HSP Application note #21
Hansen Solubility Parameter (HSP) of TiO22010.3.3
HSPiP Team Senior Developer, Dr. Hiroshi Yamamoto
I got very interesting paper about surface modification of TiO2.
J. Jpn. Soc. Colour Mater. 67[8], 489-495 (1994)
Japanese Cosmetic company Shiseido researcher wrote this paper in Japanese.
They use very old technology (Teas plot) to determine HSP of modified-TiO2.
Hansen Solubility Parameters (HSP)Hansen Solubility Parameters(HSP) were developed by Charles M. Hansen as a way of predicting if one material will dissolve in another and form a solution. They are based on the idea that "like dissolves like" where one molecule is defined as being 'like' another if it bonds to itself in a similar way.
What can perhaps be surprising is that one can assign HSP to so many different things. Gases like carbon dioxide, solids like carbon-60, sugar, and biological materials like human skin, depot fat, DNA, and even some proteins all have HSP. The list can be continued with drugs, polymers, plasticizers, and in fact any organic material and even many inorganic materials like salts. The only requirement for an experimental confirmation is that the material must behave differently in a sufficient number of test solvents upon contact. Pirika JAVA Demo Applet calculate HSP. HSPLight is available here. |
This is very good example to determine HSP for inorganic materials, so I analyze with latest method.
They synthesis surface modified-TiO2 with above Scheme.
And put them to several solvents, and evaluate how stable M-TiO2 in solvents.
| no | name | Hcode | dD | dP | dH | volume | origial |
OH-1 | OH-2 | OH-3 | OH-4 |
| 1 | hexane | 417 | 14.9 | 0 | 0 | 131.4 | 1 | 1 | 1 | 1 | 1 |
| 2 | diethylether | 255 | 15.49 | 2.9 | 4.6 | 104.7 | 1 | 1 | 1 | 1 | 1 |
| 3 | cyclohexane | 181 | 16.8 | 0 | 0.2 | 108.9 | 1 | 1 | 1 | 1 | 1 |
| 4 | butylmethylketone | 474 | 15.3 | 6.1 | 4.1 | 124.1 | 4 | 3 | 3 | 2 | 2 |
| 5 | methylal | 836 | 19.6 | 1.8 | 8.6 | 89.1 | 1 | 2 | 3 | 2 | 2 |
| 6 | m-xylene | 5323 | 18.4 | 2.6 | 2.3 | 121.3 | 1 | 1 | 1 | 1 | 1 |
| 7 | ethylacetate | 269 | 16.2 | 5.1 | 9.2 | 175.1 | 3 | 3 | 3 | 4 | 2 |
| 8 | benzene | 52 | 18.4 | 0 | 2 | 89.5 | 1 | 1 | 1 | 1 | 1 |
| 9 | chloroform | 156 | 17.8 | 3.1 | 5.7 | 80.5 | 4 | 2 | 2 | 2 | 2 |
| 10 | ethylmethylketone | 481 | 16 | 9 | 5.1 | 90.2 | 4 | 3 | 3 | 3 | 3 |
| 11 | chlorobenzene | 148 | 19 | 4.3 | 2 | 102.1 | 2 | 2 | 3 | 3 | 2 |
| 12 | acetophenone | 11 | 18.8 | 10 | 4 | 117.4 | 4 | 3 | 4 | 4 | 3 |
| 13 | acetone | 7 | 15.5 | 10.4 | 7 | 73.8 | 1 | 2 | 2 | 2 | 1 |
| 14 | 2-ethyl-1-hexanol | 345 | 15.9 | 3.3 | 11.8 | 156.9 | 4 | 4 | 4 | 2 | 2 |
| 15 | cyclohexanone | 183 | 17.8 | 8.5 | 5.1 | 104.2 | 4 | 4 | 4 | 4 | 4 |
| 16 | butyronitrile | 116 | 15.3 | 12.4 | 5.1 | 87.9 | 3 | 3 | 3 | 3 | 2 |
| 17 | l,4-dioxane | 306 | 17.5 | 1.8 | 9 | 85.7 | 2 | 3 | 2 | 2 | 2 |
| 18 | diacetonalcohol | 209 | 15.8 | 8.2 | 10.8 | 124.3 | 4 | 4 | 4 | 4 | 4 |
| 19 | l-pentanol | 552 | 15.9 | 5.9 | 13.9 | 108.6 | 3 | 4 | 4 | 4 | 4 |
| 20 | nitrobenzene | 531 | 20 | 10.6 | 3.1 | 102.7 | 3 | 2 | 2 | 2 | 2 |
| 21 | aniline | 46 | 20.1 | 5.8 | 11.2 | 91.6 | 4 | 3 | 2 | 2 | 2 |
| 22 | l-butanol | 92 | 16 | 5.7 | 15.8 | 92 | 2 | 4 | 4 | 4 | 4 |
| 23 | acetonitrile | 10 | 15.3 | 18 | 6.1 | 52.9 | 4 | 3 | 2 | 2 | 2 |
| 24 | ethylcellosolve | 376 | 15.9 | 7.2 | 14 | 97.5 | 2 | 4 | 4 | 4 | 2 |
| 25 | methylcellosolve | 380 | 16 | 8.2 | 15 | 79.3 | 3 | 4 | 4 | 4 | 4 |
| 26 | N,N-dimethylformamide | 297 | 17.4 | 13.7 | 11.3 | 77.4 | 4 | 3 | 3 | 3 | 3 |
| 27 | nitromethane | 534 | 15.8 | 18.8 | 5.1 | 54.1 | 4 | 2 | 1 | 2 | 2 |
| 28 | ethanol | 325 | 15.8 | 8.8 | 19.4 | 58.6 | 3 | 4 | 4 | 4 | 4 |
| 29 | methanol | 456 | 14.7 | 12.3 | 22.3 | 40.6 | 2 | 3 | 3 | 2 | 2 |
| 30 | 2-aminoethanol | 326 | 17.5 | 6.8 | 18 | 60.3 | 4 | 4 | 4 | 2 | 2 |
| 31 | water | 696 | 15.5 | 16 | 42.3 | 18 | 2 | 1 | 1 | 1 | 1 |
1: Powder settled down within 30 min. and left a clear supernatant liquid.
2: A part of the powder remained suspended for up to 4h
3: A part of the powder remained suspended for up to 24h
4: The powder remained suspended for the period of more than 24h
And from Teas Plot, they determined each HSP.
| dD | dP | dH | Ra | |
| original-TiO2 | 17.02 | 9.2 | 13.2 | 4.87 |
| OH1 | 17.02 | 9.2 | 11 | 4.08 |
| OH2 | 16.92 | 11.8 | 12.2 | 4.62 |
| OH3 | 16.28 | 8.2 | 10.8 | 3.62 |
| OH4 | 16.38 | 7.4 | 12.4 | 2.85 |
It was very good research, but as you see the Teas plot for original TiO2, class iV pattern is very complicated. So, I re-calculated them with latest Sphere algorithm.
Hansen SphereTo determine if the parameters of two molecules (usually a solvent and a polymer) are within range a value called interaction radius (R0) is given to the substance being dissolved. This value determines the radius of the sphere in Hansen space and its center is the three Hansen parameters.
From version 3.1.X, Double Spheres function is available. Pirika provide JAVA 3D Demo Applet to browse the Sphere(s). |
There are 31 solvents, and I set class iV solvent as score=1 and others score=0.
I show you my result below.
| dD | dP | dH | Ra | exceptions | |
| original-TiO2 | 15.14 | 15.16 | 5.18 | 9.65 | 6 |
| OH1 | 15.24 | 6.13 | 16.77 | 6.55 | 1 |
| OH2 | 15.95 | 7.10 | 17.14 | 7.45 | 2 |
| OH3 | 15.42 | 9.08 | 13.45 | 6.04 | 2 |
| OH4 | 15.18 | 8.87 | 15.03 | 5.32 | 2 |
Their result of dH for original TiO2 is 13.2.
That is very strange for me. dH term is hydrogen bonding term, and modification with hydroxy groups cause to reduce dH.
My result of dH for original TiO2 is 5.18 and with modification, it is increasing.
And the OH2 type of modification have maximum dH.
This is very reasonable because introduced OH groups is different.
original TiO2
OH1
OH2
OH3
OH4
2011.4.12
Drag=Rotate, Drag+Shift=Larger/Smaller, Drag+Alt or Command(Window key)=Translate.
If you are using HTML5 enable browser such as Chrome, Safari or FireFox (IE9 is out of support), you will see the Canvas. If you pick solvent, solvent name will appear.
Green Sphere is calculated by me. Cyane Sphere is listed in the paper.
The Sphere model is very simple.
If the HSP distance is shorter than interaction radius(Ra) it will dissolve/disperse.
Out of the sphere, it will not.
There are several exceptions.
HSP DistanceTo calculate the distance (Ra) between Hansen parameters in Hansen space the following formula is used:
HSP distance(Ra)={4*(dD1-dD2)2 + (dP1-dP2)2 +(dH1-dH2)2 }0.5 |
for OH1, Cyclohexanone is exception. HSP distance / Ra becomes 1.99 but disperse very well.
For OH2, OH3, Cyclohexanone and Acetophenone become exception.
For OH4, Cyclohexanone and Ethylcellosolve become exception.
Why Cyclohexanone always become exception?
Actually, original TiO2 case Cyclohexanone is not exception and disperse very well.
So, what I think about this phenomena, the original TiO2 surface have several character.
OverAll HSP is [15.14, 15.16, 5.18] but some part of surface have different values.
So, original TiO2 have 6 exceptions.
For OH1, OH2 some parts are modified.
Even though, N parts are remain.
This N parts are very similar to Cyclohexanone.
So, Cyclohexanone can disperse.
For OH3, OH4 still N parts are remain and can disperse with Cyclohexanone.
And maybe, this work as colloidal protection, and show some other exceptions and Radius of Sphere become small.
I can say that, large materials that have several nature of surface, it become complicated.
Even though, with using HSP, things become clear.
These materials are used for face powder and interaction with skin is also very interesting theme.
If you want to know HSP of skin, please buy HSPiP and read e-Book.
HSPiP(Hansen Solubility Parameters in Practice)The first edition of HSPiP that appeared in November, 2008, greatly enhanced the usefulness of the Hansen solubility parameters (HSP). The HSP values of over 1200++ chemicals and 500 polymers are provided in convenient electronic format and have been revised and updated using the latest data sources in the second edition (March, 2009). A third edition of the HSPiP appeared in March, 2010. There are now 10,000 compounds in the HSP file which also includes data on density, melting point, boiling point, critical parameters, Antoine constants and much more. The user is able to carry out many different sorts of optimisations of solubility, evaporation, diffusion, adhesion, create their own datasets (automatically if required) and explore the huge range of applications for HSP in coatings, paints, nanoparticles, cosmetics, pharma, organic photovoltaics and much more. The 3rd Edition v3.1 was released on 12 December 2010. Current users can upgrade free (now v3.1.09) by downloading the latest .msi installer from http://hansen-solubility.com The 4th Edition v4.0.x was released on 2 Jan. 2013. The Current users can upgrade with free charge. 2013.1.28 The Visual How to manual of HSPiP. You can understand what HSPiP can do. |
Notice:
I used HSP developer version 3.1 to calculate sphere.
If you are using HSPiP version 3, calculation result may differ.
If you want to calculate pigments, Split dH into donor/acceptor may work well.
