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Durability is a key factor to determine the service life of organic coating. The addition of nanomaterials can improve the mechanical properties and compactness of the organic coatings. As a kind of nanomaterial, g-C₃N₄ has lamellar structure and can be excited by visible light. At the same time, its cost is low. So it can be selected as a filler to prepare organic coating. The lamellar structure of g-C₃N₄ is favorable for its dispersion in organic coatings. Stearic acid is an environmentally friendly material with low surface energy. It can improve the hydrophobicity of the coating. In this research, porous g-C₃N₄ nanosheets were used as filler and stearic acid was used as surface modifier to prepare waterborne acrylic resin-based organic composite coating. The chemical reagent durability, electrochemical durability and mechanical properties of the composite coating were tested. At the same time, the photocatalytic degradation performance of the coating surface was also tested. The results showed that g-C₃N₄ as filler and stearic acid could effectively improve the durability of the waterborne acrylic resin coating. Meanwhile, the coating surface has obvious visible light-activated photocatalytic performance due to the addition of g-C₃N₄.

The surface of calcium carbonate (CaCO₃) particles was modified with stearic acid (SA) and the chemical structures of the product were characterized by FT-IR analysis. The interaction between polydimethylsiloxane (PDMS) and CaCO₃ fillers with different surface character was investigated by means of dynamic rheological and bound rubber tests for uncured compounds and mechanical properties measurements for the corresponding vulcanites. The results of dynamic tests indicate that with the increase of SA mass fraction, the span of the linear viscoelastic region broadens and the height of the modulus plateau decreases. The reasons for these are ascribed to that the SA decreases the surface energy of filler particles and weakens their tendency to agglomerate. Moreover, the results of mechanical measurements reveal that the vulcanized compound filled with modified filler has a relative high tensile strength induced by a reinforced interaction between filler and polymer matrix, which is confirmed by the bound rubber tests and transmission electron microscopy (TEM) observations.

Mesoporous silica was prepared using tetrathoxysilane (TEOS), cetadecyltrimethylammonium bromide (CTAB), aqueous ammonia, acetone and water as silica source, template agent, precipitator and solvent respectively. Stearic acid and polyvinylpyrrolidone (PVP) were employed as additional templates to tailor the pore size in the resultant porous silica. BET, SAXRD and SEM analyses were used to characterize the surface area, pore size, pore structure, pore regularity and morphology of the sample. BET measurement results showed that PVP could increase the surface area but diminish the pore size while stearic acid could decrease the surface area but enlarge the pore size. SAXRD analysis indicated that more additional template introduction gave rise to less order-structured products. All these various results could be attributed to the differently modified CTAB micelles involving stearic acid and PVP addition.

This paper reported on the preparation of a novel stearic acid (SA)/wollastonite (W) composite as a form-stable phase change material (PCM) for thermal energy-storage (TES) by vacuum impregnation, and especially investigated the effect of the size grade of W on the thermal properties of the SA/W composite. Samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), laser particle-size analysis, and differential scanning calorimetry (DSC). Natural W (Wr) was classified into four size grades by wet screening. The results indicate that no chemical reaction took place between SA and W, and the SA load in the SA/W composite increased with an increase in the length/diameter (L/D) ratio of the W. The SA/W composite with a W L/D ratio of 22.5 exhibited latent heats of melting and freezing of 58.64 J/g and 56.95 J/g, respectively, which was higher than those of the composite incorporating natural W. We believe that the as-prepared form-stable PCM composite could provide a potential means of TES for the concentrated solar power.

Dielectric permittivity and relaxation dynamics of binary and ternary mixture of stearic acid on various concentration and their thermodynamic effects are studied. The static dielectric constant (${\epsilon }_0$), dielectric permittivity (${\epsilon }^{\prime }$) and dielectric loss (${\epsilon }^{\prime \prime }$) are found by bilinear calibration. The relaxation time ($\tau$), dielectric strength ($\mathrm{\Delta }\epsilon$) and the excess permittivity (${\epsilon }^{\mathit{\text{E}}}$) are found. The thermodynamic parameters such as enthalpy ($\mathrm{\Delta }H$), entropy ($\mathrm{\Delta }S$) and Gibb’s free energy ($\mathrm{\Delta }G$) are evolved. The significant changes in dielectric parameters are due to the intramolecular and intermolecular interactions in response to the applied frequency. The permittivity spectra of stearic acid–alcohol in the frequency range of 10MHz to 30GHz have been measured using picoseconds Time Domain Reflectometry (TDR). The dielectric parameters (${\epsilon }_0$, ${\epsilon }^{\prime }$, ${\epsilon }^{\prime \prime }$) are found by bilinear calibration method. Influence of temperature in intermolecular interaction and the relaxation process are also studied. The FT-IR spectral analysis reveals that the conformation of functional groups and formation for hydrogen bonding are present in both binary and ternary mixtures of stearic acid.