{"id":2957,"date":"2024-05-06T09:00:00","date_gmt":"2024-05-06T01:00:00","guid":{"rendered":"https:\/\/globalquartztube.com\/?p=2957"},"modified":"2024-06-26T20:49:52","modified_gmt":"2024-06-26T12:49:52","slug":"hydroxyl-groups-in-quartz-tubes","status":"publish","type":"post","link":"https:\/\/globalquartztube.com\/cs\/hydroxyl-groups-in-quartz-tubes\/","title":{"rendered":"Hydroxylov\u00e9 skupiny v k\u0159emenn\u00fdch trubk\u00e1ch"},"content":{"rendered":"

 <\/p>\n\n\n\n

Hydroxyl v k\u0159emenn\u00e9m skle<\/strong><\/h2><\/div>\n\n\n\n

Hydroxyl rozpu\u0161t\u011bn\u00fd v k\u0159emenn\u00e9m skle je zn\u00e1m\u00fd jako hydroxyl. Hydroxyl je hlavn\u00ed ne\u010distotou v k\u0159emenn\u00e9m skle a prim\u00e1rn\u00edmi faktory ovliv\u0148uj\u00edc\u00edmi jeho obsah jsou suroviny, procesy a v\u00fdrobn\u00ed metody. Jak se m\u011bn\u00ed obsah hydroxyl\u016f v k\u0159emenn\u00e9m skle, m\u011bn\u00ed se i v\u00fdkon skla. Zv\u00fd\u0161en\u00ed obsahu hydroxyl\u016f vede ke sn\u00ed\u017een\u00ed viskozity, hustoty a indexu lomu a ke zv\u00fd\u0161en\u00ed infra\u010derven\u00e9ho absorb\u010dn\u00edho a expanzn\u00edho koeficientu.<\/p>\n\n\n\n

Dehydroxylace<\/strong><\/h2><\/div>\n\n\n\n

Na z\u00e1klad\u011b chov\u00e1n\u00ed hydroxylu v k\u0159emenn\u00e9m skle jej lze rozd\u011blit do dvou kategori\u00ed: k\u0159emenn\u00e9 sklo vyroben\u00e9 v oxida\u010dn\u00ed atmosf\u00e9\u0159e a k\u0159emenn\u00e9 sklo taven\u00e9 v reduk\u010dn\u00ed atmosf\u00e9\u0159e. Hydroxyl v prvn\u011b jmenovan\u00e9m se obt\u00ed\u017en\u011b odstra\u0148uje zah\u0159\u00edv\u00e1n\u00edm, zat\u00edmco ve druh\u00e9m se odstra\u0148uje snadn\u011bji.<\/p>\n\n\n\n

K\u0159emenn\u00e9 sklo vyroben\u00e9 v oxida\u010dn\u00ed atmosf\u00e9\u0159e zahrnuje:<\/p>\n\n\n\n

    \n
  1. Syntetick\u00e9 k\u0159emenn\u00e9 sklo<\/strong>: Chlorid k\u0159emi\u010dit\u00fd se tepeln\u011b rozkl\u00e1d\u00e1 v plameni vod\u00edku s obsahem hydroxyl\u016f kolem 1000-2000 ppm.<\/li>\n\n\n\n
  2. K\u0159emenn\u00e9 sklo rafinovan\u00e9 plynem<\/strong>: K\u0159emenn\u00fd pr\u00e1\u0161ek roztaven\u00fd v plameni vod\u00edku s obsahem hydroxyl\u016f 100-200 ppm.<\/li>\n\n\n\n
  3. Plazmov\u00e9 k\u0159emenn\u00e9 sklo<\/strong>: K\u0159emenn\u00fd pr\u00e1\u0161ek roztaven\u00fd v plazmov\u00e9m plameni s obsahem hydroxyl\u016f 20-30 ppm.<\/li>\n\n\n\n
  4. Taven\u00fd k\u0159emen<\/strong>: K\u0159emenn\u00fd pr\u00e1\u0161ek roztaven\u00fd ve vzdu\u0161n\u00e9 atmosf\u00e9\u0159e s obsahem hydroxyl\u016f 300-500 ppm.<\/li>\n<\/ol>\n\n\n\n

    Hydroxylov\u00e9 skupiny tohoto typu k\u0159emenn\u00e9ho skla se obt\u00ed\u017en\u011b odstra\u0148uj\u00ed tepeln\u00fdm zpracov\u00e1n\u00edm a pouze viditeln\u011b dehydroxyluj\u00ed nad teplotou krystalizace p\u0159i teplot\u011b kolem 1350 stup\u0148\u016f Celsia.<\/p>\n\n\n\n

    K\u0159emenn\u00e9 sklo taven\u00e9 v redukuj\u00edc\u00ed atmosf\u00e9\u0159e<\/strong>:<\/h2><\/div>\n\n\n\n

    Ve vod\u00edkov\u00e9 atmosf\u00e9\u0159e je obsah hydroxylov\u00fdch skupin 100-200 ppm; zah\u0159\u00edv\u00e1n\u00ed nad 900 stup\u0148\u016f Celsia m\u016f\u017ee odstranit v\u011bt\u0161inu hydroxylu. V podm\u00ednk\u00e1ch helia nebo vakua je obsah hydroxylov\u00fdch skupin velmi n\u00edzk\u00fd (pod 5 ppm).<\/p>\n\n\n\n

    Hydroxylov\u00e1 skupina v k\u0159emenn\u00e9m skle tavenina ve vod\u00edkov\u00e9 atmosf\u00e9\u0159e souvis\u00ed s n\u00e1sleduj\u00edc\u00edmi faktory:<\/p>\n\n\n\n

      \n
    1. Souvis\u00ed s vlastnostmi surovin<\/strong><\/li>\n<\/ol>\n\n\n\n

      A. Rozpu\u0161t\u011bn\u00e1 voda; b. krystalick\u00e1 voda; C. Interstici\u00e1ln\u00ed voda; b. povrchov\u011b adsorbovan\u00e1 voda; E. Inkluze plyn-kapalina;<\/p>\n\n\n\n

      2. Souvis\u00ed s obsahem a typem ne\u010distot v surovin\u011b<\/strong><\/p>\n\n\n\n

      A. oxidy alkalick\u00fdch kov\u016f; b. oxidy kov\u016f alkalick\u00fdch zemin; C. oxidy vz\u00e1cn\u00fdch zemin;<\/p>\n\n\n\n

      3. Souvis\u00ed s podm\u00ednkami t\u00e1n\u00ed<\/strong><\/p>\n\n\n\n

      Teplota; \u010cas; Atmosf\u00e9ra;<\/p>\n\n\n\n

      4. Souvisej\u00edc\u00ed s podm\u00ednkami dehydroxylace<\/strong><\/p>\n\n\n\n

      Prost\u0159ed\u00ed, \u00farove\u0148 vakua; \u010cas; Teplota;<\/p>\n\n\n\n

      P\u0159etaven\u00e9 k\u0159emenn\u00e9 sklo vyroben\u00e9 v oxida\u010dn\u00ed atmosf\u00e9\u0159e ve vod\u00edkov\u00e9 atmosf\u00e9\u0159e nevykazuje \u017e\u00e1dnou zm\u011bnu v p\u00edku absorpce hydroxylu p\u0159i 2,73 mikronu; to ukazuje, \u017ee teplota t\u00e1n\u00ed nen\u00ed p\u0159\u00ed\u010dinou rozd\u00edlu v dehydroxyla\u010dn\u00edm v\u00fdkonu mezi t\u011bmito dv\u011bma typy skla.<\/p>\n\n\n\n

      Pr\u00e1\u0161kov\u00e9 k\u0159emenn\u00e9 sklo roztaven\u00e9 v oxida\u010dn\u00ed atmosf\u00e9\u0159e (velikost \u010d\u00e1stic 0,2\u20130,05 mm) vykazuje v\u00fdznamnou zm\u011bnu hydroxylov\u00e9ho p\u00edku p\u0159i 2,73 mikronu po op\u011btovn\u00e9m roztaven\u00ed v atmosf\u00e9\u0159e vod\u00edku, co\u017e usnad\u0148uje odstran\u011bn\u00ed hydroxylu a jeho vlastnosti jsou podobn\u00e9 jako u k\u0159emene. sklo roztaven\u00e9 ve vod\u00edkov\u00e9 atmosf\u00e9\u0159e. To ukazuje, \u017ee velikost \u010d\u00e1stic je d\u016fle\u017eit\u00fdm faktorem v rozd\u00edlech v dehydroxylaci.<\/p>\n\n\n\n

      Pr\u00e1\u0161ek z n\u00edzkohydroxylov\u00e9ho k\u0159emenn\u00e9ho skla<\/strong> znovu roztaven\u00fd ve vod\u00edkov\u00e9 atmosf\u00e9\u0159e zvy\u0161uje hydroxyl z 3 ppm na 100 ppm, co\u017e ukazuje, \u017ee vod\u00edkov\u00e1 atmosf\u00e9ra m\u016f\u017ee zv\u00fd\u0161it obsah hydroxylu v k\u0159emenn\u00e9m skle. N\u00edzkohydroxylov\u00e9 k\u0159emenn\u00e9 sklen\u011bn\u00e9 bloky p\u0159etaven\u00e9 ve vod\u00edkov\u00e9 atmosf\u00e9\u0159e nevykazuj\u00ed prakticky \u017e\u00e1dnou zm\u011bnu v obsahu hydroxylov\u00fdch skupin (3 ppm), co\u017e ukazuje, \u017ee interakce mezi vod\u00edkem a k\u0159emenn\u00fdm sklem za\u010d\u00edn\u00e1 na povrchu (doba t\u00e1n\u00ed asi 30 minut).<\/p>\n\n\n\n

      Metoda spektr\u00e1ln\u00ed absorpce pro v\u00fdpo\u010det hydroxylu<\/strong>:<\/h2><\/div>\n\n\n\n

      Vzorec od GE: C = 910\/T * LOG10(Ta\/Tb) mm-1<\/p>\n\n\n\n