Inhibition of Ostwald ripening and crystal growth of lithium bromide hydrates by selective adsorption of inhibitor molecules

Research Project

Project/Area Number	17H03187
Research Category	Grant-in-Aid for Scientific Research (B)
Allocation Type	Single-year Grants
Section	一般
Research Field	Thermal engineering
Research Institution	National Institute of Advanced Industrial Science and Technology
Principal Investigator	Inada Takaaki 国立研究開発法人産業技術総合研究所, エネルギー・環境領域, 研究グループ長 (60356491)
Project Period (FY)	2017-04-01 – 2020-03-31
Project Status	Completed (Fiscal Year 2019)
Budget Amount *help	¥17,550,000 (Direct Cost: ¥13,500,000、Indirect Cost: ¥4,050,000) Fiscal Year 2019: ¥5,590,000 (Direct Cost: ¥4,300,000、Indirect Cost: ¥1,290,000) Fiscal Year 2018: ¥5,980,000 (Direct Cost: ¥4,600,000、Indirect Cost: ¥1,380,000) Fiscal Year 2017: ¥5,980,000 (Direct Cost: ¥4,600,000、Indirect Cost: ¥1,380,000)
Keywords	熱工学 / 結晶成長 / 吸収冷凍機 / 臭化リチウム / 合成高分子
Outline of Final Research Achievements	Absorption refrigerators using lithium bromide (LiBr) solution as an absorbent can be operated by utilizing waste heat. However, the operation of absorption refrigerators using LiBr solution is often hampered by crystallization of LiBr hydrates. In this study, we found that poly(vinyl alcohol) molecules can inhibit Ostwald ripening and crystal growth of LiBr hydrates in LiBr solution in a nonequilibrium fashion, by interacting with the crystal surfaces.
Academic Significance and Societal Importance of the Research Achievements	本研究では、ポリビニルアルコールが臭化リチウム（LiBr）水和物の結晶面に作用して、非平衡状態のまま結晶の粗大化や成長を抑制することを明らかにした。非平衡状態での結晶成長抑制は、バイオミネラルなどの無機結晶の成長制御や、細胞凍結保存における氷の結晶成長の制御においても重要な課題であり、本研究の成果の学術的な波及効果は大きい。また、今後は吸収冷凍機への応用技術開発に発展する可能性があり、社会的意義も大きい。