排序方式: 共有2条查询结果,搜索用时 0 毫秒
1
1.
Emmanuel Urandu Mapesa Ludwig Popp Wycliffe Kiprop Kipnusu Martin Tress Friedrich Kremer 《Soft Materials》2014,12(4):S22-S30
Broadband Dielectric Spectroscopy (BDS) is used to probe the molecular dynamics of Type A polymer, poly(cis-1,4-isoprene), when confined in the 1-dimensional (1D) exploring space of thin layers and the 2-dimensional (2D) constraining geometry of unidirectional anodic aluminum oxide (AAO) nanopores. For both cases, it was observed that the structural relaxation remains bulk-like in its mean relaxation rate, although the distribution of its relaxation times is broadened in 2D confinement. Furthermore, the fluctuation of the end-to-end vector is interrupted, with the 1D case being relatively less pronounced. By this clear-cut comparison, it is demonstrated that the effects of confinement on molecular dynamics depend, inter alia, on the dimensionality of the restricting space. 相似文献
2.
Wycliffe Kiprop Kipnusu Carlos Doñate-Buendía Mercedes Fernández-Alonso Jesús Lancis Gladys Mínguez-Vega 《Particle & Particle Systems Characterization》2020,37(6):2000093
Multifunctional triple color photoluminescent (PL) nitrogen–boron doped carbon quantum dots (CQDs) with high quantum yield (QY) of 58% are fabricated by one step femtosecond pulsed laser irradiation of a single precursor (2-aminopyrimidine-5-boronic acid) in solution. In situ generated non-linear and linear emissions are used to monitor CQDs formation which results in enhanced second harmonic generation, two photon absorption (2PA), and linear fluorescence; implying triple mode emission. These CQDs present blue, green, and possible red color rendering which are mostly independent to the respective excitation wavelengths (λ) with large stokes shift of 100 nm. Solid-state photoluminescence with QY of 46% is achieved by incorporating CQDs into thin transparent nanoporous silica (pSiO2) films (thickness 50 µm) to form a CQDs-pSiO2 composite which exhibits reverse saturable absorption at λ = 800 nm with 2PA coefficient and excited state absorption cross-section of 4.94 × 10−10 m W−1 and 6.23 × 10−17 cm2, respectively. CQDs-pSiO2 is also sensitive to glucose concentration down to 1.0 mg dL−1 in a wide linear range up to 100 mg dL−1. This work therefore demonstrates facile, controllable, and up-scalable bottom-up fabrication of CQDs forming multifunctional solid-state CQDs-pSiO2 with proven application in optical limiting and glucose sensing. 相似文献
1