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Sultan U, Götz A, Schlumberger C, Drobek D, Bleyer G, Walter T, Löwer E, Peuker UA, Thommes M, Spiecker E, Apeleo Zubiri B, Inayat A, Vogel N. From Meso to Macro: Controlling Hierarchical Porosity in Supraparticle Powders. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023:e2300241. [PMID: 36932894 DOI: 10.1002/smll.202300241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 02/19/2023] [Indexed: 06/18/2023]
Abstract
A drying droplet containing colloidal particles can consolidate into a spherical assembly called a supraparticle. Such supraparticles are inherently porous due to the spaces between the constituent primary particles. Here, the emergent, hierarchical porosity in spray-dried supraparticles is tailored via three distinct strategies acting at different length scales. First, mesopores (<10 nm) are introduced via the primary particles. Second, the interstitial pores are tuned from the meso- (35 nm) to the macro scale (250 nm) by controlling the primary particle size. Third, defined macropores (>100 nm) are introduced via templating polymer particles, which can be selectively removed by calcination. Combining all three strategies creates hierarchical supraparticles with fully tailored pore size distributions. Moreover, another level of the hierarchy is added by fabricating supra-supraparticles, using the supraparticles themselves as building blocks, which provide additional pores with micrometer dimensions. The interconnectivity of the pore networks within all supraparticle types is investigated via detailed textural and tomographic analysis. This work provides a versatile toolbox for designing porous materials with precisely tunable, hierarchical porosity from the meso- (3 nm) to the macroscale (≈10 µm) that can be utilized for applications in catalysis, chromatography, or adsorption.
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Affiliation(s)
- Umair Sultan
- Institute of Particle Technology, Department of Chemical and Biological Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, Cauerstrasse 4, 91058, Erlangen, Germany
- Institute of Chemical Reaction Engineering, Department of Chemical and Biological Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstrasse 3, 91058, Erlangen, Germany
| | - Alexander Götz
- Institute of Micro- and Nanostructure Research (IMN), Center for Nanoanalysis and Electron Microscopy (CENEM), IZNF, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058, Erlangen, Germany
| | - Carola Schlumberger
- Institute of Separation Science and Technology, Department of Chemical and Biological Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstrasse 3, 91058, Erlangen, Germany
| | - Dominik Drobek
- Institute of Micro- and Nanostructure Research (IMN), Center for Nanoanalysis and Electron Microscopy (CENEM), IZNF, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058, Erlangen, Germany
| | - Gudrun Bleyer
- Institute of Particle Technology, Department of Chemical and Biological Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, Cauerstrasse 4, 91058, Erlangen, Germany
| | - Teresa Walter
- Institute of Particle Technology, Department of Chemical and Biological Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, Cauerstrasse 4, 91058, Erlangen, Germany
| | - Erik Löwer
- Institute of Mechanical Process Engineering and Mineral Processing, Technische Universität Bergakademie Freiberg, 09599, Freiberg, Germany
| | - Urs Alexander Peuker
- Institute of Mechanical Process Engineering and Mineral Processing, Technische Universität Bergakademie Freiberg, 09599, Freiberg, Germany
| | - Matthias Thommes
- Institute of Separation Science and Technology, Department of Chemical and Biological Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstrasse 3, 91058, Erlangen, Germany
| | - Erdmann Spiecker
- Institute of Micro- and Nanostructure Research (IMN), Center for Nanoanalysis and Electron Microscopy (CENEM), IZNF, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058, Erlangen, Germany
| | - Benjamin Apeleo Zubiri
- Institute of Micro- and Nanostructure Research (IMN), Center for Nanoanalysis and Electron Microscopy (CENEM), IZNF, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058, Erlangen, Germany
| | - Alexandra Inayat
- Institute of Chemical Reaction Engineering, Department of Chemical and Biological Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstrasse 3, 91058, Erlangen, Germany
| | - Nicolas Vogel
- Institute of Particle Technology, Department of Chemical and Biological Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, Cauerstrasse 4, 91058, Erlangen, Germany
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Fang R, Liang H, Li J, Chen Y, Luo X, Li Y, Li B, Liu S. Microencapsulation of astaxanthin based on emulsion solvent evaporation and subsequent spray drying. J Food Sci 2022; 87:998-1008. [PMID: 35170050 DOI: 10.1111/1750-3841.16063] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 12/16/2021] [Accepted: 01/04/2022] [Indexed: 12/15/2022]
Abstract
Astaxanthin (AXT) is widely used in the food, drug, and cosmetics fields, but its applications are extremely limited by its intrinsic properties. Herein, a novel encapsulation system had been performed to fabricate AXT-loaded microcapsules through emulsion solvent evaporation and spray-dried methodologies. The influence of polylactic acid (PLA) concentrations on the characteristics of AXT-loaded dispersions and resultant microcapsules were investigated. The results showed that the sizes and zeta potentials of dispersions and microcapsules increased with increasing PLA content (9.8 to 24.6 wt%). The encapsulation efficiency (EE) of the microcapsules increased with increasing PLA concentration up to 21.4 wt%. The moisture content values, flowability, and bulk density of the obtained microcapsules decreased with increasing PLA content (9.8 to 24.6 wt%). Furthermore, the cell culture experiment indicated that the obtained microcapsules had no cytotoxicity and possessed excellent antioxidant activity. This work provides a new strategy for fabricating AXT-enriched microcapsules and expands their application in nutritional products. PRACTICAL APPLICATION: This work fabricated a novel encapsulation system for AXT through emulsion solvent evaporation and spray drying methodologies. The obtained AXT-loaded microcapsules possessed great physical stability and could expand potential applications of AXT.
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Affiliation(s)
- Rongxi Fang
- College of Food Science & Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Hongshan Liang
- College of Food Science & Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Jing Li
- College of Food Science & Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Yijie Chen
- College of Food Science & Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Xiaogang Luo
- School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan, Hubei, China.,School of Materials and Engineering, Zhengzhou University, Zhengzhou City, Henan, China
| | - Yan Li
- College of Food Science & Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Bin Li
- College of Food Science & Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Shilin Liu
- College of Food Science & Technology, Huazhong Agricultural University, Wuhan, Hubei, China.,School of Materials and Engineering, Zhengzhou University, Zhengzhou City, Henan, China
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Trunov D, Muzika F, Kříž A, Štětina J, Sedlářová I, Dendisová M, Hassouna F, Šoóš M. Ambient-temperature porogen-free method for preparation of silica-based macroporous materials. Colloids Surf A Physicochem Eng Asp 2022. [DOI: 10.1016/j.colsurfa.2021.128033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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4
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Wang J, Kang E, Sultan U, Merle B, Inayat A, Graczykowski B, Fytas G, Vogel N. Influence of Surfactant-Mediated Interparticle Contacts on the Mechanical Stability of Supraparticles. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2021; 125:23445-23456. [PMID: 34737841 PMCID: PMC8558861 DOI: 10.1021/acs.jpcc.1c06839] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 09/15/2021] [Indexed: 05/14/2023]
Abstract
Colloidal supraparticles are micron-scale spherical assemblies of uniform primary particles, which exhibit emergent properties of a colloidal crystal, yet exist as a dispersible powder. A prerequisite to utilize these emergent functionalities is that the supraparticles maintain their mechanical integrity upon the mechanical impacts that are likely to occur during processing. Understanding how the internal structure relates to the resultant mechanical properties of a supraparticle is therefore of general interest. Here, we take the example of supraparticles templated from water/fluorinated oil emulsions in droplet-based microfluidics and explore the effect of surfactants on their mechanical properties. Stable emulsions can be generated by nonionic block copolymers consisting of a hydrophilic and fluorophilic block and anionic fluorosurfactants widely available under the brand name Krytox. The supraparticles formed in the presence of both types of surfactants appear structurally similar, but differ greatly in their mechanical properties. While the nonionic surfactant induces superior mechanical stability and ductile fracture behavior, the anionic Krytox surfactant leads to weak supraparticles with brittle fracture. We complement this macroscopic picture with Brillouin light spectroscopy that is very sensitive to the interparticle contacts for subnanometer-thick adsorbed layers atop of the nanoparticle. While the anionic Krytox does not significantly affect the interparticle bonds, the amphiphilic nonionic surfactant drastically strengthens these bonds to the point that individual particle vibrations are not resolved in the experimental spectrum. Our results demonstrate that seemingly subtle changes in the physicochemical properties of supraparticles can drastically impact the resultant mechanical properties.
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Affiliation(s)
- Junwei Wang
- Institute
of Particle Technology, Friedrich-Alexander
University Erlangen-Nürnberg, Cauerstrasse 4, 91058 Erlangen, Germany
| | - Eunsoo Kang
- Max
Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Umair Sultan
- Institute
of Particle Technology, Friedrich-Alexander
University Erlangen-Nürnberg, Cauerstrasse 4, 91058 Erlangen, Germany
- Institute
of Chemical Reaction Engineering, Friedrich-Alexander
University Erlangen-Nürnberg, Egerlandstrasse 3, 91058 Erlangen, Germany
| | - Benoit Merle
- Materials
Science and Engineering I and Interdisciplinary Center for Nanostructured
Films (IZNF), Friedrich-Alexander University
Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - Alexandra Inayat
- Institute
of Chemical Reaction Engineering, Friedrich-Alexander
University Erlangen-Nürnberg, Egerlandstrasse 3, 91058 Erlangen, Germany
| | - Bartlomiej Graczykowski
- Max
Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
- Faculty
of Physics, Adam Mickiewicz University, Uniwersytetu Poznanskiego 2, Poznan 61-614, Poland
| | - George Fytas
- Max
Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
- E-mail:
| | - Nicolas Vogel
- Institute
of Particle Technology, Friedrich-Alexander
University Erlangen-Nürnberg, Cauerstrasse 4, 91058 Erlangen, Germany
- E-mail:
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5
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Wang J, Schwenger J, Ströbel A, Feldner P, Herre P, Romeis S, Peukert W, Merle B, Vogel N. Mechanics of colloidal supraparticles under compression. SCIENCE ADVANCES 2021; 7:eabj0954. [PMID: 34644116 PMCID: PMC11095630 DOI: 10.1126/sciadv.abj0954] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 08/23/2021] [Indexed: 05/16/2023]
Abstract
Colloidal supraparticles are finite, spherical assemblies of many primary particles. To take advantage of their emergent functionalities, such supraparticles must retain their structural integrity. Here, we investigate their size-dependent mechanical properties via nanoindentation. We find that the deformation resistance inversely scales with the primary particle diameter, while the work of deformation is dependent on the supraparticle diameter. We adopt the Griffith theory to such particulate systems to provide a predictive scaling to relate the fracture stress to the geometry of supraparticles. The interplay between primary particle material and cohesive interparticle forces dictates the mechanical properties of supraparticles. We find that enhanced stability, associated with ductile fracture, can be achieved if supraparticles are engineered to dissipate more energy via deformation of primary particles than breaking of interparticle bonds. Our work provides a coherent framework to analyze, predict, and design the mechanical properties of colloidal supraparticles.
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Affiliation(s)
- Junwei Wang
- Institute of Particle Technology, Friedrich-Alexander University Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - Jan Schwenger
- Institute of Particle Technology, Friedrich-Alexander University Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - Andreas Ströbel
- Institute of Particle Technology, Friedrich-Alexander University Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - Patrick Feldner
- Materials Science & Engineering I and Interdisciplinary Center for Nanostructured Films (IZNF), Friedrich-Alexander University Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - Patrick Herre
- Institute of Particle Technology, Friedrich-Alexander University Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - Stefan Romeis
- Institute of Particle Technology, Friedrich-Alexander University Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - Wolfgang Peukert
- Institute of Particle Technology, Friedrich-Alexander University Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - Benoit Merle
- Materials Science & Engineering I and Interdisciplinary Center for Nanostructured Films (IZNF), Friedrich-Alexander University Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - Nicolas Vogel
- Institute of Particle Technology, Friedrich-Alexander University Erlangen-Nürnberg, 91058 Erlangen, Germany
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Miethke L, Prziwara P, Finke JH, Breitung-Faes S. Opposing Effects of Additives in Dry Milling and Tableting of Organic Particles. Pharmaceutics 2021; 13:pharmaceutics13091434. [PMID: 34575509 PMCID: PMC8467332 DOI: 10.3390/pharmaceutics13091434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 09/06/2021] [Accepted: 09/07/2021] [Indexed: 11/16/2022] Open
Abstract
Applying additives and excipients during the dry processing of fine particles is a common measure to control the particle–particle interactions, to specifically influence the powder properties and to enhance the process efficiency or product quality. In this study, the impacts of a particulate lubricant, a nano-disperse flow additive and liquid grinding aids on the dry fine milling and subsequent tableting of the ground material were investigated for three different organic model compounds. It is presented that the three additive classes cause varying and partly opposing effects during these process steps. Especially the lubricant and the grinding aids were shown to increase the efficiency of the milling process as well as the product fineness of the ground material, and to avoid critical product adhesions on the machine surfaces. Thereby, stable and efficient grinding conditions were partially not possible without the addition of such additives. However, as these positive effects are attributed to a reduction of the adhesive forces between the particles, much lower tablet strengths were achieved for these additives. This propagation of powder, and in turn, final product properties over whole process chains, has not been studied in detail so far. It was further revealed that the material behavior and the microstructure of the product particles is decisive for the processing as well, which is why additive effects may be product-specific and can even be suppressed under certain processing conditions. In comparison to the process performances, the powder properties and surface energies of the product particles were less influenced by the additives. On the contrary, particle-based morphologies or deformation behavior seem to play a major role in comparison to inorganic materials. Thus, it can be stated that global bulk properties and surface energies provide first indications of powder behavior and susceptibility. However, additional specific properties need to be evaluated to more clearly understand the influences of additives.
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Affiliation(s)
- Lina Miethke
- Institute for Particle Technology, Technische Universität Braunschweig, 38104 Braunschweig, Germany; (L.M.); (P.P.)
| | - Paul Prziwara
- Institute for Particle Technology, Technische Universität Braunschweig, 38104 Braunschweig, Germany; (L.M.); (P.P.)
| | - Jan Henrik Finke
- Institute for Particle Technology, Technische Universität Braunschweig, 38104 Braunschweig, Germany; (L.M.); (P.P.)
- Center of Pharmaceutical Engineering—PVZ, Technische Universität Braunschweig, 38106 Braunschweig, Germany
- Correspondence: (J.H.F.); (S.B.-F.)
| | - Sandra Breitung-Faes
- Institute for Particle Technology, Technische Universität Braunschweig, 38104 Braunschweig, Germany; (L.M.); (P.P.)
- Correspondence: (J.H.F.); (S.B.-F.)
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7
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Canziani H, Chiera S, Schuffenhauer T, Kopp SP, Metzger F, Bück A, Schmidt M, Vogel N. Bottom-Up Design of Composite Supraparticles for Powder-Based Additive Manufacturing. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2020; 16:e2002076. [PMID: 32578351 DOI: 10.1002/smll.202002076] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 05/06/2020] [Indexed: 05/16/2023]
Abstract
Additive manufacturing promises high flexibility and customized product design. Powder bed fusion processes use a laser to melt a polymer powder at predefined locations and iterate the scheme to build 3D objects. The design of flowable powders is a critical parameter for a successful fabrication process that currently limits the choice of available materials. Here, a bottom-up process is introduced to fabricate tailored polymer- and composite supraparticles for powder-based additive manufacturing processes by controlled aggregation of colloidal primary particles. These supraparticles exhibit a near-spherical shape and tailored composition, morphology, and surface roughness. These parameters can be precisely controlled by the mixing and size ratio of the primary particles. Polystyrene/silica composite particles are chosen as a model system to establish structure-property relations connecting shape, morphology, and surface roughness to the adhesion within the powder, which is accessed by tensile strength measurements. The adhesive properties are then connected to powder flowability and it is shown that the resulting powders allow the formation of dense powder films with uniform coverage. Finally, successful powder bed fusion is demonstrated by producing macroscopic single layer specimens with uniform distribution of nanoscale silica additives.
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Affiliation(s)
- Herbert Canziani
- Institute of Particle Technology, Friedrich-Alexander-University Erlangen-Nürnberg, Cauerstraße 4, Erlangen, 91058, Germany
- Interdisciplinary Center for Functional Particle Systems, Friedrich-Alexander-University Erlangen-Nürnberg, Haberstraße 9a, Erlangen, 91058, Germany
| | - Salvatore Chiera
- Institute of Particle Technology, Friedrich-Alexander-University Erlangen-Nürnberg, Cauerstraße 4, Erlangen, 91058, Germany
- Interdisciplinary Center for Functional Particle Systems, Friedrich-Alexander-University Erlangen-Nürnberg, Haberstraße 9a, Erlangen, 91058, Germany
| | - Thomas Schuffenhauer
- Bayerisches Laser Zentrum GmbH, Konrad-Zuse-Straße 2-6, Erlangen, 91052, Germany
- Erlangen Graduate School in Advanced Optical Technologies (SAOT), Paul-Gordan-Straße 6, Erlangen, 91052, Germany
| | - Sebastian-Paul Kopp
- Bayerisches Laser Zentrum GmbH, Konrad-Zuse-Straße 2-6, Erlangen, 91052, Germany
- Erlangen Graduate School in Advanced Optical Technologies (SAOT), Paul-Gordan-Straße 6, Erlangen, 91052, Germany
| | - Florian Metzger
- Institute of Particle Technology, Friedrich-Alexander-University Erlangen-Nürnberg, Cauerstraße 4, Erlangen, 91058, Germany
| | - Andreas Bück
- Institute of Particle Technology, Friedrich-Alexander-University Erlangen-Nürnberg, Cauerstraße 4, Erlangen, 91058, Germany
- Interdisciplinary Center for Functional Particle Systems, Friedrich-Alexander-University Erlangen-Nürnberg, Haberstraße 9a, Erlangen, 91058, Germany
| | - Michael Schmidt
- Bayerisches Laser Zentrum GmbH, Konrad-Zuse-Straße 2-6, Erlangen, 91052, Germany
- Erlangen Graduate School in Advanced Optical Technologies (SAOT), Paul-Gordan-Straße 6, Erlangen, 91052, Germany
- Institute of Photonic Technologies, Friedrich-Alexander-University Erlangen-Nürnberg, Konrad-Zuse-Straße 3-5, Erlangen, 91052, Germany
| | - Nicolas Vogel
- Institute of Particle Technology, Friedrich-Alexander-University Erlangen-Nürnberg, Cauerstraße 4, Erlangen, 91058, Germany
- Interdisciplinary Center for Functional Particle Systems, Friedrich-Alexander-University Erlangen-Nürnberg, Haberstraße 9a, Erlangen, 91058, Germany
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Shrestha S, Wang B, Dutta P. Nanoparticle processing: Understanding and controlling aggregation. Adv Colloid Interface Sci 2020; 279:102162. [PMID: 32334131 DOI: 10.1016/j.cis.2020.102162] [Citation(s) in RCA: 101] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 04/13/2020] [Accepted: 04/14/2020] [Indexed: 12/22/2022]
Abstract
Nanoparticles (NPs) are commonly defined as particles with size <100 nm and are currently of considerable technological and academic interest, since they are often the starting materials for nanotechnology. Novel properties develop as a bulk material is reduced to nanodimensions and is reflected in new chemistry, physics and biology. With reduction in size, a greater function of the atoms is at the surface, and promote different interaction with its environment, as compared to the bulk material. In addition, the reduction in size alters the electronic structure of the material, resulting in novel quantum effects. Size also influences mobility, primarily controlled by Brownian motion for NPs, and relevant in biological and environmental processes. However, the small size also leads to high surface energy, and NPs tend to aggregate, thereby lowering the surface energy. In all applications, the uncontrolled aggregation of NPs can have negative effects and needs to be avoided. There are however examples of controlled aggregation of NPs which give rise to novel effects. This review article is focused on the NP features that influences aggregation. Common strategies for synthesis of NPs from the gas and liquid phases are discussed with emphasis on aggregation during and after synthesis. The theory involving Van der Waals attractive force and electrical repulsive force as the controlling features of the stability of NPs is discussed, followed by examples of how repulsive and attractive forces can be manipulated experimentally to control NP aggregation. In some applications, NPs prepared by liquid methods need to be isolated for further applications. The process of solvent removal introduces new forces such as capillary forces that promote aggregation, in many cases, irreversibly. Strategies for controlling aggregation upon drying are discussed. There are also many methods for redispersing aggregated NPs, which involve mechanical forces, as well as manipulating capillary forces and surface characteristics. We conclude this review with a discussion of aggregation relevant real-world applications of NPs. This review should be relevant for scientists and technologists interested in NPs, since emphasis has been on the practical aspects of NP-based technology, and especially, strategies relevant to controlling NP aggregation.
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Affiliation(s)
- Sweta Shrestha
- ZeoVation, 1275 Kinnear Road, Columbus, OH 43212, United States of America
| | - Bo Wang
- ZeoVation, 1275 Kinnear Road, Columbus, OH 43212, United States of America
| | - Prabir Dutta
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, United States of America.
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9
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Feng Y, Lee Y. Microfluidic fabrication of wrinkled protein microcapsules and their nanomechanical properties affected by protein secondary structure. J FOOD ENG 2019. [DOI: 10.1016/j.jfoodeng.2018.10.028] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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10
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Wong WSY. Surface Chemistry Enhancements for the Tunable Super-Liquid Repellency of Low-Surface-Tension Liquids. NANO LETTERS 2019; 19:1892-1901. [PMID: 30726096 PMCID: PMC6728126 DOI: 10.1021/acs.nanolett.8b04972] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Super-hydrophobic, super-oleo(amphi)phobic, and super-omniphobic materials are universally important in the fields of science and engineering. Despite rapid advancements, gaps of understanding still exist between each distinctive wetting state. The transition of super-hydrophobicity to super-(oleo-, amphi-, and omni-)phobicity typically requires the use of re-entrant features. Today, re-entrant geometry induced super-(amphi- and omni-)phobicity is well-supported by both experiments and theory. However, owing to geometrical complexities, the concept of re-entrant geometry forms a dogma that limits the industrial progress of these unique states of wettability. Moreover, a key fundamental question remains unanswered: are extreme surface chemistry enhancements able to influence super-liquid repellency? Here, this was rigorously tested via an alternative pathway that does not require explicit designer re-entrant features. Highly controllable and tunable vertical network polymerization and functionalization were used to achieve fluoroalkyl densification on nanoparticles. For the first time, relative fluoro-functionalization densities are quantitatively tuned and correlated to super-liquid repellency performance. Step-wise tunable super-amphiphobic nanoparticle films with a Cassie-Baxter state (contact angle of >150° and sliding angle of <10°) against various liquids is demonstrated. This was tested down to very low surface tension liquids to a minimum of ca. 23.8 mN/m. Such findings could eventually lead to the future development of super-(amphi)omniphobic materials that transcend the sole use of re-entrant geometry.
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11
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Effects of Silica Nanoparticles and Silica-Zirconia Nanoclusters on Tribological Properties of Dental Resin Composites. JOURNAL OF NANOTECHNOLOGY 2018. [DOI: 10.1155/2018/7589051] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Roughness and hardness are among the most important variables in the wear (resistance) performance of dental resin composites. In this study, silica nanoparticles and nanoclusters of silica and silica-zirconia nanoparticles were evaluated for use as reinforcement agents in dental resin composites. Nanoclusters with spherical morphology were obtained from aqueous dispersions of nanoparticles by spray drying. Roughness was measured through atomic force microscopy (AFM) while nanohardness was evaluated by nanoindentation. The roughness values obtained with silica nanoparticles were lower (22.6 ± 6.6 nm) than those obtained with silica and silica-zirconia nanoclusters (138.1 ± 36.6 nm, 116.2 ± 32.2 nm, resp.), while the hardness values of all composites were similar (nanoparticles = 0.24 ± 0.01 GPa, silica nanoclusters = 0.25 ± 0.04 GPa, and silica-zirconia nanoclusters = 0.22 ± 0.02 GPa). Based on this study, it can be established that particle size is a determining factor in the roughness of the final material, while the key variable for nanohardness was the concentration of the reinforcement materials.
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12
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Wintzheimer S, Granath T, Oppmann M, Kister T, Thai T, Kraus T, Vogel N, Mandel K. Supraparticles: Functionality from Uniform Structural Motifs. ACS NANO 2018; 12:5093-5120. [PMID: 29763295 DOI: 10.1021/acsnano.8b00873] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Under the right process conditions, nanoparticles can cluster together to form defined, dispersed structures, which can be termed supraparticles. Controlling the size, shape, and morphology of such entities is a central step in various fields of science and technology, ranging from colloid chemistry and soft matter physics to powder technology and pharmaceutical and food sciences. These diverse scientific communities have been investigating formation processes and structure/property relations of such supraparticles under completely different boundary conditions. On the fundamental side, the field is driven by the desire to gain maximum control of the assembly structures using very defined and tailored colloidal building blocks, whereas more applied disciplines focus on optimizing the functional properties from rather ill-defined starting materials. With this review article, we aim to provide a connecting perspective by outlining fundamental principles that govern the formation and functionality of supraparticles. We discuss the formation of supraparticles as a result of colloidal properties interplaying with external process parameters. We then outline how the structure of the supraparticles gives rise to diverse functional properties. They can be a result of the structure itself (emergent properties), of the colocalization of different, functional building blocks, or of coupling between individual particles in close proximity. Taken together, we aim to establish structure-property and process-structure relationships that provide unifying guidelines for the rational design of functional supraparticles with optimized properties. Finally, we aspire to connect the different disciplines by providing a categorized overview of the existing, diverging nomenclature of seemingly similar supraparticle structures.
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Affiliation(s)
- Susanne Wintzheimer
- Fraunhofer Institute for Silicate Research, ISC , Neunerplatz 2 , 97082 Würzburg , Germany
| | - Tim Granath
- Chair of Chemical Technology of Materials Synthesis , University Würzburg , Röntgenring 11 , 97070 Würzburg , Germany
| | - Maximilian Oppmann
- Fraunhofer Institute for Silicate Research, ISC , Neunerplatz 2 , 97082 Würzburg , Germany
| | - Thomas Kister
- INM-Leibniz Institute for New Materials , Campus D2 2, 66123 Saarbrücken , Germany
| | - Thibaut Thai
- INM-Leibniz Institute for New Materials , Campus D2 2, 66123 Saarbrücken , Germany
| | - Tobias Kraus
- INM-Leibniz Institute for New Materials , Campus D2 2, 66123 Saarbrücken , Germany
- Colloid and Interface Chemistry , Saarland University , Campus D2 2, 66123 Saarbrücken , Germany
| | - Nicolas Vogel
- Institute of Particle Technology , Friedrich-Alexander Universität Erlangen-Nürnberg (FAU) , Haberstrasse 9A , 91058 Erlangen , Germany
| | - Karl Mandel
- Fraunhofer Institute for Silicate Research, ISC , Neunerplatz 2 , 97082 Würzburg , Germany
- Chair of Chemical Technology of Materials Synthesis , University Würzburg , Röntgenring 11 , 97070 Würzburg , Germany
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Oppmann M, Miller F, Thürauf S, Groppe P, Prieschl J, Stauch C, Mandel K. Core-Satellite Supraparticles To Ballistically Stamp Nanostructures on Surfaces. ACS APPLIED MATERIALS & INTERFACES 2018; 10:14183-14192. [PMID: 29582985 DOI: 10.1021/acsami.8b02404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Nanostructured surfaces are of great importance in a very wide range of fields. They can be obtained by imprint or deposition techniques. However, these are usually sophisticated to perform. Generally, it is not easy to equip an object/product with a nanostructure after manufacturing. Yet, it would be very beneficial to achieve a modification of an arbitrary surface with a nanostructure of choice at a later stage by an approach that is simple to perform without the need of sophisticated equipment or excessive treatment by physicochemical methods. Herein, such a process is reported, which combines two "old-fashioned" techniques, namely, sandblasting and rubber-stamping, and translates them to the "nanoworld". By creating core-satellite supraparticles via spray-drying, a ballistic core-satellite stamp particle system is obtained, which can be used to easily transfer a wide range of nanoparticles to a great variety of surfaces to equip these with a nanostructure and subsequently advanced properties. These include water-repellant, antifouling, or antidust surfaces. Moreover, it is also demonstrated that the approach can be used to manufacture well-defined nanoimprinted surfaces. Such surfaces showed an improved spreading behavior for aliphatic alcohols, thus making such surfaces, for instance, very susceptible for disinfectants. All in all, the simple technique described herein has a great potential for creating nanostructured surfaces on nearly any surface.
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Affiliation(s)
- Maximilian Oppmann
- Fraunhofer Institute for Silicate Research, ISC , Neunerplatz 2 , D-97082 Würzburg , Germany
| | - Franziska Miller
- Fraunhofer Institute for Silicate Research, ISC , Neunerplatz 2 , D-97082 Würzburg , Germany
| | - Sandra Thürauf
- Fraunhofer Institute for Silicate Research, ISC , Neunerplatz 2 , D-97082 Würzburg , Germany
| | - Philipp Groppe
- Chair of Chemical Technology of Materials Synthesis, Department Chemistry and Pharmacy , Julius-Maximilians-University Würzburg , Röntgenring 11 , D-97070 Würzburg , Germany
| | - Johannes Prieschl
- Fraunhofer Institute for Silicate Research, ISC , Neunerplatz 2 , D-97082 Würzburg , Germany
| | - Claudia Stauch
- Fraunhofer Institute for Silicate Research, ISC , Neunerplatz 2 , D-97082 Würzburg , Germany
- Chair of Chemical Technology of Materials Synthesis, Department Chemistry and Pharmacy , Julius-Maximilians-University Würzburg , Röntgenring 11 , D-97070 Würzburg , Germany
| | - Karl Mandel
- Fraunhofer Institute for Silicate Research, ISC , Neunerplatz 2 , D-97082 Würzburg , Germany
- Chair of Chemical Technology of Materials Synthesis, Department Chemistry and Pharmacy , Julius-Maximilians-University Würzburg , Röntgenring 11 , D-97070 Würzburg , Germany
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Spray drying of amorphous ibuprofen nanoparticles for the production of granules with enhanced drug release. Colloids Surf A Physicochem Eng Asp 2018. [DOI: 10.1016/j.colsurfa.2017.07.028] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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