Abstract:
This document provides a dual flask for laboratory use, methods of using a dual flask, and systems including a dual flask. A dual flask can include a first flask structure and a second flask structure. Each flask structure can include a body and a neck. The first body and the second body in a dual flask provided herein can be connected together and have a filter there between such that fluids can be filtered between said first and second bodies.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application Ser. No. 61/954,136, filed Mar. 17, 2014. The disclosure of the prior applications is considered part of (and is incorporated by reference in) the disclosure of this application. 
     
    
     STATEMENT AS TO FEDERALLY SPONSORED RESEARCH 
       [0002]    This invention was made with government support under DE-FC07-06ID14781 awarded by The Department of Energy. The government has certain rights in the invention. 
     
    
     TECHNICAL FIELD 
       [0003]    This document relates to a dual flask and methods and systems employing a dual flask. In some cases, a dual flask provided herein can include two flasks joined near their based by a filter. 
       BACKGROUND 
       [0004]    Flasks come in a number of shapes and a wide range of sizes. In some cases, flasks include a wider vessel “body” and one (or sometimes more) narrower tubular sections at the top called necks which have an opening at the top. Laboratory flask sizes are typically specified by the volume they can hold, typically in metric units such as milliliters (mL or ml) or liters (L or l). Laboratory flasks have traditionally been made of glass, but can also be made of plastic. 
         [0005]    Flasks can be used for making solutions or for holding, containing, collecting, or sometimes volumetrically measuring chemicals, samples, solutions, etc. for chemical reactions or other processes such as mixing, heating, cooling, dissolving, precipitation, boiling (as in distillation), or analysis. 
       SUMMARY 
       [0006]    A dual flask provided herein includes at least a first flask structure and a second flask structure. Each flask structure can include a body and a neck. The first body and the second body in a dual flask provided herein can be connected together and have a filter there between such that fluids can be filtered between said first and second bodies. A body in each flask structure provided herein can be a wider part of the vessel, and a neck in each flask structure provided herein can be a narrower tubular part of the vessel. In some cases, each flask structure can have a round-bottom flask structure, where each body comprises a rounded vessel. In some cases, each flask structure can have a flat bottom (e.g., have a structure of an Erlenmeyer flask). In some cases, one or more flask structures can have a side arm. In some cases, each side arm can include a valve. In some cases, each flask structure can have a structure of a Schlenk flask. 
         [0007]    A dual flask provided herein can include glass. In some cases, a dual flask provided herein can be formed of glass. In some cases, a filter connecting bodies of the flask structures can be a glass filter. In some cases, a dual flask provided herein can include a borosilicate glass. In some cases, a dual flask provided herein can include a polymer (e.g., PTFE). 
         [0008]    A filter between the flask structures in a dual flask provided herein can have any appropriate structure and/or be made of any appropriate material. In some cases, the filter is a glass filter. In some cases, the filter can have an average pore size of between 0.5 μm and 300 μm. In some cases, the filter can have an average pore size of between 1 μm and 100 μm. In some cases, the filter can have an average pore size of between about 2 μm and about 5 μm. In some cases, the filter can have an average pore size of between about 50 μm and about 75 μm. 
         [0009]    A dual flask provided herein can have any appropriate size. In some cases, the dual flask can have a total internal volume of between 50 mL and 10 L. In some cases, each of the flask structures can have an internal volume of between 50 mL and 1 L. In some cases, each of the flask structures can have an internal volume of between 100 mL and 150 mL (e.g., about 125 mL). 
         [0010]    A dual flask provided herein can allow reactions to be undertaken in the body of one flask structure and filtered into another flask structure while both bodies are retained in a controlled bath and each neck is outside of that controlled bath. In some cases, each neck is at least 5 cm long (e.g., between 5 cm and 15 cm long). In some cases, a dual flask provided herein can allow a solution to be separated from insoluble material while being kept in an inert atmosphere, and while being kept at a certain temperature by submersion in a hot/cold bath. For example, a dual flask provided herein can be a dual Schenk flask where each body has a round bottom and air can be evacuated through side arms in a long neck outside of a bath, such that air and water can be excluded. Because the round bottoms of the Schenk flask structures are connected, the reaction products can be filtered while in a controlled bath. Passing reaction products through vessels which are not submersed in a temperature controlled bath can be dangerous when a reaction product includes a solvent that boils below room temperature. 
         [0011]    The details of one or more embodiments are set forth in the accompanying description below. Other features and advantages will be apparent from the description, drawings, and the claims. 
     
    
     
       DESCRIPTION OF DRAWINGS 
         [0012]      FIG. 1  depicts an exemplary dual flask. 
           [0013]      FIG. 2  depicts the exemplary dual flask of  FIG. 1  in a temperature controlled bath. 
           [0014]      FIGS. 3A and 3B  show how the exemplary dual flask of  FIG. 1  can be used to filter reaction products. 
       
    
    
       [0015]    Like reference symbols in the various drawings indicate like elements. 
       DETAILED DESCRIPTION 
       [0016]    A dual flask provided herein includes at least a first flask structure and a second flask structure connected at a wider body portion of each flask structure, with a filter there between, such that fluids can be filtered between the flask structures. A filter being near the bottom of the dual flask can allow fluids to be filtered without the fluid leaving a controlled environment (e.g., a hot or cold water bath). A dual flask provided herein can have flask structures having any appropriate shape and/or structure. In some cases, each flask structure can have a Schlenk flask structure, such as depicted in  FIG. 1 . 
         [0017]    As shown in  FIG. 1 , a first flask structure  101  can include a first body  151  and a first neck  155 . A second flask structure  102  can include a second body  152  and a second neck  156 . First body  151  and second body  152  are fluidly connected and have a filter  140  there between such that fluids can be filtered there between. First body  151  and second body  152  are wider parts of each flask structure, and first neck  155  and second neck  156  are narrower tubular part of each flask structure. In some cases, as shown in  FIG. 1 , a connecting bridge  160  can connect first neck  155  to second neck  156 . A connecting bridge, such as bridge  160 , can provide stability, and can have any suitable structure. In some cases, not shown, a connecting bridge can connect first neck  155  and second neck  156  at multiple points or continuously along the lengths of first neck  155  and second neck  156 . In some cases, such as that shown in  FIG. 1 , each flask structure  101  and  102  can have a round-bottom body. In some cases (not shown), each flask structure can have a flat bottom (e.g., have a structure of an Erlenmeyer flask). 
         [0018]    First flask structure  101 , as shown in  FIG. 1 , includes an opening  121  at the top of first neck  155 . Opening  121  can include a ground glass joint adapted to receive a septum (e.g., septum  181  as shown in  FIGS. 2 ,  3 A, and  3 B). In some cases, not shown, opening  121  can include an O-ring. In some cases, not shown, opening  121  can include a Teflon valve and a stopper. First flask structure  101 , as shown in  FIG. 1 , includes a first side arm  131 . First side arm  131  can include joint  111  adapted to receive a valve (e.g., valve  171  as shown in  FIGS. 2 ,  3 A, and  3 B). First side arm  131  can include any suitable type of valve. Joint  111  can, in some cases, be a ground glass joint. In some cases, first side arm  131  can include a Teflon valve and stopper. In some cases first side arm  131  can include a connector including a hose-barb shape, a metal valve, or another fitting. In some cases, first flask structure  101  can have a structure of a Schlenk flask. 
         [0019]    Second flask structure  102 , as shown in  FIG. 1 , includes an opening  122  at the top of second neck  155 . Opening  122  can include a ground glass joint adapted to receive a septum (e.g., septum  182  as shown in  FIGS. 2 ,  3 A, and  3 B). In some cases, not shown, opening  122  can include an O-ring. In some cases, not shown, opening  122  can include a Teflon valve and a stopper. Second flask structure  102 , as shown in  FIG. 1 , includes a second side arm  132 . Second side arm  132  can include joint  112  adapted to receive a valve (e.g., valve  172  as shown in  FIGS. 2 ,  3 A, and  3 B). Second side arm  132  can include any suitable type of valve. Joint  112  can, in some cases, be a ground glass joint. In some cases, second side arm  132  can include a Teflon valve and stopper. In some cases second side arm  132  can include a connector including a hose-barb shape, a metal valve, or another fitting. In some cases, second flask structure  102  can have a structure of a Schlenk flask. 
         [0020]    Dual flask  100  can be formed out of any suitable material or combination of materials. In some cases, dual flask  100  can include glass. In some cases, dual flask  100  can be formed of glass. In some cases, filter  140  can be a glass filter. In some cases, dual flask  100  can include a borosilicate glass. In some cases, dual flask  100  can include a polymer (e.g., PTFE). Other suitable materials include ceramics and metals. 
         [0021]    Filter  140  between flask structures  101  and  102  can have any appropriate structure and/or be made of any appropriate material. In some cases, the filter is a glass filter. In some cases, the filter can have an average pore size of between 0.5 μm and 300 μm. In some cases, the filter can have an average pore size of between 1 μm and 100 μm. In some cases, the filter can have an average pore size of between about 2 μm and about 5 μm. In some cases, the filter can have an average pore size of between about 50 μm and about 75 μm. In some cases, the filter can be made of glass frit, silica frit, Celite frit, or a combination thereof. 
         [0022]    Dual flask  100  can have any appropriate size. In some cases, dual flask  100  can have a total internal volume of between 50 mL and 10 L. In some cases, each flask structure  101  and  102  can have an internal volume of between 50 mL and 1 L. In some cases, each flask structure  101  and  102  can have an internal volume of between 100 mL and 150 mL (e.g., about 125 mL). 
         [0023]    A dual flask provided herein can allow reactions to be undertaken in the body of one flask structure and filtered into another flask structure while both bodies are retained in a controlled bath and each neck is outside of that controlled bath. In some cases, each neck is at least 5 cm long (e.g., between 5 cm and 15 cm long). In some cases, a dual flask provided herein can allow a solution to be separated from insoluble material while being kept in an inert atmosphere, and while being kept at a certain temperature by submersion in a hot/cold bath. For example, a dual flask provided herein can be a dual Schenk flask where each body has a round bottom and air can be evacuated through side arms in a long neck outside of a bath, such that air and water can be excluded. Because the round bottoms of the Schenk flask structures are connected, the reaction products can be filtered while in a controlled bath. In some cases, round bottoms of bodies  151  and  152  can allow reactions to be undertaken, and then filtered into the other body. Passing reaction products through vessels which are not submersed in a temperature controlled bath can be dangerous when a reaction product includes a solvent that boils below room temperature. For example, dual flasks provided herein can allow a solution to be separated from insoluble material while being kept in an inert atmosphere, and while being kept at a certain temperature by submersion in a hot/cold bath. 
         [0024]      FIG. 2  depicts an example of how dual flask  100  can be positioned with both first body  151  and second body  152  in a hot/cold bath  210  such that contents  251  and  252  are maintained at a desired temperature. Clamps  202  can hold first or second necks  155  or  156 . Septum  181  and  182  can be in openings  121  and  122 , and held in place using cap holders  221  and  222 . For example, Schenk lines  231  and  232  can be connected to side arms  131  and  132  to pull a vacuum or introduce a fluid from ports  233  and  234 .  FIGS. 3A and 3B  demonstrate how dual flask  100  can be tilted while held by clamps  301  to filter a precipitate from a solution. 
         [0025]    Dual flasks provided herein, such as dual flask  100  as shown in  FIG. 1 , can in some cases be used to synthesize uranium nitrides by conversion of uranium amide/imide mixtures obtained from a reaction of uranium tetrachloride and sodium amide in liquid ammonia in the presence of dissolved sodium metal. Uranium tetrachloride and sodium amide in liquid ammonia gave an amorphous material composed of uranium dioxide, disodium uranium dinitride, and uranium chloronitride upon heating under vacuum. When a sub-stoichiometric amount of sodium metal, relative to the uranium, is dissolved in the liquid ammonia, a mixture of uranium nitrides is formed upon heating under vacuum. For example, referring to  FIG. 3A , UCl 4  and NaNH 2  can be added to first flask structure  101  of dual flask  100 . In some cases, sodium metal can be added to first flask structure  101 . Dual flask  100  can be cooled by a dry ice/acetone bath (not shown in  FIG. 3A ) and anhydrous NH 3  can be cannulated onto the mixture through first side arm  131  from Schenk line  331  to form a mixture  351  in first body  151 . In some cases, NH 3  liquid can be condensed in first body  151 . In some cases, a brown precipitate can form after 3 hours. After the precipitate is formed in the mixture  351  the first body  151 , the slurry can be filtered through filter  140  by tilting dual flask  100  as shown in  FIG. 3B , to leave a precipitate  353  in the first body  151  and have a solution  352  in second body  152 . The solution  352  in second body  152  can be allowed to boil off to leave a second residue (e.g., a white residue). Dual flask  100  can then be placed under vacuum and transferred to a glovebox. Precipitate  353  can then be heated at 700° C.-800° C. for three hours under vacuum to leave an off-black material. By using a dual flask provided herein, slurry  351  can be filtered to separate solution  352  from precipitate  353  while keeping slurry  351  under vacuum and in the dry ice/acetone bath.