In order to improve the thermal storage capacity of expanded vermiculite（EV） based formstable composite PCM（FS-PCM） via organic modification of EV, first, EV was modified with a sodium stearate（Na St） as surface...In order to improve the thermal storage capacity of expanded vermiculite（EV） based formstable composite PCM（FS-PCM） via organic modification of EV, first, EV was modified with a sodium stearate（Na St） as surface modifier, and organic EV（OEV） with hydrophobicity and higher adsorption capacity for fatty acid was obtained. A novel capric-stearic acid eutectic（CA-SA）/OEV FS-PCM with high thermal storage capacity was then developed. OEV and CA-SA/OEV were characterized by scanning electron microscopy（SEM）, X-ray diffraction（XRD）, Fourier transform infrared spectroscopy（FTIR）, differential scanning calorimetry（DSC）, thermal gravimetry（TG）, and thermal cycling test. Results showed that OEV has obvious hydrophobicity and a higher adsorption capacity for fatty acid. Its adsorption ratio has increased by 48.71% compared with that of EV. CA-SA/OEV possesses high thermal storage density（112.52 J/g）, suitable melting temperature（20.49 ℃）, good chemical compatibility, excellent thermal stability and reliability, indicating great application potential for building energy efficiency. Moreover, organic modification of inorganic matrix may offer novel options for improving its adsorption capacity for organic PCMs and increasing heat storage capacity of corresponding FS-PCMs.展开更多
通常采用大量掺加辅助性胶凝材料的方式提高胶凝材料的抗Cl^(–)渗透性能,进而提升混凝土结构的耐久性和服役寿命,但会显著降低早期力学性能.为提高早期强度和抗Cl^(–)渗透性能,基于初始浆体密堆积与水化过程孔隙有效填充,设计细、中...通常采用大量掺加辅助性胶凝材料的方式提高胶凝材料的抗Cl^(–)渗透性能,进而提升混凝土结构的耐久性和服役寿命,但会显著降低早期力学性能.为提高早期强度和抗Cl^(–)渗透性能,基于初始浆体密堆积与水化过程孔隙有效填充,设计细、中、粗粒度区间胶凝材料的种类和掺量,提高浆体的初始堆积密度和水化产物固氯能力,从而细化孔径并增大孔隙曲折度,采用59%的水泥熟料(粒径范围4~55μm),成功制备了3 d抗压强度27.3 MPa、28 d Cl^(–)扩散系数低至0.36×10^(–12)m^(2)/s的高抗渗透复合胶凝材料,为水泥基材料微结构调控和抗渗性能提升奠定基础.展开更多
基金Funded by the Major State Research Development Program of China during the 13th Five-Year Plan Period(No.2016YFC0700904)the Science and Technology Support Program of Hubei Province(Nos.2014BAA134 and 2015BAA107)
文摘In order to improve the thermal storage capacity of expanded vermiculite（EV） based formstable composite PCM（FS-PCM） via organic modification of EV, first, EV was modified with a sodium stearate（Na St） as surface modifier, and organic EV（OEV） with hydrophobicity and higher adsorption capacity for fatty acid was obtained. A novel capric-stearic acid eutectic（CA-SA）/OEV FS-PCM with high thermal storage capacity was then developed. OEV and CA-SA/OEV were characterized by scanning electron microscopy（SEM）, X-ray diffraction（XRD）, Fourier transform infrared spectroscopy（FTIR）, differential scanning calorimetry（DSC）, thermal gravimetry（TG）, and thermal cycling test. Results showed that OEV has obvious hydrophobicity and a higher adsorption capacity for fatty acid. Its adsorption ratio has increased by 48.71% compared with that of EV. CA-SA/OEV possesses high thermal storage density（112.52 J/g）, suitable melting temperature（20.49 ℃）, good chemical compatibility, excellent thermal stability and reliability, indicating great application potential for building energy efficiency. Moreover, organic modification of inorganic matrix may offer novel options for improving its adsorption capacity for organic PCMs and increasing heat storage capacity of corresponding FS-PCMs.
文摘通常采用大量掺加辅助性胶凝材料的方式提高胶凝材料的抗Cl^(–)渗透性能,进而提升混凝土结构的耐久性和服役寿命,但会显著降低早期力学性能.为提高早期强度和抗Cl^(–)渗透性能,基于初始浆体密堆积与水化过程孔隙有效填充,设计细、中、粗粒度区间胶凝材料的种类和掺量,提高浆体的初始堆积密度和水化产物固氯能力,从而细化孔径并增大孔隙曲折度,采用59%的水泥熟料(粒径范围4~55μm),成功制备了3 d抗压强度27.3 MPa、28 d Cl^(–)扩散系数低至0.36×10^(–12)m^(2)/s的高抗渗透复合胶凝材料,为水泥基材料微结构调控和抗渗性能提升奠定基础.
