Effect of drying control chemical additives in Sol-Gel-Glass Monolith processing

Nikolić, Ljubiša; Radonjić, L.

doi:10.1016/0272-8842(94)90047-7

Cited by 10 publications

(6 citation statements)

References 7 publications

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“…The effects of various additives on the sol−gel reaction process to silica gels has been the subject of many recent reports. For example, drying control chemical additives (DCCAs) such as formamide, N , N -dimethylformamide, N , N -dimethylacetamide, and ethylene glycol featured in attempts to control gelation time and monolith cracking .…”

Section: Resultsmentioning

confidence: 99%

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Effects of Molecular Organic Additives on Formation and Properties of Organosilicate and Silica Xerogels Correlated to Structural Properties of the Additive

1997

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This paper describes the effects of some polar organic additives on the sol-gel processing of organodisilicate and silica precursors. For a range of organic additives investigated, those for which molecular stacking is a feature of the crystal structure (type A) promote extensive fragmentation of organosilicate and silica xerogels into thin plates and small (∼1 mm diameter) granules during the final drying stages. Two organic additives that do not exhibit such stacking (type B) were investigated, these did not promote such fragmentation, and the organic additive-treated monoliths were formed. Sol-gel mixtures investigated with type A organic additives include: 1,4-bis(Cl 3 SiCH 2 ) 2 C 6 H 4 and organic additives transcinnamic acid (TCA), crotonic acid, or benzoic acid; 1,4-bis[(n-BuO) 3 SiCH 2 )] 2 C 6 H 4 and m-nitroaniline; 1,4-bis[(EtO) 3 Si]C 6 H 4 and [(EtO) 4 Si] with trans-cinnamic acid. Sol-gel mixtures containing type B organic additives investigated were 1,4-bis(Cl 3 SiCH 2 ) 2 C 6 H 4 and the organic additives phenol or pinacol; 1,4-bis[(EtO) 3 Si]C 6 H 4 or (EtO) 4 Si with PhOH. The additives may be removed by extraction of the xerogel materials with THF. The effects of tetrahydrofuran solutions of types A and B additives on monolithic additive-free organosilicate xerogels and silica gels is also reported. The materials have been variously studied by SEM(EDAX), XRD, 29 Si solid-state NMR, and 13 C solid-state NMR. The THF-extracted products were studied by nitrogen sorption porosimetry. BET measurements on THF extracted materials showed that type A additives generally gave low surface area materials while type B additives gave high surface area materials. 29 Si solid-state NMR and BET measurements revealed nonsystematic effects of TCA loading on local chemical structure and surface area, respectively.

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Section: Resultsmentioning

confidence: 99%

“…Varying the concentration of formamide in sol−gel mixtures was shown to have pronounced effects on gel particle morphology . The modification of pore structure by additives (ranging from DCCAs, , water-soluble polymers, surfactants, inorganic salts 18 ) is widely discussed.…”

Section: Resultsmentioning

confidence: 99%

Effects of Molecular Organic Additives on Formation and Properties of Organosilicate and Silica Xerogels Correlated to Structural Properties of the Additive

1997

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“…In the second step, 0,6 mL acetic acid which was used as a chelating agent [22] and 6,43 mL of titanium (IV) tetraisopropoxide were mixed and then 29,36 mL of isopropanol (99,5% Aldrich) was added to the solution while stirring. Predetermined amount of solution A (65 mol% Fe2O3) then was added to a mixture B dropwise while stirring and then 0,4 mL of glycerol (98%, Fluka) as a drying process controlling chemical additive [23] was added obtaining sol solution. Finally obtained sol was treated by ultrasound for 5 minutes.…”

Section: Methodsmentioning

confidence: 99%

Hydrophobic properties of high Fe³⁺ ion containing Fe₂O₃-TiO₂ coatings

Zukuls

Mežinskis

2017

IOP Conf. Ser.: Mater. Sci. Eng.

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Abstract. The treatment of environmental pollution using semiconductor photo catalysis converts contaminants to innocuous products, such as CO2 and H2O. The most promising semiconductor photo catalysts are titania based materials. However, the main drawback of titania anatase polymorph is the large band gap which limits the spectrum of photons that can create electron−hole pairs to participate in oxidation or reduction. In this study Fe2O3-TiO2 coatings were successfully prepared on soda-lime silicate glass slide substrates using sol-gel method. Coating surface and morphology has been studied using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM). Coatings were obtained using dip-coating method. The present research is devoted to the studies of aging time and heat treatment effects on films hydrophobicity. The purpose of this contribution was the development of iron oxide rich Fe2O3-TiO2 hydrophobic thin films depending on different preparation parameters. SEM and AFM investigation revealed the formation of two layered, porous coating microstructure consisting of rough flattened areas which formed the backbone for irregularly shaped particles.

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“…Uzun yıllardan beri çeşitli kaplama tabakaları sol-jel metodu kullanılarak elde edilmektedir. Bu metodun genel aşamaları jel oluşumu, yaşlandırma, kurutma ve sinterleme olarak nitelendirilmektedir [15]. Elde edilen silika jelini ıslak halden direkt olarak kurutarak bir silika monolit elde etmek oldukça zordur.…”

Section: Introductionunclassified

Ti6Al4V Alaşımına Sol-Jel Yöntemi ile Yapılan Hidroksiapatit Kaplamalarda Dietanolaminin Kaplama Morfolojisine ve Korozyon Dayanımına Etkisi

Gül¹,

Mutaf²,

Durmuş³

2020

DÜMF Mühendislik Dergisi

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Titanyum ve alaşımları, mekanik dayanımları ve biyotolerant yapıda olmaları nedeni ile biyomalzeme uygulamalarında tercih edilirler. Fakat insan vücudu içinde korozyona uğraması durumunda zararlı iyonların salınımına neden olabilirler. Hidroksiapatit ise seramik ve biyoaktif yapıda bir malzeme olup biyomalzemelerin korozyon dayanımlarını arttırmaya yönelik kaplama tabakası olarak kullanımı da mevcuttur. Bu çalışmada Ti6Al4V alaşımının korozyon dayanımını geliştirmek amacı ile sol-jel yöntemi kullanılarak hidroksiapatit kaplamalar yapılmıştır. Hazırlanan hidroksiapatit solüsyonlarına farklı oranlarda dietanolamin (DEA, C4H11NO2) eklenerek sol-jel prosesinde oluşması muhtemel olan çatlaklı yapılar kontrol edilmiş ve azaltılmaya çalışılmış ve kaplamanın genel morfolojisinde ve korozyon dayanımında meydana gelen değişikliklerin gözlemlenmesi amaçlanmıştır. Numuneler taramalı elektron mikroskobu (SEM-EDS) ve X-Işını kırınımı (XRD) kullanılarak analiz edilmiştir. Hazırlanan yapay vücut sıvısı içinde elektrokimyasal-potansiyodinamik korozyon testleri gerçekleştirilmiştir. Çalışmanın sonucunda DEA katkı oranının artması ile morfolojide çatlaklı yapıların azaldığı ve kaplama kalınlığının arttığı gözlemlenmiştir. DEA eklenmesinin korozyon dayanımını arttırdığı fakat DEA miktarındaki artışın korozyon dayanımını negatif etkilediği görülmüştür.

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Effect of drying control chemical additives in Sol-Gel-Glass Monolith processing

Cited by 10 publications

References 7 publications

Effects of Molecular Organic Additives on Formation and Properties of Organosilicate and Silica Xerogels Correlated to Structural Properties of the Additive

Effects of Molecular Organic Additives on Formation and Properties of Organosilicate and Silica Xerogels Correlated to Structural Properties of the Additive

Hydrophobic properties of high Fe³⁺ ion containing Fe₂O₃-TiO₂ coatings

Ti6Al4V Alaşımına Sol-Jel Yöntemi ile Yapılan Hidroksiapatit Kaplamalarda Dietanolaminin Kaplama Morfolojisine ve Korozyon Dayanımına Etkisi

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Effect of drying control chemical additives in Sol-Gel-Glass Monolith processing

Cited by 10 publications

References 7 publications

Effects of Molecular Organic Additives on Formation and Properties of Organosilicate and Silica Xerogels Correlated to Structural Properties of the Additive

Effects of Molecular Organic Additives on Formation and Properties of Organosilicate and Silica Xerogels Correlated to Structural Properties of the Additive

Hydrophobic properties of high Fe3+ ion containing Fe2O3-TiO2 coatings

Ti6Al4V Alaşımına Sol-Jel Yöntemi ile Yapılan Hidroksiapatit Kaplamalarda Dietanolaminin Kaplama Morfolojisine ve Korozyon Dayanımına Etkisi

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Hydrophobic properties of high Fe³⁺ ion containing Fe₂O₃-TiO₂ coatings