scholarly journals Simple Vanilla Derivatives for Long-Lived Room-Temperature Polymer Phosphorescence as Invisible Security Inks

Research ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Yongfeng Zhang ◽  
Zhonghao Wang ◽  
Yan Su ◽  
Yan Zheng ◽  
Wenji Tang ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Polyvinyl Alcohol ◽  
Room Temperature ◽  
Reading Strategy ◽  
Ambient Conditions ◽  
Data Encoding ◽  
Emission Time ◽  
Phosphorescence Emission ◽  
Multiple Cycles ◽  
Application Scope

Developing novel long-lived room-temperature polymer phosphorescence (RTPP) materials could significantly expand their application scope. Herein, a series of RTPP materials based on eight simple vanilla derivatives for security ink application are reported. Attributed to strong mutual hydrogen bonding with polyvinyl alcohol (PVA) matrix, vanilla-doped PVA films exhibit ultralong phosphorescence emission under ambient conditions observed by naked eyes, where methyl vanillate shows the longest emission time up to 7 s. Impressively, when vanilla-doped PVA materials are utilized as invisible security inks, and the inks not only present excellent luminescent emission stability under ambient conditions but also maintain perfect reversibility between room temperature and 65°C for multiple cycles. Owing to the unique RTPP performance, an advanced anticounterfeiting data encoding/reading strategy based on handwriting technology and complex pattern steganography is developed.

scholarly journals Two Unexpected Temperature-Induced Supermolecular Isomers from Multi-Topic Carboxylic Acid: Hydrogen Bonding Layer or Helix Tube

Molecules ◽  
2021 ◽  
Vol 26 (22) ◽  
pp. 6938
Author(s):  
Chunyang Li ◽  
Chunhong Tan ◽  
Juan Zhou ◽  
Yan-Yong Lin ◽  
Xiao-Feng Wang
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Carboxylic Acid ◽  
Room Temperature ◽  
Bonding Layer ◽  
Supramolecular Framework ◽  
Ambient Conditions ◽  
Temperature Dependent ◽  
Single Crystal Structures ◽  
Supramolecular Isomerism

Under ambient conditions or 160 °C, two supramolecular isomers, namely [(H4PTTA)(H2O)2(DMF)] and [(H4PTTA)(H2O)3]··Guest (1-L and 1-H, H4PTTA = N-phenyl-N′-phenyl bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxdiimide tetra-carboxylic acid, Guest = DMF and H2O), were obtained through the reaction of H4PTTA in a mixture of H2O and dimethylformamide. The single crystal structures reveal the temperature-dependent supramolecular isomerism derived from the torsion of semi-rigid of H4PTTA. The 1-L prepared at room temperature is a hydrogen bond based achiral layer, while the hydrothermal synthesized 1-H is isomer resulted in an H-bond-based chiral tubes-packed supramolecular framework.

Hydrogen bonding in liquid methanol at ambient conditions and at high pressure

2000 ◽  
Vol 98 (3) ◽  
pp. 125-134 ◽  
Author(s):  
T. Weitkamp, J. Neuefeind, H. E. Fisch
Keyword(s):  
High Pressure ◽  
Hydrogen Bonding ◽  
Ambient Conditions

Visible-light-initiated Catalyst-free Oxidative Cleavage of Triaryl-Substituted Alkenes C=C Bonds under Ambient Conditions

2021 ◽  
Author(s):  
Wenjing Li ◽  
Shun Li ◽  
Lihua Luo ◽  
Yichen Ge ◽  
Jiaqi Xu ◽  
...  
Keyword(s):  
Visible Light ◽  
Room Temperature ◽  
Ambient Air ◽  
Oxidative Cleavage ◽  
Ambient Conditions ◽  
Blue Led ◽  
Catalyst Free

The catalyst-free oxidative cleavage of (Z)-triaryl-substituted alkenes bearing pyridyl motif with ambient air under irradiation of blue LED at room temperature has been developed. The reaction was facile and scalable,...

scholarly journals Foldable and washable textile-based OLEDs with a multi-functional near-room-temperature encapsulation layer for smart e-textiles

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
So Yeong Jeong ◽  
Hye Rin Shim ◽  
Yunha Na ◽  
Ki Suk Kang ◽  
Yongmin Jeon ◽  
...  
Keyword(s):  
Room Temperature ◽  
Wearable Electronics ◽  
Ambient Conditions ◽  
Light Emitting ◽  
Stable Operating ◽  
Mechanical Durability ◽  
Potential Applications ◽  
Wearable Electronic ◽  
Data Signal ◽  
Wearable Electronic Devices

AbstractWearable electronic devices are being developed because of their wide potential applications and user convenience. Among them, wearable organic light emitting diodes (OLEDs) play an important role in visualizing the data signal processed in wearable electronics to humans. In this study, textile-based OLEDs were fabricated and their practical utility was demonstrated. The textile-based OLEDs exhibited a stable operating lifetime under ambient conditions, enough mechanical durability to endure the deformation by the movement of humans, and washability for maintaining its optoelectronic properties even in water condition such as rain, sweat, or washing. In this study, the main technology used to realize this textile-based OLED was multi-functional near-room-temperature encapsulation. The outstanding impermeability of TiO2 film deposited at near-room-temperature was demonstrated. The internal residual stress in the encapsulation layer was controlled, and the device was capped by highly cross-linked hydrophobic polymer film, providing a highly impermeable, mechanically flexible, and waterproof encapsulation.

scholarly journals Exploring the Structural Chemistry of Pyrophosphoramides: N,N′,N″,N‴-Tetraisopropylpyrophosphoramide

Chemistry ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 149-163
Author(s):  
Duncan Micallef ◽  
Liana Vella-Zarb ◽  
Ulrich Baisch
Keyword(s):  
Crystal Structure ◽  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Hydrogen Bonding ◽  
Nmr Spectroscopy ◽  
Ir Spectroscopy ◽  
Room Temperature ◽  
Intermolecular Hydrogen Bonding ◽  
X Ray Diffraction ◽  
X Ray

N,N′,N″,N‴-Tetraisopropylpyrophosphoramide 1 is a pyrophosphoramide with documented butyrylcholinesterase inhibition, a property shared with the more widely studied octamethylphosphoramide (Schradan). Unlike Schradan, 1 is a solid at room temperature making it one of a few known pyrophosphoramide solids. The crystal structure of 1 was determined by single-crystal X-ray diffraction and compared with that of other previously described solid pyrophosphoramides. The pyrophosphoramide discussed in this study was synthesised by reacting iso-propyl amine with pyrophosphoryl tetrachloride under anhydrous conditions. A unique supramolecular motif was observed when compared with previously published pyrophosphoramide structures having two different intermolecular hydrogen bonding synthons. Furthermore, the potential of a wider variety of supramolecular structures in which similar pyrophosphoramides can crystallise was recognised. Proton (1H) and Phosphorus 31 (31P) Nuclear Magnetic Resonance (NMR) spectroscopy, infrared (IR) spectroscopy, mass spectrometry (MS) were carried out to complete the analysis of the compound.

Pure room temperature phosphorescence emission of organic host-guest doped system with quantum efficiency of 64%

2021 ◽  
Author(s):  
Xiaoqing Liu ◽  
Wenbo Dai ◽  
Qian Junjie ◽  
Yunxiang Lei ◽  
Miaochang Liu ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
Room Temperature ◽  
Room Temperature Phosphorescence ◽  
Halogen Atoms ◽  
System P ◽  
Phosphorescence Emission

A new doped system with pure phosphorescent emission is constructed using four 1-(4-(diphenylamino)phenyl)-2-phenylethan-1-one derivatives containing halogen atoms as the guests and benzophenone as the host. That is, the doped system...

scholarly journals Optical switching of topological phase in a perovskite polariton lattice

2021 ◽  
Vol 7 (21) ◽  
pp. eabf8049
Author(s):  
Rui Su ◽  
Sanjib Ghosh ◽  
Timothy C. H. Liew ◽  
Qihua Xiong
Keyword(s):  
Optical Switching ◽  
Room Temperature ◽  
Optical Pumping ◽  
Optical Nonlinearity ◽  
Edge States ◽  
Ambient Conditions ◽  
Strong Light ◽  
Exciton Polaritons ◽  
Matter Interaction ◽  
Light Matter Interaction

Strong light-matter interaction enriches topological photonics by dressing light with matter, which provides the possibility to realize active nonlinear topological devices with immunity to defects. Topological exciton polaritons—half-light, half-matter quasiparticles with giant optical nonlinearity—represent a unique platform for active topological photonics. Previous demonstrations of exciton polariton topological insulators demand cryogenic temperatures, and their topological properties are usually fixed. Here, we experimentally demonstrate a room temperature exciton polariton topological insulator in a perovskite zigzag lattice. Polarization serves as a degree of freedom to switch between distinct topological phases, and the topologically nontrivial polariton edge states persist in the presence of onsite energy perturbations, showing strong immunity to disorder. We further demonstrate exciton polariton condensation into the topological edge states under optical pumping. These results provide an ideal platform for realizing active topological polaritonic devices working at ambient conditions, which can find important applications in topological lasers, optical modulation, and switching.

scholarly journals Luminescence from Droplet-Etched GaAs Quantum Dots at and Close to Room Temperature

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 690
Author(s):  
Leonardo Ranasinghe ◽  
Christian Heyn ◽  
Kristian Deneke ◽  
Michael Zocher ◽  
Roman Korneev ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Penetration Depth ◽  
Gaas Substrate ◽  
Room Temperature ◽  
Green Laser ◽  
Significant Loss ◽  
Blue Laser ◽  
Ambient Conditions ◽  
Thermal Escape ◽  
Intensity Loss

Epitaxially grown quantum dots (QDs) are established as quantum emitters for quantum information technology, but their operation under ambient conditions remains a challenge. Therefore, we study photoluminescence (PL) emission at and close to room temperature from self-assembled strain-free GaAs quantum dots (QDs) in refilled AlGaAs nanoholes on (001)GaAs substrate. Two major obstacles for room temperature operation are observed. The first is a strong radiative background from the GaAs substrate and the second a significant loss of intensity by more than four orders of magnitude between liquid helium and room temperature. We discuss results obtained on three different sample designs and two excitation wavelengths. The PL measurements are performed at room temperature and at T = 200 K, which is obtained using an inexpensive thermoelectric cooler. An optimized sample with an AlGaAs barrier layer thicker than the penetration depth of the exciting green laser light (532 nm) demonstrates clear QD peaks already at room temperature. Samples with thin AlGaAs layers show room temperature emission from the QDs when a blue laser (405 nm) with a reduced optical penetration depth is used for excitation. A model and a fit to the experimental behavior identify dissociation of excitons in the barrier below T = 100 K and thermal escape of excitons from QDs above T = 160 K as the central processes causing PL-intensity loss.

The hydrogen-bonding properties of a room temperature phosphorescence cellulose substrate

1986 ◽  
Vol 90 (21) ◽  
pp. 4941-4945 ◽  
Author(s):  
Georg W. Suter ◽  
Alan J. Kallir ◽  
Urs P. Wild ◽  
Tuan Vo-Dinh
Keyword(s):  
Hydrogen Bonding ◽  
Room Temperature ◽  
Room Temperature Phosphorescence ◽  
Cellulose Substrate ◽  
Bonding Properties

Heat Transfer Analysis of Room-Temperature Finned-Tube Evaporator for Cryogenic Nitrogen

2011 ◽  
Vol 133 (9) ◽  
Author(s):  
Shun Ching Lee ◽  
Tzu-Min Chen
Keyword(s):  
Heat Flux ◽  
Room Temperature ◽  
Integrated Model ◽  
Finned Tube ◽  
Heat Transfer Analysis ◽  
Outlet Temperature ◽  
Ambient Conditions ◽  
Governing Equations ◽  
Initial Value ◽  
Two Phase

Abstract The behavior of cryogenic nitrogen in a room-temperature evaporator six meters long is analyzed. Trapezoid fins are employed to enhance the heat flux supplied by the environment. The steady-state governing equations specified by the mixed parameters are derived from the conservations of momentum and energy. The initial value problem is solved by space integration. The fixed ambient conditions are confirmed by way of the meltback effect. An integrated model is utilized to analyze the convective effect of two-phase flow, which dominates the evaporation behavior. Another integrated model is employed to determine the total heat flux from the environment to the wet surface of the evaporator. The foundation of the formation of an ice layer surrounding the evaporator is presented. If the fin height is shorter than 0.5 m, the whole evaporator is surrounded by ice layer. If the fin height is longer than 0.5 m, the total pressure drop of nitrogen in the tube is negligible. The outlet temperature is always within the range between −12 °C and 16 °C for the evaporator with the fin height of 1.0 m. For the evaporator with dry surface, the nitrogen has the outlet temperature less than the ambient temperature at least by 5 °C.

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