In particular, metasurface holograms, one of the metamaterial-based systems with non-naturally occurring optical properties, have gained great interest due to the reproducibility of full-color three-dimensional (3D) images through the manipulation of light. By rationally utilizing the orthogonal reaction mechanisms of the G agent simulant and the blood agent (ClCN), oxime- and benzaldehyde-modified diacetylene monomers capable of rapid recognition of CWAs gases were synthesized. Note that the activation energy of each reaction is the case of the lowest activation energy in Fig.
Introduction
- Bio-inspired Photonics
- Optical metamaterials
- Polymer based-hologram systems
- Polydiacetylene (PDA)
- References
Copyright © 2015 Springer Nature, Copyright © 2015 Springer Nature, Copyright © 2016 American Chemical Society, Copyright © 2016 American Chemical Society, og Copyright © 2020 WILEY-VCH Verlag GmbH & Co. Copyright © 1999 Springer Nature, Copyright © 2008 American Chemical Society , Copyright © 2000 Springer Nature, Copyright © 2019 American Chemical Society og Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim, Copyright © 2013 American Chemical Society, Copyright © 2018 American Chemical Society, Copyright © 2014 WILEY-VCH Verlag GmbH.
Dynamic Multimodal Holograms of Conjugated Organogels via Dithering mask
Conclusion
In conclusion, we have developed a conjugated organogel that reversibly displays 3 modes of holograms in a single architecture. Using dithering mask lithography, we realized two-dimensional patterns with varying crosslink density on a conjugated polydiacetylene. In protic solvents, the organogel contracts anisotropically to develop optical and structural heterogeneities along the third dimension, displaying holograms in the form of three-dimensional full parallax signals, both in fluorescence and brightfield.
In aprotic solvents, these heterogeneities diminish as the organogels expand, recovering the two-dimensional periodicity to exhibit a third hologram mode based on iridescent structural colors.
Highly Stable Upconverting nanocrystal-Polydiacetylenes nanoplates for
- Introduction
- Results and Discussion
- Experimental Section
- Conclusion
- References
Color changes observed in highly stacked PCDA-Co nanosheets prepared using different RPCDA/Co and exposed to CN ions (25 mM). Color changes observed in highly stacked PCDA-Co nanosheets prepared using different RPCDA/Co and treated with different concentrations of CN ions. XRD patterns of isolated PCDA-Co nanoplates and highly stacked PCDA-Co nanoplates before/after the addition of CN ions.
Orthogonal dual signaling of Chemical warfare agents using
Introduction
Polydiacetylene (PDA), one of the conjugated polymers, has been extensively studied for the development of various sensor systems due to their unique optical properties such as color change and fluorescence emission1-4. Diacetylene molecules are polymerized by 1-4 addition polymerization under 254 nm UV irradiation, and blue-phase PDA with an alternating "yn-ene" backbone is generated5-7. PDAs undergo a blue-to-red color transition and fluorescence emission upon the conformational change of conjugated backbone by the applied external stimuli1-3.
Based on these stimuli-responsive optical property changes of PDAs, much effort has been spent on detecting toxic molecules by introducing structurally distinct recognition units into diacetylene monomers. One of the toxic molecules, Chemical Warfare Agents (CWAs), has been considered a weapon of mass destruction (WMD), and the use of these weapons of mass destruction is prohibited under international humanitarian law (IHL). Nevertheless, to maximize killing capacity, CWAs were often illegally sprayed day and night during the civil war.
To selectively recognize DMMP and ClCN, we propose nucleophilic oxime (OX) modified PCDA-OX and electrophilic benzaldehyde (BA) modified PCDA-BA molecules. We further fabricate PCDA-OX/UCNs and PCDA-BA/UCNs nanocomposite embedded fiber patches that exhibit a dual signaling capability of yellow-to-red luminescence transition and a blue-to-red color change upon exposure to DMMP and ClCN gases . In addition, we provide a color standard for convenient use by military PDA sensors that does not require scientific analysis tools.
This design principle of the PDA/UCN nanocomposite based sensor system extends the applicability of PDA sensor systems for military use in the development of gas CWA detection systems.
Results and Discussion
To extend the flexibility of the PDA sensor system, PCDA-OX was coated on fiber patch (see the experimental section for details). To test the colorimetric response of the PCDA-OX system, the reflectance spectra of PCDA-OX coated cotton fiber were measured before and after the exposure of DMMP liquid. We further exposed the PCDA-OX fiber patch to DMMP droplets with a diameter of 100 µm which corresponds to the detection limit of conventional CWA detection papers such as M-8 and M-9.
Several DMMP droplets were sprayed onto the PCDA-OX fiber patch (see the experimental section for details), and the PCDA-OX fiber patch exhibited a blue-to-red color transition (Fig. 4.2e). To find out whether our PDA sensor systems can detect gaseous CWAs selectively and rapidly, PCDA-OX or PCDA-BA fiber patch was exposed to DMMP gas (390 ppm) and ClCN gas (1720 ppm). see the experimental section for details). PCDA-OX coated fiber patch showed blue to red color transition in 7 sec. after exposure to DMMP gas, but it showed no color change when exposed to ClCN gas.
PCDA-OX fiber patch was assigned as a cloudy blue color before and after exposure to ClCN and the H value was located at 210˚ and 212˚. The resulting PCDA-OX/UCNs or PCDA-BA/UCNs fiber patches were exposed to DMMP and ClCN gases, and the luminescence color changes were measured in the darkroom. The PCDA-OX/UCNs fiber patch presented the luminescence color change from yellow to red with blue-to-red color change upon exposure to DMMP gas, but no luminescence and color change upon exposure to ClCN gas (Fig. 4.4f).
The PCDA-OX/UCN system showed the luminescence color transition with the decrease in emission at a wavelength of 540 nm due to the absorption change of PCDA-OX upon exposure to DMMP gas (Fig. 4.4h).
Experimental Section
15.7 mmol oxalyl chloride was added dropwise to a solution of 5.33 mmol PCDA in 20 ml dichloromethane. After concentration in vacuo, the residue was dissolved in 2-butanone and added to a solution containing 5.27 mmol 2,4-dihydroxybenzaldehyde and 6.17 mmol TEA in 50 ml 2-butanone. To a solution of 2.02 mmol PCDA-HBA in 100 ml ethanol was added dropwise 4.04 mmol hydroxylamine hydrochloride solution in 20 ml DI-water/ethanol (1/1) mixture.
To a solution of 5.33 mmol PCDA in 20 ml dichloromethane was added dropwise 15.7 mmol oxalyl chloride, and a catalytic amount of DMF was added. After concentration in vacuo, the residue was dissolved in THF and added to a solution containing 5.27 mmol 4-hydroxybenzaldehyde in 20 ml pyridine. The DMMP and ClCN solution was evaporated to dryness and transferred to the gas storage container.
The mixture precursor solution was moved to a stainless steel autoclave and heated for 2 hours at 200 ° C in a vacuum oven. A cotton fiber patch was coated with UCNs/PCDA-OX mixture solution and polymerized by 254 nm UV light irradiation for 1 min. A cotton fiber patch was coated with UCNs/PCDA-BA mixture solution and polymerized by 254 nm UV light irradiation for 30 s.
The images of the PCDA-OX and PCDA-BA system were taken using a charge-coupled device (CCD) camera (EOS M3, Canon).
Conclusion
The concentration of DMMP (390 ppm) and ClCN (1720 ppm) gases was controlled by a constant flow controller. The photoluminescence spectra of UCN were recorded with a spectrometer (QE Pro, Ocean Optics) using a 980 nm laser (MDL-H-980, Changchun New Industries Optoelectronics Tech. Co., Ltd.).
Polydiacetylene liposome microarray for detection of influenza viruses: effect of target size on switch-on signaling.
Summary and Future Perspectives
Summary
PCDA-OX/UCN and PCDA-BA/UCN rapidly reacted with organophosphonate and cyanide, resulting in selective blue-to-red and yellow-to-red luminescence changes in DMMP and ClCN. In conclusion, we have investigated new photonic systems that exhibit multimodal holograms or dual optical signals. We anticipate that our two universal design principles established in the above-mentioned four chapters can be used to efficiently extend other responsive systems and to develop new systems that exhibit unprecedented optical signals for various photonics applications.
Future Perspectives
먼저 지도교수이신 이지석 교수님에게 깊은 감사의 말씀을 전하고 싶습니다. 저에게 주신 조언들 잊지 않고 더 좋은 사람이 될 수 있도록 더욱 노력하겠습니다. 제가 연구실에서 일하는 동안 많은 일을 함께 해준 연구실 식구들에게 감사 인사를 전하고 싶습니다.
함께 연구를 해주신 다혜님과 혜리님에게도 감사드립니다. 모두들 원하는 일 모두 이루시길 바랍니다. 박사님께도 감사드립니다. 14년 전 고등학교 1학년 때 만났고, 울산과학기술원에서 학부, 대학원을 거쳐 함께 일했던 이승진 씨.
또한, 학부부터 대학원까지 저와 함께 체육관에서 훈련하며 함께 연구의 꿈을 키워주고, 현재 미국에서 유학 중인 박범수 학생에게도 감사의 말씀을 전하고 싶습니다. 마지막으로 늘 믿음과 사랑으로 응원해주시고 응원해주시는 사랑하는 어머니, 아버지, 남동생 나현이님께 진심으로 감사와 사랑의 마음을 전합니다. 오랫동안 공부하는 아들을 늘 응원하고 믿어주셔서 감사합니다.
더 열심히 해서 자랑스러운 아들, 형이 되도록 하겠습니다.
