Extended Surfactants: Origins, Features, Performances, Applications

1. 2018 Surfactants in Solution Symposium Oklahoma Extended Surfactants: Origin, Distinctive Features Performances, Applications J.L.Salager, A.M. Forgiarini, R. Marquez Lab. FIRP, University of the Andes Mérida, Venezuela

2. Outline • Formulation of SOW Systems • Origins of Extended Surfactants • Distinctives features and performances • Potential Applications Salager J. L., Antón R. E., Sabatini D. A., Harwell J. H., Acosta E., Tolosa L. Enhancing Solubilization in Microemulsions – State of the Art and Current Trends. J. Surfactants Detergents 2005, 8 (1) 3-21

3. SOW Ternary Diagram constant formulation or temperature Representative point of SOW system composition S % O % W % S W O

4. Winsor’s Ratio (1954) R oil (O) surfactant (C) Aco Aco R = between molecular interaction energies Acw water (W) very pedagogical but qualitative! Acw R < 1, R = 1 or R > 1 related to phase behavior Winsor P., Solvent Properties of Amphiphilic Compounds, Butterworth London (1954)

5. Phase behavior (in two-phase zone at ) Winsor showed a relation between R and the phase behavior S1 micelle S2 micelle S S O O W W R < 1 R > 1 _ _ 2 2 W I W II

6. M 2 M 1 Winsor showed a relation between R and the phase behavior liquid crystal microemulsion R = 1 W III S W O complex phase behavior

7. surfactant (C) oil (O) Aco water (W) Acw Formulation Scan Produces changes in the interactions in R and in the phase behavior Aco R = Acw Salinity (type and conc.) ACN and oil structure Surfactant (Hidro group) Surfactant (Lipo group) Temperature Alcohol (type and conc.) ...

8. Formulation scam is a general phenomenon ultralow interfacial tension in WIII system (HLD = 0) in a narrow zone of any formulation scan >>> EOR

9. Formulation Scan (e.g. Salinity >>>) S S O O W W o/w µem bicontinuous µem w/o µem slightly swollen S1 micelles slightly swollen S2 micelles Microemulsion types

10. What is Solubilization? surfactant (+ alcohol) Micro-emulsion region S+A Macro-, mini-, nano-emulsions zone it is the ability of a surfactant to produce a monophasic system containing both oil and water monophasic zone polyphasic zone “height” of polyphasic zone generally at center water oil

11. S Winsor's diagrams W I W III W II O W Surfactant Concentration vs Formulation Microemulsion S (+A) f 1 Tricritical Point f 2 f 2 3 f sometimes called “fish” diagram W I W II Formulation (e.g. Salinity or Temperature)

12. Optimum Formulation 1 2 Minimum amount of surfactant at R =1 = highest performance = maximum solubilization = lowest tension 2 3 the “cross” (at tricritical point) locates the point with highest performance Formulation Scan R=1 HLD=0 General relationships (1979 & 1980) ionic HLD = LnS- K ACN + f(A) + s - aT ∆T = 0 nonionic HLD = a - EON - K ACN + f(A) + cT ∆T = 0

13. 5 6 7 8 Ethoxylated nonionic + alcohol number of C atoms in n-alcohol Effect of cosurfactant (alcohol) Very A constant concentration of alcohol (with different chain length) is added COMPLEX No alcohol Effect on Formulation EON Bourrel M. et al.,Society Petroleum Engineers J., 23: 327-338 (1983)

14. S+A Alcoholsin C8-10 + number of C atoms in n-alcohol better than without alcohol ? • hydrophobic alcohol shifts ... ... formulación ( ) (EON decreases) • does not adsorb at interface but ... ... produces an increase in solubilization ( ) ? no alcohol CANNOT BE EXPLAINED ! 5 6 7 EON ? ?

15. This is evidently a new phenomenon that cannot be interpreted from Winsor’s solubilization concept : CONCLUSION: An (oil soluble) long chain alcohol increases solubilization !!! • This was called the LIPOPHILIC LINKEReffect

16. INTERFACE The Lipophilic Linker increases interactions on the oil side by “ordering” the molecules deeper inside the oil bulk phase Proposed Mechanism OIL OIL “ordered” zone Lipophilic Linker “ordered” zone Interface WATER WATER

17. The Lipophilic Linker is ... ... a very lipophilic amphiphile • or a slightly polar oil ... ... which acts at very low concentration • because it locates itself ... ... near interface It is not a case of adsorption ... ... but of segregation

18. Lipophilic and Hydrophilic Linkers Result in : Better match (oil does not contact water) Smoother variation of polarity Increase in interfacial zone thickness Oil Lipohilic Linker Adsorbed Surfactant Hydrophilic Linker Water

19. What can be concluded ? as far as solubilization is concerned • Linkers increase interfacial zone thickness • Smooth Transition at interface pays off • As a corrolary, good matchingon both sides >>> better performance, lower gmin But linkers can fractionate and if so, they are LOSTin the bulk phases Sabatini D. A., et al., Current Opinion Colloid Interface Science 8:316-326 (2003) Salager J. L., et al., J. Surfactants Detergents 8: 3-21 (2005)

20. How to avoid it ? with Extended Surfactants Extended Surfactant Structure Solubilization Performance Current Trends

21. hydrophobic chain ? Spacer arm is hydrophobic but slightly polar POLY-PROPYLENE OXIDE ... the same effect could be attained with a single molecule : “extended” surfactant hydrophilicgroup Surfactant + Linker Extended Surfactant

22. Extended Surfactants (1rst Generation) ~ LL DodecylTail poly-propylene oxide (variable length) ethoxy (2EO) sulfate sodium salt Head ~ HL Miñana-Pérez M. et al., Colloids & Surfaces A, 100 :217-224 (1995) Miñana-PérezM. et al., Progress Colloid & Polymer Science, 98 :177-179 (1995)

23. My story of Extended Surfactants started at ULA-UPPA in the 1990’s and continued in 2000 also here at UO (with Seppic, Sasol and Huntsman) • Other people brough this kind of surfactants with other names • Exxon Alkyl alkoxylatedsulfonates • Aoudia … Propoxylated alcohol sulfates • Alexandridis … graded surfactant • Huang … triblock surfactant

24. W O O O W W O Actually these surfactants were designed to Solubilize polar oils! Typical bad matching of HC tails Head Tail Polar oil water Badinteraction Typical structure at optimum formulation where POLAR OIL has a BAD interaction with surfactant (hydrocarbon) tail >>> BAD SOLUBILIZATION

25. Even better matching with polar oilwith a single moleculeof EXTENDED SURFACTANT (ES) Polypropylene oxide spacer = slightly polar extension Polar oil Lipophilic Tail ES tail head water High solubilization of polar oil is an unique characteristic of extended surfactants Polar oil Intermediate zone (PON) allows interaction with polar oil and increases solubilization Salager J. L. et al., 8th World Surfactants Congress, CESIO Vienna (2011)

26. Extended Surfactant Properties depend on Propylene Oxide Number (PON) When PON increases • CMC decreases • Cloud Point is lowered • Optimum Salinity (3) decreases Conclusion: • When PON increases ... • ... surfactant becomes more lipophilic PPO chain is part of the "tail"

27. Extended Surfactant Properties Usual behavior of extended sulfate Ln S* - 0.10 EACN + 0.25 NC + 0.16 NPO + cTDT … = HLD = 0 -CH2- -CH2-CH-CH2-O- l Alkyl extended ethoxy sulfates CH3 MiñanaM. et al., Prog Colloid Polym Sci. 98: 177 (1995). Velasquez et al. J Surfactants Detergents 13: 69 (2010)

28. PO is Lipophilic ~ as 0.6-0.7 methylene in tail but not very much (PO14 does not precipitate) 4 WOR = 1 T = 35 °C 1.25 wt.% extended sulfate Surfactants Ln S* n-Hexadecane 3 Soya Oil 2 They produce bicontinuousmicroemulsions with various oil phases triglyceride diglyceride Ethyl 1 Myglyol Oleate 812 0 6 8 10 12 14 PROPYLENE OXIDE NUMBER (PON) MiñanaM. et al.,, Colloids Surfaces A. 100 : 217-224 (1995).

29. Extended Surfactant Properties SP WOR = 1 T = 35 °C (ml/g) 1.25 wt.% extended sulfate Surfactants 40 Hexadecane Ethyl Oleate 30 Mygyol 812 20 Soya oil = natural triglyceride produce a HIGH SOLUBILIZATION and LOW TENSION particularly with natural oils 10 Soya oil 0 6 10 14 PROPYLENE OXIDE NUMBER Miñana-Perez M. et al., Colloids and Surfaces A. 100 : 217-224 (1995).

30. Extended Surfactant Properties Usually SP* decreases as ACN increases At low PON it does too! At high PON it increases with ACN Good for LONG ALKANES SP* increases with alkyl tail At PON=10 SP* does not vary with ACN Salager et al. CESIO Paris 2008 With tension en g*minWitthayapanyanon et al., JSD 2010

31. Extended Surfactant Properties ES with PPO less hydrophilic as Temp increases First 2-3 POs are wet by water ! ANIONICS PolyEO NONIONICS EXS with POs Independent of PON Velasquez J. et al., J Surfactants Detergents 13: 69 (2010)

32. Extended Surfactant Properties ES with PPO less hydrophilic as Temp increases Other POs are not ! First 2-3 PO groups are wet by water ! Twisting = disorder that eliminates LC Water affinity reduces precipitation in spite of long tail

33. Extended surfactant mixtures with conventional species • Extended surfactant insures solubilization • ± independently of formulation change due to conventional surfactant (HLB) or salinity SP* (ml/g) SP* (ml/g) ~ SPsoya oil = 0

34. Ternary surfactant mixturefor EOR g< 0.001 mN/m g< 0.001 mN/m Constant ACN, T, S Cut

35. Crude oil dehydration/desalting C12PO14-EO2 X X = carboxylate sulfate posphate C12PO14-EON S N = 2, 7, 12, 20

36. Crude oil dehydration/desalting Commercial EON-PON-EON Pluronics (BASF) C12PON-EON hydrophilic extended nonionic surfactants

37. Many Potential Applications • Current industrial attractiveness • Enhanced Oil Recovery (asphaltenes = polar oils) • Crude oil Dehydration/desalting • Completion fluids in petroleum recovery • Single phase water-oil mixtures • bladder stone dissolution • vegetable oil extraction • environmental remediation • cleaner combustion • Microemulsionsfor injections — most pharmaceutical products are oil soluble • Soak-only Detergent Formulation — when no stirring is required

38. 2nd Generation of extended surfactants for biocompatible applications sugar polar head taylored spacer arm extension Fatty acid derivatives (hydrophobic tail) The Physico-chemical Properties of these products have been studied a lot

39. NEW NEW NEW What's new in 2018 in Emulsion Stability ? The Interfacial Rheology at Optimum Formulation

40. Interfacial rheology is related to emulsion stability … because of the interdrop film drainage Pendent drop apparatus allows to calculate g and A With oscillating drop Dilational Modulus E, Interfacial Viscosity hE, Phase angle f Interfacial Rheology Interfacial Rheology E = dg/dlnA = E’ + i E” E’ = Elastic contribution E”= Viscous contribution tan f = E”/E’

41. It is known that minimum stability is at optimum formulation Emulsion Stability (min) Interfacial Tension mN/m

42. Interfacial rheologyis said > related to stability Thus it must be studied at optimum formulation But at optimum formulation tension is ultralow … g ~ 0.001 mN/m But if g < 2-3 mN/m, it does not work, because the pendent drop is not stable, it elongates and falls

43. A D B E C We made a new apparatus to oscillate the drop without falling The spinning drop tensiometer with oscillating velocity Theory: 78_JCIS_Slattery_Spinning dropPractical new apparatus: 18_JCIS_Zamora et al

44. Properties close to optimum formulation (SDS/C5OH/kerosene/water) 3 phase behavior, minimum tension g, minimum emulsion stability … at optimum formulation >NEW >Minimum dilational modulus E Minimum interfacial viscosity hE, and Minimum phase angle f g E optimum Salinity Scan New Interfacial Rheology at Optimum Formulation hE f

45. New Interfacial Rheology Properties at optimum formulation Temperature Scan Extended Nonionic Surfactant C18PO18EO10 The same with different EACN oils g hEc f

46. tension stability New Interfacial Rheology Properties at optimum formulation Salinity and EON Scan Super-ExtendedAnionic Surfactant C12PO14EO10SO4Na and polyethoxylate nonionic C9FEO6-8 hE E f

47. The story of this research teaches us a few things about R & D strategy EXTENDED SURFACTANT ExS Properties last 20 years LIPOPHILIC LINKER PROGRESS Property interpretation innovation According to Winsor anomaly diagnostic TIME ExS even better with NEW Prop. 2018 1990 ———— 1995 1954

48. Visit Lab. FIRP web site at: www.firp@ula.ve Thank you for your Attention Salager@ula.ve