Hansen, Charles

Hnnatto Food Colors Charles Hansen s Laboratory, Milwaukee, Wis. A brief description of what annatto is and how it is used. 

Solubility parameters were developed by Charles 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. The Hildebrand solubility parameter (8) provides a numerical estimate of the degree of interaction between materials, and can be a good indication of solubility, particularly for non-polar materials such as many rubbers. Materials with similar values of solubility parameters are likely to be miscible [7]. 

In the evaluation of Q (cgs units) a — 0,1, p = 1, R — 8.317 107, V = 102, Mc = 25,000, H = 1.96. Since PS repeat units and PMMA repeat units have very different polar and hydrogen-bonding character, the work of Charles Hansen (16,17) was used in the calculation of / . That is, contributions from dispersion forces, polar forces, and hydrogenbonding forces were added according to the equation ... 

Charles M. Hansen (4) was working in the area of paint technology. He was aware oT the Hildebrand/Scott solubility parameter, and explored the use of the solubility parameter in polymer-solvent interactions. He began his research with the consideration of the thermodynamic equation for the energy of mixing... 

About the same time, perhaps a little earlier, another walk took place. Bloch finished up at Harvard in late summer of 1945, but shortly before returning to Stanford, he went to lunch with Stanford colleague William W. Hansen, who was visiting MIT. Bloch and Hansen walked east along Massachusetts Avenue to a restaurant across the Charles River. During their lunch, Bloch told Hansen about an experiment he wanted to do when he returned to Stanford. Bloch s experiment was to take a bulk sample of a material rich in hydrogen, place it in a magnetic field, and see if the... 

Joel D. Cline, Charles N. Katz, and Kimberly Kelly-Hansen ... 

The inadequacy of using the total solubility parameter to describe the behavior of polar and hydrogen bonded solvents in polymer systems led Charles Hansen(2.) to generalize Hildebrand s parameter. 

The many theories behind the various models developed to calculate the solubility of polymers, and to predict the ability of liquids to dissolve them, are described clearly and in high detail by Burke (Burke, 1984). All define a term known as solubility parameter for liquids and polymers using one or more of the intermolecular force components and represent the parameter in two or three dimensions. Calculating solubility parameters is a mathematically complex process which will not be discussed here. The most widely used method today for predicting whether a polymer is soluble in a liquid was developed by Charles M. Hansen in 1966. Hansen parameters ( ) for solvents and polymers are calculated from the dispersion force component ( d), polar component ((5p) and hydrogen bonding component ( h) for each using the formula ... 

Aventis Pharmaceuticals BASF http //www.basf.com] Barrington http //www.barringtonchem.com] C.P. Hall http //WWW. ephaii. com Camida Ltd http //www.camida.com] Cerac http //www.cerac.com] Charkit http //www.charkit.com] Charles B. Chrystal http //www.cbchrystai.com] Chemacon GmbH http //WWW. chemacon. de Chr. Hansen Inc Cornelius Chem. Co. Ltd http //www.corneiius.co.uk] DMV Int l. Pharma http //www.dmv-internationai.com] Degussa AG/Health Nutrition http //www.degussa-heaith-nutrition.de] Delta Distributors http //WWW. deitadist. com... 

Boith China http //www.boith.com, Charles Bowman http //www.chariesbowman.com, Generi chem http //www.generichem. com, Morre-Tec Ind. http //www.morretec.com, P.L. Thomas http //www.pithomas.com R.W. Greeff http //www.pechiney-chemicais.com, RIA Int l. http //www.riausa.com. Seltzer http //www.seitzerchemicais.com. Sigma Synasia Fine Chem. http //www.synasia.com Universal Preserv-A-Chem http //www.upichem.com, Vopak USA http //WWW. vopakusa. com Trade Name Synonyms Potassium Sodium Copper Chlorophyllin 033280 t[Chr. Hansen Inc] Uniphyllin SC [Universal Preserv-A-Chem http //www.upichem.com]... 

The concept of solubility parameters (Hansen, 1967) was first introduced by Charles M. Hansen in 1967 in his PhD thesis where he evaluated whether one material would... 

Charles Hansen introduced the concept of 3D solubility parameters, which offers an extension of the regular solution theory to polar and hydrogen bonding systems. Hansen observed that when the solubility parameter increments of the solvents and polymers are plotted in 3D plots, then the good solvents lie approximately within a sphere of radius R (with the polymer being in the center). This can be mathematically expressed as shown in Equation 3.2. The quantity under the square root is the distance between the solvent and the polymer. Hansen found empirically that a universal value 4 should be added as a factor in the dispersion term to approximately attain the shape of a sphere. This universal factor has been confirmed by many experiments. Hansen in his book provides a review of the method together with extensive tables of parameters. 

Comments from many conservation practitioners and students, users of the book and associated professional updating courses have made me think more deeply about some of the detail and observations. Many scientists who had never previously heard of conservation have freely shared their knowledge and data. These are acknowledged appropriately in the text. The American Institute of Conservation kindly asked me to help in the design and delivery of their Adhesives course. The resultant critical conversations with the other participants have been fed into this revision. Alan Phenix commented on the Solvents chapter. Amy Davidson commented on the Glossary. Steven Abbott and Charles Hansen provided access to Hansen Solubility Parameters in Practice software. The preparation of the manuscript was made possible by generous access to the resources, particularly electronic, of the John Rylands University Library (Manchester University) and the British Library. 

Annatto Food Colors, Charles Hansen s Laboratory, Milwaukee, Wis. 

K. Meyn, 2002 Charles Medom Hansen A life with solubility parameters. Dansk Kemi, 83 (3), page 10 (in Danish). 

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