Coordination Polymer Nanofibers Generated by Microfluidic Synthesis

Abstract

One-dimensional coordination polymer nanostructures are an emerging class of nanoscale materials with many potential applications. Here, we report the first case of coordination polymer nanofibers assembled using microfluidic technologies. Unlike common synthetic procedures, this approach enables parallel synthesis with an unprecedented level of control over the coordination pathway and facilitates the formation of 1D coordination polymer assemblies at the nanometer length scale. Finally, these nanostructures, which are not easily constructed with traditional methods, can be used for various applications, for example as templates to grow and organize functional inorganic nanoparticles.

Multi-scale crystal engineering of metal organic frameworks

“…Puigmartí-Luis et al [185] Interestingly, these Ag(I)-CYS nanofibers were used by Amabilino and co-workers [186] as a sacrificial hard template to fabricate the functional crystalline MOF Ag(I)-TCNQ (TCNQ = tetracyanoquinodimethane). With the microfluidic system represented in Figure 20 a certain degree of control in the position of the interphase, and thus of the metal-organic nanofibers, could be achieved by changing flow ratios and flow rate.…”

“…From the examples above it seems that using a microfluidic reactor under laminar flow is an effective way to confine the synthesis to the interphase between two solutions (one containing the metal precursor and the other one containing the ligand); hence, allowing to control the MOF shape by tuning the liquid-liquid interphase [185][186][187].…”

Microfluidic Pneumatic Cages: A Novel Approach for In-chip Crystal Trapping, Manipulation and Controlled Chemical Treatment

“…The valve actuation ensures the trapping of the Ag(I)Cys CP generated at the interface of the two reagent streams and facilitates the formation of a new coordination pathway ( Figure 3A). A detailed chemical characterization of the Ag(I)Cys CP generated at the interface of the two reagent streams can be found in previous studies 17,18 . Additionally, and after removal of the surplus reagents solutions with a flow of pure water (Figure 3B), a saturated ascorbic acid solution in ethanol can be added to the microfluidic channel for controlled chemical reduction of on-chip trapped structures ( Figure 3C).…”

“…Put simply, in continuous flows and at low Reynolds numbers a stable interface between two or more reagent streams can be achieved, which affords the formation of a well-controlled reaction zone inside the flow path, where mixing only occurs through diffusion [13][14][15][16] . Indeed, we have previously employed laminar flows to localize the synthetic pathway of crystalline molecular materials such as coordination polymers (CPs) inside microfluidic channels 17 . Although this methodology has shown great promise in realizing novel CP nanostructures, the direct integration of such structures onto surfaces, as well as controlled chemical treatment after their formation has yet to be realized in situ 18 .…”

Guided assembly of nanowires and their integration in microfluidic devices

“…Here, we present a novel and effective microfluidic strategy, in which synthesis, localization, and direct integration of functional wires are accomplished in situ, and at desired locations inside multilayer microfluidic platforms. Two types of materials are utilized: Hybrid wires made of gold and tetrathiafulvalen (Au-TTF) [5] and nanoscaled coordination polymers (here: copper-aspartic acid) [6,7].…”