A Research Agenda for a New Era in Separations Science: Understanding Synthesis for Separations. Benny Freeman

Transcription

1 A Research Agenda for a New Era in Separations Science: Understanding Synthesis for Separations Benny Freeman The University of Texas at Austin John J. McKetta Jr. Department of Chemical Engineering Center for Energy and Environmental Resources Texas Materials Institute, Environmental & Water Resources Engineering 2 April 2018

2 Broad Cavity/Pore Size Distribution Gas Separation (dense polymer membrane) Ultrafiltration (porous polymer membrane) 54 kda 900 L/(m 2 h bar) Greenfield and Theodorou, Macromolecules, 26(20), 5461 (1993) Kasemset et al., J. Membrane Sci., 522,100 (2017).

3 Broad Cavity/Pore Size Distribution Leads to Permeability/Selectivity Tradeoff Gas Separation Water/Salt Separation Robeson, J. Membrane Sci., 320, 390 (2008). Zhang & Geise, J. Membrane Sci., 520, 790 (2016).

4 Broad Cavity/Pore Size Distribution Leads to Permeability/Selectivity Tradeoff Ultrafiltration Mehta & Zydney, J. Membrane Sci., 249, 245 (2005).

5 Isoporous Membranes

6 Block Copolymers Enable Isoporous Asymmetric UF Membrane Formation Gives pore sizes ~20 nm (ultrafiltration) Qiu, Yu, Karunakaran, Pradeep, Nunes, Peinemann, ACS Nano, 7, (2013).

7 Isoporous Membranes Have Favorable Permeability/Selectivity Features Isoporous Membranes

8 Ion Specific Separations

9 Comrani, Desalination, 317, (2013) Zhang et al., Sci. Adv., 4 (2018) Richards, Small, 8(11), (2012) Li et al., In preparation (2018). Hong, Langmuir, 23, (2007) Amouha, IPCBEE, 17 (2011) van Voorthuizen, Water Res., 39, (2005) Xu, J. Hazardous Mat., 260, (2013) Traditional Water Filtration Membranes Have Poor Selectivity for Ions of the Same Valence and Often Permeate Ions Based on Hydrated Radius Dow Filmtec NF90 Li + /Na + : 0.91 Na + /K + : 0.88 K + /Rb + : 1.0 Li + /K + : 0.8 Li + /Rb + : 0.8 F - /Cl - : 1.0 Permeation Order: Li + < Na + < K + ~ Rb A/m 2 of Post-RO Water Li + /Na + : 0.8 Na + /K + : 0.87 Li + /K + : 0.7 F - /Cl - : 0.4 Hydrated Diameter (A ) Dehydrated Diameter (A ) Li + Na + K + Rb + F - Cl - Br - I

10 Metal-Organic Framework with Subnanometer Pores Permeate Cations in Order of Dehydrated Size Permeation Order: Li + > Na + > K + > Rb + Li + Na + K + Rb + Zhang et al., Sci. Adv. 4 (2018) Dehydrated Diameter (A )

11 Metal-Organic Framework with Subnanometer Pores Permeate Anions in Order of Dehydrated Size PET Pore Structure UiO-66 MOF filled pore Single-nanochannel PET-UiO-66-X membranes permeate anions in order of dehydrated ion size Permeation Order: F - > Cl - > Br - > I - F - Cl - Br - I - Dehydrated Diameter (A ) X. Li. et al. In preparation (2018). Single-Channel PET

12 Gas Separation in Polymers of Controlled Microporosity

13 Microporous Polymers Using Iptycene Building Blocks 9.0 Å 31 Å Å internal free volume (IFV) Bulky, shape-persistent skeletons for high fractional free volume (high permeability) 10.2 Å triptycene Intrinsic IFV enabling superior size sieving and selectivity tunability 133 Å Å Versatile chemistry allowing for fine manipulation of structure and functionality 10.5 Å pentiptycene 7.2 Å π-π stacking chain threading & interlocking Supramolecular interactions for molecular-level reinforcement Review article: Wiedman & Guo, Ind. Eng. Chem. Res., 2017, 56(15),

14 Finely Tailorable Microporosity of Iptycene-based Polymers R = H CH 3 CF 3 m m + n = 0.25 a, 0.5 b, 0.75 d, 1.0(c) CH 3 H CF 3 J. Membr Sci, 2015, 20-30; 2016, Luo, S., et al., 2018, under review

15 Backup Slides

16 Iptycene-based PBOs show superior separation performance Triptycene-PBOs (TPBOs) O 2 /N 2 H 2 /CH 4 CO 2 /CH film aged for 70 days 1.0 film 50:50 CO 2 :CH 4 20:80 CO 2 :CH 4 Superior size-sieving ability tuned by composition TPBOs derived from OH precursors TPBOs derived from OAc precursors The numbers (0.25, 0.5, 0.75, 1.0) next to the data points indicate triptycene molar content. Physical aging resistant Plasticization resistant Luo, S., et al., 2018, under review

17 Mixtures of Block Copolymers Used to Tailor Pore Size to Nanofiltration Range High flux (~400 LMH/bar) ~1.7 nm pore diameter Complete separation of lysine (0.15 kda) from protoporphyrin IX (0.56 kda) Yu, Qiu, Moreno, Ma, Calo, Nunes, Peinemann, Angew. Chem. Int. Ed., 15, (2015).