Improved efficiency of reversed-phase carbon/nanodiamond/polymer core-shell particles for HPLC using carbonized poly(divinylbenzene) microspheres as the core materials

Abstract

Here, we report efficiencies up to 112,000 plates per meter (a reduced plate height, h, of 2.22) for RP, carbon/nanodiamond/aminopolymer particles using conventional injection conditions in HPLC. This efficiency greatly exceeds our best previously reported value of 71,000 N/m (h = 3.52). The carbon cores used in this study were derived from carbonized poly(divinylbenzene) spheres that were either made in-house by a two-step polymerization procedure or obtained commercially. The resulting particles showed good uniformity and were oxidized in nitric acid to increase their dispersability. X-ray photoelectron spectroscopy confirms particle oxidation and subsequent aminopolymer deposition. Layer-by-layer (LbL) growth of poly(allyamine) and nanodiamond was demonstrated to produce core-shell particles. After LbL growth, the particles were functionalized, sieved, and packed into columns. The column functionalization and packing were reproducible. Van Deemter curves indicated that the commercially obtained poly(divinylbenzene) spheres outperformed those synthesized in our laboratory. The columns appear to be stable at 120°C in a pH 11.3 mobile phase. Longer columns (2.1 × 50 mm) than previously reported were packed. Four essential oils were separated by gradient elution.

Multi‐instrument characterization of poly(divinylbenzene) microspheres for use in liquid chromatography: as received, air oxidized, carbonized, and acid treated

“…Carbon based materials are well known for their chemical, thermal, and mechanical stability. Accordingly, they are often suitable for applications under harsh conditions . They can be made from natural materials, such as wood or coal .…”

“…To increase its oxygen content, the carbon may be treated with an oxidizing agent, such as an oxygen plasma, nitric acid, or hydrogen peroxide . Oxygen‐containing moieties on the surface of carbon increase its surface free energy, hydrophilicity, and dispersability . These may include carboxyl groups, carbonyls, quinones, phenols, carboxylic anhydrides, and lactones .…”

“…Some of us have studied the preparation and properties of carbon/polymer/nanodiamond core‐shell particles for high‐performance liquid chromatography (HPLC) . These particles exhibit excellent pH and thermal stability.…”

Fabrication of Hierarchical Layer-by-Layer Assembled Diamond-based Core-Shell Nanocomposites as Highly Efficient Dye Absorbents for Wastewater Treatment

“…It can be expected that a combination of diamond-based composites involved in diamond modification and LbL self-assembled technique should be particularly advantageous owing to their excellent biocompatibility, moderate nanostructures, and enhanced mechanical and chemical properties. Up to now, various water soluble molecules including poly(allylamine hydrochloride), zinc porphyrin complex, dipeptide (Phe-Lys) conjugated doxorubicin hydrochloride (DOX), protein bovine serum albumin (BSA), conductive polymers (polyaniline, polypyrrole, polythiophene and polyazopyridine), poly(diallyldimethylammonium chloride), have been reported to modify diamond surface via the LbL method for controlled drug release and other analytical applications252627282930313233. However, it is still challenging to design and obtain diamond-based composites with facile and effective process in LbL self-assembled technique.…”

Comparison of the equivalent width, the autocorrelation width, and the variance as figures of merit for XPS narrow scans

“…These nanodiamond materials have been used in the preparation of core-shell particles for liquid chromatography [19][20][21].…”