Polymer-modulated evaporation flow enables scalable self-assembly of highly aligned nanowires
Year: 2025
Type: preprint
Abstract: Highly aligned nanowire networks are essential for enabling anisotropic optical, electrical, and sensing functionalities in next-generation devices. However, achieving such alignment typically requires complex fabrication methods or high-energy processing. Here, we present a simple and scalable self-assembly strategy that uses a viscosity-enhancing polymer additive to modulate fluid flows during solvent evaporation. The addition of carboxymethylcellulose sodium (CMC-Na) reshapes the evaporation-driven flow field and generates a compressional flow region near the drying edge. Within this region, rotation-inducing velocity gradients progressively align silver nanowires (AgNWs) into highly ordered arrays. This unique mechanism yields uniform AgNW coatings with a high degree of nanowire alignment and tunable areal density across centimeter-scale areas. The resulting films exhibit strong broadband anisotropy, including polarization-dependent transmission in both visible and terahertz (THz) regimes and angle-dependent electrical conductivity. The approach also integrates naturally with dip-coating-based shear alignment, enabling programmable control over alignment direction and spatial patterning. This work establishes a robust, polymer-enabled mechanism for bottom-up nanowire alignment and offers a passive, energy-efficient route for fabricating anisotropic nanostructured coatings.
Source: arXiv (Cornell University)
Authors: Tao, Liyiming, Jiang, Zechao, Hu, Shiyuan, Du, Lin, Zhang, Qiuting, Zhou, Jiajia, Doi, Masao, Wu, Xiaojun, Man, Xingkun, Xu, Ye
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W6979345472
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