THE SURFACE ENERGIES OF AMORPHOUS SILICA AND HYDROUS AMORPHOUS SILICA

THE TOTAL SURFACE ENERGIES OF AMORPHOUS SILICA AND HYDROUS AMORPHOUS SILICA WERE DETERMINED BY MEASURING THE HEATS OF SOLUTION IN A MIXTURE OF NITRIC ACID AND HYDROFLUORIC ACID OF SAMPLES HAVING DIFFERING SPECIFIC SURFACE AREAS AND BOUND WATER CONTENTS, AND BY MEASURING THE SURFACE AREAS BY THE B. E. T. METHOD, USING NITROGEN AS ADSORBATE. THE SURFACE ENERGY OF AMORPHOUS SILICA OF ZERO WATER CONTENT (OR THE ENERGY OF THE PURE SILOXANE SURFACE) AT 23 C WAS FOUND TO BE 259 PLUS OR MINUS 3 ERGS/SQ CM. THE HEAT OF HYDRATION BY LIQUID WATER OF THE SILOXANE SURFACE TO SILANOL SURFACE AT 23C WAS FOUND TO BE 258.6 PLUS OR MINUS 13.0 CAL./GM. OF WATER. FROM THESE TWO VALUES THE SURFACE ENERGY OF HYDROUS AMORPHOUS SILICA WAS CALCULATED TO BE 129 PLUS OR MINUS 8 ERGS/SQ CM. /PCA/

• Authors:
  • Brunauer, S
  • Kantro, D L
  • Weise, C H
• Publication Date: 0

Media Info

• Serial:
  • Portland Cement Assoc R & D Lab Bull
  • Issue Number: 0

Subject/Index Terms

• TRT Terms: Nitric acid; Silica; Solutions (Chemistry); Surface energy; Temperature measurement
• Old TRIS Terms: Amorphous; Hydrofluoric acid; Solutions
• Subject Areas: Highways; Materials;

Filing Info

• Accession Number: 00213525
• Record Type: Publication
• Source Agency: Portland Cement Association
• Report/Paper Numbers: No 76
• Files: TRIS
• Created Date: May 25 1970 12:00AM