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The '''Hildebrand solubility parameter''' (δ) 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 [[polymer]]s. Materials with similar values of δ are likely to be [[miscible]]. | |||
==Definition== | |||
The Hildebrand solubility parameter is the [[square root]] of the cohesive energy density: | |||
<math>\delta = \sqrt{\frac{\Delta H_v -RT}{V_m}}</math> | |||
The cohesive energy density is the amount of [[energy]] needed to completely remove unit volume of [[molecule]]s from their neighbours to infinite separation (an [[ideal gas]]), which is equal to the [[enthalpy of vaporization|heat of vaporization]] divided by [[molar volume]]. In order for a material to dissolve, these same interactions need to be overcome as the molecules are separated from each other and surrounded by the solvent. Dr. [[Joel Henry Hildebrand]] suggested the square root of the cohesive energy density as a numerical value indicating solvency behavior. This later became known as the “Hildebrand solubility parameter”. Materials with similar solubility parameters will be able to interact with each other, resulting in [[solvation]], [[miscibility]] or swelling. | |||
==Uses and Limitations== | |||
Its principal utility is that it provides simple predictions of phase equilibrium based on a single parameter that is readily obtained for most materials. These predictions are often useful for non-polar and slightly polar ([[bond dipole moment|dipole moment]] <2 [[debye]]s{{Citation needed|date=September 2009}}) systems without hydrogen bonding. It has found particular use in predicting solubility and swelling of polymers by solvents. More complicated 3 dimensional solubility parameters, such as [[Hansen Solubility Parameters]], have been proposed for polar molecules. | |||
The principal limitation of the solubility parameter approach is that it applies only to associated solutions ("like dissolves like" or, technically speaking, positive deviations from [[Raoult's law]]): it cannot account for negative deviations from Raoult's law that result from effects such as solvation or the formation of electron donor acceptor complexes. Like any simple, predictive theory it can inspire overconfidence: it is best used for screening with data used to verify the predictions. | |||
==Units== | |||
The conventional units for the solubility parameter are ([[calories]] per cm<sup>3</sup>)<sup>1/2</sup>, or cal<sup>1/2</sup> cm<sup>-3/2</sup>. The [[SI units]] are J<sup>1/2</sup> m<sup>-3/2</sup>, equivalent to the [[pascal (unit)|pascal]]<sup>1/2</sup>. 1 calorie is equal to 4.184 J. | |||
1 cal<sup>1/2</sup> cm<sup>-3/2</sup> = (4.184 J)<sup>1/2</sup> (0.01 m)<sup>-3/2</sup> = 2.045 × 10<sup>3</sup> Pa<sup>1/2</sup> | |||
Given the non-exact nature of the use of δ, it is often sufficient to say the number of MPa<sup>1/2</sup> is twice the number of (cal<sup>1/2</sup> cm<sup>-3/2</sup>). | |||
Where the units are not given, for example in older books, it is usually safe to assume the non SI unit. | |||
==Examples== | |||
{| class="wikitable sortable" | |||
|- | |||
! Substance | |||
! δ<ref name="burke">{{cite web | url=http://www.cool.conservation-us.org/byauth/burke/solpar/ | title=Part 2. Hildebrand Solubility Parameter | accessdate=2013-12-04 | author=John Burke | year=1984}}</ref> [cal<sup>1/2</sup> cm<sup>-3/2</sup>] | |||
! δ [MPa<sup>1/2</sup>] | |||
|- | |||
| [[n-Pentane]] | |||
| 7.0 | |||
| 14.4 | |||
|- | |||
| [[n-hexane]] | |||
| 7.24 | |||
| 14.9 | |||
|- | |||
| [[Diethyl Ether]] | |||
| 7.62 | |||
| 15.4 | |||
|- | |||
| [[Ethyl Acetate]] | |||
| 9.1 | |||
| 18.2 | |||
|- | |||
| [[Chloroform]] | |||
| 9.21 | |||
| 18.7 | |||
|- | |||
| [[Dichloromethane]] | |||
| 9.93 | |||
| 20.2 | |||
|- | |||
| [[Acetone]] | |||
| 9.77 | |||
| 19.7 | |||
|- | |||
| [[2-propanol]] | |||
| 11.6 | |||
| 23.8 | |||
|- | |||
| [[Ethanol]] | |||
| 12.92 | |||
| 26.2 | |||
|- | |||
| [[PTFE]] | |||
| 6.2<ref name="jstoffer">{{cite web | url=http://web.mst.edu/~jstoffer/Solution/solparaexp.html | title=Examples of Solubility Parameters | accessdate=2007-11-20}}</ref> | |||
| | |||
|- | |||
| [[Poly(ethylene)]] | |||
| 7.9<ref name=jstoffer /> | |||
| | |||
|- | |||
| [[Poly(propylene)]] | |||
| 8.2<ref name="vandenburg">{{Cite journal | |||
| last = Vandenburg | |||
| first = H. ''et al.'' | |||
| coauthors = et al. | |||
| title = A simple solvent selection method accelerated solvent extraction of additives from polymers | |||
| journal = The Analyst | |||
| volume = 124 | |||
| pages = 1707–1710 | |||
| url = http://www.rsc.org/Publishing/Journals/AN/article.asp?doi=a904631c | |||
| year = 1999 | |||
| doi = 10.1039/a904631c | |||
| postscript = <!--None--> | |||
| issue = 11 }} | |||
</ref> | |||
| 16.6 | |||
|- | |||
| [[Poly(styrene)]] | |||
| 9.13<ref name=jstoffer /> | |||
| | |||
|- | |||
| [[Poly(phenylene oxide)]] | |||
| 9.15<ref name=jstoffer /> | |||
| | |||
|- | |||
| [[PVC]] | |||
| 9.5<ref name=vandenburg /> | |||
| 19.5 | |||
|- | |||
| [[Polyethylene terephthalate|PET]] | |||
| 10.1<ref name=vandenburg /> | |||
| 20.5 | |||
|- | |||
| [[Nylon 6,6]] | |||
| 13.7<ref name=vandenburg /> | |||
| 28 | |||
|- | |||
| [[Poly(methyl methacrylate)]] | |||
| 9.3<ref name=vandenburg /> | |||
| 19.0 | |||
|- | |||
| [[(Hydroxyethyl)methacrylate]] | |||
| 25-26<ref name="kwok">{{cite journal | title=Synthetic hydrogels 3. Solvent effects on poly(2-hydroxyethyl methacrylate) networks | last=Kwok | first=Alan Y. | coauthors=Greg G. Qiao David H. Solomon | journal=Polymer | year=2004 | volume=45 | pages=4017–4027}}</ref> | |||
| | |||
|- | |||
| [[Polyhydroxyethylmethacrylate|poly(HEMA)]] | |||
| 26.93<ref name="kwok"/> | |||
| | |||
|- | |||
| [[Ethylene Glycol]] | |||
| 29.9<ref name=vandenburg /><ref name="kwok"/> | |||
| | |||
|} | |||
From the table, [[polyethylene|poly(ethylene)]] has a solubility parameter of 7.9 cal<sup>1/2</sup> cm<sup>-3/2</sup>. Good solvents are likely to be [[diethyl ether]] and [[hexane]]. (However, PE only dissolves at temperatures well above 100°C.) Poly(styrene) has a solubility parameter of 9.1 cal<sup>1/2</sup> cm<sup>-3/2</sup> | |||
, and thus ethyl acetate is likely to be a good solvent. [[Nylon 6,6]] has a solubility parameter of 13.7 cal<sup>1/2</sup> cm<sup>-3/2</sup>, and ethanol is likely to be the best solvent of those tabulated. However, the latter is polar, and thus we should be very cautions about using just the Hildebrand solubility parameter to make predictions. | |||
== See also == | |||
* [[Solvent]] | |||
* [[Hansen Solubility Parameters]] | |||
==References== | |||
===Notes=== | |||
{{reflist}} | |||
===Bibliography=== | |||
{{cite book | |||
| last = Barton | |||
| first = AFM | |||
| title = Handbook of Solubility Parameters and Other Cohesion Parameters, 2nd edition | |||
| publisher = CRC Press | |||
| year = 1991}} | |||
{{cite book | |||
| last = Barton | |||
| first = AFM | |||
| title = Handbook of Polymer Liquid Interaction Parameters and Other Solubility Parameters | |||
| publisher = CRC Press | |||
| year = 1990}} | |||
==External links== | |||
* <!--http://scrub.lanl.gov/pdf/williams/04_chapter_04.pdf Information on theory and derivation of Hildebrand solubility parameters by Laurie L. Williams]--> | |||
* Abboud J.-L. M., Notario R. (1999) [http://old.iupac.org/publications/pac/1999/71_04_pdf/abboud.pdf Critical compilation of scales of solvent parameters. part I. pure, non-hydrogen bond donor solvents – technical report]. Pure Appl. Chem. 71(4), 645-718 (IUPAC document with large table (1b) of Hildebrand solubility parameter (δ<sub>H</sub>)) | |||
{{DEFAULTSORT:Hildebrand Solubility Parameter}} | |||
[[Category:Polymer chemistry]] |
Revision as of 11:34, 17 August 2013
The Hildebrand solubility parameter (δ) 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 polymers. Materials with similar values of δ are likely to be miscible.
Definition
The Hildebrand solubility parameter is the square root of the cohesive energy density:
The cohesive energy density is the amount of energy needed to completely remove unit volume of molecules from their neighbours to infinite separation (an ideal gas), which is equal to the heat of vaporization divided by molar volume. In order for a material to dissolve, these same interactions need to be overcome as the molecules are separated from each other and surrounded by the solvent. Dr. Joel Henry Hildebrand suggested the square root of the cohesive energy density as a numerical value indicating solvency behavior. This later became known as the “Hildebrand solubility parameter”. Materials with similar solubility parameters will be able to interact with each other, resulting in solvation, miscibility or swelling.
Uses and Limitations
Its principal utility is that it provides simple predictions of phase equilibrium based on a single parameter that is readily obtained for most materials. These predictions are often useful for non-polar and slightly polar (dipole moment <2 debyesPotter or Ceramic Artist Truman Bedell from Rexton, has interests which include ceramics, best property developers in singapore developers in singapore and scrabble. Was especially enthused after visiting Alejandro de Humboldt National Park.) systems without hydrogen bonding. It has found particular use in predicting solubility and swelling of polymers by solvents. More complicated 3 dimensional solubility parameters, such as Hansen Solubility Parameters, have been proposed for polar molecules.
The principal limitation of the solubility parameter approach is that it applies only to associated solutions ("like dissolves like" or, technically speaking, positive deviations from Raoult's law): it cannot account for negative deviations from Raoult's law that result from effects such as solvation or the formation of electron donor acceptor complexes. Like any simple, predictive theory it can inspire overconfidence: it is best used for screening with data used to verify the predictions.
Units
The conventional units for the solubility parameter are (calories per cm3)1/2, or cal1/2 cm-3/2. The SI units are J1/2 m-3/2, equivalent to the pascal1/2. 1 calorie is equal to 4.184 J.
1 cal1/2 cm-3/2 = (4.184 J)1/2 (0.01 m)-3/2 = 2.045 × 103 Pa1/2
Given the non-exact nature of the use of δ, it is often sufficient to say the number of MPa1/2 is twice the number of (cal1/2 cm-3/2). Where the units are not given, for example in older books, it is usually safe to assume the non SI unit.
Examples
Substance | δ[1] [cal1/2 cm-3/2] | δ [MPa1/2] |
---|---|---|
n-Pentane | 7.0 | 14.4 |
n-hexane | 7.24 | 14.9 |
Diethyl Ether | 7.62 | 15.4 |
Ethyl Acetate | 9.1 | 18.2 |
Chloroform | 9.21 | 18.7 |
Dichloromethane | 9.93 | 20.2 |
Acetone | 9.77 | 19.7 |
2-propanol | 11.6 | 23.8 |
Ethanol | 12.92 | 26.2 |
PTFE | 6.2[2] | |
Poly(ethylene) | 7.9[2] | |
Poly(propylene) | 8.2[3] | 16.6 |
Poly(styrene) | 9.13[2] | |
Poly(phenylene oxide) | 9.15[2] | |
PVC | 9.5[3] | 19.5 |
PET | 10.1[3] | 20.5 |
Nylon 6,6 | 13.7[3] | 28 |
Poly(methyl methacrylate) | 9.3[3] | 19.0 |
(Hydroxyethyl)methacrylate | 25-26[4] | |
poly(HEMA) | 26.93[4] | |
Ethylene Glycol | 29.9[3][4] |
From the table, poly(ethylene) has a solubility parameter of 7.9 cal1/2 cm-3/2. Good solvents are likely to be diethyl ether and hexane. (However, PE only dissolves at temperatures well above 100°C.) Poly(styrene) has a solubility parameter of 9.1 cal1/2 cm-3/2 , and thus ethyl acetate is likely to be a good solvent. Nylon 6,6 has a solubility parameter of 13.7 cal1/2 cm-3/2, and ethanol is likely to be the best solvent of those tabulated. However, the latter is polar, and thus we should be very cautions about using just the Hildebrand solubility parameter to make predictions.
See also
References
Notes
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Bibliography
20 year-old Real Estate Agent Rusty from Saint-Paul, has hobbies and interests which includes monopoly, property developers in singapore and poker. Will soon undertake a contiki trip that may include going to the Lower Valley of the Omo.
My blog: http://www.primaboinca.com/view_profile.php?userid=5889534
20 year-old Real Estate Agent Rusty from Saint-Paul, has hobbies and interests which includes monopoly, property developers in singapore and poker. Will soon undertake a contiki trip that may include going to the Lower Valley of the Omo.
My blog: http://www.primaboinca.com/view_profile.php?userid=5889534
External links
- Abboud J.-L. M., Notario R. (1999) Critical compilation of scales of solvent parameters. part I. pure, non-hydrogen bond donor solvents – technical report. Pure Appl. Chem. 71(4), 645-718 (IUPAC document with large table (1b) of Hildebrand solubility parameter (δH))
- ↑ Template:Cite web
- ↑ 2.0 2.1 2.2 2.3 Template:Cite web
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting
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Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules
Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.
A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running
The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more
There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang - ↑ 4.0 4.1 4.2 One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting
In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang
Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules
Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.
A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running
The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more
There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang