Polymeric Network Hierarchically Organized on Carbon Nano-onions: Block Polymerization as a Tool for the Controlled Formation of Specific Pore Diameters

Abstract

The organization of specific pores in carbonaceous three-dimensional networks is crucial for efficient electrocatalytic processes and electrochemical performance. Therefore, the synthesis of porous materials with ordered and well-defined pores is required in this field. The incorporation of carbon nanostructures into polymers can create material structures that are more ordered in comparison to those of the pristine polymers. In this study we applied polymer-templated methods of carbon material preparation, in which outer blocks of the star copolymers form the carbon skeleton, while the core part is pore-forming. Well-defined 6- star -(poly(methyl acrylate)- b -poly(4-acetoxystyrene)) dendrimers were synthesized by reversible addition–fragmentation chain-transfer polymerization. They were then transformed into poly(4-vinylphenol) derivatives (namely 6- star -(poly(methyl acrylate)- b -poly(4-vinylphenol)), subjected to polycondensation with formaldehyde, and pyrolyzed at 800 °C. Cross-linking of phenolic groups provides a polymer network that does not depolymerize by pyrolysis, unlike poly(methyl acrylate) chains. The selected star polymers were attached to carbon nano-onions (CNOs) to improve the organization of the polymer chains. Herein, the physicochemical properties of CNO-polymer hybrids, including the textural and the electrochemical properties, were compared with those of the pristine pyrolyzed polymers obtained under analogous experimental conditions. For these purposes, we used several experimental and theoretical methods, such as infrared, Raman, and X-ray photoelectron spectroscopy, nitrogen adsorption/desorption measurements, scanning and transmission electron microscopy, and electrochemical studies, including cyclic voltammetry. All of the porous materials were evaluated for use as supercapacitors.

Rational design of carbon nanocomposites with hierarchical porosity: a strategy to improve capacitive energy storage performance

“…7 Moreover, combining faradaic and non-faradaic processes in SCs can achieve higher energy and power density while maintaining long-term electrochemical stability. Our studies show that using CNOs during the synthesis of macromolecular systems may organize the organic framework of oligomers, 8 polymers 9,10 or CTFs 5 and alter the uniform distribution of pores and pore sizes (micropores (<2 nm), mesopores (2–50 nm) and macropores (>50 nm)) within the materials. Additionally, the combination of two components also guarantees an increase in the total porosity of the material, which is critical when using them as electrodes in SCs.…”

Composites containing resins and carbon nano-onions as efficient porous carbon materials for supercapacitors

“…The hierarchical distribution of CN, in the amount of only ca. 5%, in a porous carbon matrix was responsible for increasing of the porosity and C S value compared to pristine pyrolyzed polymers 54 .…”

“…However, the range of CNO content was high, equal to 5–75 wt%, in the starting synthesized gels before the thermal treatments. Furthermore, our group developed polymer-templated carbon materials derived from star-block copolymers and CNOs 54 , 55 . The hierarchical distribution of CN, in the amount of only ca.…”

Fluorescent Nanocarbons: From Synthesis and Structure to Cancer Imaging and Therapy

“…Since the initial discovery of CNOs, many attempts have been made to identify the reaction conditions that yield high-purity CNOs in large quantities. These attempts have employed numerous methods using various raw-carbon precursors to synthesize CNOs, including annealing, [191] arc discharge, [192] gas-liquid detonation, [193] electrochemical, [194] CVD, [195] ambient electrospray deposition, [196] and plasma-spray from NDs. [197,198] However, our thorough analysis of the literature revealed that amongst these methods, only a few techniques have occupied the main streams of current research due to their substantial potential in producing significant quantities of CNOs that might meet the stringent demands of commercial production.…”