Three-dimensional freeze extrusion for the manufacture of homogeneous and graded rods and tubes

Abstract

In an aspect, the present disclosure pertains to a method of making a material. Generally, the method includes one or more of the following steps of: (1) placing a mixture having one or more components in a container; and (2) extruding the mixture out of at least one opening of at least one nozzle. In an additional aspect, the present disclosure pertains to a material. In some embodiments, the material includes one or more components. In some embodiments, the one or more components are in the form of a multi-layered structure.

What is claimed is: 
     
         1 . A method of making a material, said method comprising:
 placing a mixture comprising a plurality of different components in a container,
 wherein the container comprises a first end and a second end, and 
 wherein the second end of the container comprises at least one opening; and 
   extruding the mixture out of the at least one opening,
 wherein the mixture comprises a plurality of layers during the extruding, 
 wherein the extruding comprises freezing the mixture, and 
 wherein the freezing results in the solidification of the mixture into the material. 
   
     
     
         2 . The method of  claim 1 , wherein the mixture is in the form of a solution, a colloid, a gel, a slurry, a suspension, a particle suspension, an emulsion, or combinations thereof. 
     
     
         3 . The method of  claim 1 , wherein the plurality of different components are selected from the group consisting of water, polymers, ceramics, metals, composites, particles, solid beads, hollow beads, platelets, flakes, fibers, fibrils, whiskers, tubes, hydrogels, capsules, hydrogel capsules, carbohydrates, mono-, di- and polysaccharides, lipids, peptides, proteins, blood, cells, biological factors, hormones, growth factors, viral vectors, antibacterial agents, stains, magnetic materials, piezoelectric materials, semiconductors, electrically conducive materials, thermally conductive materials, solutions thereof, colloids thereof, emulsions thereof, gels thereof, slurries thereof, ice particles thereof, ice crystals thereof, and combinations thereof. 
     
     
         4 . The method of  claim 1 , wherein each of the plurality of layers comprise a gradient, wherein the gradient is selected from the group consisting of a property gradient, a compositional gradient, a concentration gradient, a structural gradient, a mechanical property gradient, a physical property gradient, or combinations thereof. 
     
     
         5 . The method of  claim 1 , wherein the at least one opening is at the center of the second end of the container. 
     
     
         6 . The method of  claim 1 , wherein the freezing comprises directional freezing of the mixture through a temperature gradient in the mixture, wherein the temperature gradient gradually decreases in the mixture from the first end of the container to the second end of the container. 
     
     
         7 . The method of  claim 1 , wherein the freezing occurs within the at least one opening. 
     
     
         8 . The method of  claim 1 , wherein the freezing occurs during the extruding. 
     
     
         9 . The method of  claim 1 , wherein the freezing occurs while the mixture exits the at least one opening. 
     
     
         10 . The method of  claim 1 , wherein the freezing occurs after the mixture exits the at least one opening. 
     
     
         11 . The method of  claim 1 , wherein the freezing occurs by freeze-casting. 
     
     
         12 . The method of  claim 1 , wherein the freezing occurs by exposure of the mixture to a cooling source. 
     
     
         13 . The method of  claim 12 , wherein the cooling source does not contact the mixture or any component of the container. 
     
     
         14 . The method of  claim 12 , wherein the cooling source directly contacts the at least one opening. 
     
     
         15 . The method of  claim 12 , wherein the cooling source comprises a plurality of cooling units, wherein the plurality of cooling units are positioned at different regions of the container in order to create the temperature gradient in the mixture. 
     
     
         16 . The method of  claim 1 , wherein the at least one opening is in the form of a nozzle that protrudes out of the second end of the container, wherein the at least one nozzle comprises a first end proximal to the second end of the container and a second end distal to the second end of the container. 
     
     
         17 . The method of  claim 16 , wherein the at least one nozzle has a shorter length and a narrower diameter than the container 
     
     
         18 . The method of  claim 16 , wherein a cooling source is in direct contact with the nozzle for freezing the mixture during the extruding. 
     
     
         19 . The method of  claim 18 , wherein the freezing comprises directional freezing of the mixture through a temperature gradient in the mixture, wherein the temperature gradient gradually decreases in the mixture from the first end of the nozzle to the second end of the nozzle. 
     
     
         20 . The method of  claim 1 , further comprising a step of applying the material to a surface, wherein the application occurs as the material exits the extruder. 
     
     
         21 . The method of  claim 1 , further comprising a step of subliming the material. 
     
     
         22 . The method of  claim 21 , wherein the subliming forms a hollow cavity within the material. 
     
     
         23 . The method of  claim 21 , wherein the hollow cavity comprises a non-uniform diameter. 
     
     
         24 . The method of  claim 21 , wherein the hollow cavity comprises a graded diameter, and wherein the graded diameter becomes narrower from one end of the material to another end of the material 
     
     
         25 . The method of  claim 1 , wherein the material comprises a diameter of less than about 50 mm and a length of more than about 50 mm. 
     
     
         26 . The method of  claim 1 , wherein the method occurs in a continuous manner, wherein the mixture is continuously placed in a container and continuously extruded out of the container in order to continuously make the materials of the present disclosure for a certain amount of time. 
     
     
         27 . The method of  claim 1 , further comprising controlling a temperature of the container; wherein the temperature of the container is controlled before extruding, during extruding, after extruding, or combinations thereof; wherein the temperature of the container is controlled spatially, temporally, or combinations thereof; wherein the controlling comprises controlling the temperature of a nozzle associated with the container, controlling a temperature profile within the container, controlling a temperature profile along a nozzle of the container, controlling a temperature gradient of the container or a nozzle of the container, controlling a profile of the temperature gradient of the container or a nozzle of the container, or combinations thereof.