Abstract: Functional components of spacecraft structures can be subject to detrimental impacts by energetic particles produced from an electric propulsion system. A graphene coating applied to a functional component can maintain electrical conductivity upon a surface of the functional component, thereby allowing charge dissipation to take place, while also resisting sputtering erosion resulting from impacts of the energetic particles. Accordingly, spacecraft structures can include an electric propulsion system, a functional component that is at least partially impacted by an outflow of the electric propulsion system, and a graphene coating upon the functional component. Methods for operating such spacecraft structures can include generating an outflow of energetic particles from an electric propulsion system of a spacecraft structure, and at least partially impacting the outflow of energetic particles upon a functional component of the spacecraft structure, where the functional component has a graphene coating thereon.

Abstract: Multi-layer sheets of graphene-based material having a plurality of pores extending therethrough are described herein. Methods for making the sheets are also provided and include exposing a graphene-based material comprising multilayer graphene having from 2 to 10 layers of graphene to a particle beam comprising nanoparticles, the nanoparticles having an energy of at least 2 keV per nanoparticle.

Abstract: A system for magnetic detection includes a magneto-optical defect center material including at least one magneto-optical defect center that emits an optical signal when excited by an excitation light; a radio frequency (RF) exciter system configured to provide RF excitation to the magneto-optical defect center material; an optical light source configured to direct the excitation light to the magneto-optical defect center material; and an optical detector configured to receive the optical signal emitted by the magneto-optical defect center material.

Abstract: Various systems and methods relating to two-dimensional materials such as graphene. A membrane include a cross-linked graphene platelet polymer that includes a plurality of cross-linked graphene platelets. The cross-linked graphene platelets include a graphene portion and a cross-linking portion. The cross-linking portion contains a 4 to 10 atom link. The cross-linked graphene platelet polymer is produced by reaction of an epoxide functionalized graphene platelet and a (meth)acrylate or (meth)acrylamide functionalized cross-linker.

Abstract: It can be difficult to remove atomically thin films, such as graphene, graphene-based material and other two-dimensional materials, from a growth substrate and then to transfer the thin films to a secondary substrate. Tearing and conformality issues can arise during the removal and transfer processes. Processes for forming a composite structure by manipulating a two-dimensional material, such as graphene or graphene-base material, can include: providing a two-dimensional material adhered to a growth substrate; depositing a supporting layer on the two-dimensional material while the two-dimensional material is adhered to the growth substrate; and releasing the two-dimensional material from the growth substrate, the two-dimensional material remaining in contact with the supporting layer following release of the two-dimensional material from the growth substrate.

Abstract: Sheets of graphene-based material comprising single layer graphene and suitable for formation of a plurality of perforations in the single layer graphene are provided. In an aspect, the sheets of graphene-based material are formed by chemical vapor deposition followed by one or more conditioning steps. In a further aspect, the sheets of graphene-based material include non-graphenic carbon-based material and may be characterized the amount, mobility and/or volatility of the non-graphenic carbon-based material.

Abstract: Some embodiments comprise membranes comprising a first layer comprising a porous graphene-based material; a second layer comprising a porous graphene-based material; a channel positioned between the first layer and the second layer, wherein the channel has a tunable channel diameter; and at least one spacer substance positioned in the channel, wherein the spacer substance is responsive to the environmental stimulus. In some cases, the membranes have more than two layers of porous graphene-based material. Permeability of a membrane can be altered by exposing the membrane to an environmental stimulus. Membranes can be used in methods of water filtration, immune-isolation, timed drug release (e.g., sustained or delayed release), hemodialysis, or hemofiltration.

Abstract: A method and system for detecting a target molecule. The method includes allowing a fluid containing the target molecule to pass by a complementary moiety attached to a paramagnetic ion so as to cause the complementary moiety and the paramagnetic ion to change a position. A magnetic effect change caused by the change in position of the paramagnetic ion is detected. The target molecule is identified based on the identity of the complementary moiety and the detected magnetic effect change.

Abstract: A method of forming a filter with uniform pore sizes includes synthesizing a moiety so as to form a plurality of like platelets having a precisely sized pore extending therethrough, distributing the plurality of like platelets about a membrane having apertures therethrough, and bonding the plurality of platelets around the apertures to form precisely sized pores through the membrane. A filtration membrane is also disclosed which provides a porous membrane having a plurality of apertures therethrough, and a plurality of platelets, wherein each platelet has a pore therethrough. The platelets are positioned over or in the apertures.

Abstract: Production of perforated two-dimensional materials with holes of a desired size range, a narrow size distribution, and a high and uniform density remains a challenge, at least partially, due to physical and chemical inconsistencies from sheet-to-sheet of the two-dimensional material and surface contamination. This disclosure describes methods for monitoring and adjusting perforation or healing conditions in real-time to address inter- and intra-sheet variability. In situ or substantially simultaneous feedback on defect production or healing may be provided either locally or globally on a graphene or other two-dimensional sheet. The feedback data can be used to adjust perforation or healing parameters, such as the total dose or efficacy of the perforating radiation, to achieve the desired defect state.

Abstract: A method for transferring a graphene sheet from a copper substrate to a functional substrate includes forming the graphene sheet on the copper substrate using chemical vapor deposition, and irradiating the graphene sheet disposed on the copper substrate with a plurality of xenon ions using broad beam irradiation to form a prepared graphene sheet. The prepared graphene sheet is resistant to forming unintentional defects induced during transfer of the prepared graphene sheet to the functional substrate. The method further includes removing the copper substrate from the prepared graphene sheet using an etchant bath, floating the prepared graphene sheet in a floating bath, submerging the functional substrate in the floating bath, and decreasing a fluid level of the floating bath to lower the prepared graphene sheet onto the functional substrate.

Abstract: A method and system for detecting a target molecule. The method includes allowing a fluid containing the target molecule to pass by a complementary moiety attached to a paramagnetic ion so as to cause the complementary moiety and the paramagnetic ion to change a position. A magnetic effect change caused by the change in position of the paramagnetic ion is detected. The target molecule is identified based on the identity of the complementary moiety and the detected magnetic effect change.

Abstract: Perforating graphene and other two-dimensional materials with holes inclusively having a desired size range, a narrow size distribution, and a high hole density can be difficult to achieve. A layer in continuous contact with graphene, graphene-based materials and other two-dimensional materials can help promote hole formation. Processes for perforating a two-dimensional material can include exposing to an ion source a two-dimensional material in continuous contact with at least one layer, and interacting a plurality of ions from the ion source with the two-dimensional material and with the at least one layer. The ion source may be a broad ion beam.

Abstract: Functional components of spacecraft structures can be subject to detrimental impacts by energetic particles produced from an electric propulsion system. A graphene coating applied to a functional component can maintain electrical conductivity upon a surface of the functional component, thereby allowing charge dissipation to take place, while also resisting sputtering erosion resulting from impacts of the energetic particles. Accordingly, spacecraft structures can include an electric propulsion system, a functional component that is at least partially impacted by an outflow of the electric propulsion system, and a graphene coating upon the functional component. Methods for operating such spacecraft structures can include generating an outflow of energetic particles from an electric propulsion system of a spacecraft structure, and at least partially impacting the outflow of energetic particles upon a functional component of the spacecraft structure, where the functional component has a graphene coating thereon.

Abstract: Perforated graphene sheets can be used in forming separation membranes. Separation membranes of the present disclosure, which can be used in gas separation processes in some embodiments, can include one or more polymer layers and one or more layers of perforated graphene. Methods for separating a gas mixture can include contacting a gas mixture with the separation membranes, and transiting one or more of the gases through the perforated graphene so as to affect separation.

Abstract: A fluid deionizer includes at least one graphene sheet perforated with apertures dimensioned to allow a flow of fluid and to disallow at least one particular type of ion contained in the flow of fluid. A purge valve is placed in an open position so as to collect the at least one particular type of ion disallowed by the graphene sheet so as to clean off the at least one graphene sheet. Another embodiment provides a deionizer with graphene sheets in cylindrical form. A separation apparatus is also provided in a cross-flow arrangement where a pressurized source directs a medium along a path substantially parallel to at least one sheet of graphene from an inlet to an outlet. The medium flows through the plural perforated apertures while a remaining portion of the medium and the disallowed components in the medium flow out the outlet.

Abstract: A system for magnetic detection includes a magneto-optical defect center material including at least one magneto-optical defect center that emits an optical signal when excited by an excitation light; a radio frequency (RF) exciter system configured to provide RF excitation to the magneto-optical defect center material; an optical light source configured to direct the excitation light to the magneto-optical defect center material; and an optical detector configured to receive the optical signal emitted by the magneto-optical defect center material.

Abstract: Articles containing a matrix material and plurality of copper nanoparticles in the matrix material that have been at least partially fused together are described. The copper nanoparticles are less than about 20 nm in size. Copper nanoparticles of this size become fused together at temperatures and pressures that are much lower than that of bulk copper. In general, the fusion temperatures decrease with increasing applied pressure and lowering of the size of the copper nanoparticles. The size of the copper nanoparticles can be varied by adjusting reaction conditions including, for example, surfactant systems, addition rates, and temperatures. Copper nanoparticles that have been at least partially fused together can form a thermally conductive percolation pathway in the matrix material.

Abstract: A method of forming a membrane is described. A graphenic-based membrane is formed on a growth substrate, where the graphenic-based membrane have one or more layers of graphenic-based material. The graphenic-based membrane is removed from the growth substrate. A region of the graphenic-based membrane having intrinsic or native defects is identified. The region of the graphenic-based membrane is irradiated with charged particles while introducing carbonaceous material on a surface of the one or more layers of graphenic-based material to heal the intrinsic or native defects.

Abstract: Production of perforated two-dimensional materials with holes of a desired size range, a narrow size distribution, and a high and uniform density remains a challenge, at least partially, due to physical and chemical inconsistencies from sheet-to-sheet of the two-dimensional material and surface contamination. This disclosure describes methods for monitoring and adjusting perforation or healing conditions in real-time to address inter- and intra-sheet variability. In situ or substantially simultaneous feedback on defect production or healing may be provided either locally or globally on a graphene or other two-dimensional sheet. The feedback data can be used to adjust perforation or healing parameters, such as the total dose or efficacy of the perforating radiation, to achieve the desired defect state.