Two-dimensional (2D) titanium carbide MXene (Ti3C2T
x
) has attracted significant
attention due to its combination of properties and great promise for
various applications. The size of the 2D sheets is a critical parameter
affecting multiple properties of assembled films, fibers and 3D structures.
The increased lateral size of MXene flakes can benefit not only their
assemblies by improving the interflake contacts and alignment but
also fundamental studies at the individual flake level, allowing for
facile patterning and investigation of intrinsic physical properties
of MXenes. Increasing the average size of the parent MAX phase is
one of the strategies previously used to increase the flake size of
the resultant MXene. Here, we show that the protocol used for the
next step of the synthesis procedure, delamination of multilayer MXene
into individual nanosheets, significantly affects the lateral size
of the resultant flakes. We developed a soft delamination approach,
which prevents fracture of flakes and preserves their size. Combining
this approach with the large-grain Ti3AlC2 MAX
phase precursor, we achieved individual flakes of up to 40 μm
in lateral size. These flakes can be used for patterning multiple
contacts and fabrication of field-effect transistors for multiprobe
electrical characterization and other measurements. These findings
indicate the importance of controlling the delamination process in
order to achieve large MXene flakes and improve properties of MXene-based
materials and devices.
Magnetic molecularly imprinted polymers have been synthesized for the selective preconcentration and trace determination of lamotrigine (LTG) in urine and plasma samples. The magnetic nanoparticles were modified by tetraethyl orthosilicate and 3-methacryloxypropyl trimethoxysilane before imprinting. The magnetic molecularly imprinted polymers were prepared via surface molecular imprinting technique, using Fe3 O4 as a magnetic component, LTG as template molecule, methacrylic acid as a functional monomer, ethylene glycol dimethacrylate as a cross-linker, and 2,2'-azobisisobutyronitrile as a radical initiator in methanol/acetonitrile (50:50, v/v) as the porogen. The obtained sorbent was characterized using scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, and thermal analysis. Separation of the sorbent from the sample solution was simply achieved by applying an external magnetic field. Determination of the extracted drug was performed by high-performance liquid chromatography with UV detection. Under the optimum extraction conditions, the method detection limits were 0.7 μg/L (based on S/N of 3) for urine samples and 0.5 μg/L for plasma samples. A linear dynamic range of 1-1000 μg/L was obtained for LTF in plasma and urine samples. Finally, the applicability of the proposed method was evaluated by extraction and determination of LTG in urine and plasma samples.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.