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Euan Bain. Hypercrosslinked resins as carbon precursors for supercapacitor electrodes. Supervisor: Prof. P. J. Hall. Today's Story. Characterisation Methods Discussed N 2 Adsorption @ 77K Small Angle Neutron Scattering (SANS) Contrast Matched Small Angle Neutron Scattering (CM-SANS).
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Euan Bain Hypercrosslinked resins as carbon precursors for supercapacitor electrodes Supervisor: Prof. P. J. Hall
Today's Story Characterisation Methods Discussed • N2 Adsorption @ 77K • Small Angle Neutron Scattering (SANS) • Contrast Matched Small Angle Neutron Scattering (CM-SANS) Raw Materials Gel-Type Resin Hypercrosslinked Resin Carbon
Gel-Type Resin Synthesis 2 %wt 98 %wt + 80°C 6hr or AIBN (0.75 %wt) Suspension Polymerisation + 212-300mm • No internal pore structure in dry state • Can be reversibly swollen • Surface Areas generally <10 m2.g-1
Gel-Type Resin N2 Adsorption • Pseudo-Type II Isotherm • Non-porous solids • Interstitial pores only
Gel-Type Resin SANS • Scattering from interstitial macroporosity • High error due to incoherent scattering
Hypercrosslinked Resin Synthesis 1,2 Dichloroethane 30 mins FeCl3 @ 80°C for 3 hrs Friedel-Crafts reaction Final structure a function of • Solvent • Swelling Time • Catalyst Abundance • Reaction time
HXL Resin N2 Adsorption • Type I isotherm – microporous material • Prolonged Hysteresis – broad mesopore distribution
HXL Resin SANS • Df = 2.8 – scattering from volume fractal • Increase in scattering at high Q - microporosity Df = 2.8
Carbon Synthesis Carried out under Argon
Carbon N2 Adsorption • Type II isotherm – meso/macropores • Prolonged Hysteresis – broad distribution of mesopores • Low Surface Area
Carbon SANS • Increase in whole Q-range • Df = 2.6- Weakly Segregated 3D network
Carbon SANS/CM-SANS • Large areas of closed porosity over whole Q-range • Low mesopores and micropores more abundant in closed porosity
Conclusions • HXL resins possess a large surface area within a fractal pore structure containing large amounts of microporosity with a broad distribution of mesopores • Carbons produced from HXL resins, although having a diminished surface area, possess large areas of closed porosity over the entire range
What now? • CO2 activation and optimisation of carbons • Monolithic electrode synthesis • Supercapacitor characterisation Chemical and Process Engineering