English  |  正體中文  |  简体中文  |  Items with full text/Total items : 74010/74010 (100%)
Visitors : 24691366      Online Users : 302
RC Version 7.0 © Powered By DSPACE, MIT. Enhanced by NTU Library IR team.
Scope Tips:
  • please add "double quotation mark" for query phrases to get precise results
  • please goto advance search for comprehansive author search
  • Adv. Search
    HomeLoginUploadHelpAboutAdminister Goto mobile version

    Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/71262

    Title: Spherical Agglomerates of Poly(ethylene glycol)/Silica Fume Composites as Phase Change Materials
    Authors: 王智霖;Wang,Chih-Lin
    Contributors: 化學工程與材料工程學系
    Keywords: 相轉移材料;混掺;聚乙二醇;燻矽;結晶溫度延長;phase change material;blending;polyethylene glycol;silica fume;transition zone broadening
    Date: 2016-06-16
    Issue Date: 2016-10-13 12:38:56 (UTC+8)
    Publisher: 國立中央大學
    Abstract: 本篇論文研究的主要目的是找到固-液態轉換上型態穩定的相轉移材料,聚乙二醇/燻矽複合物,以及透過混摻不同比例的聚乙二醇/燻矽複合物來調製出擁有寬廣使用溫度範圍的相轉移材料,使得此材料在相轉移材料方面有更多不同的應用。接著,經由球晶製程的方式將原本做出來不規則狀的聚乙二醇/燻矽複合物製作成球形來改善此材料的流動性。聚乙二醇/燻矽複合物是透過含浸法來製備,以不同重量比例的聚乙二醇負載於燻矽載體上。其中附載較高的複合物PEG75/SF擁有重量百分比為47.9%的聚乙二醇,其熔點範圍約在攝氏55-58度,結晶點約在攝氏18-24度。我們將負載較高的複合物PEG75/SF及負載相對較低的複合物PEG25/SF或是無負載的燻矽混摻在一起,發現比例為重量比1:1時有較為寬廣的使用溫度範圍。
    ;The aim of this thesis was to prepare a solid-liquid shape-stabilized phase change materials, polyethylene glycol/silica fume (PEG/SF) composite, and study the blends of different PCM composites to broaden application temperature to suit for more applications of PCM, then through spherical crystallization to conglomerate the PCM composites become spherical agglomerates to improve the flowability. PEG 4000 was embedded in a low-cost SF to form the PEG75/SF composite with a PEG wt% of 47.9 wt%. The melting point and crystallization temperature of the PEG75/SF composite or spherical agglomerates were around 55-58゚C and 18-24゚C as determined by the temperature cycle of DSC with a heating rate of 10゚C/min and a cooling rate of 10゚C/min, respectively. Blends of PEG75/SF composites with PEG25/SF composites or with low-cost SF having a ratio of 1:1 could be used as a phase change material that had a broad crystallization temperature range. The spherical agglomerates of SF and PEG75/SF were made by the spherical crystallization process. Two agitation speeds in the spherical crystallization process about 400 and 600 rpm were studied. It was found that the particle size distribution of agglomerates prepared from different agitation speeds could vary significantly. There were more than 40 wt% of fine particles (< 250 μm) PEG75/SF composites did not conglomerate to become spherical agglomerates at 400 rpm. The particle size distribution was more uniform at 600 rpm. However, the morphology of agglomerates produced at 400 rpm was more spherical than those made at 600 rpm. The effect of the agitation speed on the particle fracture force of agglomerates in the range of 355-500 μm and 710-1000 μm was not obvious. The particle fracture force of agglomerates of 355-500 μm, and 710-1000 μm were 0.18±0.06, and 0.52±0.02 N by 400 rpm and 0.16±0.03, and 0.53±0.04 N by 600 rpm, respectively. There were similar properties between different size cuts of spherical agglomerates of PEG75/SF. Spherical agglomerates of PEG75/SF produced at 400 rpm and 600 rpm had good homogeneity in thermal properties and low Carr’s index indicating good flowability.
    Appears in Collections:[化學工程與材料工程研究所] 博碩士論文

    Files in This Item:

    File Description SizeFormat

    All items in NCUIR are protected by copyright, with all rights reserved.

    社群 sharing

    ::: Copyright National Central University. | 國立中央大學圖書館版權所有 | 收藏本站 | 設為首頁 | 最佳瀏覽畫面: 1024*768 | 建站日期:8-24-2009 :::
    DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU Library IR team Copyright ©   - 隱私權政策聲明