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Li Y, Zhang J, Zeng H, Zhang H. Ion association behaviors in the initial stage of calcium carbonate formation: An ab initio study. J Chem Phys 2024; 161:014503. [PMID: 38949280 DOI: 10.1063/5.0206841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Accepted: 06/12/2024] [Indexed: 07/02/2024] Open
Abstract
In this work, we performed static density functional theory calculations and ab initio metadynamics simulations to systematically investigate the association mechanisms and dynamic structures of four kinds of ion pairs that could be formed before the nucleation of CaCO3. For Ca2+-HCO3- and Ca2+-CO32- pairs, the arrangement of ligands around Ca2+ evolves between the six-coordinated octahedral structure and the seven-coordinated pentagonal bipyramidal structure. The formation of ion pairs follows an associative ligand substitution mechanism. Compared with HCO3-, CO32- exhibits a stronger affinity to Ca2+, leading to the formation of a more stable precursor phase in the prenucleation stage, which promotes the subsequent CaCO3 nucleation. In alkaline environments, excessive OH- ions decrease the coordination preference of Ca2+. In this case, the formation of Ca(OH)+-CO32- and Ca(OH)2-CO32- pairs favors the dissociative ligand substitution mechanism. The inhibiting effects of OH- ion on the CaCO3 association can be interpreted from two aspects, i.e., (1) OH- neutralizes positive charges on Ca2+, decreases the electrostatic interactions between Ca2+ and CO32-, and thus hinders the formation of the CaCO3 monomer, and (2) OH- decreases the capacity of Ca2+ for accommodating O, making it easier to separate Ca2+ and CO32- ions. Our findings on the ion association behaviors in the initial stage of CaCO3 formation not only help scientists evaluate the impact of ocean acidification on biomineralization but also provide theoretical support for the discovery and development of more effective approaches to manage undesirable scaling issues.
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Affiliation(s)
- Yue Li
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Jiarui Zhang
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Hongbo Zeng
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Hao Zhang
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
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Atomistic Simulations of Plasma-Enhanced Atomic Layer Deposition. MATERIALS 2019; 12:ma12162605. [PMID: 31443331 PMCID: PMC6719897 DOI: 10.3390/ma12162605] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 08/07/2019] [Accepted: 08/12/2019] [Indexed: 11/17/2022]
Abstract
Plasma-enhanced atomic layer deposition (PEALD) is a widely used, powerful layer-by-layer coating technology. Here, we present an atomistic simulation scheme for PEALD processes, combining the Monte Carlo deposition algorithm and structure relaxation using molecular dynamics. In contrast to previous implementations, our approach employs a real, atomistic model of the precursor. This allows us to account for steric hindrance and overlap restrictions at the surface corresponding to the real precursor deposition step. In addition, our scheme takes various process parameters into account, employing predefined probabilities for precursor products at each Monte Carlo deposition step. The new simulation protocol was applied to investigate PEALD synthesis of SiO2 thin films using the bis-diethylaminosilane precursor. It revealed that increasing the probability for precursor binding to one surface oxygen atom favors amorphous layer growth, a large number of –OH impurities, and the formation of voids. In contrast, a higher probability for precursor binding to two surface oxygen atoms leads to dense SiO2 film growth and a reduction of –OH impurities. Increasing the probability for the formation of doubly bonded precursor sites is therefore the key factor for the formation of dense SiO2 PEALD thin films with reduced amounts of voids and –OH impurities.
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Brandt EG, Agosta L, Lyubartsev AP. Reactive wetting properties of TiO2 nanoparticles predicted by ab initio molecular dynamics simulations. NANOSCALE 2016; 8:13385-13398. [PMID: 27341183 DOI: 10.1039/c6nr02791a] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Small-sized wet TiO2 nanoparticles have been investigated by ab initio molecular dynamics simulations. Chemical and physical adsorption of water on the TiO2-water interface was studied as a function of water content, ranging from dry nanoparticles to wet nanoparticles with monolayer coverage of water. The surface reactivity was shown to be a concave function of water content and driven by surface defects. The local coordination number at the defect was identified as the key factor to decide whether water adsorption proceeds through dissociation or physisorption on the surface. A consistent picture of TiO2 nanoparticle wetting at the microscopic level emerges, which corroborates existing experimental data and gives further insight into the molecular mechanisms behind nanoparticle wetting. These calculations will facilitate the engineering of metal oxide nanoparticles with a controlled catalytic water activity.
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Affiliation(s)
- Erik G Brandt
- Department of Materials and Environmental Chemistry, Stockholm University, Stockholm, Sweden.
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Ahmed A, Elvati P, Violi A. Size-and phase-dependent structure of copper(ii) oxide nanoparticles. RSC Adv 2015. [DOI: 10.1039/c5ra04276c] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Core (3 nm diameter) and outer surface layer (0.5 nm width) of a CuO nanoparticle of 4 nm in diameter.
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Affiliation(s)
- Alauddin Ahmed
- Department of Mechanical Engineering
- Chemical Engineering
- University of Michigan
- Ann Arbor
- USA
| | - Paolo Elvati
- Department of Mechanical Engineering
- Chemical Engineering
- University of Michigan
- Ann Arbor
- USA
| | - Angela Violi
- Department of Mechanical Engineering
- Chemical Engineering
- University of Michigan
- Ann Arbor
- USA
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Fan Z, Koster RS, Wang S, Fang C, Yalcin AO, Tichelaar FD, Zandbergen HW, van Huis MA, Vlugt TJH. A transferable force field for CdS-CdSe-PbS-PbSe solid systems. J Chem Phys 2014; 141:244503. [DOI: 10.1063/1.4904545] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Zhaochuan Fan
- Process and Energy Department, Delft University of Technology, Leeghwaterstraat 39, 2628 CB Delft,The Netherlands
| | - Rik S. Koster
- Debye Institute for Nanomaterials Science and Center for Extreme Matter and Emergent Phenomena, Utrecht University, Princetonplein 5, 3584 CC Utrecht, The Netherlands
| | - Shuaiwei Wang
- Institute of Nanostructured Functional Materials, Huanghe Science and Technology College, Zhengzhou, Henan 450006, China
| | - Changming Fang
- Debye Institute for Nanomaterials Science and Center for Extreme Matter and Emergent Phenomena, Utrecht University, Princetonplein 5, 3584 CC Utrecht, The Netherlands
| | - Anil O. Yalcin
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - Frans D. Tichelaar
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - Henny W. Zandbergen
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - Marijn A. van Huis
- Debye Institute for Nanomaterials Science and Center for Extreme Matter and Emergent Phenomena, Utrecht University, Princetonplein 5, 3584 CC Utrecht, The Netherlands
| | - Thijs J. H. Vlugt
- Process and Energy Department, Delft University of Technology, Leeghwaterstraat 39, 2628 CB Delft,The Netherlands
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Andreev YG, Panchmatia PM, Liu Z, Parker SC, Islam MS, Bruce PG. The Shape of TiO2-B Nanoparticles. J Am Chem Soc 2014; 136:6306-12. [DOI: 10.1021/ja412387c] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Yuri G. Andreev
- School
of Chemistry, University of St Andrews, St Andrews KY16 9ST, U.K
| | - Pooja M. Panchmatia
- School
of Applied Sciences, University of Huddersfield, Huddersfield HD1 3DH, U.K
| | - Zheng Liu
- School
of Chemistry, University of St Andrews, St Andrews KY16 9ST, U.K
| | | | - M. Saiful Islam
- Department
of Chemistry, University of Bath, Bath BA2 7AY, U.K
| | - Peter G. Bruce
- School
of Chemistry, University of St Andrews, St Andrews KY16 9ST, U.K
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Gebauer D, Kellermeier M, Gale JD, Bergström L, Cölfen H. Pre-nucleation clusters as solute precursors in crystallisation. Chem Soc Rev 2014; 43:2348-71. [PMID: 24457316 DOI: 10.1039/c3cs60451a] [Citation(s) in RCA: 431] [Impact Index Per Article: 43.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Crystallisation is at the heart of various scientific disciplines, but still the understanding of the molecular mechanisms underlying phase separation and the formation of the first solid particles in aqueous solution is rather limited. In this review, classical nucleation theory, as well as established concepts of spinodal decomposition and liquid-liquid demixing, is introduced together with a description of the recently proposed pre-nucleation cluster pathway. The features of pre-nucleation clusters are presented and discussed in relation to recent modifications of the classical and established models for phase separation, together with a review of experimental work and computer simulations on the characteristics of pre-nucleation clusters of calcium phosphate, calcium carbonate, iron(oxy)(hydr)oxide, silica, and also amino acids as an example of small organic molecules. The role of pre-nucleation clusters as solute precursors in the emergence of a new phase is summarized, and the link between the chemical speciation of homogeneous solutions and the process of phase separation via pre-nucleation clusters is highlighted.
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Affiliation(s)
- Denis Gebauer
- Department of Chemistry, Physical Chemistry, University of Konstanz, Universitätsstrasse 10, Box 714, D-78464 Konstanz, Germany.
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Mi L, Chen Y, Wei W, Chen W, Hou H, Zheng Z. Large-scale urchin-like micro/nano-structured NiS: controlled synthesis, cation exchange and lithium-ion battery applications. RSC Adv 2013. [DOI: 10.1039/c3ra42859a] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
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