Directed Emission from Self‐Assembled Microhelices

Helmbrecht, Lukas; Tan, Mélissa; Röhrich, Ruslan; Bistervels, Marloes H.; Kessels, Bruno Ortiz; Koenderink, A. Femius; Kahr, Bart; Noorduin, Wim L.

doi:10.1002/adfm.201908218

Cited by 14 publications

(21 citation statements)

References 34 publications

(39 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[ 1,2,5,6,13,14 ] Importantly, coprecipitation of carbonate salts and silica enables the formation of nanocomposites that can be sculpted into a wide diversity of shapes ranging from stems and coral‐like forms to helices by modulating the reaction conditions such as temperature, pH, and CO 2 concentration. [ 8–10,29–31 ] However, the reaction mechanism restricts the chemical composition of the resulting nanocomposites to amorphous silica and crystalline barium, strontium, or calcium carbonate. Consequently, the resulting nanocomposites have limited functionalities by themselves.…”

Section: Figurementioning

confidence: 99%

Shape‐Preserving Chemical Conversion of Architected Nanocomposites

et al. 2020

Self Cite

View full text Add to dashboard Cite

microscopic 3D shapes has remained challenging. Synthesis inherently entangles shape and composition; hence, current assembly routes offer control over either 3D shape or composition, but not both. In principle, chemically converting existing 3D shapes to a specified composition allows control over both the chemical composition and 3D geometry. The viability of this strategy is indicated by naturally occurring geochemical fossilization processes, [1] and laboratory demonstrations of shape-preserving ion-exchange and oxidation/reduction reactions on individual and ensembles of nanocrystals, as well as biominerals. [5,23-28] Nevertheless, conversion of arbitrary microscopic architectures is still challenging as conversion is diffusion-limited and slow, and significant changes in the atomistic unit cells could yield uncontrollable dissolution/ recrystallization, large deformations, and even fracture failure. We recognize that successful conversion reactions require a paradoxical combination of reactivity and stability to enable: i) diffusion of reactants and products in the solid phase, ii) crystal lattice rearrangements and unit-cell volume changes, while iii) preserving the overall 3D shape. We thus hypothesize that nanocomposites consisting of nanocrystals in an amorphous matrix have excellent characteristics to overcome these issues. Traditionally, nanocomposites have mainly been studied for their excellent mechanical properties. [1,2,5,6,13,14] Importantly, coprecipitation of carbonate salts Forging customizable compounds into arbitrary shapes and structures has the potential to revolutionize functional materials, where independent control over shape and composition is essential. Current self-assembly strategies allow impressive levels of control over either shape or composition, but not both, as self-assembly inherently entangles shape and composition. Herein, independent control over shape and composition is achieved by chemical conversion reactions on nanocrystals, which are first self-assembled in nanocomposites with programmable microscopic shapes. The multiscale character of nanocomposites is crucial: nanocrystals (5-50 nm) offer enhanced chemical reactivity, while the composite layout accommodates volume changes of the nanocrystals (≈25%), which together leads to complete chemical conversion with full shape preservation. These reactions are surprisingly materials agnostic, allowing a large diversity of chemical pathways, and development of conversion pathways yielding a wide selection of shape-controlled transition metal chalcogenides (cadmium, manganese, iron, and nickel oxides and sulfides). Finally, the versatility and application potential of this strategy is demonstrated by assembling: 1) a scalable and highly reactive nickel catalyst for the dry reforming of butane, 2) an agile magnetic-controlled particle, and 3) an electron-beam-controlled reversible microactuator with sub-micrometer precision. Previously unimaginable customization of shape and composition is now achievable for assembling advance...

show abstract

Section: Figurementioning

confidence: 99%

Shape‐Preserving Chemical Conversion of Architected Nanocomposites

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…The exquisite complexity and hierarchical structuring of biominerals offer an inexhaustible source of inspiration for the assembly of new materials with advanced functionalities. − In particular, bioinspired self-assembly can be exploited for hierarchical ordering of amorphous and crystalline substances in functional nanocomposites, while the inherent autonomous character of self-assembly is advantageous for straightforward upscaling. − Consequently, bioinspired nanocomposites have already been applied in fields such as robotics, sensing, and optics, ,− yet the full potential of self-assembly for advanced materials remains untapped.…”

Section: Introductionmentioning

confidence: 99%

“…An attractive system to overcome this limitation is the bioinspired coprecipitation of barium carbonate (BaCO 3 ) nanocrystals and amorphous silica (SiO 2 ). − Here, the crystallization of BaCO 3 is steered by the precipitation of SiO 2 through an acid-regulated feedback mechanism, resulting in intricate and controllable microshapes (Figure ). − This system inherently produces the desired material properties for supported catalysts: (i) programmable microshapesincluding coral-like geometries that maximize the surface area; (ii) a nanocomposite layout with a high metal-to-silica molar ratio of 4:1; (iii) nanocrystals of ca.…”

Section: Introductionmentioning

confidence: 99%

Rational Design of Bioinspired Nanocomposites with Tunable Catalytic Activity

Hendrikse

Aguirre

Weijden

et al. 2021

Crystal Growth & Design

Self Cite

View full text Add to dashboard Cite

Biological assembly processes offer inspiration for ordering building blocks across multiple length scales into advanced functional materials. Such bioinspired strategies are attractive for assembling supported catalysts, where shaping and structuring across length scales are essential for their performance but still remain tremendously difficult to achieve. Here, we present a simple bioinspired route toward supported catalysts with tunable activity and selectivity. We coprecipitate shape-controlled nanocomposites with large specific surface areas of barium carbonate nanocrystals that are uniformly embedded in a silica support. Subsequently, we exchange the barium carbonate to cobalt while preserving the nanoscopic layout and microscopic shape, and demonstrate their catalytic performances in the Fischer–Tropsch synthesis as a case study. Control over the crystal size between 10 and 17 nm offers tunable activity and selectivity for shorter (C 5 –C 11 ) and longer (C 20+ ) hydrocarbons, respectively. Hence, these results open simple, versatile, and scalable routes to tunable and highly reactive bioinspired catalysts.

show abstract

“…Bioinspired strategies offer tremendous opportunities for ordering building blocks across multiple length scales into advanced functional materials. − The coprecipitation of metal carbonate nanocrystals (MCO 3 , with M = Ba 2+ , Sr 2+ , or Ca 2+ ) and amorphous silica (SiO 2 ) offers an ideal system to explore this potential, as their co-assembly yields highly intricate, yet easily controllable 3D nanocomposite shapes also known as biomorphs. − Rational modulation of the reaction conditions (pH, CO 2 concentration, temperature, etc.) enables steering of the assembly toward a wide diversity of shapes (e.g., coral, vase, and helix forms) that can be further patterned and hierarchically organized.…”

mentioning

confidence: 99%

Shaping Tin Nanocomposites through Transient Local Conversion Reactions

Hendrikse

Hémon-Charles

Helmbrecht

et al. 2021

Crystal Growth & Design

Self Cite

View full text Add to dashboard Cite

Shape-preserving conversion offers a promising strategy to transform self-assembled structures into advanced functional components with customizable composition and shape. Specifically, the assembly of barium carbonate nanocrystals and amorphous silica nanocomposites (BaCO 3 /SiO 2 ) offers a plethora of programmable three-dimensional (3D) microscopic geometries, and the nanocrystals can subsequently be converted into functional chemical compositions, while preserving the original 3D geometry. Despite this progress, the scope of these conversion reactions has been limited by the requirement to form carbonate salts. Here, we overcome this limitation using a single-step cation/anion exchange that is driven by the temporal pH change at the converting nanocomposite. We demonstrate the proof of principle by converting BaCO 3 /SiO 2 nanocomposites into tin-containing nanocomposites, a metal without a stable carbonate. We find that BaCO 3 /SiO 2 nanocomposites convert in a single step into hydroromarchite nanocomposites (Sn 3 (OH) 2 O 2 /SiO 2 ) with excellent preservation of the 3D geometry and fine features. We explore the versatility and tunability of these Sn 3 (OH) 2 O 2 /SiO 2 nanocomposites as a precursor for functional compositions by developing shape-preserving conversion routes to two desirable compositions: tin perovskites (CH 3 NH 3 SnX 3 , with X = I or Br) with tunable photoluminescence (PL) and cassiterite (SnO 2 )—a widely used transparent conductor. Ultimately, these findings may enable integration of functional chemical compositions into advanced morphologies for next-generation optoelectronic devices.

show abstract

Directed Emission from Self‐Assembled Microhelices

Cited by 14 publications

References 34 publications

Shape‐Preserving Chemical Conversion of Architected Nanocomposites

Shape‐Preserving Chemical Conversion of Architected Nanocomposites

Rational Design of Bioinspired Nanocomposites with Tunable Catalytic Activity

Shaping Tin Nanocomposites through Transient Local Conversion Reactions

Contact Info

Product

Resources

About