is proposed that measures the ratio of the number of elementary charges z to the mass m of charged solutes such as charged colloids and nanoparticles. The sensor comprises a small, membrane-encapsulated salt solution volume that absorbs neutral salt molecules in response to the release of mobile counter-ions by charge carriers in the surrounding suspension. The sensor state emerges as a limiting case of the equilibrium salt imbalance, and the ensuing osmotic pressure difference, between arbitrary salt and suspension volumes. A weight concentration of charge carriers c is predicted to significantly increase the sensor's salt number density from its initial value ρs,0 to ρRs, according to the relation (ρRs/ρs,0)(2)-1=zc/mρs,0, under the assumption that the mobile ions involved in the thermodynamic sensor-suspension equilibrium are ideal and homogeneously distributed.
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Affiliation(s)
- Albert P Philipse
- Van't Hoff Laboratory for Physical and Colloid Chemistry, Utrecht University, Debye Institute for Nano-materials Science, Padualaan 8, 3584 CH Utrecht, The Netherlands.
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14
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Peukert W, Segets D, Pflug L, Leugering G. Unified Design Strategies for Particulate Products. MESOSCALE MODELING IN CHEMICAL ENGINEERING PART I 2015. [DOI: 10.1016/bs.ache.2015.10.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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