Water soluble gold nanoparticle supraspheres can hold 2 million guest molecules

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first_imgIn an effort to keep the larger supraspheres from precipitating out of solution, Wang et al. replaced the remaining polyoxometalates at the cluster-water interface with thiolate-capping ligands. It is the chemical properties of these ligands that allowed for the selective uptake of certain hydrophobic guests over others. They experimented with three caps: a positively changed one, a negatively charged one, and mercapto-polyethylene glycol (PEG-SH). For their model hydrophobic guest, Wang, et al. used bisphenol A (BPA). Because PEG-S-capped supraspheres are soluble in both water and methylene chloride, they confirmed that guest uptake was due to hydrophobic effects. Adsorption properties were determined with ultraviolet-visible spectroscopy and 1H NMR. They confirmed that each suprasphere hosts the same number of BPA molecules and that the number of guests was around 2 million per suprasphere.They then explored host-guest properties with other hydrophobic guests. They tested azulene (a dye, TNT (an explosive), RDX (an explosive), alachlor (a common herbicide), para-xylene, and para-dichlorobenzene. At first, they did not observe guest uptake with TNT, which they attributed to kinetic effects. By changing the capping molecules from PEG-SH to a mixture of PEG-SH and hex-SH, they observed the uptake of over 2 million TNT or RDX molecules. This idea of kinetically controlling the uptake of certain guests was used to chemo-selectively adsorb BPA over TNT in a solution containing both molecules.Analysis of the suprasphere architecture indicated that there was an extensive internal hydrophobic porous system that allowed guests to diffuse throughout the suprasphere structure. The authors described the interior of the suprasphere as a percolated network of hydrophobic holes that can house the more than 2 million guest molecules.Gold nanoparticle supraspheres are a relatively new area for host-guest chemistry. This research shows how functionalizing the surface of the nanoparticles with a hydrophilic leaving group will allow the formation of water soluble supraspheres that are able to easily and selectively adsorb and release guests. Citation: Water soluble gold nanoparticle supraspheres can hold 2 million guest molecules (2016, December 8) retrieved 18 August 2019 from https://phys.org/news/2016-12-soluble-gold-nanoparticle-supraspheres-million.html Journal information: Nature Nanotechnology Explore further (Phys.org)—Researchers from Ben-Gurion University of the Negev in Israel and École Polytechnique Fédérale de Lausanne in Switzerland have developed porous 200 nm supraspheres from gold nanoparticles whose surface is functionalized with polyoxometalate leaving groups that allows for dispersion in pure water. The hydrophobic effect promotes the spontaneous adsorption of alkyl and alkylaromatic guests. © 2016 Phys.org a, Schematic showing how citrate ligands are replaced by AlW11O399- (1), to give 1-protected Au NPs. A reaction with hexanethiol then leads to the formation of colloidal supraspheres. The structure of 1 is shown in polyhedral notation: W(VI)-centred polyhedra are in blue (oxygen atoms are present at all vertices) and the centrally located, four-coordinate Al(III) ion is in red; b, Cryo-TEM images illustrating colloidal suprasphere formation: (i) and (ii) show individual citrate- and 1-protected Au NPs, respectively; (iii) shows a representative intermediate-sized colloidal suprasphere, with a radius of around 45 nm. Scale bar, 10 nm; c, The uptake of bisphenol A (black dots) by the PEG capped supraspheres from aqueous solution; d, Illustration (drawn to scale) of an Oh-symmetry hole hosting approximately 1 nm bisphenol A guests. Credit: Wang et al. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. In their research article in Nature Nanotechnology, Wang et al. demonstrate that their leaving groups are easily displaced by hexane thiol, allowing for the formation of suprasphere colloids in water and uptake of around 2 million hydrophobic guests, a mass-per-volume level that rivals zeolites and metal-organic frameworks. Furthermore, by tailoring the surface of the suprasphere, they were able to chemo-selectively control the uptake of guest molecules.While there have been several gold nanoparticle suprasphere studies reported in the literature, none of them explore the hydrophobic effect for host-guest interactions. Those interactions largely arise from the formation of aggregates. Supraspheres are gold nanoparticle colloids that are held together by weak interactions between alkylthiolate ligands, which form a hydrophobic monolayer around the nanoparticles. This results in aggregates in pure water.However, this same hydrophobic effect can be used to promote host-guest interactions. Supraspheres are highly porous compounds that can serve as a reservoir of hydrophobic cavities for non-polar guests in an aqueous environment.To avoid the problem of uncontrolled precipitation, Wang et al. functionalized the surface of the gold nanoparticles with negatively charged cluster anion, AlW11O399-. They then incrementally added small amounts of hexane thiols (hex-SH) to the solution. Domains of hydrophobic thiol clusters and hydrophilic polyoxometalate clusters formed on the surface of the gold nanoparticles. This eventually leads to the controlled hydrophobic assembly of supraspherical clusters, as evidenced by surface plasmon resonance studies and in situ imaging by cryogenic transmission electron microscopy. These clusters are soluble in water.Importantly, because there is a linear correlation between the addition of hex-SH and the average hydrodynamic radius, they were able to tailor supracluster formation. Additional studies confirmed supraspheres were formed in water, but that larger supraspheres (approximately 200 nm) were less stable than intermediate-sized ones (approximately 150 nm). Energetics of the adsorption of ethanol on calcite nanoparticles More information: Yizhan Wang et al. Host–guest chemistry with water-soluble gold nanoparticle supraspheres, Nature Nanotechnology (2016). DOI: 10.1038/nnano.2016.233AbstractThe uptake of molecular guests, a hallmark of the supramolecular chemistry of cages and containers, has yet to be documented for soluble assemblies of metal nanoparticles. Here we demonstrate that gold nanoparticle-based supraspheres serve as a host for the hydrophobic uptake, transport and subsequent release of over two million organic guests, exceeding by five orders of magnitude the capacities of individual supramolecular cages or containers and rivalling those of zeolites and metal–organic frameworks on a mass-per-volume basis. The supraspheres are prepared in water by adding hexanethiol to polyoxometalate-protected 4 nm gold nanoparticles. Each 200 nm assembly contains hydrophobic cavities between the estimated 27,400 gold building blocks that are connected to one another by nanometre-sized pores. This gives a percolated network that effectively absorbs large numbers of molecules from water, including 600,000, 2,100,000 and 2,600,000 molecules (35, 190 and 234 g l−1) of para-dichorobenzene, bisphenol A and trinitrotoluene, respectively.last_img

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Kew House / Piercy&Company

first_img United Kingdom Year:  2014 Projects ArchDaily Year:  Kew House / Piercy&CompanySave this projectSaveKew House / Piercy&Company Photographs Area:  3960 ft² Area:  3960 ft² Year Completion year of this architecture project CopyHouses•Richmond, United Kingdom photographs:  Jack HobhousePhotographs:  Jack HobhouseSave this picture!© Jack HobhouseRecommended ProductsWindowsKalwall®Facades – Window ReplacementsDoorsEGGERWood Laminate Doors in Molecular Plant Science InstituteEnclosures / Double Skin FacadesFranken-SchotterFacade System –  LINEADoorsGorter HatchesRoof Hatch – RHT AluminiumText description provided by the architects. Set within the Kew Green Conservation Area of south-west London, this four bedroom family house is formed of two pre-fabricated weathering steel volumes inserted behind a retained nineteenth century stable wall.Save this picture!© Jack HobhouseFirst and foremost a family home, the tone is informal but rich with incidental spaces, unexpected light, and complex vertical volumes. Approaching the design as a kind of built diagram of the way the family wanted to live, Piercy&Company created an internal landscape of alternative routes, levels, and spaces – many of which are aimed more at children than adults.Save this picture!First Floor PlanThe simple plan makes the most of the constrained site, reduces the building’s mass in the streetscape, and responds to the living patterns of the family. Two rectangular wings each have living spaces on the ground floor and bedrooms above. Connecting the wings is a glass encased circulation link, allowing light to fill the house and courtyard.Save this picture!© Jack HobhouseThe two shells housing each wing are formed of 4mm thick weathering steel – a hardworking combination of structure and façade. The weathering steel is maintenance free, essential for the enclosed site, and softened by a patchwork of expressed welds and perforated panels. The deep orange tones and perforations within the skin echo the dappled light and autumnal palette of nearby Kew Gardens. Inside, oak veneer panelling and Dinesen flooring are the basis of a warm and natural material palette.Save this picture!SectionKew House was an experimental build, driven by the architect’s and clients’ shared interest in a ‘kit-of-parts’ approach, prefabrication, and the self-build possibilities emerging from digital fabrication. CNC milling and an on-site joinery workshop were used to create a bespoke fit-out that could be installed by the client and a small team of architecture graduates.Save this picture!© Jack HobhouseProject gallerySee allShow lessCattle Back Mountain Volunteer House / dEEP ArchitectsSelected Projects’The Future Will Just Have to Wait’: London’s 10,000 Year MasterplanArchitecture News Share Houses Architects: Piercy&Company Area Area of this architecture project Kew House / Piercy&Company “COPY” 2014 ShareFacebookTwitterPinterestWhatsappMailOrhttps://www.archdaily.com/769830/kew-house-piercy-and-co Clipboard “COPY” Save this picture!© Jack Hobhouse+ 18 Share ShareFacebookTwitterPinterestWhatsappMailOrhttps://www.archdaily.com/769830/kew-house-piercy-and-co Clipboard CopyAbout this officePiercy&CompanyOfficeFollowProductsWoodGlassConcrete#TagsProjectsBuilt ProjectsSelected ProjectsResidential ArchitectureHousesRichmondUnited KingdomPublished on July 08, 2015Cite: “Kew House / Piercy&Company” 08 Jul 2015. ArchDaily. Accessed 11 Jun 2021. ISSN 0719-8884Read commentsBrowse the CatalogVentilated / Double Skin FacadeTechnowoodClick Façade SystemWindowsMitrexSolar WindowMetal PanelsAurubisOxidized Copper: Nordic BrownAcousticKvadrat AcousticsAcoustic Panel System in AMOREPACIFIC HeadquartersStonesCosentinoSilestone® Surfaces – Loft SeriesWoodLunawoodThermo Timber and Industrial ThermowoodLightsLouis PoulsenOutdoor Lighting – Flindt PlazaTiles / Mosaic / GresiteLove TilesPorcelain Tiles – NestAluminium CompositesMetawellAluminum Panels for Interior DesignMetallicsRHEINZINKZinc Roof Systems – Double Lock Standing SeamStoolsWilkhahnOffice Stool – Aline-SBulbs / Spots / Wall LightsUniosHorticultural Luminaire – Kobe FloMore products »Read commentsSave想阅读文章的中文版本吗?Kew住宅 / Piercy&Company是否翻译成中文现有为你所在地区特制的网站?想浏览ArchDaily中国吗?Take me there »✖You’ve started following your first account!Did you know?You’ll now receive updates based on what you follow! Personalize your stream and start following your favorite authors, offices and users.Go to my streamlast_img

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