Electrospun melamine‐blended activated carbon nanofibers for enhanced control of indoor CO₂

Abstract

Electrospun carbon nanofibers were activated with melamine-polyacrylonitrile [melamine-blended carbon nanofibers (MACNFs)] for use as a fibrous adsorbent for indoor CO 2 removal. Although, melamine doping was intended solely to incorporate basic nitrogen functionalities on the nanofibers, it also shortened fabrication time, conserving time, and energy cost. The specific surface area and microporosity of the fibers were enhanced from 412 m 2 g −1 and 0.1646 cm 3 g −1 to 547 m 2 g −1 and 0.220 cm 3 g −1 , respectively, upon final CO 2 activation of the nanofibers. With the chemical properties, we observed significant tethering of pyridine functionality. The sample, MACNF-7 (10 mL of polymer solution doped with 0.7 g of melamine), provided the optimum melamine doping condition to achieve the highest CO 2 adsorption capacity of 3.15 mmol g −1 . The adsorption performance was based on simultaneous improvement in microporosity (physical) and surface basicity (chemical) properties of the adsorbent. However, in a binary mixture with nitrogen, the selective adsorption of CO 2 showed the predominance of the improved surface basicity over microporosity. The highest CO 2 selective capture (1.22 mmol g −1 ) was occurred for a CO 2 :N 2 ratio of 0.15:0.85, with a selectivity of 58.19 at 273 K. In a regeneration test, stable and robust performance was achieved more than five cycles.

Isosteric Enthalpy Behavior of CO2 Adsorption on Micro-Mesoporous Materials: Carbon Microfibers (CMFs), SBA-15, and Amine-Functionalized SBA-15

“…Heo et al explored CNF with and without activation, CNF and ACNF, respectively; CNF presented a small area (12 m 2 g −1 ) and small adsorption (0.55 mmol CO 2 g −1 ), while ACNF with area of 925 m 2 g −1 had an adsorption of 2.21 mmol CO 2 g −1 [34]. Jeong et al, prepared CNFs added melamine, but the material without melamine named MACNF-0 with a specific surface area of 412 m 2 g −1 , at 273 K and 1 bar adsorbed 1.61 mmol CO 2 g −1 compared with 3.22 mmol CO 2 g −1 for CMF (synthesized in this work) at the same conditions [35]; an enhanced adsorption in this case may be due to the presence of nitrogen and oxygen functional groups.…”

N,P-Doped Carbon-Based Freestanding Electrodes Enabled by Cellulose Nanofibers for Superior Asymmetric Supercapacitors

“…Figure g shows the formation process between glucose and dicyandiamide. During pyrolysis, the melamine evolved from dicyandiamide decomposed and generated NH 3 , which in turn transformed into amine radicals, including −NH 2 , NH, and −N. , The fragile CO bond in the aldehyde group of glucose is easily broken and then connected with other carbons in the main chain via the annulation reaction. Along with reconstruction, dicyandiamide gets a chance to join the new structure, leading to the formation of the N–H bond, and this should be responsible for the evolution of pyrrolic-N.…”

Electrospun Nanofibrous Scaffolds: Review of Current Progress in the Properties and Manufacturing Process, and Possible Applications for COVID-19

“…In the last decade, nanofibers have been generated by electrospinning under pressurized CO 2 . In fact, an evolution of the traditional technique was clarified by several researchers by adding CO 2 in the liquid polymeric solution [ 56 , 57 , 58 ]. The presence of CO 2 in the solution reduced the surface tension of the liquid to be processed and its viscosity.…”