推 荐 人:刘静静

文献信息1Yafei Sun, Peiwei Gao, Fei Geng, Haoran Li, Lifang Zhang, Hongwei Liu, Thermal conductivity and mechanical properties of porous concrete materials, Materials Letters, 2017, 209, 349-352.

推荐理由:建筑材料的节能已成为亟需解决的重要问题,采用体积密度小、热导率低的多孔混凝土材料是解决此问题的有效途径之一。作者通过改变多孔混凝土材料中的水/胶凝材料比、水泥/飞灰比和减水剂添加量,对其吸水率、热导率和耐压强度等性能进行了研究和分析。通过优化工艺参数,所制备的多孔混凝土材料吸水率为12%、热导率为0.116 W/(m•K),维护28天后强度高达4.37 MPa,可应用于建筑屋顶隔热层,拓宽了其应用范围。作者在大量既有数据上做了大量和深入的分析,在文章撰写上值得大家学习。特别是前言部分的撰写非常精彩,精炼的介绍了多孔混凝土材料的研究现状,是一篇建筑保温研究工作者必读的文章。

下载地址: http://www.sciencedirect.com/science/article/pii/S0167577X17312417

AbstractThe aim of this research is to examine the effect of the water-binder (W/B) ratio, replacement of cement by fly ash and incorporation of water-reducing agent on the thermal insulation and mechanical properties of porous concrete with a density of 600 kg/m3 . It was found that porous concrete achieved the optimum performance with a W/B ratio of 0.32, a fly ash replacement percentage of 30% and the addition of 0.65% of water-reducing agent. Under these optimal conditions, in the porous concrete specimen obtained the 28-day compressive strength up to 4.37 MPa, a 12% rate of water absorption and a heat conductivity coefficient of 0.116 W/(m•K). Overall, the findings show that the fabricated porous concrete (with a 150 mm thickness and a density of 600 kg/m3 ) fulfills the requirements of ultimate capacity and thermal insulation of the insulation layer for accessible flat roofing. More attractive, the product is cost-effective and may be useful in a wide range of applications.

Fig. 1-1. Effects of W/B ratio on the water absorption and thermal conductivity of porous concrete.

Fig. 1-2. Effects of Fa on the water absorption and thermal conductivity of 600 kg/m3 porous concrete.

Fig. 1-3. Effects of Wra content on the water absorption and thermal conductivity of 600 kg/m3 porous concrete.

文献信息2Jin-Ju Chen, Huo-Jun Li, Xiao-Hua Zhou, En-Zhu Li, Yan Wang, Yan-Long Guo, Zhe-Sheng Feng, Efficient synthesis of hollow silica microspheres useful for porous silica ceramics, Ceramics International, 43 (2015) 14645-14651.

推荐理由:作者利用水热合成的碳球为模板,在其表面水解合成SiO2,经600℃高温煅烧去除模板合成氧化硅空心微球,并以制备的氧化硅空心微球为原料制备了具有三维网状结构的氧化硅多孔陶瓷。其中,作者对氧化硅空心微球的水解过程及机理进行了深入的研究和分析。此外,作者还对所制备的样品的热导率和介电常数与致密氧化硅陶瓷进行对比,为低热导率和低介电常数陶瓷的制备提供了一条新的思路。作者在大量既有数据上做了大量和深入的分析。在文章撰写上值得大家学习,特别是前言部分的撰写非常精彩,层层深入介绍了多孔氧化硅材料的研究现状,思路非常清晰,在文章写作方面具有较大的借鉴意义。

下载地址:http://www.sciencedirect.com/science/article/pii/S0272884217315614

AbstractHollow silica microspheres (HSMs) have been successfully synthesized in large quantities using colloidal carbon spheres (CCSs) as template, cetyltrimethylammonium bromide (CTAB) as modifying agent and tetraethylortho-silicate (TEOS) as silicon source. The CCSs are fabricated by a simple hydrothermal treatment of D -glucose, which exhibit well monodisperse and homogeneous in dimension. The CTAB effectively modifies the surface charge characteristics of CCSs, which provides a favorable circumstance for the deposition of TEOS hydrolysis products. The HSMs can be eventually obtained after CCSs and CTAB being removed by sintering. The as-prepared HSMs are nearly uniform in dimension with particle size of about 500 nm. Porous silica ceramics with a three-dimensional network structure is prepared using these HSMs as raw material. Such ceramics possesses low density and dielectric constant, which make it very potential in the application of lightweight or low dielectric materials.

  

Fig. 2-1. (a) SEM image and (b) TEM image of CCSs; (c) FT-IR spectrum of CCSs fabricated via hydrothermal synthesis.

Fig. 2-2. Schematic procedure for the preparation of HSMs.

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