Colloidally Stable Monolayer Nanosheets with Colorimetric Responses

Abstract

Despite the discovery of chromogenic‐layered materials for decades of years, fabrication of colloidally stable monolayer organic 2D nanosheets in aqueous media with colorimetric responses is still challenging. Herein reported is the first solution synthesis of chromic monolayer nanosheets via the topochemical polymerization of self‐assembled amphiphilic diacetylenes in aqueous media. The polydiacetylene (PDA) nanosheets are ≈3–4 nm thick in solution and only ≈1.9 nm thick in the dried state, while the lateral size can reach several micrometers. Moreover, the aqueous stability endows PDA nanosheets with excellent processability, which can further assemble into films via vacuum filtration or act as an ink for high‐resolution inkjet printing. The filtrated films and printed patterns exhibit fully reversible blue‐to‐red thermochromism, and the film also displays an interesting reversible colorimetric transition in response to near‐infrared light, which is not reported for other PDA‐only systems. The present colloidal PDA nanosheets should represent a new kind of chromic organic 2D nanomaterials that may be applied as novel building blocks for developing intelligent hybrid materials and may also find diverse sensing, display and/or anticounterfeiting applications.

Highly Sensitive Polydiacetylene Ensembles for Biosensing and Bioimaging

“…van der Asdonk et al prepared PDA nanowires from the micron to centimeter scale using liquid crystal template (van der Asdonk et al, 2016). Recently Hu et al prepared PDA nanosheets with an one-layer thickness (Hu et al, 2019). They first adopted a novel diacetylene amphiphile molecule: maleic acid as the head, the hydrophobic diacetylene as the tail, and 1,1,3,3-tetramethylyuanidine as the linker.…”

“…In recent years, the preparation methods for PDA have been greatly advanced. PDA structures have been enriched from traditional films, micelles and vesicles to 3D-PDA structures, porous structures, hydrogels, macrocyclic structures, and single-layer nanosheets (Bang et al, 2016;Chae et al, 2016;Krishnan et al, 2016;Okaniwa et al, 2016;Jordan et al, 2017;Li et al, 2017a;Romera et al, 2017;Jeong et al, 2018;Takeuchi et al, 2018;Terada et al, 2018;Heo et al, 2019;Hu et al, 2019;Seo et al, 2019;Shin et al, 2020). Great progresses have also been made in the preparation of reversible and chiral PDA (Chen et al, 2016;He et al, 2020).…”

Intercalation and flexibility chemistries of soft layered materials

“…[107][108][109] In previous works, the designed DA monomers were synthesized for tuning the responsivity and sensing the desired targets. [110][111][112][113][114][115][116][117][118][119][120][121][122][123] Kim et al, designed and synthesized a variety of DA monomers to achieve control of the color-change properties and their versatile applications. 98,99,101,103,[110][111][112]116,120,121,123 Among a variety of monomers, amphiphilic DA monomer forms the lamellar-like layered structures (Fig.…”

Imidazolium‐Functionalized Diacetylene Amphiphiles: Strike a Lighter and Wear Polaroid Glasses to Decipher the Secret Code

“…[ 26–28 ] The blue‐to‐red transition of PDA resulting from the structural distortion of the alternating ene–yne polymeric backbone by external stimuli such as heat, solvents, and mechanical stress is the most common. [ 29–35 ] PDAs have been widely proposed as ideal candidates for sensing materials, but their practical application as secret inks is quite limited because DA solutions in organic solvents should be transferred to a substrate and then evaporated for printed patterns.…”