Abstract: A printhead for three-dimensional printing of concrete includes a main body and a regulator device. The main body includes a multi-stage, convergent-divergent cylinder, shearing blades, a pressure chamber, and a secondary inlet. The pressure chamber surrounds the cylinder for temporary storage and regulated processing of a secondary fluid. The secondary inlet transfers the secondary fluid from the pressure chamber to the multi-stage, convergent-divergent cylinder to form a mixture, which is discharged from the printhead. The printhead can, for example, be used for additive manufacturing of cement-based materials.

Abstract: The method of inhibiting free radical polymerization of styrene includes adding multi-walled carbon nanotubes are added to the styrene monomer. The addition of the multi-walled carbon nanotubes at a concentration of 5% by weight is found to provide effective inhibition of the polymerization of the styrene. Greater decreases in the conversion rate of styrene to polystyrene are found through the addition of multi-walled carbon nanotubes functionalized with a carboxylic group (COOH). Still greater decreases in the conversion rate of styrene to polystyrene are found through the addition of multi-walled carbon nanotubes functionalized with octadecylamine (C18H39N). The multi-walled carbon nanotubes may also be functionalized with other functional groups, such as octadecanoate, polyethylene glycol or phenol. The functionalized multi-walled carbon nanotubes only require addition at a concentration of 1% by weight to be effective in polymerization inhibition.

Abstract: The method of inhibiting free radical polymerization of styrene includes adding multi-walled carbon nanotubes are added to the styrene monomer. The addition of the multi-walled carbon nanotubes at a concentration of 5% by weight is found to provide effective inhibition of the polymerization of the styrene. Greater decreases in the conversion rate of styrene to polystyrene are found through the addition of multi-walled carbon nanotubes functionalized with a carboxylic group (COOH). Still greater decreases in the conversion rate of styrene to polystyrene are found through the addition of multi-walled carbon nanotubes functionalized with octadecylamine (C18H39N). The multi-walled carbon nanotubes may also be functionalized with other functional groups, such as octadecanoate, polyethylene glycol or phenol. The functionalized multi-walled carbon nanotubes only require addition at a concentration of 1% by weight to be effective in polymerization inhibition.

Abstract: The orifice chemical vapor deposition reactor provides controlled and regulated reaction gas and vapor flow in order to produce high yields of carbon nanotubes with relatively high purity. The reactor includes a first reaction chamber having an inlet and an outlet, with an input gas being injected therein. A catalyst boat is received within the first reaction chamber for receiving a volume of reaction catalyst. A second reaction chamber is provided, having an inlet and an outlet. The inlet thereof is in fluid communication with the outlet of the first reaction chamber. A flow-regulating member is positioned within the second reaction chamber adjacent the inlet thereof, with the flow-regulating member having an orifice formed therethrough for regulating gas flow. At least one product boat is received within the second reaction chamber for receiving at least one substrate upon which carbon nanotubes are formed.