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Liu JW, Zhang SY, Qi H, Wen WC, Yu SH. A general strategy for self-assembly of nanosized building blocks on liquid/liquid interfaces. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2012; 8:2412-20. [PMID: 22544810 DOI: 10.1002/smll.201200172] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2012] [Revised: 02/28/2012] [Indexed: 05/20/2023]
Abstract
A family of water/oil interfaces is introduced to provide effective platforms for rapid fabrication of large-area self-assembled nanofilms composed of various nanosized building blocks, including nanoparticles (NPs), nanocubes (NC), nanowires (NWs), and nanosheets, at room temperature. As a general interfacial assembly method, NWs and NPs are co-assembled at the liquid/liquid interface. The as-prepared co-assembled Ag NW and Ag NC films show high surface-enhanced Raman spectroscopy (SERS) intensity, the SERS performance being strongly dependent on the number ratio of the two kinds of nanosized building blocks. The results demonstrate that this interfacial system provides a general method for the assembly of various nanosized building blocks with different shapes and dimensionalities, and thus paves an alternative pathway for further applications of macroscopic assemblies with different functionalities.
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Affiliation(s)
- Jian-Wei Liu
- Division of Nanomaterials and Chemistry, Hefei National Laboratory for Physical Sciences at Microscale, Department of Chemistry, The National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230026, PR China
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53
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Motornov M, Malynych SZ, Pippalla DS, Zdyrko B, Royter H, Roiter Y, Kahabka M, Tokarev A, Tokarev I, Zhulina E, Kornev KG, Luzinov I, Minko S. Field-directed self-assembly with locking nanoparticles. NANO LETTERS 2012; 12:3814-20. [PMID: 22716475 DOI: 10.1021/nl301780x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
A reversible locking mechanism is established for the generation of anisotropic nanostructures by a magnetic field pulse in liquid matrices by balancing the thermal energy, short-range attractive and long-range repulsive forces, and dipole-dipole interactions using a specially tailored polymer shell of nanoparticles. The locking mechanism is used to precisely regulate the dimensions of self-assembled magnetic nanoparticle chains and to generate and disintegrate three-dimensional (3D) nanostructured materials in solvents and polymers.
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Affiliation(s)
- Mikhail Motornov
- Department of Chemistry and Biomolecular Science, Clarkson University, Potsdam, New York 13699, United States
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54
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Nagao D, Sugimoto M, Okada A, Ishii H, Konno M, Imhof A, van Blaaderen A. Directed orientation of asymmetric composite dumbbells by electric field induced assembly. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:6546-6550. [PMID: 22458374 DOI: 10.1021/la204493m] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Assembly and directed orientation of anisotropic particles with an external ac electric field in a range from 1 kHz to 2 MHz were studied for asymmetric composite dumbbells incorporating a silica, titania, or titania/silica (titania:silica = 75:25 vol %) sphere. The asymmetric composite dumbbells, which were composed of a polymethylmethacrylate (PMMA)-coated sphere (core-shell part) and a polystyrene (PSt) lobe, were synthesized with a soap-free emulsion polymerization to prepare PMMA-coated inorganic spheres and another soap-free emulsion polymerization to form a polystyrene (PSt) lobe from the PMMA-coated inorganic spheres. The composite dumbbells dispersed in water were directly observed with optical microscopy. The dumbbells incorporating a silica sphere oriented parallel to an electric field in the whole frequency range and they formed a pearl chain structure at a high frequency of 2 MHz. The titania-incorporated dumbbells formed chain structures, in which they contacted their core-shell parts and oriented perpendicularly to a low-frequency (kHz) field, whereas they oriented parallel to a high-frequency (MHz) field. Since the alignment of dumbbells in the chains depends not only on the interparticle forces but also on the torque that the induced dipoles in the dumbbells experience in the electric field, the orientation of dumbbells perpendicular to the electric field was the case dominated by the interparticle force, whereas the other orientation was the case dominated by the torque. The present experiments show that the incorporation of inorganic dumbbells is an effective way to control the assembled structure and orientation with an electric field.
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Affiliation(s)
- Daisuke Nagao
- Department of Chemical Engineering, Tohoku University , 6-6-07 Aoba, Aramaki-aza Aoba-ku, Sendai, 980-8579, Japan
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55
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Suh SK, Yuet K, Hwang DK, Bong KW, Doyle PS, Hatton TA. Synthesis of nonspherical superparamagnetic particles: in situ coprecipitation of magnetic nanoparticles in microgels prepared by stop-flow lithography. J Am Chem Soc 2012; 134:7337-43. [PMID: 22462394 DOI: 10.1021/ja209245v] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We present the synthesis of nonspherical magnetic microparticles with multiple functionalities, shapes, and chemistries. Particle synthesis was performed in two steps: polymeric microparticles functionalized homogenously with carboxyl groups were generated using stop-flow lithography, and then in situ coprecipitation was used to grow magnetic nanoparticles at these carboxyl sites. With successive growth of magnetic nanoparticles, we obtained polymeric particles with saturation magnetizations of up to 42 emu/g microparticle. The growth in the magnetic nanoparticle mean size and polydispersity was determined from the magnetization curves obtained following each growth cycle; nanoparticle sizes were limited by the physical constraint of the effective mesh within the hosting gel microparticle. Particles with spatially segregated domains of varying magnetic properties (e.g., Janus particles, particles with step changes in magnetite concentration, etc.) can be synthesized readily using this approach.
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Affiliation(s)
- Su Kyung Suh
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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56
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Tawfick S, De Volder M, Copic D, Park SJ, Oliver CR, Polsen ES, Roberts MJ, Hart AJ. Engineering of micro- and nanostructured surfaces with anisotropic geometries and properties. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2012; 24:1628-1674. [PMID: 22396318 DOI: 10.1002/adma.201103796] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2011] [Revised: 12/06/2011] [Indexed: 05/28/2023]
Abstract
Widespread approaches to fabricate surfaces with robust micro- and nanostructured topographies have been stimulated by opportunities to enhance interface performance by combining physical and chemical effects. In particular, arrays of asymmetric surface features, such as arrays of grooves, inclined pillars, and helical protrusions, have been shown to impart unique anisotropy in properties including wetting, adhesion, thermal and/or electrical conductivity, optical activity, and capability to direct cell growth. These properties are of wide interest for applications including energy conversion, microelectronics, chemical and biological sensing, and bioengineering. However, fabrication of asymmetric surface features often pushes the limits of traditional etching and deposition techniques, making it challenging to produce the desired surfaces in a scalable and cost-effective manner. We review and classify approaches to fabricate arrays of asymmetric 2D and 3D surface features, in polymers, metals, and ceramics. Analytical and empirical relationships among geometries, materials, and surface properties are discussed, especially in the context of the applications mentioned above. Further, opportunities for new fabrication methods that combine lithography with principles of self-assembly are identified, aiming to establish design principles for fabrication of arbitrary 3D surface textures over large areas.
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Affiliation(s)
- Sameh Tawfick
- Mechanosynthesis Group, Department of Mechanical Engineering, Ann Arbor, MI 48109, USA.
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57
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Panda P, Bong KW, Hatton TA, Doyle PS. Branched networks by directed assembly of shape anisotropic magnetic particles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:13428-13435. [PMID: 21932770 DOI: 10.1021/la2022962] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The directed assembly of shape anisotropic magnetic particles into targeted macrostructures requires judicious particle design. We present a framework to understand the self-assembly of magnetic non-Brownian H-shaped particles and the formation of branched networks under an applied magnetic field. A finite element integration (FEI) method is developed to identify the preferred particle orientation (relative to the applied field) at different values of the geometric parameters defining H shapes, and used to construct a phase diagram to generalize the results. Theoretical predictions are validated by comparing with experiments performed using magnetic hydrogels synthesized using stop-flow lithography (SFL). We demonstrate the ability of H-shaped particles to form chains parallel to the field that can thicken in a direction orthogonal to the field, and in some cases with branching. The assembly of a suspension containing H-shaped particles, or rods, or a combination of both, is reported.
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Affiliation(s)
- Priyadarshi Panda
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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58
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Heinrich D, Goñi AR, Smessaert A, Klapp SHL, Cerioni LMC, Osán TM, Pusiol DJ, Thomsen C. Dynamics of the field-induced formation of hexagonal zipped-chain superstructures in magnetic colloids. PHYSICAL REVIEW LETTERS 2011; 106:208301. [PMID: 21668267 DOI: 10.1103/physrevlett.106.208301] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2010] [Indexed: 05/30/2023]
Abstract
Combining nuclear magnetic resonance and molecular dynamics simulations, we unravel the long-time dynamics of a paradigmatic colloid with strong dipole-dipole interactions. In a homogeneous magnetic field, ionic ferrofluids exhibit a stepwise association process from ensembles of monomers over stringlike chains to bundles of hexagonal zipped-chain patches. We demonstrate that attractive van der Waals interactions due to charge-density fluctuations in the magnetic particles play the key role for the dynamical stabilization of the hexagonal superstructures against thermal dissociation. Our results give insight into the dynamics of self-organization in systems dominated by dipolar interactions.
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Affiliation(s)
- D Heinrich
- Institut für Festkörperphysik, EW 5-4, Technische Universität Berlin, Hardenbergstrasse 36, 10623 Berlin, Germany
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59
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Solomon MJ. Directions for targeted self-assembly of anisotropic colloids from statistical thermodynamics. Curr Opin Colloid Interface Sci 2011. [DOI: 10.1016/j.cocis.2011.01.006] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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60
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Sacanna S, Pine DJ. Shape-anisotropic colloids: Building blocks for complex assemblies. Curr Opin Colloid Interface Sci 2011. [DOI: 10.1016/j.cocis.2011.01.003] [Citation(s) in RCA: 358] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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61
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Parracino A, Gajula GP, di Gennaro AK, Correia M, Neves-Petersen MT, Rafaelsen J, Petersen SB. Photonic immobilization of BSA for nanobiomedical applications: creation of high density microarrays and superparamagnetic bioconjugates. Biotechnol Bioeng 2011; 108:999-1010. [PMID: 21125586 DOI: 10.1002/bit.23015] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Revised: 09/27/2010] [Accepted: 11/01/2010] [Indexed: 11/11/2022]
Abstract
Light assisted molecular immobilization has been used for the first time to engineer covalent bioconjugates of superparamagnetic nanoparticles and proteins. The technology involves disulfide bridge disruption upon UV excitation of nearby aromatic residues. The close spatial proximity of aromatic residues and disulfide bridges is a conserved structural feature in proteins. The created thiol groups bind thiol reactive surfaces leading to oriented covalent protein immobilization. We have immobilized a model carrier protein, bovine serum albumin, onto Fe(3)O(4)@Au core-shell nanoparticles as well as arrayed it onto optically flat thiol reactive surfaces. This new immobilization technology allows for ultra high dense packing of different bio-molecules on a surface, allowing the creation of multi-potent functionalized active new biosensor materials, biomarkers identification and the development of nanoparticles based novel drug delivery system.
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Affiliation(s)
- Antonietta Parracino
- Department of Physics and Nanotechnology, Aalborg University, Skjernvej 4A, Aalborg, Denmark
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62
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Pradhan GK, Parida KM. Fabrication, growth mechanism, and characterization of α-Fe(2)O(3) nanorods. ACS APPLIED MATERIALS & INTERFACES 2011; 3:317-323. [PMID: 21214197 DOI: 10.1021/am100944b] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
This work reports the facile synthesis of α-Fe(2)O(3) nanorods and nano-hexagons and its application as sunlight-driven photocatalysis. The obtained products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), scanning electron microscopy (SEM), diffused reflectance spectroscopy (DRUV-vis), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The phase and crystallinity were confirmed from the XRD study. Electron microscopy study clearly indicates the formation of different morphologies of nanocrystals. These hematite nanostructures were used as a model system for studying the shape-dependent photocatalytic degradation of phenol, methylene blue, and congo red. Amongst all the nanostructured semiconductors, Pt-doped hematite nanorod showed 55% efficiency towards the decolonization of methylene blue and 63% toward congo red under sun light illumination. The difference in photocatalytic activity is discussed in terms of their crystallize size and morphological ordering.
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Affiliation(s)
- Gajendra K Pradhan
- Colloids and Materials Chemistry Department, Institute of Minerals & Materials Technology (CSIR) , Bhubaneswar-751013, Orissa, India
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63
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Zhang Y, Wang J, Huang Y, Song Y, Jiang L. Fabrication of functional colloidal photonic crystals based on well-designed latex particles. ACTA ACUST UNITED AC 2011. [DOI: 10.1039/c1jm10977d] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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64
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Wagner CS, Shehata S, Henzler K, Yuan J, Wittemann A. Towards nanoscale composite particles of dual complexity. J Colloid Interface Sci 2010; 355:115-23. [PMID: 21211805 DOI: 10.1016/j.jcis.2010.12.017] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2010] [Revised: 12/02/2010] [Accepted: 12/02/2010] [Indexed: 11/25/2022]
Abstract
The fabrication of heteroaggregates comprising inorganic and organic nanoparticles of different sizes is reported. Control over the assembly of nanoscale functional building units is of great significance to many practical applications. Joining together different spherical nanoparticles in a defined manner allows control over the shape of the composites. If two types of constituents are chosen that differ in size, the surfaces of the composites exhibit two specific radii of curvature, yielding aggregates of dual surface roughness. Moreover, if the constituents consist of different materials, the resulting heteroaggregates feature both compositional and interfacial anisotropy, offering unprecedented perspectives for custom-tailored colloids. This study describes a two-step approach towards such designer particles. At first, amine-modified polystyrene particles with 154 nm diameter were assembled into clusters of well-defined configurations. Onto these, oppositely charged inorganic particles with diameters of only a few nanometres were deposited by direct uptake from solution, resulting in numerous functional entities all over the surface of the polymer clusters. Despite the fact that oppositely charged constituents are brought together, charge reversal by uptake of nanoparticles allows for stable suspensions of heterocomposites. Hence, the possibility to assemble particles into nanoscale heterocomposites with full control over shape, composition, and surface roughness is demonstrated.
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Affiliation(s)
- Claudia Simone Wagner
- Physikalische Chemie I, Universität Bayreuth, Universitätsstr. 30, 95440 Bayreuth, Germany
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65
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Demirörs AF, Johnson PM, van Kats CM, van Blaaderen A, Imhof A. Directed self-assembly of colloidal dumbbells with an electric field. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:14466-14471. [PMID: 20715872 DOI: 10.1021/la102134w] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We demonstrate the assembly of colloidal particles with the shape of diatomic molecules ("dumbbells") into crystals that we study with confocal microscopy. The literature on the preparation of nonspherical colloidal particles has grown steadily. Assembly of these particles into regular three-dimensional crystalline lattices, however, is rarely, if ever, achieved and has not yet been studied quantitatively in 3D real space. We find that, by application of an electric field, such particles assemble quite readily. By varying the particle aspect ratio, range of interactions, and electric field strength, we find several different crystal structures of which three have never before been observed. Moreover, the electric field can be used to switch between different structures and manipulate/switch the photonic properties. Moreover, our work sheds light on fundamental questions related to the self-assembly of nonspherical particles.
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Affiliation(s)
- Ahmet Faik Demirörs
- Soft Condensed Matter, Debye Institute for Nanomaterials Science, Department of Physics and Astronomy, Utrecht University, Princetonplein 5, 3584 CC Utrecht, The Netherlands.
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66
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Grzelczak M, Vermant J, Furst EM, Liz-Marzán LM. Directed self-assembly of nanoparticles. ACS NANO 2010; 4:3591-605. [PMID: 20568710 DOI: 10.1021/nn100869j] [Citation(s) in RCA: 1294] [Impact Index Per Article: 92.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Within the field of nanotechnology, nanoparticles are one of the most prominent and promising candidates for technological applications. Self-assembly of nanoparticles has been identified as an important process where the building blocks spontaneously organize into ordered structures by thermodynamic and other constraints. However, in order to successfully exploit nanoparticle self-assembly in technological applications and to ensure efficient scale-up, a high level of direction and control is required. The present review critically investigates to what extent self-assembly can be directed, enhanced, or controlled by either changing the energy or entropy landscapes, using templates or applying external fields.
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Affiliation(s)
- Marek Grzelczak
- Departamento de Química Física and Unidad Asociada CSIC-Universidade de Vigo, 36310 Vigo, Spain
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67
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Self-assembly behavior of hematite nanoparticles with controllable anisotropic morphology. J Colloid Interface Sci 2010; 349:519-26. [PMID: 20584529 DOI: 10.1016/j.jcis.2010.06.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2010] [Revised: 05/30/2010] [Accepted: 06/02/2010] [Indexed: 11/23/2022]
Abstract
In this work, complex structures such as long chain, "semi-flexible" chain, "threefold junction" and network were formed by self-assembly of colloidal hematite nanoparticles. Morphology of these colloidal nanoparticles used as building blocks transformed from truncated rhombohedra, hexagon to pseudo-hexagon by altering reaction time and surfactants. By further observation using HRTEM, these nanoparticles were confirmed to grow along the c-axis. It was found that the molecular structures of surfactants make great influence on the transformation of bonding modes between carboxyl and iron atom on the surface. Then crystal growth rate was changed. It led to two opposite growth trends along the c-axis. More interestingly, the chains formed by these colloidal nanoparticles were also assembled along the c-axis. Meanwhile, configuration diversity seemed related to the morphological anisotropy along the c-axis. It was believed that two main forces between the nanoparticles were responsible for the various configurations, magnetic dipole-dipole and exchange-coupling interaction. The morphological anisotropy was considered to play a key role in the coordination of the two interactions which led to different complex structures by self-assembly. Discussion was taken to explain the formation of these interesting configurations.
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