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Based on the cement hydration theory and nucleation seeding, the nano-SiO2 and Al2O3 were introduced into the cement slurry system; then, the low-field nuclear magnetic resonance (NMR) was used to follow the cement hydration process and investigate the effect of the different nanometer materials directly comparable with each other. The relaxation peak location and peak area were used to further characterize the controlling effect of nanoparticles on the cement hydration. Meanwhile,the initial hydration process of the cement slurry systems was investigated by using the Carr–Purcell–Meiboom–Gill (CPMG) technique. As a result, it shows that the nano-SiO2 can accelerate the hydration of cement slurry, while nano-Al2O3 can retard the hydration of cement slurry system. Moreover, the change of compressive strength of cement stone was also studied, which found that the influence of nano-SiO2 and Al2O3 on cement hydration mainly focus on the initial hydration stage of cement, and the influence on the strength of cement stone in the later stage of hydration is very small.. The results of the current study show that the low-field NMR have great potential in exploring the effect of different nanoparticles on oil cement hydration. [ABSTRACT FROM AUTHOR]

During this study, paraffin wax with low melting point was encapsulated in a urea–formaldehyde resin to prepare a novel microencapsulated phase change material (Micro‐P6) for temperature regulation and thermal energy storage. The structure and properties of Micro‐P6 were characterized by using Fourier transform infrared spectroscopy, differential scanning calorimeter, laser particle size analyzer, thermogravimetric analysis, contact angle analysis, and scanning electron microscope. The results indicated that the chemical structure of Micro‐P6 meets the designed core–shell structure; and the paraffin wax with low melting point was successfully encapsulated by using urea–formaldehyde resin; and the Micro‐P6 shows a spherical structure and rough surface, and the average size is 8.0–10.0 μm. Then, the performances of Micro‐P6, such as core content, mechanical property, thermal conductivity and durability, were tested. Based on above characterization and performance test, it was indicated that the synthesized Micro‐P6 could be used in the field of cementing and construction for temperature regulation and thermal energy storage. The applications of Micro‐P6 in the field of cementing and construction will be completed in our next study. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48578. [ABSTRACT FROM AUTHOR]