Temperature-sensitive Properties Research Articles

Non-isothermal wicking in polymer sintered bead wicks: Experimentation, analytical solutions, and numerical validation

Though models and applications abound for spontaneous imbibition of liquids into porous media (also called wicking), this is perhaps the first attempt to propose (and rigorously test) any model under non-isothermal conditions. This paper evaluates non-isothermal wicking phenomena through experiments, theoretical models, and numerical simulations. Experiments measure the wicking height of hexadecane in a heated beaker with a polypropylene wick at room temperature. An analytical solution predicts the wicking rate based on temperature-sensitive liquid properties, such as viscosity, surface tension, and density. Three temperature models are introduced: Liquid Temperature Model, Average Temperature Model, and Dynamic Temperature Model. The first two models incorporate temperature-induced changes in liquid properties but have limitations. The Liquid Temperature Model overestimates wicking height, while the Average Temperature Model improves predictions but still faces challenges. The Dynamic Temperature Model, using numerical simulation, accurately calculates fluid properties at dynamically determined temperatures, leading to better predictions of wicking height. Comparisons with experimental data show increasing accuracy across the three models. The Dynamic Temperature Model also successfully demonstrates temperature transitions in the wick observed through thermal imaging.

Promotion of fluorescence and temperature sensitive properties for 8YSZ:Eu3+ thermo-sensitive ceramic powders by nitrogen-modified Ti3C2Tx MXene

Fluorescence temperature measurement technology offers a promising approach for real-time monitoring of internal temperature in thermal barrier coatings (TBCs). However, under high-temperature and corrosion environments of TBCs, luminescent materials experience substantial challenges, including reduced fluorescence intensity, shortened decay lifetime and diminished temperature sensitivity. In this paper, nitrogen modified Ti3C2Tx MXene (N-MXene, Tx represents -O, -OH, -F, and -N functional groups) was prepared and mechanically grounded with Eu-doped 8 mol% yttria-stabilized zirconia (8YSZ:Eu3+, Zr0.92Y0.08O1.96: Eu3+) ceramic materials to produce N-MXene/8YSZ:Eu3+ composites, enhancing the fluorescence and temperature sensitive properties of Eu3+. Results showed that homogenous N-MXene/8YSZ:Eu3+ composites with uniformly distributed Zr, Y, O, Eu, Ti, C, F and N elements were successfully synthetized. The 8YSZ:Eu3+ ceramic particles, with an average particle size of about 18 nm, were embedded within the porous, wrinkled structure of N-MXene. The addition of N-MXene did not alter the symmetry or electron transitions of Eu3+ but significantly improved luminescence intensity, fluorescence lifetime and temperature sensitivity of 8YSZ:Eu3+ powders. The optimal fluorescence characteristics were observed in composites containing 0.6 wt% N-MXene. The emission intensities for 5D0→7D1 and 5D0→7D2 transition were up to 7 times higher than those of pure 8YSZ:Eu3+ powders at room temperature and nearly 6 times higher at 500 K. The fluorescence lifetime of 8YSZ:Eu3+ powders were extended from 1.41 to 1.50 ms by N-MXene. The absolute and relative sensitivity of Y/NM-6 thermo-sensitive ceramic powders were SA (Y/NM-6) = 3.32 % K−1@350K, SR (Y/NM-6) = 0.32 % K−1@350K respectively, compared to SA (8YSZ:Eu3+) = 0.49 % K−1@350K, SR (8YSZ:Eu3+) = 0.16 % K−1@350K for 8YSZ:Eu3+. These findings demonstrate the N-MXene/8YSZ:Eu3+ composition is a potential thermos-sensitive ceramic with excellent fluorescence properties for monitoring service temperature in TBCs.

A novel strategy inspired by Luban lock towards endowing polyzwitterionic electrolyte hydrogel with UCST behaviors

The electrostatic interaction in polyzwitterionic electrolyte hydrogels is the prerequisite for materials to exhibit temperature-sensitive behaviors. Few reports mention the potential temperature-sensitive properties of these hydrogels, although amounts of polyzwitterionic electrolyte hydrogels with bright prospects in advanced fields have been reported. PMAD (copolymer of AM, AA and DMC) is a typical polyzwitterionic electrolyte, which is taken as an example to elucidate the essential conditions for the UCST behaviors of polyzwitterionic electrolyte hydrogels. The temperature-sensitive properties of PMAD hydrogels depends on the tight stacking of zwitterionic polymer chains, while the introduction of chemical crosslinker could limit the movement of PMAD chains and increase the difficulty of forming effective electrostatic interactions between zwitterionic segments resulting in the disappearance of UCST behaviors. Accordingly, the strategy inspired by the Chinese Luban lock for compressing the distance of PMAD chains by utilizing the “mortise-tenon” structure could recovery the UCST behaviors of PMAD and are expected to endow more polyzwitterionic electrolyte hydrogels with temperature-responsive properties.

Tunable impact resistant materials: Synergistic enhancement of paraffin/MRP/re-entrant structures

In the realm of safety protection, there is a critical demand for materials capable of superior energy absorption and adaptability across diverse application scenarios. Here, this study presents integrated two-phase negative Poisson’s ratio (NPR) composites with adjustable mechanical properties sensitive to magnetic field, temperature and impact load. It is achieved by substituting the vacancy of re-entrant structures (frame phase) with soft paraffin/magnetorheological plastomer (MRP) fillers (matrix phase). The paraffin/MRP exhibits temperature-sensitive properties, enhanced magnetorheological (MR) effect (up to 4178%) and shear thickening (ST) effect (up to 2365%). Through quasi-static compression and dynamic impact tests, the composites demonstrate remarkable adaptability in impact resistance. Specifically, the first peak force exhibits responsiveness to changes in magnetic flux density, temperature, and impact velocity, with respective variations of 80.6%, 68.2%, and 30.3%. The design strategy paves the way for tunable impact resistant materials with potential for extreme environment buffering applications.

Chitosan-based self-healing thermosensitive hydrogel loaded with siHMGB1 for treatment of rheumatoid arthritis via macrophage repolarization

Rheumatoid arthritis (RA) is a prevalent autoimmune disease marked by immune cell activation, particularly macrophages. An imbalance between pro-inflammatory M1 and anti-inflammatory M2 macrophages causes synovial inflammation and joint damage, worsening RA. This study presents a biomacromolecular hydrogel delivery system with apoferritin nanoparticles for effective delivery of small interfering high mobility group protein (siHMGB1). The system was designed to promote the polarization of M1 macrophages to the M2 phenotype by downregulating the HMGB1/TLR4/NF-κB-p65 signaling pathway, offering a potential therapeutic approach for the treatment of RA. The oxidized chondroitin sulfate - chitosan - sodium glycerol β - phosphate - Fn/siHMGB1 (OCF/siHMGB1) hydrogel system possessed temperature-sensitive and self-healing properties, enabling the sustained, stable, and efficient release of siHMGB1 at the affected joint. After effective uptake by macrophages, siHMGB1 could effectively repolarize M1-phenotype macrophages to M2-phenotype via the HMGB1/TLR4/NF-κB-p65 signaling pathway both in vitro and in vivo. Additionally, it suppressed the release of pro-inflammatory cytokines and upregulated anti-inflammatory cytokines, which significantly blocked the TLR4/p65-mediated inflammatory signaling. In conclusion, the siHMGB1-loaded hydrogel delivery system designed in this study is effective in treating RA and highlights the potential of gene therapy to induce repolarization of M1 to M2 macrophages for RA treatment.

Fluorescence and temperature sensitive properties of Tb and Eu co-doped 8YSZ thermosensitive ceramic

Incorporating a small amount of rare-earth luminescent elements into thermal barrier coatings is currently the most promising method for determining the temperature distribution of engine blade coatings. In this study, Tb and Eu co-doped 8YSZ ceramic powder (8YSZ:Tb3+&Eu3+) was synthesized using chemical co-precipitation method, and the optimal powder was sintered into ceramic sheet through dry pressing. The phase, morphology, fluorescence properties and temperature sensitivity of 8YSZ:Tb3+&Eu3+ ceramic were studied. Results indicated that 8YSZ:Tb3+&Eu3+ was tetragonal with average grain size ranging from 22 to 28 nm. The luminescence intensity and lifetime of 8YSZ:Tb3+&Eu3+ both reach their maximum when the doping amount of Tb3+ is 1.5 mol%, with the existence of energy transfer from Tb3+ to Eu3+. And the forming processes has little influence on fluorescence performance of 8YSZ:Tb3+&Eu3+ materials. Meanwhile, 8YSZ:1.5 Tb&1Eu ceramic reveals excellent temperature sensitivity. At 500 K, the relative sensitivities are 0.519 % K−1 and 0.369 % K−1 respectively for 8YSZ:1.5 Tb&1Eu powder and sheet, while absolute sensitivities are 0.731 % K−1 and 0.751 % K−1. Consequently, 8YSZ:Tb3+&Eu3+ ceramic is a potential temperature detection material for practical applications.

Opto/Thermoresponsive Multimode Luminescence in Eu- and Er-Activated CaF2 Phosphor for High-Security Anticounterfeiting.

As the landscape of information storage and security continues to evolve, the deployment of sophisticated anticounterfeiting strategies with robust security features and multimodal luminescent capabilities becomes imperative. In this work, Eu3+ and Er3+ ions are codoped into CaF2 phosphors to achieve multimodel optical output. The self-reduction of Eu3+ within the CaF2 matrix gives rise to the coexistence of Eu3+ and Eu2+ ions, which manifests as a color transition from orange to blue as the excitation wavelength is varied from 300 to 335 nm. Moreover, the distinct temperature-dependent behaviors of Eu3+ and Eu2+ ions underscore the material's visible temperature-sensitive luminescence properties, characterized by remarkable thermal sensitivity (Sa = 0.0156 K-1, Sr = 0.83%K-1). Additionally, the strategic introduction of Er3+ ions adds an extra dimension, enabling the realization of color-tunable upconversion luminescence through the fine-tuning of Er3+ concentration. This synergistic integration culminates in the establishment of an efficient three-path authentication model within the CaF2 host matrix, facilitating a dynamic multicolor response to changes in the excitation wavelength and temperature. By harnessing these diverse luminescent modalities, the study delivers a versatile and potent anticounterfeiting solution, advancing the frontiers of information security.

Temperature-sensitive injectable chitosan-based hydrogel for endoscopic submucosal dissection

Endoscopic submucosal dissection (ESD) is an effective treatment for polyps and early gastrointestinal cancers, but requires a high level of operator skill. Injecting submucosal materials (SIM) helps create a fluid cushion between the mucosal and muscular layers, making the procedure easier and reducing associated risks. However, SIMs commonly used in current clinical practice tend to spread quickly and fail to provide long-lasting submucosal fluid cushions (SFC). Thus, there is a critical need for a material that is easy to inject while also maintaining a durable barrier. We prepared succinylated hydroxybutyl chitosan (HBC-SA) by adding succinic anhydride (SA) to hydroxybutyl chitosan (HBC). The hydrogel had excellent temperature-sensitive properties and was able to be injected via an endoscopic injection needle even after gel formation. In vitro and in vivo studies showed that it has satisfactory biocompatibility. Functional experiments showed that the submucosal lifting properties of this hydrogel were significantly better than that of normal saline (NS) and sodium hyaluronate (SH), two commonly used clinical materials. In addition, the hydrogel possessed excellent hemostatic properties. Based on these results, HBC-SA is a promising candidate for submucosal injection during ESD.

A Temperature-Sensitive Fluorescent Supramolecular Polymer Constructed by Discrete Platinum(II) Metallacycle and Pillar[5]arene-Based Host-Guest Interactions.

The application of thermosensitive fluorescent supramolecular polymers in advanced optical materials, chemical sensors, artificial optical devices, and external stimulus responses remains underdeveloped. In this study, we introduced a novel method for constructing a mechanically interlocked fluorescent supramolecular polymer utilizing host-guest interactions, including C-H···π interactions and π-π stacking. This polymer exhibits outstanding temperature-sensitive fluorescence properties and is environmentally friendly due to its recyclability. Leveraging the polymer's fluorescence response at critical temperature ranges, we developed a high-temperature warning device. This device utilizes the temperature-sensitive fluorescence characteristic of the polymer to indicate dangerous temperature levels, thereby demonstrating its potential in practical safety applications.

Energy-Transfer-Enhanced Cr3+/Ni2+ Co-doped Broadband Near-Infrared Phosphor for Fluorescence Thermometers and Near-Infrared Window Imaging.

Here, near-infrared broad dual-band emission phosphors were achieved through energy transfer between Cr3+ and Ni2+ ions in the β-Ga2O3 host. All samples co-doped with Cr3+ and Ni2+ exhibit dual-band emission covering 600-1700 nm under 430 nm excitation. Thanks to the doping of Cr3+ ions, the emission intensity of Ga2O3:Cr3+, Ni2+ phosphors has increased by about 2.4 times and the internal quantum efficiency has increased by 83.2% compared to Ga2O3:Ni2+ phosphors. Meanwhile, when the fluorescence lifetime was monitored at 745 nm, an efficient energy transfer between Cr3+ and Ni2+ ions in the β-Ga2O3 host was verified. Due to the significant differences in the emission temperature-sensitive properties of Cr3+ and Ni2+ ions, a thermometer was designed utilizing fluorescence intensity ratio technology, achieving a maximum relative sensitivity of 5.26% K-1, which surpasses most optical temperature measurement phosphors. This suggests that Ga2O3:Cr3+, Ni2+ samples hold promise as potential candidates for optical thermometer materials. Additionally, the broadband near-infrared emission of the Ga2O3:Cr3+, Ni2+ sample has been investigated for potential applications in component analysis and night vision, demonstrating its versatility for multifunctional applications.

Two-Dimensional Physical Model Experimental Study on Sweep Efficiency of Offshore Heavy Oil Hot Water Flooding

Abstract The conventional water flooding approach for the development of ordinary heavy oil faces challenges such as high injection-production mobility, rapid increase in water cut, and low final recovery. By using the temperature-sensitive properties of heavy oil, the viscosity can be effectively reduced, and the flow capacity within porous media can be enhanced by increasing the temperature of injected water. Onshore hot water flooding is primarily used to exploit the remaining oil potential during the later stages of steam stimulation, while offshore is used to enhance efficiency during the mid to late stages of water flooding. The key to the success of hot water flooding technology lies in the improvement of the sweep coefficient. Firstly, a two-dimensional physical experiment model is designed in accordance with the geological and reservoir characteristics of the target oilfield, based on the principle of similarity. Secondly, parameters that quantitatively characterize the development law of the plane temperature field, such as the effective sweep coefficient, regular factor, and plane expansion speed of the high-temperature region, are studied. Then, through two-dimensional experiments, the effects of injection medium, formation rhythm, and timing of hot water injection on sweep efficiency and temperature field development were discussed. Finally, on the basis of two-dimensional experiments, the effects of heat injection temperature, timing of heat injection, hot water injection speed, and high permeability strip on the improvement of sweep efficiency were quantitatively analyzed by numerical simulation. The results show that compared with hot water flooding, hot water composite flooding can increase the effective sweep coefficient from 15.05 % to 28.71 %. The anti-rhythm is helpful to the upward expansion of the high temperature zone, which can increase the oil displacement efficiency by 1.5 %. Water channeling can be effectively controlled by injecting hot water with low water cut. The increase of heat injection temperature is helpful to increase the proportion of high temperature heating area. The higher the injection speed, the greater the expansion speed of the heating chamber. The research results provide a direction for the development of heavy oil conventional water flooding to improve oil recovery in offshore heavy oil.

Integrated Amorphous Carbon Film Temperature Sensor with Silicon Accelerometer into MEMS Sensor.

Amorphous carbon (a-C) has promising potential for temperature sensing due to its outstanding properties. In this work, an a-C thin film temperature sensor integrated with the MEMS silicon accelerometer was proposed, and a-C film was deposited on the fixed frame of the accelerometer chip. The a-C film was deposited by DC magnetron sputtering and linear ion beam, respectively. The nanostructures of two types of films were observed by SEM and TEM. The cluster size of sp2 was analyzed by Raman, and the content of sp2 and sp3 of the carbon film was analyzed by XPS. It showed that the DC-sputtered amorphous carbon film, which had a higher sp2 content, had better temperature-sensitive properties. Then, an integrated sensor chip was designed, and the structure of the accelerometer was simulated and optimized to determine the final sizes. The temperature sensor module had a sensitivity of 1.62 mV/°C at the input voltage of 5 V with a linearity of 0.9958 in the temperature range of 20~150 °C. The sensitivity of the sensor is slightly higher than that of traditional metal film temperature sensors. The accelerometer module had a sensitivity of 1.4 mV/g/5 V, a nonlinearity of 0.38%, a repeatability of 1.56%, a total thermomechanical noise of 509 μg over the range of 1 to 20 Hz, and an average thermomechanical noise density of 116 µg/√Hz, which is smaller than the input acceleration amplitude for testing sensitivity. Under different temperatures, the performance of the accelerometer was tested. This research provided significant insights into the convenient procedure to develop a high-performance, economical temperature-accelerometer-integrated MEMS sensor.

Fabrication and properties of conductive films based on bacterial cellulose and poly-N-isopropylacrylamide-modified graphene oxide

A conductive film (PNIPAM-rGO/BC) was fabricated combining bacterial cellulose (BC) with poly-N-isopropylacrylamide-modified graphene oxide (PNIPAM-GO) through vacuum filtration and steam reduction techniques. The conductivity and performance of PNIPAM-GO composite and the resulting conductive film were studied. The key findings revealed that PNIPAM-GO composite exhibited a reversible temperature-sensitive behavior. Specifically, the lower critical solution temperature (LCST) increased upon the introduction of graphene oxide (GO). Detailed analyses confirmed uniform dispersion of GO nanosheets within the BC matrix. The incorporation of 10.0 % PNIPAM-GO (containing 7.0 % GO) led to a remarkable 19.6 % increase in tensile strength and approximately 37.0 % enhancement in elongation at break for the conductive film (PNIPAM-rGO/BC) compared to BC. After steam reduction, the electrical conductivity of PNIPAM-rGO/BC exhibited significant improvement over BC. Furthermore, the conductive film demonstrated temperature-dependent conductivity, with a resistivity value approximately 5.2 ± 0.2 KΩ at 25 °C. As the test temperature above the LCST of PNIPAM-GO composite, the resistance decreased. These intriguing temperature-sensitive conductive properties position PNIPAM-rGO/BC as a promising material for smart switches.

Investigating the potential of Nd and Co modified bismuth ferrite (BiFeO3) nanoparticles for advanced energy storage and electronic applications

In this study, we synthesized and characterized Nd and Co modified bismuth ferrite nanoparticles (BNFCO) using mechanical milling. X-ray diffraction (XRD) analysis has provided confirmation of the distorted rhombohedral, mixed rhombohedral-tetragonal and tetragonal perovskite structure with space group R3c and P2mm. Notably, these nanoparticles exhibited a high dielectric constant and low loss values at low frequencies and high temperatures, remaining around 103 up to 373 K before increasing to approximately 104, which opens new avenues for exploring temperature-sensitive dielectric properties. The AC conductivity adhered to Jonscher's power law, with dc conductivity values ranging from 10−5 to 10−3 s/cm, representing a significant advance in understanding electrical conduction in nanomaterials. Furthermore, we assessed the electrochemical behavior of the fabricated samples at varying concentrations using cyclic voltammetry, Galvanostatic charge and discharging (GCD), and electrochemical impedance spectroscopy (EIS) on a modified electrode. BNFCO (0.20) displayed exceptional properties with a capacitance of 510 F g−1 and a capacitance retention of 93.9 % after 5k cycles, making BNFCO nanomaterials potential candidates for supercapacitor applications. The multifunctional properties of Nd and Co modified bismuth ferrite nanoparticles presented in this study offer unparalleled opportunities for transformative applications in supercapacitors and optoelectronic devices.

LED application and temperature-sensitive properties of white carbon dots doped with aluminum triacetylacetone without the N element

CD phosphors are well light up in solution but tend to undergo powder-based solid-state aggregation quenching. Solid-state aggregation quenching is an important flaw in LED applications. Moreover, most one-component, white CD phosphors are obtained using doping of various valences of N. White CDs that are not doped with N have yet to be reported. In this work, we attempted to develop white aluminum triacetylacetone-doped CDs (Al-CDs) phosphors with resisted solid-state aggregation quenching for LED applications. The Al-CDs do not contain N element and emit broadband white light from 420 to 800 nm, and their emission centers can redshift or blueshift with increasing contents of aluminum triacetylacetone. Al-CDs phosphors exhibit excellent luminescent stability at high temperature (570 K) and under natural conditions (80 days). Their afterglow time increases as the concentration of aluminum triacetylacetone increases and can reach 10 seconds. In addition, the luminescent mechanism and temperature-sensitive properties of the Al-CDs phosphors were investigated.

A multifunctional thermosensitive hydrogel based on phototherapy for promoting the healing of dental extraction wounds.

Post-extraction wound infections are a common complication of dental extractions. More specifically, infection in the alveolar socket after tooth extraction accelerates the resorption and destruction of the alveolar bone, and ultimately affects the final restoration results. Currently, the main clinical treatment approaches applied to the socket after tooth extraction include mechanical wound debridement, chemical rinses (e.g., chlorhexidine), filling of the extraction socket with absorbent gelatin sponges, and the systemic application of antibiotics. However, these traditional treatment modalities have some limitations and their therapeutic effects are unsatisfactory. In this study, a phototherapeutic temperature-sensitive hydrogel material was constructed for injection using a tea polyphenol (TP)-modified poly-N-isopropylacrylamide (PNIPAM) hydrogel skeleton loaded with the photosensitiser indocyanine green (ICG). The resulting PNIPAM-TP/ICG system exhibited an excellent injectability and temperature-sensitive properties. In addition, it stopped haemorrhaging and acted as a wound astringent. The hydrogel steadily released ICG into the oral environment to exert photothermal/photodynamic effects along with synergistic antibacterial and anti-inflammatory properties when combined with tea polyphenols. In vivo experiments demonstrated that the application of PNIPAM-TP/ICG to infected dental extraction wounds in rats rapidly stopped the bleeding and accelerated wound healing. Overall, this study describes a drug-loaded, temperature-sensitive hydrogel for the treatment of open wound infections, and shows promise as a reference for the treatment of tooth extraction wounds.

Fabrication of methylated carbon quantum dot-based fluorescent films for highly sensitive and stable temperature probes

Due to their distinct physicochemical characteristics and outstanding biocompatibility, carbon quantum dots have shown to offer enormous potential in the field of temperature sensing. However, there is still much to learn about the mechanism underlying carbon quantum dots' thermal sensing capabilities, and developing incredibly precise thermometers based on it is still an enormous obstacle. Herein, we successfully fabricated carbon quantum dots with variable luminescence wavelength and temperature-sensitive properties by adjusting the ingredients to modify the composition of functional groups (-NH2, -OH, -COOH and -CH2OH) on the surface of quantum dots in a simple hydrothermal synthesis process, followed by encapsulation with polyvinyl alcohol (PVA). Subsequently, structural/optical characterisation and temperature-dependent studies were utilized for investigations into the quantum dot fluorescence mechanisms as well as the thermal sensing characteristics connected to surface functional groups, respectively. Notably, the designed red-emitting methylenated carbon quantum dot film probe displayed more linear segmented temperature sensing properties (R2>0.99), a wider temperature applicability range (20–160 °C), and high temperature reversibility (20–80 °C, at least 4 cycles). Finally, the mechanism by which functional groups affect the thermal characteristics of carbon quantum dots was addressed, and we hypothesized that intramolecular and intermolecular hydrogen bonding interactions are important factors affecting the thermal properties of carbon dots. This work presents great promise and theoretical guidance for the development of highly reliable carbon quantum dot temperature sensing systems.

Reactive extrusion fabrication of thermoplastic starch with Ca2+ heterodentate coordination structure for harvesting multiple-reusable PBAT/TPS films

Creating multiple-reusable PBAT/TPS (PT) films presents a novel solution to reduce carbon emissions from disposable packaging, addressing challenges like the high creep of PBAT and the glycerol migration of TPS. Consequently, adopting reactive extrusion to fabricate reversible cross-linking TPS with high shape memory performance, low migration, and homogeneous dispersion in PBAT matrix was a fascinating strategy. Herein, starch, glycerol and CaCl2 (calcium chloride) were extruded to fabricate TPS-Ca with Ca2+ heterodentate coordination structure and confirmed by XPS, 1H NMR and temperature-dependent FTIR. The results of DMA, dynamic rheology, flow activation energy and SEM revealed that TPS-Ca exhibited significant temperature-sensitive reversible properties and robust melt flow capability, enabling micro-nano scale dispersion in PBAT. Noteworthy, PBAT/TPS-Ca (PT-Ca) would recover 100 % length within 20 s by microwave heating after being loaded under the hygrothermal environment. Meanwhile, the migration weight of glycerol decreased from 2.5 % to 1.2 % for the heat-moisture-treated PBAT/TPS (HPT) and PBAT/TPS-Ca (HPTCa). Remarkably, the tensile strength and elongation at the break of HPT-Ca increased to 20.0 MPa and 924 %, respectively, due to reduced stress concentration sites in the phase interface. In summary, our study provides a streamlined strategy for fabricating multiple-reusable PT, offering a sustainable solution to eliminate carbon emissions linked to disposable plastic.

Molecular Engineering to Achieve AIE-active Fluorophore with Near-infrared (NIR) Emission and Temperature-sensitive Property.

Near-infrared organic small molecule luminescent materials have the advantages of easy modification, high quantum efficiency, good biological affinity, and color adjustability; thus, have promising application prospects in the fields of photoelectric devices, sensitive detection, photodynamic therapy, and biomedical imaging. However, traditional organic luminescent molecules have the problems of short emission wavelength, aggregation-causing emission quenching, and low quantum yield. Herein, we successfully synthesized four D-π-A-D light-emitting molecules based on electron-withdrawing malonitrile group and different electron-donating arylamine groups. These compounds showed satisfactory solvatochromism, aggregation-induced emission, red and near-infrared fluorescence, high photoluminescence quantum efficiency and temperature response properties. This successful example of molecular engineering provides a valuable reference for the development of advanced NIR materials with AIE and temperature-sensitive properties.

Application of the Arrhenius Equation in Predicting the Temperature Susceptibility of Unmodified and Modified Bituminous Binder

Bitumen is a temperature-susceptible material. The performance of the bitumen largely depends on the sensitivity of its characteristic properties to the variation in temperature. This paper uses the Arrhenius equation to predict the temperature-sensitive properties of various bitumens. Three modified and unmodified binders of various grades were tested under study shear, frequency mode (oscillatory shearing), and time mode (multiple stress creep and recovery) at different temperatures from 10 to 70ºC. This paper focuses on the activation energy to understand the temperature-susceptible behavior of the bitumen and the influence of aging on the bitumen. To analyze the temperature susceptibility of the bitumen, Steady shear, MSCR, and LAOS tests were performed. From these tests, parameters such as viscosity, dynamic modulus, energy dissipation, and creep compliance at different temperatures were observed to follow the Arrhenius equation. The activation energy constant of the Arrhenius equation is found to vary with the characteristic function used. It is also statistically proven that the activation energy depends on the shear rate or shear stress, indicating that the temperature-susceptible properties of the bitumen are shear rate-dependent. Also, as the bitumen ages, its temperature-susceptible properties improve. Doi: 10.28991/CEJ-2024-010-03-015 Full Text: PDF