Solvothermal synthesis/ Microwave & Autoclave Reactors
Solvothermal synthesis is a handy synthetic route involving mixtures of the reactants in a proper solvent, or dispersions of the reactants when solid materials participate in the reaction. A wide spectrum of synthetic applications can be realized by rational design of the desired chemical reaction. For instance, the growth of semiconducting and metallic nanoparticles (quantum dots, carbon dots, metal nanoparticles, transition metal dichalcogenides, etc) can be realized via a one-step chemical treatment. In this context, the implementation of microwave reactors and autoclave reactors constitute a powerful synthetic tool for enabling, accelerating and controlling chemical procedures towards functional materials with tailored properties. Overall, the reactor of choice is selected on the basis of the reaction procedure.
Microwave reactors utilize microwave irradiation, which efficiently penetrates the whole mass of the reaction media inducing a fast and uniform heating of the reactants. This is in contrast to conventional heating, where the transfer of heat via conduction is sluggish. Further, it can be combined with high-pressure conditions, when gaseous products are formed, or when heating above the boiling point of the involved solvents/liquids. However, the maximum pressure is much lower (due to glass-made vessels) than the operation pressure of metal-made vessels of autoclave reactors.
Autoclave reactors are mostly based on conduction heating of the media, accompanied by high pressure conditions emerging from the solvent’s vapor (when heating above its boiling point) or via external gas (hydrogen, nitrogen, argon, oxygen, etc) supply. In this case, the extreme conditions in the vessel increase the frequency of collisions and the reactants are more likely to react. Nevertheless, the thickness of the metal walls of the reactors demands higher reaction periods due to slower heating rate of the reaction mixture.
MICROWAVE REACTOR
General purpose autoclave reactor, PARR Instruments, Model 4767
Non-stirred reactor, vertical
Stainless steel T316
Inside diameter: 2.5 in., depth: 6.0 in.
Split-Ring (6 Compression Bolts)
Moveable head
VGR Valve (gage, rupture disk, fixed thermocouple)
Double valve assembly, dip tube
Model 4838EE (PID control, ramp & soak programming)
Model A2230HC2EE (for 450mL vessel, moveable)
350oC, PTFE-Flat Gasket
From the controller via the thermocouple
3000psi (200bar) at standard Temp., 2000psi (137bar) at high Temp
Pressure gauge
• bottom-up synthesis of quantum dots, carbon dots, metal nanoparticles, transition metal dichalcogenides
• hard- and soft-templating synthetic routes
• covalent functionalization of carbon nanostructures (graphene, nanotubes, nanohorns, fullerenes)
• elemental doping of carbon nanostructures (graphene, nanotubes, nanohorns)
• microwave-assisted synthesis of organic compounds, chromophores, polymers
microwave-assisted reactions (cycloadditions of azomethine ylides, aryl-diazonium salts, Bingel cycloadditions, Sonogashira cross-coupling reactions, etc)
Dr. Nikos Tagmatarchis (tagmatar@eie.gr)
AUTOCLAVE REACTOR
General purpose autoclave reactor, PARR Instruments, Model 4767
Glass, 10 mL and 75 mL vessels
Automatic sealing mount head (10 mL vessel), screw-mount head equipped with gas release line, pressure control and fiber optic temperature control (80 mL vessel)
Open vessel (all vessels), sealed vessel (all vessels), controlled gas-release (80 mL vessel)
Discover cavity high temperature spill cup
250oC
Floor mounted IR temperature sensor (for 10mL vessels), Fibber Optic Temperature Control inside the reaction vessel (for 80mL reaction vessels)
300psi
YES (low, medium, high) for all vessels
Self-Tuning Single-Mode Cavity - automatically adjusts
power output based on the polar and ionic properties of the
reaction solution
Automatically safe venting
Pressure (1-300psi, increasing by 1psi), Temperature (r.t.-300oC, increasing by 1oC), Time (0-60minutes, increasing by 1 sec, longer than 60min sessions are possible), Power (1-300Watt, increasing by 1W)
Multiple-stage sessions
Monitoring the Power vs time etc.
• bottom-up synthesis of quantum dots, carbon dots, metal nanoparticles, transition metal dichalcogenides
• hard- and soft-templating synthetic routes
• covalent functionalization of carbon nanostructures (graphene, nanotubes, nanohorns, fullerenes)
• elemental doping of carbon nanostructures (graphene, nanotubes, nanohorns)
• microwave-assisted synthesis of organic compounds, chromophores, polymers
microwave-assisted reactions (cycloadditions of azomethine ylides, aryl-diazonium salts, Bingel cycloadditions, Sonogashira cross-coupling reactions, etc)
Dr. Nikos Tagmatarchis (tagmatar@eie.gr)
