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Development of naphthalimide-functionalized thermochromic conjugated polydiacetylenes and their reversible green-to-red chromatic transition in the solid state
摘要： Development of PDAs has received great attention in many fields due to their optical and chromatic properties towards external stimuli. In this article, two novel PDAs (NPI-PDA1 and NPI-PDA2) containing naphthalimide as a head group are designed and synthesized through self-assembly followed by topochemical polymerization, and these compounds show a reversible green-to-red colorimetric transition upon heating. PEO-embedded films are fabricated to facilitate the investigation of the thermochromic properties, and the surface morphologies of the films are observed by SEM analysis. The thermochromic behavior and color transitions are observed using photography and electronic absorption spectroscopy. The changes in the extended ene-yne conjugated system of the polymer during heat treatment are successfully monitored by Raman spectrometry. Moreover, PDA-embedded crayon wax-based hand-writable pens are fabricated and used efficiently on a solid substrate. NPI-PDA1 and NPI-PDA2 display excellent reversibility in the temperature ranges of 25–120 °C and 25–160 °C, respectively in the PEO polymer and paraffin wax matrices.
关键词： Thermochromism,PEO films,Green-to-red color transition,Polydiacetylene,Crayon pen
更新于2025-11-21 10:59:37
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Colloidally Stable Monolayer Nanosheets with Colorimetric Responses
摘要： 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.
关键词： colorimetric responses,monolayer nanosheets,colloidal stability,polydiacetylene
更新于2025-09-23 15:23:52
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Controlling self-assembling and color-transition of polydiacetylene/zinc(II) ion/zinc oxide nanocomposites by varying pH: Effects of surface charge and head group dissociation
摘要： Polydiacetylene/zinc(II) ion/zinc oxide (PDA/Zn2+/ZnO) nanocomposite exhibits reversible thermochromism and dual colorimetric response to acid/base. This contribution presents our ongoing development of the PDA/Zn2+/ZnO nanocomposite for sensing applications by controlling ZnO surface charge and dissociation of PDA headgroup via pH adjustment. At pH >10, negative ZnO surface charge and PDA carboxylate headgroup significantly enhance molecular organization during the self-assembling process. An increase of the nanocomposite amount after photopolymerization is observed. Oppositely, pH <6 results in irreversible-thermochromic nanocomposites. Additionally, the nanocomposites prepared at different pH change color at different concentrations of chemical stimuli. Molecular packing, local interactions and PDA conformation are investigated.
关键词： self-assembling,color transition,sensor,polydiacetylene,dissociation,surface charge
更新于2025-09-23 15:23:52
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Polydiacetylene capacitive artificial nose
摘要： Polydiacetylenes are a class of conjugated polymers exhibiting unique color and fluorescence properties and employed as useful sensing vehicles. Here we demonstrate for the first time that the dielectric properties of polydiacetylenes can be exploited for vapor sensing. Specifically, electrodes coated with polydiacetylenes, embedded within a porous polyvinylpyrrolidone (PVP) matrix, exhibit significant capacitance transformations upon exposure to different vapors. The capacitive response of the polydiacetylene/PVP films depended upon both the structures of the diacetylene monomers, and the extent of ultraviolet irradiation (i.e. polymerization), underscoring a unique sensing mechanism affected by conjugation, structure, and dielectric properties of the polydiacetylene/polymer matrix. Importantly, the variability of polydiacetylene structures allow vapor identification through an array-based pattern recognition (i.e. artificial nose). This study opens new avenues for applications of polydiacetylene systems, particularly pointing to their dielectric properties as powerful sensing determinants.
关键词： polydiacetylene,polyvinylpyrrolidone,artificial nose,dielectric properties,capacitive vapor sensing
更新于2025-09-23 15:22:29
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Fluorescence anisotropy imaging of a polydiacetylene photopolymer film
摘要： UV-illumination of phase-separated surfactant films prepared from mixtures of photopolymerizable 10,12-pentacosadiynoic acid and perfluorotetradecanoic acid results in the formation of fluorescent polydiacetylene fibers and aggregates. In this work, the orientation of polymer strands that comprise the resulting photopolymer structures has been probed using fluorescence anisotropy imaging in combination with defocused single-molecule fluorescence imaging. Imaging experiments indicate the presence of significant fiber-to-fiber heterogeneity, as well as anisotropy within each fiber (or aggregate), with both of these properties changing as a function of film preparation conditions. This anisotropy can be attributed to various alignments of the constituent polymer strands that comprise the larger fibers and aggregates. Intriguingly, when using defocused imaging, fiber images consisted of a series of discrete 'doughnut' fluorescence emission patterns, which exhibited intermittent on–off blinking behavior; both of these properties are characteristic of individual emission transition dipoles (single molecules). Further, all of the individual emission transition dipoles had a uniform orientation with respect to the axis of the fiber, indicating a common orientation of discrete emitters in the larger polymer fiber. The implications of these results for future studies of the electronic properties of conjugated polymers in larger macroscopic systems are noted.
关键词： 12-pentacosadiynoic acid,polydiacetylene,fluorescence anisotropy imaging microscopy,single-molecule spectroscopy,10,Langmuir film
更新于2025-09-19 17:15:36
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Dissymmetry enhancement in enantioselective synthesis of helical polydiacetylene by application of superchiral light
摘要： Superchiral light, generated by the interference of two counter-propagating circularly polarized light (CPL) with same frequency, opposite handedness and different intensity, exhibits enhanced dissymmetry in its interaction with chiral molecules, and has the potential for ultrasensitive detection and characterization of chiral molecules. It is anticipated that the enhanced optical dissymmetry in superchiral light (SCL) field may be utilized to promote asymmetric photochemical reactions efficiency. Herein we reported SCL impart greater chiral bias to trigger asymmetric photo-polymerization reaction from initially achiral diacetylene (DA) monomer, and the enhanced optical dissymmetry for whole polydiacetylene (PDA) films could be achieved. An explanation based on the chiral transfer and amplification of chiral bias from SCL during the polymerization process has been proposed. Moreover, thus formed chiral PDA films polymerized by SCL exhibited enhanced enantioselective recognition ability, and can serve as a direct visual probe for the discrimination of some specific enantiomers.
关键词： polydiacetylene,asymmetric photochemical reactions,chiral molecules,enantioselective recognition,Superchiral light
更新于2025-09-10 09:29:36
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Polydiacetylene/triblock copolymer/surfactant nanoblend: A simple and rapid method for the colorimetric screening of enrofloxacin residue
摘要： Colorimetric nanosensors formed of polydiacetylene (PDA), triblock copolymer (L64 or F68), and sodium dodecyl sulfate (SDS), so-called nanoblends, were developed to detect enrofloxacin (ENRO) in aqueous media. The nanosensors show hydrodynamic diameter ranging from 234.2 ± 3.5 to 801.6 ± 17.8 nm for SDS concentrations of 13.0–21.0 mM, respectively. The lowest limit of detection was 0.054 μM, which is five times smaller than the maximum limit allowed by the European Union. The response surfaces showed that both the SDS and ENRO concentrations influenced the colorimetric response (p<0.05), and kinetic rate of colorimetric transition (RCT). SDS concentration between 11.0 and 14.0 mM in the nanoblend yielded the most sensitive nanosensors for detecting ENRO. When L64 was replaced by F68, the colorimetric response of the nanoblends was similar, but PDA/F68/SDS showed a slower RCT than PDA/L64/SDS. The developed nanosensor is a sensitive and simple device for the fast detection of ENRO.
关键词： polydiacetylene,Nanosensor,sodium dodecyl sulfate,antibiotic,triblock copolymer
更新于2025-09-04 15:30:14