Sol-Gel Gateway Forum http://www.solgel.com/sgforum This is an XML content feed of; Sol-Gel Gateway Forum : Last 10 Posts Fri, 04 Jul 2008 21:14:30 +0000 Wed, 02 Jul 2008 08:13:55 +0000 http://blogs.law.harvard.edu/tech/rss Web Wiz Forums 8.05 30 www.solgel.com/sgforum/RSS_topic_feed.asp Sol-Gel and derived Materials : sol-gel apparatus http://www.solgel.com/sgforum/forum_posts.asp?TID=1722&PID=3950#3950 Author: rama
Subject: sol-gel apparatus
Posted: 02 July 2008 at 8:13am

The sol-gel apparatus works (i.e.,rotator rotates) only when the apparatus is closed (on closing one part is touched by the metal ) . when the apparatus is not closed then the rotator does not rotates. But if the black rod type thing is when touched by any metal then it works properly even when it is not closed.

 
Please tell me why it happens.
]]> Wed, 02 Jul 2008 08:13:55 +0000 http://www.solgel.com/sgforum/forum_posts.asp?TID=1722&PID=3950#3950 Chemistry : Calcium Copper Titanate http://www.solgel.com/sgforum/forum_posts.asp?TID=1720&PID=3949#3949 Author: kaos
Subject: Calcium Copper Titanate
Posted: 02 July 2008 at 2:59am

Wow! I never realise that this place is so quite.]]> Wed, 02 Jul 2008 02:59:50 +0000 http://www.solgel.com/sgforum/forum_posts.asp?TID=1720&PID=3949#3949 Coatings & Films : CaCu3Ti4O12 http://www.solgel.com/sgforum/forum_posts.asp?TID=1721&PID=3948#3948 Author: kaos
Subject: CaCu3Ti4O12
Posted: 30 June 2008 at 10:50am

Is the fume from CaCu3Ti4O12 (calcium copper titanate) hazardous?]]> Mon, 30 Jun 2008 10:50:54 +0000 http://www.solgel.com/sgforum/forum_posts.asp?TID=1721&PID=3948#3948 Chemistry : Calcium Copper Titanate http://www.solgel.com/sgforum/forum_posts.asp?TID=1720&PID=3947#3947 Author: kaos
Subject: Calcium Copper Titanate
Posted: 29 June 2008 at 5:51am

Hi,

Does anyone here has experience with CaCu3Ti4O12? I have a lot ofquestions about this ceramic material, but I will ask one by one.

First off, I am new to material science and sol-gel technology, so please consider me as a newbie (treat me like one too Smile).

I am interested in this material because it has extremely largerelative permitivity. I know that it has to be prepared following certainquite stringent procedure in order to achieve that, be it sol-gelor any other techniques.

My main objective is to coat a layer of this ceramic on a steel sheetor tube of about 1mm thick or around that. It became apparent to me thatsol-gel is not the way to go. I wonder if plasma spray or HVOF is abetter way. I need your input. I found some articles show that thermal spraying technique  does not yield good relative permitivity. I need your opinion.

Second, I was  told that most ceramics are porous. Is this perovskite porous?

Third, I need to know your opinion about the route to prepare. I have a couple articles and they suggest:
1) Ca(NO3)2.4H2O + Cu(NO3)2.4H2O + Titanium(diisoproproxide) bis(2, 4-pentanedionate) 75 wt% in 2-
propanol.

2) Ca(NO3)2·4H2O + Cu(NO3)2·2.5H2O + TiO2 + are used as starting raw materials. Glycine (NH2-CH2-COOH) is used a oxidizer and fuel.

3) Titanium butoxide [Ti(OC3H7)4] in 2-ethyl heaxanoic acid followed by addition of monohydrated calcium acetate [Ca(C2HO2)2 · H2O] and monohydrated copper acetate [Cu(OOCCH3)2· H2O] at room temperature.

The third is prepared as sol-gel whereas the first two are not. Can they also be used for sol-gel? The second can cause (mentioned in the article) combustion when the solution is heated. Is this dangerous? Hope it is not explosion kinda combustion.

  ]]> Sun, 29 Jun 2008 05:51:01 +0000 http://www.solgel.com/sgforum/forum_posts.asp?TID=1720&PID=3947#3947 Powders, Nanoparticles and Colloidal Dispersions : crystallization of Tio2 sol into anatase phase http://www.solgel.com/sgforum/forum_posts.asp?TID=1719&PID=3946#3946 Author: david
Subject: crystallization of Tio2 sol into anatase phase
Posted: 24 June 2008 at 1:51am

Dear Sir
I am preparing Nano Tio2 sol.from titanium n-butoxide and i-proH and Acetyleacetone and water and Nitric acid with the procedure mentioned in literature. i want to have Tio2 sol which is in anatase phase. i try to do that by refluxing but Unfortunately  i was not successful
is there any body who can help
your kind help is highly appreciated
]]> Tue, 24 Jun 2008 01:51:06 +0000 http://www.solgel.com/sgforum/forum_posts.asp?TID=1719&PID=3946#3946 Encapsulation and Functionalization Techniques : SiO2 nano particle http://www.solgel.com/sgforum/forum_posts.asp?TID=1718&PID=3945#3945 Author: sutha
Subject: SiO2 nano particle
Posted: 14 June 2008 at 5:41am

dear,
  can you suggest a method for the preparation of nano silica  from  tetraethyl orthosilicate
]]> Sat, 14 Jun 2008 05:41:08 +0000 http://www.solgel.com/sgforum/forum_posts.asp?TID=1718&PID=3945#3945 Sol-Gel and derived Materials : Fully automatic surface area analyzer F-sorb X400 http://www.solgel.com/sgforum/forum_posts.asp?TID=1717&PID=3944#3944 Author: japp168
Subject: Fully automatic surface area analyzer F-sorb X400
Posted: 12 June 2008 at 10:39pm

Fully automatic surface area analyzer F-sorb X400 series

Specification
method: dynamic nitrogen flow and BET equation
Gas:    N2(99.99%) and  He(99.99%); mixed according to P/P0 value requirement
Flow velocity:  less than 100mL/min
Flow controller: high resolution digital flow sensor with accuracy up to 0.1%
P/P0 range:      0.05~0.35
Function:   (1)single-point BET, multi-point BET ( 4 sample measurement simultaneously )
           (2)rapid "reference sample comparison" surface area measurement
Applicability: specific surface area 0.1㎡/g (minimum) ~3500㎡/g(maximum)
Reproducibility:within ±2%
Efficiency:  (1) 4 sample analysis simultaneously
           (2) 20 min average for one sample with    Multi-point BET
           (3) 5 min average for one sample with single-point BET and "reference sample comparison"
Data process: window-based software developed by ourselves;  easy use and no complicated installation
Report format: multi-point P/Po and absorbed N2 volume table; BET plot;
Dewar pot: 400mL volume
Physical:  50(width)cm×35(depth)cm×59(height)cm
Weight:   about 34 kg

Main accessories: (1)computer(desktop or notebook) with data processing software
                  (2)condensed N2 and He with pressure up to 12MPa and 40L volume respectively
                  (3)liquid Nitrogen container with 10L volume

SophieWang

zuojun.wang@app-one.com.cn
]]> Thu, 12 Jun 2008 22:39:00 +0000 http://www.solgel.com/sgforum/forum_posts.asp?TID=1717&PID=3944#3944 Sol-Gel and derived Materials : Fully automatic surface area analyzer F-sorb X400 http://www.solgel.com/sgforum/forum_posts.asp?TID=1717&PID=3943#3943 Author: japp168
Subject: Fully automatic surface area analyzer F-sorb X400
Posted: 12 June 2008 at 10:37pm

 
Fully automatic editons assisting free-attended analyse process; providing optional analyse methods(singal and muti-point BET,direct reference comparison method,etc.). Windows based software allows real time data saving,archiving and final reporting.Surface area range: 0.1-3500㎡/g, reproducibility: ≤±2%.
Gold APP Instrument Corporation China
SophieWang
 
]]> Thu, 12 Jun 2008 22:37:06 +0000 http://www.solgel.com/sgforum/forum_posts.asp?TID=1717&PID=3943#3943 Powders, Nanoparticles and Colloidal Dispersions : use of THF for Stober process http://www.solgel.com/sgforum/forum_posts.asp?TID=1716&PID=3942#3942 Author: kevin
Subject: use of THF for Stober process
Posted: 12 June 2008 at 11:00am

I was wondering if anyone has experience using THF as the solvent in the Stober process. I tried a 1:1 molar substitution of THF for EtOH and found very rapid particle formation, and a tremendous (~100x) increase in particle size. I assume both effects are primarily related to the lack of hydrogen bonds with THF. It could be interesting to make this work, however, so that compounds not soluble in EtOH could be incorporated into the silica matrix. Has anyone else tried this?
Thanks]]> Thu, 12 Jun 2008 11:00:16 +0000 http://www.solgel.com/sgforum/forum_posts.asp?TID=1716&PID=3942#3942 Miscellaneous : Growing Opal http://www.solgel.com/sgforum/forum_posts.asp?TID=91&PID=3941#3941 Author: Lwilliams
Subject: Growing Opal
Posted: 28 May 2008 at 12:40pm

I suppose you've probably tried http://www.rockngem.com/showdates.asp.
I was thinking maybe if you could find out the author of the article you could get a copy.
Best of Luck
]]> Wed, 28 May 2008 12:40:24 +0000 http://www.solgel.com/sgforum/forum_posts.asp?TID=91&PID=3941#3941