The Use of Single-Sided NMR to Study Moisture Behaviour in an Activated Carbon Fibre/Phenolic Composite

Abstract Nuclear Magnetic Resonance (NMR) has been shown to be a useful technique to study the form and content of water in polymer composites. Composites using activated carbon fibres with phenolic resin have complex water absorption behaviour which would benefit from such investigation; however, the presence of the conductive fibres can make NMR problematic. In this study, single-sided NMR has been successfully used on such material by developing a method for sample-to-sample compensation for the effect of conductivity. Transverse relaxation curves showed water to be primarily in two states in the resin, corresponding to "bound" and "mobile" molecules. In addition, two much less bound states were identified in the composite, associated firstly with water adsorbed on to the fibre surface and secondly with clusters of water molecules moving more freely within the fibre pores.

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Development of Monolithic Materials with and without a Binder with Carbon Molecular Sieving Properties

Materials Science Forum ◽

10.4028/www.scientific.net/msf.587-588.805 ◽

2008 ◽

Vol 587-588 ◽

pp. 805-809

Author(s):

J.M. Valente Nabais ◽

A. Padre-Eterno ◽

Peter J.M. Carrott ◽

Manuela M.L. Ribeiro Carrott ◽

Cristina Galacho

Keyword(s):

Activated Carbon ◽

Adsorption Capacity ◽

Phenolic Resin ◽

Sem Analysis ◽

Gas Separations ◽

Carbon Fibres ◽

Acrylic Fibre ◽

Good Potential ◽

Activated Carbon Fibres ◽

Molecular Sieving

In this work we studied the production of activated carbon fibres in monolith shape from a commercial textile acrylic fibre. The monoliths were produced with and without a binder. The binders tested were phenolic resin, polystyrene, polymethylmethacrylate and clay. We also tested the influence of using a solvent. The SEM analysis indicates that the monoliths are made of filaments that can be considered activated carbon fibres. The type of binder influences the fibre orientation, degradation and materials shrinkage, the worst results being obtained from the use of polymethylmethacrylate and polystyrene in toluene. The best results are obtained when the monoliths were produced only with acrylic fibre and with phenolic resin as binder. The use of solvents has opposite effects for the carbonised and activated samples. In the former case it seems that the water can be fibre protective but during activation the presence of water leads to an increase in the monolith’s burn-off. The methodology used leads to the formation of excellent samples for performing the gas separations O2/N2 and CO2/CH4. Some samples show maximum selectivity for the referred separations because N2 and CH4 are almost totally excluded from the porous structure which indicates a good potential to be utilised in PSA systems or for natural gas purification. The adsorption capacity is very dependent on the conditions used. Nevertheless, the best sample has a considerably high adsorption capacity (32cm3g-1 for CO2 and 4cm3g-1 for O2, after 200s contact time).

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N-Doped ordered mesoporous carbon grafted onto activated carbon fibre composites with enhanced activity for the electro-Fenton degradation of Brilliant Red X3B dye

RSC Advances ◽

10.1039/c4ra11930d ◽

2014 ◽

Vol 4 (104) ◽

pp. 60168-60175 ◽

Cited By ~ 13

Author(s):

Qiaoli Peng ◽

Zehui Zhang ◽

Ze'ai Huang ◽

Wei Ren ◽

Jie Sun

Keyword(s):

Activated Carbon ◽

Mesoporous Carbon ◽

Ordered Mesoporous Carbon ◽

Carbon Composites ◽

Carbon Fibres ◽

Ordered Mesoporous ◽

Fibre Composites ◽

Activated Carbon Fibres ◽

Carbon Fibre Composites ◽

Activated Carbon Fibre

N-Doped ordered mesoporous carbon (N-OMC) was successfully prepared using dicyandiamide (C2H4N4) as the nitrogen source and was grafted onto activated carbon fibres (ACFs) to form carbon composites (ACF@N-OMC).

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