Frequently Asked Questions about HSPiP

1 Why won’t HSPiP fit on my screen?
The program is designed for a minimum 1024x768 resolution. Almost no-one uses a screen with smaller resolution. However, if in your Graphics setup you have specified Large Fonts then this effectively reduces your screen resolution and HSPiP won’t fit.

2 Why is my Toolbar in the way?
Unfortunately the minimum 1024x768 resolution requirement doesn’t leave space for your Toolbar to be on the side of the screen. You either need a bigger screen resolution, a Toolbar along the bottom or you need to set your Toolbar to Autohide.

3 How do I create my own set of solvents?
The simplest method is to load one of the small Example sets (such as Chapter2), then highlight and delete all the solvents! You then click the Add from Master List option and find each of your solvents in turn, Double-click (or Alt-Click) on the solvent and that sends it automatically into your own solvent list. The software stops you from accidentally adding the same solvent twice. To find your solvent in the big master list use the search functionality by name (it’s not case sensitive and looks for whatever you enter in any part of the name field), by Cas No. or by Molecular Formula – whichever gets you to your solvent the fastest. The Getting Started video shows you how to do all this. Another way is to simply open the complete Sphere Solvent Data, search for the solvents to be included, and note their score. Unused solvents can be deleted with the delete unused function.

4 Why isn’t solvent X in the Solvent Optimizer list?
Probably because we didn’t think to add it. Remember that it’s really easy to add it yourself from within Solvent Optimizer. But if you want us to do it, let us know and we’ll try. The solvent list for the 2nd Edition was enlarged significantly thanks to the requests from some HSPiP power-users. You may have trouble finding the Antoine Coefficients for your solvent. We’ve accessed some large databases, but sometimes we’ve failed to find anything on our molecule of interest and have therefore used a reasonable approximation. A good approximation is better than not entering any values.

5 Why do the HSP of chemical X differ from those I’ve found elsewhere (or those published in the 2nd Edition of the Hansen Book)?
There will never be a perfect list of HSP. New information means that we have to update the values. For example, between the 1st and 2nd editions we’ve had good reason to change maybe 6 values and we expect to go on tweaking/revising for future editions. Fortunately many of these changes are minor, and as a percentage of the overall list they are tiny. We encourage all HSPiP users to keep challenging us about particular HSP and whenever we can get good data from other sources to support a change, we will carry on making the changes.

6 Why do the predicted values from Y-MB, S-P,  Hoy etc. sometimes differ significantly?
Group contribution methods can never be perfect. They depend both on the quality of the data fed to them and on the choice of subgroups and subgroup interactions. We never tire of saying that ultimately you must be the judge of what constitutes a reasonable HSP set for a particular molecule. Use all the tools in DIY and, above all, try to pin down the δTot from enthalpy of vapourisation so you can at least be sure that your overall HSP values fit, even if the internal balance might be questionable. The more we can get independently measured values (e.g. by IGC) the better we can revise/update group contribution methods. Behind the scenes we’re also working on objective molecular dynamics methods – but don’t expect results any time soon!

7 We sometimes get strange results from the Polymer HSP predictions. Why?
Yes, we get them too – just look at the last example in the Polymer video. As we said, this is early days with this new technique. We could have waited to improve it, but we wanted to get it out there so that the HSPiP user base could experiment with it and maybe provide ideas of how to improve the technique. And, as we often say, the more we can get good experimental HSP (e.g. from IGC) the more we can refine the technique to everyone’s benefit. Experimental data are always preferred if possible.

8 Why doesn’t HSPiP do X?
There are three possible reasons. The first is that it’s not possible to do it. The second is that it’s possible and that we’re working on it – and we will welcome any help from someone who is interested in it. The third is that we’ve not thought of adding it to HSPiP. We love getting requests for extra features for HSPiP, so give us your wish-list and we’ll do our best to add features that increase HSPiP’s practical usefulness.

9 Why do I get so much variation in my Sphere fit each time I press the Calculate button? 
Sphere quite deliberately explores fits over the widest possible range. If the data are really good and the solvent points cover a good range of HSP space then the calculated values vary only very slightly - this is evidence that you have a good, unambiguous fit. But if the data aren’t good and, especially, they don’t provide points surrounding the real sphere, then there are very many mathematically equivalent fits. The fact that you see large variation is proof, unfortunately, that your data aren’t good enough to give an unambiguous fit.

What can you do about it? Usually the quickest solution is to look at the Sphere plot and spot areas of dD, dP, dH where you don’t have any relevant solvent(s). All you have to do is repeat your experiments with the extra few solvents and add the results to HSPiP. There is no need, of course, to repeat your other data points - so the extra work is really quite small. We have used this approach ourselves many times and the quality of the fit improves hugely with just a few carefully chosen extra solvents. We have to stress "carefully chosen". If, for example, Methanol is very far away from any reasonable fit, adding extra data points for Ethanol, Propanol, Butanol... will be extra work for no real benefit."

10 Do I get a receipt from the SWReg eCommerce website when I purchase the HSPiP? 
Yes. We can also provide a receipt of what is on the eCommerce website, or other electronic confirmation, but naturally prefer not to handle such matters. This is one reason why we are using this procedure. The eCommerce website handles all the VAT situations, so depending on your situation, you may be required to include this.

11 I get an error when I Search in the eBook – what should I do?
The eBook uses the Microsoft Web Browser. If this isn’t fully installed on your PC then you might be missing mshtml.dll. It is easily found on the web, or a re-install of Microsoft Internet Installer will fix the problem.

12 My 64-bit computer will not run the program. What do I do so it can run?
Users of 64-bit computers may need to download PDFLibNet.dll and use it to replace PDFLibNet.dll that is automatically installed with the software. 

13 How can I calculate the sphere radius for a polymer or any other solute?
The short answer is that you can’t. This is often a disappointment to HSP users, but there are many reasons why it’s impossible. 

1 The radius only has meaning to you in your specific application. So two users of the same polymer might have totally different radii. Why? Suppose one user is worried about swelling of the polymer over a long period. Many solvents will swell a polymer without dissolving it. So the radius will be large. Suppose a different user is interested only in creating concentrated polymer solutions. Many fewer solvents will be good solvents, so the radius will be significantly lower. 

2 Even if two users of the “same” polymer have the same general application (e.g. creating solutions) one might be using a low molecular weight grade and another a high molecular weight grade. The radius of the former will be larger than the latter. 

3 Even if two users of the “same” polymer use the same molecular weights, it’s still possible that the degree of branching, (accidental) cross-linking, “blockiness” etc. of the two polymers might be different. 

4 The science behind radii predictions, though well-known is really only applicable to ideal polymers under ideal circumstances, not the real-world polymers we prefer to use. 

These issues are not a limitation of HSP – they are a strength! The Sphere method is designed to give you two pieces of information that you can subsequently use for formulating. The first is the centre. This will generally be the same for all users. The second is the radius, which is specific to your polymer and your criterion. HSPiP even encourages you to create multiple radii for the same polymer. By scoring not just 0, 1 but 1, 2, 3, 4… you can calculate different Spheres from one dataset. Those solvents that give instant, easy solution score 1, those that score a slow solution score 2, those that just swell give a 3 and so forth. If you include the 3’s as “good” solvents, then you get a large radius, applicable to swelling applications. By just including the 1’s you get a radius relevant to solution applications. 

As mentioned in (4) it’s not all subjective. The fundamental science of dissolving polymers in solvents (and solvents in polymers) is well-known and HSPiP includes a modeller for exploring that science. The science works well for pure, mono-disperse polymers under careful experimental conditions, so the radii, and their variations, are at least explicable in hindsight. But the large gap between the results of such pure polymers and the reality of commercial polymers used in real-world applications means that the Sphere method to measure the radius (or radii) is the one that most of us use most of the time.