1
|
Luo JP, Yin N, Lu JB, Tan ZC, Shi Q. Design and construction of a refrigerator-cooled adiabatic calorimeter for heat capacity measurement in liquid helium temperature region. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2024; 95:035114. [PMID: 38466030 DOI: 10.1063/5.0159807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 02/21/2024] [Indexed: 03/12/2024]
Abstract
Heat capacity is a fundamental thermodynamic property of a substance. Although heat capacity values and related thermodynamic functions are available for many materials, low-temperature heat capacity measurements, especially for novel materials, can still provide valuable insights for research in physics, chemistry, thermodynamics, and other fields. Reliable low-temperature heat capacity data are typically measured using classical adiabatic calorimeters, which use liquid helium as the refrigerant to provide a cryogenic environment for heat capacity measurements. However, liquid helium is not only expensive but also not easy to obtain, which greatly limits the application of adiabatic calorimetry. In this work, an accurate adiabatic calorimeter equipped with a Gifford-MacMahon refrigerator was designed and constructed for measuring the heat capacity of condensed matter in the temperature range from 4 to 100 K. The Gifford-MacMahon refrigerator was utilized to provide a stable liquid helium-free cryogenic environment. A simple mechanical thermal switch assembly was designed to facilitate switching between the refrigeration mode and the adiabatic measurement mode of the calorimeter. Based on the measurement results of standard reference materials, the optimized repeatability and accuracy of heat capacity measurements were determined to be within 0.8% and 1.5%, respectively. The heat capacity of α-Fe2O3 nanoparticles was also investigated with this device. Furthermore, this adiabatic calorimeter only requires electricity to operate in the liquid helium temperature range, which may significantly advance the research on low-temperature heat capacity based on adiabatic calorimetry.
Collapse
Affiliation(s)
- Ji-Peng Luo
- Thermochemistry Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian Technology Innovation Center for Energy Materials Thermodynamics, Liaoning Province Key Laboratory of Thermochemistry for Energy and Materials, Dalian National Laboratory for Clean Energy, Dalian 116023, People's Republic of China
| | - Nan Yin
- Thermochemistry Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian Technology Innovation Center for Energy Materials Thermodynamics, Liaoning Province Key Laboratory of Thermochemistry for Energy and Materials, Dalian National Laboratory for Clean Energy, Dalian 116023, People's Republic of China
| | - Jia-Bao Lu
- Thermochemistry Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian Technology Innovation Center for Energy Materials Thermodynamics, Liaoning Province Key Laboratory of Thermochemistry for Energy and Materials, Dalian National Laboratory for Clean Energy, Dalian 116023, People's Republic of China
| | - Zhi-Cheng Tan
- Thermochemistry Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian Technology Innovation Center for Energy Materials Thermodynamics, Liaoning Province Key Laboratory of Thermochemistry for Energy and Materials, Dalian National Laboratory for Clean Energy, Dalian 116023, People's Republic of China
| | - Quan Shi
- Thermochemistry Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian Technology Innovation Center for Energy Materials Thermodynamics, Liaoning Province Key Laboratory of Thermochemistry for Energy and Materials, Dalian National Laboratory for Clean Energy, Dalian 116023, People's Republic of China
| |
Collapse
|
2
|
Chen Y, Song X, Wang Y, Huang Y, Wang Y, Zhu C. The effect of Pluronic P123 on shape memory of cross-linked polyurethane/poly(l-lactide) biocomposite. Int J Biol Macromol 2024; 259:128788. [PMID: 38154706 DOI: 10.1016/j.ijbiomac.2023.128788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 12/02/2023] [Accepted: 12/12/2023] [Indexed: 12/30/2023]
Abstract
Polyurethane (PU) and poly(l-lactide) (PLLA) have attracted increasing attention in the development of shape memory polymers (SMPs) due to their good biocompatibility and degradability. Although Pluronic P123 can be used to tune polymeric surface hydrophilicity, its effect on SM performance is a mystery. In this study, a soluble cross-linked PU is synthesized as the switching phase and combined with PLLA and P123 to construct a hydrothermally responsive SM composite. The water contact angle of PU/PLLA/P123 decreases from 22.7° to 5.1° within 2 min. PU and P123 form the switching group, which enhances the SM behavior of the composite. The shape fixity (Rf) and shape recovery (Rr) of PU/PLLA/P123 are 94.4 % and 98 % in 55 °C water, respectively, and the shape recovery time is only 10 s. P123 plays the role of "turbine" in the SM process. PU/PLLA/P123 exhibits a balance between stiffness and elasticity, and good degradability. Furthermore, PU/PLLA/P123 is also biocompatible and beneficial to cell proliferation and growth. Therefore, it offers an alternative approach to developing hydrothermally responsive SM biocomposites based on P123, PU and PLLA for biomedical applications.
Collapse
Affiliation(s)
- Youhua Chen
- School of Chemical Engineering, Changchun University of Technology, China
| | - Xiaofeng Song
- School of Chemical Engineering, Changchun University of Technology, China; Jiangxi Center of Modern Apparel Engineering and Technology, Jiangxi Institute of Fashion Technology, China.
| | - Ying Wang
- School of Chemical Engineering, Changchun University of Technology, China
| | - Yuan Huang
- School of Chemical Engineering, Changchun University of Technology, China
| | - Yanhe Wang
- Jiangxi Center of Modern Apparel Engineering and Technology, Jiangxi Institute of Fashion Technology, China
| | - Chuanming Zhu
- School of Chemical Engineering, Changchun University of Technology, China
| |
Collapse
|