Subscriber access provided by University of South Dakota
Article
Phase transformation from brucite to highly crystalline layered double hydroxide through a combined dissolution-reprecipitation and substitution mechanism Jinseop Shin, Chan-Ju Choi, Tae-Hyun Kim, and Jae-Min Oh Cryst. Growth Des., Just Accepted Manuscript • DOI: 10.1021/acs.cgd.8b00786 • Publication Date (Web): 16 Jul 2018 Downloaded from http://pubs.acs.org on July 24, 2018
Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.
is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.
Page 1 of 28 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Crystal Growth & Design
Phase transformation from brucite to highly crystalline layered double hydroxide through a combined dissolution-reprecipitation and substitution mechanism
Jinseop Shin1, Chan-Ju Choi1, Tae-Hyun Kim1,2, Jae-Min Oh1* Affiliations 1
Department of Chemistry and Medical Chemistry, College of Science and Technology, Yonsei University, Wonju 26493, Republic of Korea 2 Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
Correspondence Prof. Jae-Min Oh Department of Chemistry and Medical Chemistry, College of Science and Technology, Yonsei University, Wonju 26493, Republic of Korea Tel: +82 33 760 2368 Fax: +82 33 760 2182 E-mail:
[email protected] Web address: www.ysnbml.com ACS Paragon Plus Environment
Crystal Growth & Design 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Abstract We propose the phase transformation of magnesium hydroxide (brucite) to magnesium-aluminum hydroxide (layered double hydroxide: LDH) utilizing solid state brucite and aqueous aluminum (III) as precursors in order to obtain highly crystalline and large-sized LDH. Under hydrothermal reaction at 150°C, the brucite was partially dissolved and aqueous aluminum precipitated in the form of boehmite within 1.5 h. Then, the precipitated aluminum migrated into the brucite framework to transform the crystal phase of brucite to LDH within 2.3 h of reaction. Time dependent X-ray diffraction, scanning electron microscopy, and highresolution transmission electron microscopy analyses showed the time-dependent evolution of LDH from brucite. The transformed LDH exhibited crystal growth along the ab-plane direction first followed by crystal growth along the c-axis. Quantitative analysis utilizing inductively coupled plasma-optical emission spectroscopy for both the solid part and supernatant confirmed that the phase transformation was mediated by both dissolution-reprecipitation and isomorphous substitution in the solid state. The solid-state magic angle spin nuclear magnetic resonance spectroscopy for
27
Al indicated that the crystal growth of phase-
transformed LDH was accompanied by local ordering around Al (III) in LDH.
ACS Paragon Plus Environment
Page 2 of 28
Page 3 of 28 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Crystal Growth & Design
Introduction Layered double hydroxide (LDH), which is a hydrotalcite-like layered compound, is attractive in a variety of industrial fields such as catalysts,1 catalytic supports,2 adsorbents,3 drug delivery systems,4 and polymer-inorganic nanocomposites.5 The basic form of LDH, i.e., hydrotalcite, has brucite-like nanolayers in which Mg2+ is partially replaced by Al3+ to evolve a positive layer charge.6-7 The positive charge of the layer is compensated for by hydrated interlayer anions which are stabilized by electrostatic interaction but easily exchanged by other anionic species, resulting in expansion of the gallery space.8-9 The anisotropic layered structure, anion capacity, and expandable layers provide LDHs with versatility in various applications. In general, LDHs can be prepared by precipitating aqueous metal cations with bases like sodium hydroxide solution or ammonia water under low or high supersaturation.7 On the other hand, LDHs could also be synthesized by salt-oxide method in which metal oxide suspension is reacted with metal salt solution to produce LDH after appropriate aging.10 Although it is relatively simple to prepared LDHs with the previously mentioned method, it is not easy to obtain high crystallinity and large lateral size, of which properties are critical in the viewpoint of controlling drug release or the properties of polymer-inorganic nanocomposites. For example, Zhang et al. reported that the lateral size of LDHs determined the release rate of the incorporated drug, showing faster release with a smaller size. Specifically, LDHs with a lateral size of tens of nanometers showed a fast drug release (70% within 100 min), while a lateral size of hundreds of nanometers releases drugs in a sustained manner (46% up to 100 min).11 In polymer-inorganic nanocomposites, large lateral dimensions are reported to be advantageous to improve the gas barrier,12 thermal,5 and mechanical properties13 of nanocomposites. For instance, nanocomposites of LDH (~3.42 µm lateral size) and cellulose acetate resulted in a flexible and transparent film with a highly suppressed oxygen transmission rate (
