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Time to Choose a Topic for Term Paper

Time to Choose a Topic for Term Paper. Send me your title and choose a presentation date ASAP – first come first serve!. Week #10 in Perspective. Chemistry and Thermodynamics of Water Amphilicity from the perspective of solvent. Coarse Breakdown of Adsorption Mechanisms.

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Time to Choose a Topic for Term Paper

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  1. Time to Choose a Topic for Term Paper Send me your title and choose a presentation date ASAP – first come first serve! E. A. Vogler MatSE 597c Lecture 15

  2. Week #10 in Perspective • Chemistry and Thermodynamics of Water Amphilicity from the perspective of solvent E. A. Vogler MatSE 597c Lecture 15

  3. Coarse Breakdown of Adsorption Mechanisms Not an EITHER OR PROPOSITION!!! Some of both can occur simultaneously, esp. w/complex multifunctional macromolecules… E. A. Vogler MatSE 597c Lecture 15

  4. Adsorption Mechanisms • Ion exchange • Ion pairing • Hydrogen bonding • Polarization of aromatic rings • Dispersion forces • Hydrophobic bonding From M. J. Rosen, "Surfactants and Interfacial Phenomena," Wiley, New York, 1978, pp 34-35. E. A. Vogler MatSE 597c Lecture 15

  5. Adsorption Mechanisms • Ion exchange • Ion pairing • Hydrogen bonding • Polarization of aromatic rings • Dispersion forces • Hydrophobic bonding All of these solute-surface reactions occur in competition with solvent-surface reactions From M. J. Rosen, "Surfactants and Interfacial Phenomena," Wiley, New York, 1978, pp 34-35. E. A. Vogler MatSE 597c Lecture 15

  6.  - HOH  +  - 0.25 nm Water is approximately the size of atomic oxygen – a very small molecule. E. A. Vogler MatSE 597c Lecture 15  +

  7. Review some important thermodynamic properties of water Interpreted in terms of biological consequences Discuss molecular origin of water’s special properties Interpreted in terms of self association Explore mechanismS of surface hydration Interpreted in terms of biomaterial properties E. A. Vogler MatSE 597c Lecture 15

  8. Supporting Literature E. A. Vogler, in Water in Biomaterials Surface Science, M. Morra, ed., John Wiley & Sons – From Vogler Web Site Chapter 1 “Biological Properties of Water” Chapter 6 “On the Origins of Water Wetting Terminology” Chapter 10 “How Water Wets Biomaterials” …and many, many citations therein. E. A. Vogler MatSE 597c Lecture 15

  9. Where Does Water Come From???

  10. Water is Ubiquitous in the Cosmos “Huge water factories in space” ITHACA, N.Y. -- A team of U.S. astronomers, led by Cornell University astrophysicist Martin Harwit, has discovered a massive concentration of water vapor within a cloud of interstellar gas close to the Orion nebula. The amount of water measured is so high -- enough to fill the Earth's oceans 60 times a day -- that the researchers believe it provides an important clue to the origin of water in the solar system. Cernicharo, J., J. R. Pardo, et al. (1999). “Observations of Water in Orion.” Astrophys. J. Lett.520: L131-L134. E. A. Vogler MatSE 597c Lecture 15

  11. Water from Space???? as it approached the Sun Images from the Estimated to carry 3.6 million tons of water! http://www.gsfc.nasa.gov/GSFC/SpaceSci/origins/linearwater/linearwater.htm E. A. Vogler MatSE 597c Lecture 15

  12. Evidence for Extra-Solar System Water Fire and Ice: Sizzling Comets Around a Dying Star The Submillimeter Wave Astronomy Satellite(SWAS) detects water vapor near an expanding star as it vaporizes local icy comets http://sao-www.harvard.edu/swas/pr010711.html E. A. Vogler MatSE 597c Lecture 15

  13. From Space to Your Home Liberally mix O and H atoms, heat to > 90 oC and voilà

  14. Q: How long has water been on Earth? A: Nearly as long as Earth has existed.

  15. Oceans that cover 75% of the Earth’s surface have existed for 4 billion years… …with constant volume for the last 500 million years. E. A. Vogler MatSE 597c Lecture 15

  16. Water on Earth • Powers atmospheric cycling and processes solar radiation • Mediates diurnal and seasonal temperature swings • Geological “chisel” • Biological solvent system, mobile transport medium, physiologic mediator…

  17. Some Physical Properties of Water (from 52nd Handbook of Chemistry and Physics) “Anomalous” Properties of Water Property, units Value Heat Capacity (Cp) cal/g oC 0.998 @ 25 oC Heat of Fusion, cal/g 76.4 @ 0 oC M.P. Heat of Vaporization, cal/g 539.6 @ 100 oC B.P. Density () g/cc 0.99823 @ 20 oC 1.00000 @ 3.98 oC 0.99987 @ 0 oC 0.916 – ice Interfacial Tension (lv) dyne/cm 72.75 @ 20 oC

  18. Some Physical Properties of Water (from 52nd Handbook of Chemistry and Physics) “Anomalous” Properties of Water Property, units Value Heat Capacity (Cp) cal/g oC 0.998 @ 25 oC Heat of Fusion, cal/g 76.4 @ 0 oC M.P. Heat of Vaporization, cal/g 539.6 @ 100 oC B.P. Density () g/cc 0.99823 @ 20 oC 1.00000 @ 3.98 oC 0.99987 @ 0 oC 0.916 – ice Interfacial Tension (lv) dyne/cm 72.75 @ 20 oC Large amount of heat must be absorbed by water for a unit increase in temperature If water had a low Cp then… Environmental temperature swings would be unfavorable & life would boil over without a high heat-capacity solvent system to dissipate metabolic heat: r=rexp(-E/kT)

  19. Some Physical Properties of Water (from 52nd Handbook of Chemistry and Physics) “Anomalous” Properties of Water Property, units Value Heat Capacity (Cp) cal/g oC 0.998 @ 25 oC Heat of Fusion, cal/g 76.4 @ 0 oC M.P. Heat of Vaporization, cal/g 539.6 @ 100 oC B.P. Density () g/cc 0.99823 @ 20 oC 1.00000 @ 3.98 oC 0.99987 @ 0 oC 0.916 – ice Interfacial Tension (lv) dyne/cm 72.75 @ 20 oC Large amount of heat is required to covert solid ice to liquid water (melt) and liquid water to water vapor (boil)

  20. Remarkable Water Thermal Properties Graphic taken from K. S. Davis, and J. A. Day, "Water: The Mirror of Science," Doubleday & Co., Garden City, NY, 1961.

  21. Some Physical Properties of Water (from 52nd Handbook of Chemistry and Physics) “Anomalous” Properties of Water Property, units Value Heat Capacity (Cp) cal/g oC 0.998 @ 25 oC Heat of Fusion, cal/g 76.4 @ 0 oC M.P. Heat of Vaporization, cal/g 539.6 @ 100 oC B.P. Density () g/cc 0.99823 @ 20 oC 1.00000 @ 3.98 oC 0.99987 @ 0 oC 0.916 – ice Interfacial Tension (lv) dyne/cm 72.75 @ 20 oC Large amount of heat is required to covert solid ice to liquid water (melt) and liquid water to vapor (boil) If water had a low heat of fusionthen… Heat from the sun or metabolism would induce phase transitions: melting, boiling…

  22. Some Physical Properties of Water (from 52nd Handbook of Chemistry and Physics) “Anomalous” Properties of Water Property, units Value Heat Capacity (Cp) cal/g oC 0.998 @ 25 oC Heat of Fusion, cal/g 76.4 @ 0 oC M.P. Heat of Vaporization, cal/g 539.6 @ 100 oC B.P. Density () g/cc 0.99823 @ 20 oC 1.00000 @ 3.98 oC 0.99987 @ 0 oC 0.916 – ice Interfacial Tension (lv) dyne/cm 72.75 @ 20 oC Large amount of heat is required to covert solid ice to liquid water (melt) and liquid water to vapor (boil) If water had a low heat of vaporization then… water on Earth would exist predominately as vapor

  23. Some Physical Properties of Water (from 52nd Handbook of Chemistry and Physics) “Anomalous” Properties of Water Property, units Value Heat Capacity (Cp) cal/g oC 0.998 @ 25 oC Heat of Fusion, cal/g 76.4 @ 0 oC M.P. Heat of Vaporization, cal/g 539.6 @ 100 oC B.P. Density () g/cc 0.99823 @ 20 oC 1.00000 @ 3.98 oC 0.99987 @ 0 oC 0.916 – ice Interfacial Tension (lv) dyne/cm 72.75 @ 20 oC Large amount of heat is required to covert solid ice to liquid water (melt) and liquid water to vapor (boil) If water had a low heat of vaporization then… perspiration would not effectivelycontrol body T

  24. Some Physical Properties of Water (from 52nd Handbook of Chemistry and Physics) “Anomalous” Properties of Water Property, units Value Heat Capacity (Cp) cal/g oC 0.998 @ 25 oC Heat of Fusion, cal/g 76.4 @ 0 oC M.P. Heat of Vaporization, cal/g 539.6 @ 100 oC B.P. Density () g/cc 0.99823 @ 20 oC 1.00000 @ 3.98 oC 0.99987 @ 0 oC 0.916 – ice Interfacial Tension (lv) dyne/cm 72.75 @ 20 oC Space occupied by water molecules expands and contracts with temperature

  25. 3 o E. A. Vogler MatSE 597c Lecture 15

  26. Some Physical Properties of Water (from 52nd Handbook of Chemistry and Physics) “Anomalous” Properties of Water Property, units Value Heat Capacity (Cp) cal/g oC 0.998 @ 25 oC Heat of Fusion, cal/g 76.4 @ 0 oC M.P. Heat of Vaporization, cal/g 539.6 @ 100 oC B.P. Density () g/cc 0.99823 @ 20 oC 1.00000 @ 3.98 oC 0.99987 @ 0 oC 0.916 – ice Interfacial Tension (lv) dyne/cm 72.75 @ 20 oC Water is Strange Stuff If density of ice > liquid waterthen… Ice would sink, inexorably leading to an inhospitable world frozen at the bottom and hot at the top Space occupied by water molecules expands and contracts with temperature

  27. Parable of Count Rumford’s Bucket • Born Benjamin Thompson in Woburn, Massachusetts • Loyalist politics forced Rumford to leave (hurriedly) in 1776. • Employee of the Bavarian government • Investigator into the nature of heat • Inventor of the Rumford fireplace Count Rumford of the Holy Roman Empire 1753 - 1814

  28. Parable of Count Rumford’s Bucket E. A. Vogler MatSE 597c Lecture 15

  29. Parable of Count Rumford’s Bucket Even in a container as shallow as Rumford’s bucket, the artificial circumstance of sunken ice creates a heat transfer problem that would not be resolvable in deep containers such as terrestrial lakes, oceans, and streams that are heated from the top… E. A. Vogler MatSE 597c Lecture 15

  30. The Environmental Calamity of Rumford’s Bucket: Snowball Earth • Seasonal ice would accumulate… • …reflection of sunlight (albedo) from the undoubtedly expanded poles would cause the climate to chill further… • …inexorably the world would freeze solid. All the world we know hinges on a 0.08 g/cc density differential between ice and water Graphic taken from R. A. Kerr "An Appealing Snowball Earth That's Still Hard to Swallow," Science, 287, 1734-1736 (2000).

  31. Some Physical Properties of Water (from 52nd Handbook of Chemistry and Physics) “Anomalous” Properties of Water Property, units Value Heat Capacity (Cp) cal/g oC 0.998 @ 25 oC Heat of Fusion, cal/g 76.4 @ 0 oC M.P. Heat of Vaporization, cal/g 539.6 @ 100 oC B.P. Density () g/cc 0.99823 @ 20 oC 1.00000 @ 3.98 oC 0.99987 @ 0 oC 0.916 – ice Interfacial Tension (lv) dyne/cm 72.75 @ 20 oC If water had low interfacial tension then… The driving force for adsorption and adhesion would be small… Large cohesive interaction energy

  32. Abstraction of the Adsorption/Adhesion Event Surface Dehydration P P Surface Surface Water E. A. Vogler MatSE 597c Lecture 15

  33. P = particle, protein, or surfactant S = solid surface L = liquid phase Work of adhesion or adsorption

  34. High work of cohesion favors adhesion and adsorption from water E. A. Vogler MatSE 597c Lecture 15

  35. Review some important thermodynamic properties of water  Interpreted in terms of biological consequences Discuss molecular origin of water’s special properties Interpreted in terms of self association Explore mechanismS of surface hydration Interpreted in terms of biomaterial properties E. A. Vogler MatSE 597c Lecture 15

  36. Water is a self associating molecule… E. A. Vogler MatSE 597c Lecture 15

  37. Water: Long and Controversial Subject of Intense Research Recurring theme of water “structure” E. A. Vogler MatSE 597c Lecture 15

  38. Water: Long and Controversial Subject of Intense Research “Complexes of fundamental gas molecules”, “solid particles of water”, “heavy water molecules”, “water molecule aggregates”, “ice molecules”… E. A. Vogler MatSE 597c Lecture 15

  39. Water: Long and Controversial Subject of Intense Research “…one will soon find even in the textbooks that while ice is trihydrol, and steam monohydrol, liquid water is mostly dihydrol with some trihydrol in it near the freezing point and a little monohydrol near the boiling point.” James Walker, 1910 E. A. Vogler MatSE 597c Lecture 15

  40. [CONTRIBUTION FROM THE CHEMICAL LABORATORY OF THE UNIVERSITY OF CALIFORNIA.] POLARITY AND IONIZATION FROM THE STANDPOINT OF THE LEWIS THEORY OF VALENCE. BY WENDELL M. LATIMER AND WORTH H. RODEBUSH. Received April 26, 1920.     Some years ago Abegg and Bodlander1 discussed the general facts concerning strong and weak electrolytes, the solubility of salts and the formation of complex ions in solution. They showed that these facts may be coordinated and explained to a surprising extent by attributing to each element or radical, in greater or less degree, a property which they called electro-affinity. This property has been more commonly designated as electropositive or electronegative character, and its relation to position in the periodic table is clearly recognized. “Then, in terms of the Lewis theory, a free pair of electrons on one water molecule might be able to exert sufficient force on a hydrogen held by a pair of electrons on another water molecule to bind the two molecules together.” J. Am. Chem. Soc., 42, 1419-1433 (1920). E. A. Vogler MatSE 597c Lecture 15

  41. Water: Long and Controversial Subject of Intense Research “Then, in terms of the Lewis theory, a free pair of electrons on one water molecule might be able to exert sufficient force on a hydrogen held by a pair of electrons on another water molecule to bind the two molecules together.” Latimer and Rodebush, 1920 E. A. Vogler MatSE 597c Lecture 15

  42. Water: Long and Controversial Subject of Intense Research A significant review article by Richards and Chadwell only mentions Latimer & Rodebush’s hydrogen bond idea in passing to focus more on the hot idea of water polymers… E. A. Vogler MatSE 597c Lecture 15

  43. …Missing the biggest idea in chemistry since Lewis’s notions of chemical bonding. “For years H. E. Armstrong in England has chided the physical chemists for considering water only as water, whereas it is a complex and variable mixture... Everybody admits that water is a polymerized liquid and that the degree of polymerization may change on the addition of electrolytes.” Harris Marshall Chadwell, 1927 E. A. Vogler MatSE 597c Lecture 15

  44. Basics of water chemistry not understood until the 1960’s “…There is little doubt that liquid water consists of water molecules joined together to a considerable extent by hydrogen bonds. …The complexes are not stable and rigid, but are labile.” 1959 Linus Carl Pauling 1901 - 1994 Recognized the importance of hydrogen bonding concept and the effect on water properties. E. A. Vogler MatSE 597c Lecture 15

  45. The Chemistry Behind Water’s Unusual Physical Properties Is a 3D Network E. A. Vogler MatSE 597c Lecture 15

  46. Water is a self associating molecule… Pauling was among the first to fully appreciate that hydrogen bonding was partly covalent in nature…not just an electrostatic effect… E. A. Vogler MatSE 597c Lecture 15

  47. Water: Long and Controversial Subject of Intense Research …but the exact nature of hydrogen bonding remains a topic of continued research. E. A. Vogler MatSE 597c Lecture 15

  48.  -  -  +  +  -  -  +  + Hydrogen Bonding in Water – Physics or Chemistry? “Physics” Electrostatic interaction Partial charge sharing in molecular orbitals “Chemistry” E. A. Vogler MatSE 597c Lecture 15

  49.  -  -  +  +  -  -  +  + Hydrogen Bonding in Water – Physics or Chemistry? “Physics” Force-over-distance following r-2 (center to center) relationship. Electrostatic interaction “Chemistry” Partial charge sharing in molecular orbitals “Multivalent bonding” with complex force-over-distance and angular dependence. E. A. Vogler MatSE 597c Lecture 15

  50.  -  -  +  +  -  -  +  + Hydrogen Bonding in Water – Physics or Chemistry? “Physics” Electrostatic interaction Hydrogen bond (HB) strength greater than dipole interaction by an order-of-magnitude Partial charge sharing in molecular orbitals “Chemistry” E. A. Vogler MatSE 597c Lecture 15

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