摘要
在利用相变焓储存太阳能等低温热能的研究中,人们已发现无机水合盐类物质有凝析、过冷以及熔化后液体易漏出等缺点.解决这些问题的途径之一是开发固-固相变低温储能材料.(RNH_3)_2MX_4(R=长链正烷基,M=Mn,Cu,Co,Ni,Fe和Zn等二价金属,X=Cl或Br)在300—380K间有相变焓很大的固-固相变,是很有开发前景的固-固相变低温储能材料.我们在第Ⅰ报中报道过(n-C_(12)H_(25)NH_3)_2MnCl_4的绝热量热学研究结果,本文将报道(n-C_(12)H_(25)NH_3)_2ZnCl_4(1)在280—500K间的热力学性质和相变热参数.
The heat capacity of(n-C_(12)H_(25)NH_3)_2ZnCl_4(1) was measured over the temperature range 280 to 500K by means of an automatic adiabatic calorimeter. Two phase transitions, one of which is solid-solid and the other is solid-liquid, were found at 364.3±0.1K and 435.1±0.1K. The enthalpies and entropies of these transitions were found to be 66.79±0.35kJ·mol^(-1) and 183.3±11.0J·K^(-1)·mol^(-1) for the solid-solid transition, and(9.12±0.14)kJ·mol^(-1) and(20.96±0.32)J·K^(-1)·mol^(-1) for the solid-liquid transition, respectively. The selected thermodynamic properties C_(p,m)~o, S_m^o(T)-S_m^o(298.15) and H_m^o(T)-H_m^o(298.15) were tabulated in interval 10K from 280 to 500K.
出处
《化学学报》
SCIE
CAS
1988年第3期281-284,共4页
Acta Chimica Sinica
