TY - JOUR
T1 - Ionic solids from common colloids
AU - Hueckel, Theodore
AU - Hocky, Glen M.
AU - Palacci, Jeremie
AU - Sacanna, Stefano
N1 - Funding Information:
Acknowledgements This work was supported primarily by the NSF CAREER award DMR-1653465. We are grateful for shared facilities provided through the Materials Research Science and Engineering Center (MRSEC) and MRI programmes of the National Science Foundation under award numbers DMR-1420073 and DMR-0923251. Computational resources were provided by New York University High Performance Computing. J.P. thanks the Sloan Foundation for support through grant FG-2017-9392 and the National Science Foundation under grant number DMR-1554724. We thank H. Kanwal for assistance in self-assembly experiments and H. Chun for comments on the manuscript and discussions.
Publisher Copyright:
© 2020, The Author(s), under exclusive licence to Springer Nature Limited.
PY - 2020/4/23
Y1 - 2020/4/23
N2 - From rock salt to nanoparticle superlattices, complex structure can emerge from simple building blocks that attract each other through Coulombic forces1–4. On the micrometre scale, however, colloids in water defy the intuitively simple idea of forming crystals from oppositely charged partners, instead forming non-equilibrium structures such as clusters and gels5–7. Although various systems have been engineered to grow binary crystals8–11, native surface charge in aqueous conditions has not been used to assemble crystalline materials. Here we form ionic colloidal crystals in water through an approach that we refer to as polymer-attenuated Coulombic self-assembly. The key to crystallization is the use of a neutral polymer to keep particles separated by well defined distances, allowing us to tune the attractive overlap of electrical double layers, directing particles to disperse, crystallize or become permanently fixed on demand. The nucleation and growth of macroscopic single crystals is demonstrated by using the Debye screening length to fine-tune assembly. Using a variety of colloidal particles and commercial polymers, ionic colloidal crystals isostructural to caesium chloride, sodium chloride, aluminium diboride and K4C60 are selected according to particle size ratios. Once fixed by simply diluting out solution salts, crystals are pulled out of the water for further manipulation, demonstrating an accurate translation from solution-phase assembly to dried solid structures. In contrast to other assembly approaches, in which particles must be carefully engineered to encode binding information12–18, polymer-attenuated Coulombic self-assembly enables conventional colloids to be used as model colloidal ions, primed for crystallization.
AB - From rock salt to nanoparticle superlattices, complex structure can emerge from simple building blocks that attract each other through Coulombic forces1–4. On the micrometre scale, however, colloids in water defy the intuitively simple idea of forming crystals from oppositely charged partners, instead forming non-equilibrium structures such as clusters and gels5–7. Although various systems have been engineered to grow binary crystals8–11, native surface charge in aqueous conditions has not been used to assemble crystalline materials. Here we form ionic colloidal crystals in water through an approach that we refer to as polymer-attenuated Coulombic self-assembly. The key to crystallization is the use of a neutral polymer to keep particles separated by well defined distances, allowing us to tune the attractive overlap of electrical double layers, directing particles to disperse, crystallize or become permanently fixed on demand. The nucleation and growth of macroscopic single crystals is demonstrated by using the Debye screening length to fine-tune assembly. Using a variety of colloidal particles and commercial polymers, ionic colloidal crystals isostructural to caesium chloride, sodium chloride, aluminium diboride and K4C60 are selected according to particle size ratios. Once fixed by simply diluting out solution salts, crystals are pulled out of the water for further manipulation, demonstrating an accurate translation from solution-phase assembly to dried solid structures. In contrast to other assembly approaches, in which particles must be carefully engineered to encode binding information12–18, polymer-attenuated Coulombic self-assembly enables conventional colloids to be used as model colloidal ions, primed for crystallization.
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U2 - 10.1038/s41586-020-2205-0
DO - 10.1038/s41586-020-2205-0
M3 - Article
C2 - 32322078
AN - SCOPUS:85083641550
SN - 0028-0836
VL - 580
SP - 487
EP - 490
JO - Nature
JF - Nature
IS - 7804
ER -