Sol-Gel Gateway Home page

 


 

 

 

  Active TopicsActive Topics  Display List of Forum MembersMemberlist  Search The ForumSearch  HelpHelp
  RegisterRegister  LoginLogin
Coatings & Films
 Sol-Gel Gateway Forum>Sol-Gel Forum>Coatings & Films
Message Icon Topic: Preparation of transparent TiO2 films. Post Reply Post New Topic
<< Prev Page  of 17 Next >>
Author Message
HoKra
Newbie
Newbie
Avatar

Joined: 07 May 2004
Location: Germany
Online Status: Offline
Posts: 7
Quote HoKra Replybullet Posted: 04 June 2004 at 5:44am

Hi Ram,

Do you heat the sol while stirring? I am preparing the sol at room temperature without any heating. I mix the ingredients in a nitrogen flooded glove box (humidity is <20%) under stirring (400-500rpm, depending on the total volume). One thing may also be important. The isopropanol is volatile, therefor I cover the beaker with a watch glass to reduce solvent loss during preparation. Maybe you should try to vary the catalyst solution. I used a 2M HCl solution, prepared by adding concentrated HCl to DI-Water. The amount I mentioned in the recipe is the amount of the 2M solution (not concentrated HCl). Actually I can“t think of any other reason then heating and amount of catalyst which would lead to such a fast gelling.

I hope it will work,

 

_______________________
Holger Krause
Student of Microsystemtechnology
-IMTEK Freiburg, Germany
-University of Applied       Sciences, Muenster, Germany
IP IP Logged
HoKra
Newbie
Newbie
Avatar

Joined: 07 May 2004
Location: Germany
Online Status: Offline
Posts: 7
Quote HoKra Replybullet Posted: 04 June 2004 at 5:51am

Hi Naimi,

it is right that you receive thinner coatings with increased isopropanol/Ti(isoPro) -ratio. As I wrote, the volume loss, therefor the shrinkage, is also increased. The shrinkage will take place mostly in perpendicular direction to the substrate if you apply thin coatings (<1µm). That is due to the adhesion forces of the gel to the substrate, it will prevent the shrinkage in lateral dimensions.

_______________________
Holger Krause
Student of Microsystemtechnology
-IMTEK Freiburg, Germany
-University of Applied       Sciences, Muenster, Germany
IP IP Logged
rammahipal
Newbie
Newbie
Avatar

Joined: 23 May 2004
Location: United States
Online Status: Offline
Posts: 18
Quote rammahipal Replybullet Posted: 04 June 2004 at 11:51am

Hi Holger

i did the experiment in a hood not in a nitrogen atmosphere that might  be the reason for not working.

once again thanks lot for ur reply

i will try to work it in nitrogen environemnt glove box

regards

 

Ram
Chemical Engineering)
University of arkansas
USA
IP IP Logged
loubna
Newbie
Newbie
Avatar

Joined: 04 June 2004
Location: Morocco
Online Status: Offline
Posts: 12
Quote loubna Replybullet Posted: 04 June 2004 at 2:26pm
Quote: Originally posted by Dhanus on 06 November 2001

Now, I am studying in Toyama University, Japan. I will do a research about degradation of water pollutant by TiO2 photocatalytic. The point is I want to know about detail preparation of transparent TiO2 thin film. Please tell me if know about that.


hy, i am studying in Faculty of science in Morrocco. i will do the same research but is only the second part of my research. my TiO2 thin films is prepared by the sol gel method
Bamoulid
IP IP Logged
rammahipal
Newbie
Newbie
Avatar

Joined: 23 May 2004
Location: United States
Online Status: Offline
Posts: 18
Quote rammahipal Replybullet Posted: 04 June 2004 at 3:20pm

Hi

i user M.Prassas recipe for making TiO2 film ,the soln i prepred.i kept some quantity of it in refrigerator and other beaker of soln in room temp.

the one which i kept in room temp become fully gel soln by the time after 12hrs

i used 0.2 ml 2M Hcl

the one which i kept in refrigerator in still liq soln.

did it happen for anyone, or else is there any mistake i did.

regards

Ram
Chemical Engineering)
University of arkansas
USA
IP IP Logged
loubna
Newbie
Newbie
Avatar

Joined: 04 June 2004
Location: Morocco
Online Status: Offline
Posts: 12
Quote loubna Replybullet Posted: 05 June 2004 at 7:30am

Urgent: I need somme information for Sol-Gel thin films prepared after formation of conversion layer.

thank you

Bamoulid
IP IP Logged
gabonino
Senior Member
Senior Member


Joined: 08 October 2002
Location: Germany
Online Status: Offline
Posts: 101
Quote gabonino Replybullet Posted: 05 June 2004 at 1:42pm

Holger,

regarding the preparation of binary sols, how do you exactly prepare the binary sol you have been intending to do? I have some experience in that, and maybe we can exchange experiences.

Gruessen

Oscar Gabriel Nińo A.
Chemical Engineer
Universidad Nacional de Colombia
M. Sc. Process and Energy Engineering
Technische Universität Berlin
IP IP Logged
administrator
Admin Group
Admin Group
Avatar

Joined: 01 October 2003
Location: France
Online Status: Offline
Posts: 6
Quote administrator Replybullet Posted: 06 June 2004 at 2:41pm

Quote: Originally posted by rammahipal on 04 June 2004


i user M.Prassas recipe for making TiO2 film ,the soln i prepred.i kept some quantity of it in refrigerator and other beaker of soln in room temp. the one which i kept in room temp become fully gel soln by the time after 12hrs

i used 0.2 ml 2M Hcl

the one which i kept in refrigerator in still liq soln.

did it happen for anyone, or else is there any mistake i did.

---------------------------------------------------------------------

Hi rammahipal

Nothing wrong with that. At room temperature the sol is  still reacting and therefore some how you will end up with a gel (depending on the initial concentrations and acidity, this can happens in hours, days or months). By putting your solution in a refrigerator you slow down the reactivity and therefore you increase its lifetime.

regards

Administrator
More you give more you get
IP IP Logged
gabonino
Senior Member
Senior Member


Joined: 08 October 2002
Location: Germany
Online Status: Offline
Posts: 101
Quote gabonino Replybullet Posted: 06 June 2004 at 10:33pm

Hi,

regarding Mr Prasa's recipe, I have a question......I did the experiment with the quantities given, but the sol was quite stable and gelled in a period after a week, staying very stable; I live on a very high city, over 7500 feet high. Does this affect the behavior of the sol, or its gellation time?

Oscar Gabriel Nińo A.
Chemical Engineer
Universidad Nacional de Colombia
M. Sc. Process and Energy Engineering
Technische Universität Berlin
IP IP Logged
rammahipal
Newbie
Newbie
Avatar

Joined: 23 May 2004
Location: United States
Online Status: Offline
Posts: 18
Quote rammahipal Replybullet Posted: 09 June 2004 at 1:37pm

Hi

I just wanted to make sure that the film formed is TIO2 film . i tried with spectorphotometer. But it didn't gave any useful information for me.

 can any one of u suggest me regarding the characterization to know exactly about the film i made.

 

Ram
Chemical Engineering)
University of arkansas
USA
IP IP Logged
<< Prev Page  of 17 Next >>
Post Reply Post New Topic
Printable version Printable version

Forum Jump
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot delete your posts in this forum
You cannot edit your posts in this forum
You cannot create polls in this forum
You cannot vote in polls in this forum




This page was generated in 0.016 seconds.
Privacy statement Copyright 2000-2017, Solgel.com.