Nanoscale
·
2018
·Vol. 10
·期 46
·21809-21817
·
IF 7.233
Chan Wang,Tantan Hu,Tiju Thomas,Shanliang Song,Zhuoqi Wen,Chuanxi Wang,Qijun Song,Minghui Yang
Fluorescence-based nanothermometers have potential to offer accuracy in the measurement of temperature using non-contact approaches. Herein, a C-dot/C-dot based dual-emission temperature sensing platform is fabricated through the electrostatic self-assembly of two kinds of fluorescent CDs with opposite charges. This dual-emission platform consists of several nearly-spherical CDs with two emission centers in blue (440 nm) and orange (590 nm) regions. The orange fluorescence exhibits discernible response to external temperatures in the range of ∼15 to 85 °C; on the other hand, the blue fluorescence remains nearly constant. A continuous fluorescence color change in response to temperature from orange to blue can be clearly observed by the naked eye. Thus, the as-prepared C-dot based dual-emission nanospheres can be used for optical thermometry with high reproducibility and sensitivity (0.93%/°C). Detailed characterization shows that temperature (in the 15–85 °C window) impacts the surface states of orange emissive CDs, leaving the blue emissive CDs unaffected. A model is proposed to explain the observations. Finally, by taking advantage of the excellent biocompatibility and stability, the CD based fluorescent nanothermometer is successfully used for the visual measurement of intracellular temperature variations.
研究领域:
材料科学
·
纳米技术
·
生物物理
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENERGY
·
2014
·
IF 4.159
Wen-long Cheng,Shuai Yuan,Jia-liang Song
PTC (positive temperature coefficient) material is a kind of thermo-sensitive material. In this study, a series of novel PTC materials adapted to thermal control of electron devices are prepared. By adding different low-melting-point blend matrixes into GP (graphite powder)/LDPE (low density polyethylene) composite, the Curie temperatures are adjusted to 9 °C, 25 °C, 34 °C and 41 °C, and the resistance–temperature coefficients are enhanced to 1.57/°C–2.15/°C. These PTC materials remain solid in the temperature region of PTC effect, which makes it possible to be used as heating element to achieve adaptive temperature control. In addition, the adaptive thermal control performances of this kind of materials are investigated both experimentally and theoretically. The result shows that the adaptive effect becomes more significant while the resistance–temperature coefficient increases. A critical heating power defined as the initial heating power which makes the equilibrium temperature reach terminal temperature is presented. The adaptive temperature control will be effective only if the initial power is below this value. The critical heating power is determined by the Curie temperature and resistance–temperature coefficient of PTC materials, and a higher Curie temperature or resistance–temperature coefficient will lead to a larger critical heating power.
研究领域:
材料科学
·
热力学工程
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2020
·
IF 6.785
Yueling Xu,Yi Yang,Shen Lin,Lehui Xiao
Precise sensing of intracellular temperature can provide plenty of information on disease-related cell states and promote the development of a diagnostic method. Fluorescence-based nanothermometers, as the “noncontact” sensors, exhibit great advantages over traditional thermometers due to the dual function of imaging and sensing at the molecular level. Herein, we report a red-emitting carbon nanodots (RCDs)-based nanothermometer for intracellular temperature sensing. Results indicate that RCDs exhibit favorable temperature-responsive fluorescence property with a good linear relationship, reversibility, and reproducibility under heating and cooling treatments in a wide range from 4 to 80 °C. Meanwhile, the RCDs possess satisfactory thermal sensitivity and temperature resolution, which are superior or comparable to the current nanothermometers. The low cytotoxicity and excellent temperature-responsive fluorescence property of RCDs have also been verified in living cell studies. Therefore, the RCDs will be a promising nanothermometer for intracellular temperature sensing in diverse areas.
研究领域:
纳米技术
·
生物医学工程
·
材料科学
·
细胞生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2011
·Vol. 95
·期 1
·37-40
·
IF 2.169
Songping Wu,Chan Jiang,Youxian Mei,Weiping Tu
The Sm 2 SiO 5 ceramics were synthesized and their microwave dielectric properties were investigated. The pure monoclinic Sm 2 SiO 5 phase could be obtained when the molar ratio of Sm 2 O 3 /SiO 2 was 1:1.05 at 1350°C. A small amount of hexagonal Sm 4 (SiO 4 ) 3 second phase occurred as temperature increased. The relative density of Sm 2 SiO 5 ceramics increased with increasing temperature. The Sm 2 SiO 5 ceramics sintered at 1500°C exhibited microwave dielectric properties: a dielectric constant (ε r ) of 8.44, a quality factor ( Q × f ) of 64 000 GHz, and a temperature coefficient of resonant frequency (τ f ) of −37 ppm/°C. The Sm 2 SiO 5 ceramics have a wide sintering temperature region and small negative τ f values. They are promising candidate materials for millimeter-wave devices.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
SENSORS AND ACTUATORS A-PHYSICAL
·
2025
·
IF 4.9
Pengfei Zhao,Jijun Ding,Haixia Chen,Haiwei Fu
Wearable devices have great potential for development in the fields of human health detection and human-computer interaction due to its flexibility and portability. In this work, Firstly, the resistance response performance of paper/Cu/Al 2 O 3 to temperature is optimized by changing the sputtering time of Al 2 O 3 . Combining the resistance change and stability after one month, paper/Cu/Al 2 O 3 films with 1 min Al 2 O 3 layer is selected. Then, temperature sensor based on optimized paper/Cu/Al 2 O 3 and graphene/PVDF composite temperature-sensitive layers is fabricated. The sensor shows negative temperature coefficient, high temperature response and stability, which provides significant advantages in the field of temperature monitoring. The fastest response/recovery time of the sensor is 1.4 s and 10.48 s respectively, which is fast and reliable in capturing the temperature changes and thus has the capability of real-time temperature monitoring. Another outstanding feature of the sensor is its high linearity to temperature fluctuations (R 2 =0.947). This feature suggests that the sensor enables real-time resistance-temperature interaction. In addition, its practical applications will be explored. The sensor can quickly sense the temperature of fingers, hot water, and working mobile phones. At the same time, the excellent performance of the sensor enables it to achieve the function of illuminating the LED. It lays the foundation for the application of temperature sensors in flexible wearable device applications.
研究领域:
材料科学
·
电子工程
·
健康检测
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Hang Zhang,Hang Yang,Guogang Li,Shiqi Liu,Haoran Li,Yuming Gong,Yujun Liang,Yongjun Chen
Currently, phosphor materials play an important role in designing noncontact remote optical thermometers. Although many approaches have contributed to improve thermometric performance of optical thermometers including optimization of host materials, size of nanoparticles , dopant type and concentration as well as excitation density and phonon energy engineering, the development of highly sensitive optical thermometric materials is still a challenge. Hence, we developed novel CaNb 2 O 6 (CNO):Ln 3+ (Ln 3+ = Eu 3+ /Sm 3+ /Dy 3+ /Tb 3+ ) phosphors as highly thermometric materials and proposed a novel strategy for further enhancing its thermometric performance via adding the intensity of indicator signal by co-doping Bi 3+ ions in current phosphor system. Typically, the as-prepared CNO:Ln 3+ phosphors present a broad blue emission around 470 nm originated from NbO 6 octahedral groups and some respective emission lines derived from the characteristic f-f transitions of Ln 3+ ions. Based on the diverse thermal quenching performance between blue emission and Ln 3+ ions emission , the temperature sensitivities of CNO:Ln 3+ were investigated in detail. Among them, the maximum relative sensitivity of CNO:Eu 3+ sample reached 1.991% K −1 in the range of 298–448 K and remained 97% after five temperature cycles. Furthermore, an obvious discoloration was discovered during temperature cycle testing in CNO:Ln 3+ samples under 254 nm UV lamp. Through doping Bi 3+ ion, the strongest intensity of indicator signal is 24 folds that of CNO host. Correspondingly, the relative sensitivity of CNO:Bi 3+ , Eu 3+ sample is obviously improved to 3.793% K −1 in the range of 298–523 K, owing to a larger range of the FIR value and a wider drop range of indicator signal. This work opens up an effective pathway to improving thermometric performance of optical thermometers by enhancing the intensity of indicator signal of employed phosphor materials.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
OPTIK
·
2017
·
IF 0.835
Yu Wang,Yue Yang,Peng Wang,Xue Bai
The concentration and temperature dependence of photoluminescence (PL) performance was investigated, which indicated that the main emission in CsPbBr 3 perovskite quantum dots was related to the band-edge mechanism. As the concentration increased from 0.1 to 10.0 mol/L at 293 K, the center of emission band exhibited a regular redshift, as well as the peak intensity increased initially and then declined, which could be attributed to the self-absorption processes. Along with the variation of temperature (273–353 K), peak wavelength, full width of half maximum (FWHM), and peak intensity of PL spectra presented a corresponding linear changes. In addition, the temperature reversibility revealed that CsPbBr 3 QDs were reliable candidates for temperature sensor and optoelectronic devices .
研究领域:
材料科学
·
光电技术
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry B
·
2021
·Vol. 9
·期 20
·4111-4119
·
IF 6.331
Yi Han,Yanran Liu,Haiguang Zhao,Alberto Vomiero,Ronggui Li
Optical nanothermometers have attracted much attention due to their non-contact and precise measurement with high spatial resolution at the micro- and nanoscales. They can be applied in various fields such as micro-opto-electronics, photonics, and biomedical thermal and pH sensing, while most thermal sensors reported so far contain heavy metals or have low sensitivity. Herein, we demonstrate a highly sensitive ratiometric thermal sensor based on colloidal C-dots. C-dots exhibit dual emission originating from the band gap emission and surface-dominant emission, which show a different temperature-dependent photoluminescence (PL) response. Among different surface-functionalized C-dots, C-dots@OH exhibit an absolute thermal sensitivity of −0.082 °C−1, which is the highest among various types of ratiometric thermosensors, making it a very promising candidate for high-sensitivity, self-calibrated nanoscale thermometry. As a proof-of-concept, C-dots@OH were employed to monitor the intracellular temperature (32–42 °C), showing a clear trend for temperature variation in a single cell, indicating that C-dots could offer a powerful tool for a potential precise measurement of the intracellular temperature. They could also be used as thermal sensors for nano-electronic and optoelectronic devices.
研究领域:
材料科学
·
生物医学工程
·
光学
✓ 已验证
DOI
PubMed
高影响因子
Journal of Materials Chemistry C
·
2018
·Vol. 6
·期 48
·13352-13358
·
IF 5.976
Deyin Wang,Pengpeng Zhang,Qiang Ma,Jiachi Zhang,Yuhua Wang
Submicron-sized Er3+ doped Y7O6F9 phosphors were synthesized via the precipitation method and a subsequent annealing process. The influence of the Er3+ doping concentrations and the heating temperature on the luminescence of Y7O6F9:Er3+ was investigated under the excitation of the Er3+ 4G11/2 level at 378 nm. Upon raising the Er3+ doping concentration, both the intensity and lifetime of the Er3+ green emission at 547 nm originating from 4S3/2 → 4I15/2 decrease, which is proved to be caused by energy transfer via cross relaxation between two neighboring Er3+ ions. The thermal sensing properties of Y7O6F9:Er3+ were evaluated using the temperature dependent intensity ratio between the 2H11/2–4I15/2 and 4S3/2–4I15/2 transitions of Er3+ under 378 nm excitation. The experimental results show that the thermal sensitivity decreased with an increase in the Er3+ doping content, which is caused by the increased energy transfer probability among Er3+. The increased energy transfer of Er3+ reduces the thermalized population of Er3+ in the 2H11/2 levels, which in turn decreases the thermal sensitivity. The applicability of Er3+ doped Y7O6F9 as a thermal sensor was demonstrated by measuring the chip temperature of a 1 W InGaN type near-ultraviolet light emitting diode (n-UV LED).
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2024
·Vol. 35
·期 36
·1-9
·
IF 2.8
Fu Jinxin,Zhou Changrong,Chen Jun,Yu Dongyan,Wu Di,Li Qingning,Yuan Changlai,Xu Jiwen,Rao Guanghui
The incompatibility of the large piezoelectric response ( d 33 ) and high depolarization temperature ( T d ) in lead-free piezoelectric ceramics limited their practical applications. The most used modification methods for improving d 33 or T d commonly required a delicate control of complex compositions. Here, a strategy for simply changing the sintering temperature is used to defer the T d and increase d 33 simultaneously. The T d and d 33 of unmodified Bi 0.5 Na 0.5 TiO 3 -0.2Bi 0.5 K 0.5 TiO 3 (BNKT20) ceramics increase with increasing sintering temperature until both of them reach the maximum ( d 33 ~ 174pC/N, T d ~ 177 °C) at the sintering temperature of 1100 °C. In-depth analysis unveils the critical role of multiphase coexistence and oxygen vacancies in enhancing T d by optimizing sintering temperature. Meanwhile, increasing sintering temperature promotes large grain size with easy domain orientation, thus, yielding the improved d 33 . This work provides a simple and effective method to broaden the working range of Bi 0.5 Na 0.5 TiO 3 -based (BNT) piezoelectric ceramics at high temperature under the premise of realizing high piezoelectric properties.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2024
·Vol. 26
·期 15
·11498-11505
·
IF 2.9
Jiannan Sun,Ke Yan,Aizhao Pan,Pan Zhang,Xuehang Chen,Xinyi Shi,Chengyu Shi
Fluorescence nanothermometry based on quantum dots is a current research hotspot for novel non-contact temperature monitoring, and is of vital significance for the modulation and design of the sensing properties of sensors. Herein, a design strategy to modulate the temperature-sensing characteristics of quantum dots based on the thickness of a shell is proposed. In this study, CdSe/ZnS quantum dot/POSS-based temperature probe films with varying fluorescence characteristics were developed, and the influence of the ZnS shell on temperature sensing was examined by varying the thickness of the ZnS shell. The temperature dependency, linearity, range of applications, and reversibility of quantum dot thin film probes were all considerably regulated by the ZnS shell, according to research on quantum dot/POSS-based films coated with various shell thicknesses. The CdSe/ZnS temperature probe with 4 monolayers (MLs) stood out among the rest due to its strong thermal stability (at least 5 cycles), large usable temperature range (20–80 °C), and excellent temperature sensitivity (R2 > 0.994). The results demonstrated that the temperature sensing performance of quantum dots was the consequence of the combined effect of multiple temperature response properties induced by the thickness of the shell, and the shell control of quantum dots to optimize the temperature sensing performance was an essential approach for the design of temperature probes. This work demonstrates the great potential of the shell in tuning the temperature sensing performance of quantum dots and provides a viable approach for the design of quantum dot temperature probes.
研究领域:
材料科学
·
纳米技术
·
传感器技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2019
·
IF 4.561
Dongren Cai,Nisakorn Saengprachum,Zhipeng Lin,Ting Qiu
In this study, a molecular simulation (Gaussian03) was used to analyze the chemical structure of 4-dimethylaminopyridine (DMAP) to investigate its use for the synthesis of ionic liquids (ILs). Based on DMAP, a series of new ILs was prepared and characterized by fourier transform infrared spectroscopy (FT-IR), 1 H nuclear magnetic resonance ( 1 H-NMR), thermogravimetric analysis (TGA), and differential scanning calorimeter (DSC). The density data of the studied ILs were measured from 328.15 K to 358.15 K, p = 0.101 MPa. It is shown that density decreases with an increase in the temperature and the alkyl chain length of cations. And density is also affected by the anion type. Furthermore, the volume of ions, NBO charges, and the interactions of anions and cations were calculated by Gaussian03 to explain the obtained density results. The second-order polynomial equation was adopted to correlate the relationship of density and temperature. Then, an isobaric thermal expansion coefficient , molecular volume, and lattice potential energy were obtained from the density data. Viscosity was determined from 323.15 K to 368.15 K, p = 0.101 MPa. It is determined that the viscosity of ILs decreases with an increase in the temperature but increases with an increase in the alkyl chain length of cations. The temperature dependence of viscosity was described by the Vogel-Fulcher-Tamman (VFT) model, and the activation energy of viscous flow ( E η ) was obtained. Furthermore, the decomposition temperature ( T d ), glass transition temperature ( T g ), and melting temperature ( T m ) of ILs were obtained from the results of TGA and DSC.
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）