Article
Polymer Science
Gaopeng Shi, Yuanbiao Liu, Guozhang Wu
Summary: This study proposes the design of polymeric materials with low m but high T-g by introducing ionic coordination. The results show that T-g increases with the addition of metallic ions, while m varies depending on the coordination strength. Additionally, the experiments reveal a close correlation between m and Delta C-p and Delta H-R.
Article
Polymer Science
Gaopeng Shi, Yuanbiao Liu, Guozhang Wu
Summary: This study successfully designed polymeric materials with low dynamic fragility but high glass transition temperature by introducing ionic coordination, and investigated the influence of coordination strength on T-g and m. Experimental results showed that increasing coordination strength led to higher T-g and lower m, with enthalpy change playing a significant role in m.
Article
Materials Science, Ceramics
Linfeng Ding, Karan Doss, Yongjian Yang, Kuo-Hao Lee, Michal Bockowski, Sylvie Demouchy, Manuel Thieme, Benedikt Ziebarth, Qingwei Wang, Morten M. Smedskjaer, John C. Mauro
Summary: The study investigates the effect of pressure history on the relaxation behavior of borosilicate glasses, finding that high-pressure treatment affects the glass relaxation properties. Additionally, a new relaxation model is proposed and verified for volume recovery data under different compression methods, showing the pressure and temperature dependence of volume relaxation.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2021)
Article
Materials Science, Ceramics
Ricardo Felipe Lancelotti, Ana Candida Martins Rodrigues, Edgar Dutra Zanotto
Summary: In this study, the structural relaxation kinetics of lithium disilicate glass were investigated through physical aging experiments. The results showed that the relaxation process starts faster when probed by ionic conductivity than by refractive index, although they have similar average relaxation times. These findings suggest that the relaxation dynamics is indeed dependent on the analyzed property.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Di Xu, Xin Liu, Ji Wang, Qian-Qian Liu, Rong Fu, He Lin, Ling Chen, Li-Min Wang, Li-Ming Wu
Summary: In this study, two novel AZnP(3)O(9) glasses were obtained by melting single crystals with identical compositions. It was found that these glasses exhibit structural inheritance within a range of 5 angstroms from their single crystal counterparts, revealing the atomic structural origin of the fictive temperature for the first time.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Polymer Science
Semen E. Lapuk, Marina A. Ponomareva, Andrey Galukhin, Timur A. Mukhametzyanov, Christoph Schick, Alexander Gerasimov
Summary: This study investigated the stability and kinetic parameters of glassy materials, focusing on the dynamic properties of polyvinylpyrrolidone polymer used in the pharmaceutical industry. The results can be utilized for optimizing the processing of polymer-based glassy materials and their applications in various technological fields.
Article
Multidisciplinary Sciences
Yong Zhao, Baoshuang Shang, Bo Zhang, Xing Tong, Haibo Ke, Haiyang Bai, Wei-Hua Wang
Summary: This study demonstrates that a Ce-based metallic glass can transform into a hyperstable state and exhibit strong resistance against crystallization after long-term aging. The achieved hyperstable state is similar to that of million-year-aged amber, and the Ce-based metallic glass can reach equilibrium liquid state below T-g without crystallization.
Article
Materials Science, Ceramics
Collin J. Wilkinson, John C. Mauro
Summary: This study demonstrates that glass relaxation can be accurately modeled through a simplified toy enthalpy landscape approach, bypassing the use of fictive temperature, and provides insights into the thermodynamics and kinetics of crystallization. The toy landscape approach, based on a more accurate physical framework, recovers key predictions from traditional fictive temperature descriptions, giving fundamental knowledge of glass relaxation and crystallization processes.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2022)
Article
Chemistry, Physical
Jiri Malek
Summary: This article discusses the structural relaxation phenomenon in amorphous materials using the TNM, KAHR, and AGSH models. These three phenomenological models are commonly used to describe experimental structural relaxation data through curve fitting. Parameters reported in the literature for 250 different amorphous material compositions are analyzed based on the isothermal relaxation rate R, the nonexponentiality parameter fi, and the nonlinearity contribution a = -(dln z/dTf)i. The R10 calculated at 10 K below Tg represents a scale for the structural relaxation rate, providing valuable insights into the kinetics of structural relaxation in various amorphous materials and their potential applications.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Physics, Fluids & Plasmas
Ian M. Douglass, Jeppe C. Dyre
Summary: We propose a microscopic definition and interpretation of material time, suggesting that the increase of material time reflects the distance traveled by particles in the system. Different distance measures are discussed, and computer simulations confirm the proposed viewpoint.
Article
Materials Science, Multidisciplinary
Zhiru Cui, Guisong Shao, Meixin Zhang, Ye Tian, Quan Chai, Yushi Chu, Jianzhong Zhang
Summary: Viscosity of optical fiber, which is influenced by the size of silica optical fiber and the difference in fictive temperature, is essential in high temperature applications. The size-dependent viscosity phenomenon of silica optical fiber under high temperature is identified, with larger diameter fibers exhibiting higher viscosity. An equivalent fictive temperature is used to explain the difference in equilibrium viscosity, and the relationship between equilibrium viscosity and fictive temperature for 1000°C is derived.
OPTICAL MATERIALS EXPRESS
(2023)
Article
Chemistry, Physical
Yuanbiao Liu, Gaopeng Shi, Guozhang Wu
Summary: This study explored changes in the dynamic fragility of PBMA by introducing guest hindered phenols, which can form intermolecular hydrogen bonds with the host polymer. The small molecules effectively reduced the m value, despite increasing the glass transition temperature of the mixtures. The strength of inter-HB interactions primarily governed m, while the T-g value of mixtures depended on a combined effect of additive bulkiness and HB interaction.
Article
Optics
Yichi Han, Songlin Wan, Xiaocong Peng, Guochang Jiang, Lin Wang, Chaoyang Wei, Jianda Shao
Summary: Laser beam figuring (LBF) is a key technology for ultra-precision figuring to improve optics performance. CO2 LBF was demonstrated for full-spatial-frequency error convergence without stress. Controlling subsidence and surface smoothing effectively ensures form error and roughness. The densi-melting effect and clustered overlapping processing technology provide a new high-precision, low-cost manufacturing method for optics.
Article
Chemistry, Physical
Heedong Yoon, James Heinzman, Stuart E. Smith, Manesh Gopinadhan, Kazem V. Edmond, Amy C. Clingenpeel, Nicolas J. Alvarez
Summary: Differential scanning calorimetry (DSC) was used to study the fast aging behavior of two petroleum pitch materials despite being only three to five years old. The highly aromatic pitches with broad distributions of molecular weight and aromaticity exhibited large enthalpic relaxation endotherms and significant reductions in fictive temperature and θK, indicating aged glasses. The aging rate of these materials is comparable to that of low fragility metallic glasses and faster than polymers reported in the literature.
Article
Materials Science, Ceramics
G. P. Johari
Summary: By comparing the heat capacity curves of glass and melt, the fictive temperature Tf of the glass can be estimated. It is found that the heat capacity of 20-million-year-old fossil amber and fresh amber are the same at temperatures lower than 273K, and the Tf of fossil amber is 0.89Tg->l. However, using the same heat capacity values violates the basic laws of thermodynamics at temperatures higher than 0K.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2023)
