Inkjet‐Printable Amphiphilic Polydiacetylene Precursor for Hydrochromic Imaging on Paper

Abstract

Hydrochromic materials find great utility in a wide range of applications including humidity sensing and measuring the water contents of organic solvents, as well as substrates for rewritable paper and human sweat pore mapping. Herein, an inkjet printable diacetylene (DA) is described that can be transformed by UV irradiation to a hydrochromic‐conjugated polymer on conventional paper. Specifically, an amphiphilic DA that contains an ­imidazolium ion head‐group is found to be compatible with a common office inkjet printer. Various computer‐designed images are printed on paper using this substance. UV irradiation of the printed images results in the generation of blue‐colored images associated with formation of a polydiacetylene (PDA). The resolutions of the images are almost identical to those generated using a conventional black ink. Importantly, the printed images undergo a blue‐to‐red color change upon exposure to water and the hydrochromism is found to be temperature dependent. The facile color change that occurs near body ­temperatures enables use of the hydrochromic PDA‐coated paper for rapid and precise mapping of human sweat pores from fingers, palms, and feet.

Co-assemblies of polydiacetylenes and metal ions for solvent sensing

“…Conjugated polymer-based sensors are sensitive to very minor perturbations due to amplification by a collective system response and therefore offer a remarkable advantage over small molecule-based sensors. [1][2][3][4][5][6] Polydiacetylenes (PDAs) are wellknown conjugated polymers. PDAs show stimuli-responsive blue-to-red color changes because the conformation of the conjugated backbone changes, which results in a change of the efficient conjugated length of the polymer chain.…”

Directional Self‐Assembly and Photoinduced Polymerization of Diacetylene‐Containing Platinum(II) Terpyridine Complexes

“…[3,4] The Pt···Pt interactions could be readily inducedb ye xternals timuli such as temperature, [5] solvent, [4b, 6] pH, [7] formation of metallogels, [8] and addition of polyelectrolytes [9] or nucleic acids [10] with remarkable colourc hanges and luminescence enhancement, which make the platinum(II) polypyridinec omplexes potentially applicable for the detection of variousexternalstimuli. [11] On the other hand, polydiacetylenes (PDAs), as ac lass of pconjugated polymers with quasi-one-dimensional structures, have attracted considerable interest during the past few decades [12] due to their non-linearo ptical properties and high photoconductivities, [13] which maket hem suitable for an array of potentiala pplications in sensing, [14] as bioelectronic materials, [15] as well as other opticala nd electronic materials and devices. [16] Since the first synthesis of PDA by Wegner and co-workerst hrought opochemicalp olymerization of diacetylene (DA) monomers under ambient conditions with UV irradiation in 1969, [17] with the demonstration that the molecular packing is essential to this 1,4-addition reaction, there has been increased interesti nc ontrolling the polymerization of DAs.…”

“…Nevertheless,s olutionprocessable polymerization of DA monomers is important because it enables aw ider range of applicationsi ns ensors ystems and electronic devices. [12][13][14][15][16] In this work, by taking advantage of the directional Pt···Pt interaction and strategies of rational design,anew series of DAcontaining alkynylplatinum(II) terpyridine complexes was synthesized and investigated. These complexes were found to be spectroscopically responsive in the solution state upon photoirradiation.…”

A Tetrahydrofuran‐selective Optical Solvent Sensor Based on Solvatochromic Polydiacetylene

“…PDA undergoes a color change when the dissolution of unpolymerized monomers causes some void in the PDA supramolecules. 9 Since PCDA-mBzA has a good solubility only in THF, colorimetric transition of PDA occurs only in response to THF. Since solubility of a diacetylene monomer can be manipulated by structural change of the monomer, we believe the strategy described in current investigation should be useful for the development of solvent-specific PDA sensor systems.…”

“…The C C stretching region is related to the conformational change of aliphatic alkyl chain. 4,9 The peaks at 1088 and 1127 cm −1 for the blue phase PDA are assigned to the aliphatic alkyl chain of PDA containing all-trans conformation. Upon exposure to THF, a new peak appears at 1071 cm −1 which is responsible for the formation of some gauche conformations in the PDA.…”