Ambient synthesis of nanomaterials by in situ heterogeneous metal/ligand reactions

Abstract

Coordination polymers are ideal synthons for high aspect ratio nanomaterials. Using conjugate acid-base pairs, liquid metals are etched and chelated in situ. Solubility-driven polymerization, precipitation, and self-assembly gives tunable structures.

Liquid metal nanocomposites

“…Another example of this is a study by Chang et al where they synthesize 1D coordination polymers by in situ etching of zerovalent metal particle precursors. 48 Another class of polymer coated LM nanodroplets was recently introduced for the growth of metal-organic frameworks (MOFs). 49 An aqueous solution of poly(N-vinylpyrrolidone) (PVP) and EGaIn were sonicated to form PVP coated LM nanodroplets (Fig.…”

Complexity and Opportunities in Liquid Metal Surface Oxides

“…This passivating oxide layer, however, when properly formed and/or engineered provides various advantages to a material. [46][47][48][49][50][51][52] Previous works have empirically shown the complex composition of these interface layer on a liquid binary alloy, eutectic gallium-indium EGaIn (75.5% Ga, 24.5% In), metal particles (Figure 2a-b). [5][6][7]53 On an EGaIn particle, the surface is an ordered layer of adventitious organics, a predominantly Ga 2 O 3 outer surface below which suboxides of both Ga and In are formed ( Figure 2b).…”

“…The HetMet derived coordination polymers have dimensions and reaction kinetics that cannot be achieved with traditional batch wise solvothermal methods. 50 The obtained materials assemble into interesting structures, with acetate-base Ga coordination polymers showing ligand interdigitation upon tight packing. The proximity of the terminal methyl groups is ideal for free radical inter-chain coupling.…”

Tunable Hydrophobicity via Dimensionally Confined Polymerization of Organometallic Adducts

“…In HetMet reaction, a metal ion reservoir is established as a liquid metal while a conjugate acid‐base pair etch (H + ) and in situ chelate (B − ) the metal ions [16] . Felicitous choice of reaction media sustains a saturated but dilute solution of the metal adduct resulting in ad infinitum polymerization and concomitant in situ assembly of organometallic adducts into high‐aspect ratio structures [16a,b] . The resulting material, however, are randomly dispersed in solution having no unique macro‐assembly.…”

“…HetMet reaction leads to formation of organometallic structures that assemble into dispersed high‐aspect ratio structures (Figure 1 b,c). [16b] To exert dimensional confinement, an uniform multi‐layer of ULMCS particles was pre‐spincoated on ultra‐flat Si (111) substrate (flat bed, Figure 1 g) or pre‐textured into periodic surface structures akin to a rose flower made via recently reported BIOMAP (biomimetic metal patterning) process (textured bed, Figure 1 i). [19b] When a small amount of conjugate acid‐base pair solution is added to barely cover these beds, pores and inter‐particle spacing serve as dimensional confinement to generated adducts due to creation of capillary bridges with concomitant increase in wetted particle surface area (Figure 1 d).…”