Synthesis and thermal characterization of the C-S-H/paraffin composite phase change material utilizing a discontinuous two-step nucleation method

Abstract

The novel calcium-silicate-hydrate(C-S-H)/paraffin composite phase change materials were synthesized using a discontinuous two-step nucleation method. Initially, the C-S-H precursor is separated and dried, followed by immersion in an aqueous environment to transform it into C-S-H. This two-step nucleation approach results in C-S-H with a specific surface area of 497.2 m²/g, achieved by preventing C-S-H foil overlapping and refining its pore structure. When impregnated with paraffin, the novel C-S-H/paraffin composite exhibits superior thermal properties, such as a higher potential heat value of 148.3 J/g and an encapsulation efficiency of 81.6%, outperforming conventional C-S-H. Moreover, the composite material demonstrates excellent cyclic performance, indicating its potential for building thermal storage compared to other paraffin-based composites. Compared with the conventional method, this simple technology, which only adds conversion and centrifugation steps, does not negatively impact preparation costs, the environment, and resource consumption. This study provides valuable theoretical insights for designing thermal storage concrete materials and advancing building heat management.

Keywords

two-step nucleation / C-S-H / paraffin / phase change materials / composite / building thermal management

References

[1] Fang Y L, Zhang X S, Liu C. Experimental study of lightweight radiant floor heating system with non-full-coverage heat-conducting plate[J]. Journal of Southeast University(Natural Science Edition), 2022, 52(6): 1104-1113. DOI:10.3969/j.issn.1001-0505.2022.06.010. (in Chinese)

[2] Cabeza L F, Castellón C, Nogués M, et al. Use of microencapsulated PCM in concrete walls for energy savings[J]. Energy and Buildings, 2007, 39(2): 113-119. DOI: 10.1016/j.enbuild.2006.03.030.

[3] Shen Y L, Liu S L, Zeng C, et al. Experimental thermal study of a new PCM-concrete thermal storage block(PCM-CTSB)[J]. Construction and Building Materials, 2021, 293: 123540. DOI: 10.1016/j.conbuildmat.2021.123540.

[4] Erdogmus E, Yaras A, Ustaoglu A, et al. Thermal performance analysis of novel foam concrete composites with PCM for energy storage and environmental benefits in buildings[J]. Energy and Buildings, 2023, 296: 113413. DOI: 10.1016/j.enbuild.2023.113413.

[5] Liu B, Pan G H, Gao M, et al. Influence of grinding aid on the grinding effect of iron tailings and hydration properties of blended cement[J]. Journal of Southeast University(Natural Science Edition), 2022, 52(5): 907-916. DOI:10.3969/j.issn.1001-0505.2022.05.011. (in Chinese)

[6] Wang P G, Fu H, Li G G, et al. Effects of Nano-C-S-H-PCE on performance of C50 non-steam cured concrete for coastal subway segment[J]. Journal of Southeast University(Natural Science Edition), 2022, 52(2): 254-262. DOI:10.3969/j.issn.1001-0505.2022.02.007. (in Chinese)

[7] Jiang J Y, Zheng Q, Yan Y R, et al. Design of a novel nanocomposite with C-S-H@LA for thermal energy storage: A theoretical and experimental study[J]. Applied Energy, 2018, 220: 395-407. DOI: 10.1016/j.apenergy.2018.03.134.

[8] Shamsaei E, de Souza F B, Fouladi A, et al. Graphene oxide-based mesoporous calcium silicate hydrate sandwich-like structure: Synthesis and application for thermal energy storage[J]. ACS Applied Energy Materials, 2022, 5(1): 958-969. DOI: 10.1021/acsaem.1c03356.

[9] Shen X Y, Feng P, Zhang Q, et al. Toward the formation mechanism of synthetic calcium silicate hydrate(C-S-H)-pH and kinetic considerations[J]. Cement and Concrete Research, 2023, 172: 107248. DOI: 10.1016/j.cemconres.2023.107248.

[10] Sowoidnich T, Damidot D, Ludwig H M, et al. The nucleation of C-S-H via prenucleation clusters[J]. The Journal of Chemical Physics, 2023, 158(11): 114309. DOI: 10.1063/5.0141255.

[11] Liu Z M, Shao C Y, Jin B, et al. Crosslinking ionic oligomers as conformable precursors to calcium carbonate[J]. Nature, 2019, 574(7778): 394-398. DOI: 10.1038/s41586-019-1645-x.

[12] Shen X Y, Feng P, Liu X, et al. New insights into the non-classical nucleation of C-S-H[J]. Cement and Concrete Research, 2023, 168: 107135. DOI: 10.1016/j.cemconres.2023.107135.

[13] Salunkhe P B, Shembekar P S. A review on effect of phase change material encapsulation on the thermal performance of a system[J]. Renewable and Sustainable Energy Reviews, 2012, 16(8): 5603-5616. DOI: 10.1016/j.rser.2012.05.037.

[14] Matsuyama H, Young J F. Effects of pH on precipitation of quasi-crystalline calcium silicate hydrate in aqueous solution[J]. Advances in Cement Research, 2000, 12(1): 29-33. DOI: 10.1680/adcr.2000.12.1.29.

[15] Liu X, Feng P, Li W, et al. Effects of pH on the nano/micro structure of calcium silicate hydrate(C-S-H)under sulfate attack[J]. Cement and Concrete Research, 2021, 140: 106306. DOI: 10.1016/j.cemconres.2020.106306.

[16] Wu Y J, Sha S L, Liu H Y, et al. Variable temperature infrared spectroscopy of paraffin[J]. Measurement Technique, 2020, 3:5-10. (in Chinese)

[17] Niculescu O, Leca M, Moldovan Z, et al. Obtaining and characterization of an ecologic wax emulsions for finishing natural leathers and furs[J]. Revista De Chimie, 2015, 66(8): 1173-1176.

[18] Zhao G, Zhu B D, Zou N N, et al. Research progress of paraffin-based microencapsulated phase change materials[J]. Polymer Bulletin, 2023, 36(9): 1136-1146. DOI:10.14028/j.cnki.1003-3726.2023.09.003. (in Chinese)

[19] Han S J, Chen Y P, Lü S Y, et al. Effects of processing conditions on the properties of paraffin/melamine-urea-formaldehyde microcapsules prepared by in situ polymerization[J]. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2020, 585: 124046. DOI: 10.1016/j.colsurfa.2019.124046.

[20] Huo J H, Peng Z G, Feng Q. Synthesis and properties of microencapsulated phase change material with a urea-formaldehyde resin shell and paraffin wax core[J]. Journal of Applied Polymer Science, 2020, 137(16): e48578. DOI: 10.1002/app.48578.

[21] Wan X, Zhang H Y, Chen C, et al. Synthesis and characterization of phase change materials microcapsules with paraffin core/cross-linked hybrid polymer shell for thermal energy storage[J]. Journal of Energy Storage, 2020, 32: 101897. DOI: 10.1016/j.est.2020.101897.

[22] Zhang Q Q, Sun Z C, Li G M, et al. Preparation and printing application of paraffin@silica phase change microcapsules[J]. Digital Printing, 2021, 3: 85-91. DOI:10.19370/j.cnki.cn10-1304/ts.2021.03.008. (in Chinese)

[23] Ma X C, Liu Y J, Liu H, et al. Synthesis and characterization of microencapsulated paraffin with TiO₂ shell as thermal energy storage materials[J]. Journal of Materials Science: Materials in Electronics, 2018, 29(17): 15241-15248. DOI: 10.1007/s10854-018-9666-z.

[24] Shi J, Wu X L, Sun R, et al. Synthesis and performance evaluation of paraffin microcapsules with calcium carbonate shell modulated by different anionic surfactants for thermal energy storage[J]. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2019, 571: 36-43. DOI: 10.1016/j.colsurfa.2019.03.029.

[25] Zhuang X H, Zhang Y, Cai C, et al. Design the magnetic microencapsulated phase change materials with poly(MMA-MAA)@n-octadecane modified by Fe₃O₄[J]. Scientific Reports, 2018, 8(1): 16379. DOI: 10.1038/s41598-018-34583-5.

Funding

The National Natural Science Foundation of China(52122802); The National Natural Science Foundation of China(52078126); Jiangsu Provincial Department of Science and Technology Innovation Support Program(BK20222004); Jiangsu Provincial Department of Science and Technology Innovation Support Program(BZ2022036)