In this work, poly(methyl methacrylate)/ammonia borane/multiwall carbon nanotube (PMMA/AB/ MWCNT) nanofiber composites have been fabricated and the synergetic nanoconfinement effect of nanofiber and CNT components on dehydrogenation temperature and liberating unwanted byproducts of AB (NH 3 BH 3 ) have been studied. The results of dehydrogenation of PMMA/AB and PMMA/ AB/MWCNT samples show 112 and 85°C exothermic reaction temperatures, which are dramatically lower than pure AB (120°C). Furthermore, by capture and interaction of AB molecules in the MWCNT and PMMA nanofiber structures, the enthalpy of exothermic decomposition decreases from -21.00 to -1.83 kJ mol -1 H 2 , suggesting that this type of AB nanofiber composite can provide a convenient reversible hydrogen storage material. The utilization of MWCNT as carbon catalyst and confining of AB result in a decrease of ammonia borane weight loss from 60.00 to 2.88 wt% which in turn can vigorously decline the emission of byproduct impurities. The synthesis process of PMMA/AB/MWCNT nanofiber composites causes the crystal structure of AB particles changed to the amorphous structure which has been clearly confirmed by X-ray diffraction analyses. The strategy of combining nanofiber structure and MWCNT as carbon catalyst with AB particles can be presented as a practicable solution to reach lower operational temperature and to decline undesirable volatile products.

In this work, poly(methyl methacrylate) (PMMA)/ammonia borane (AB) nanofiber composites were fabricated and the synergetic nanoconfinement effect of nanofibers on dehydrogenation temperature and the removal of unwanted by-products of AB (NH3 BH3) were studied. The results of the dehydrogenation of PMMA/AB samples showed an exothermic reaction temperature of 112°C, which is significantly lower than that of pure AB (120°C). Furthermore, the interaction between AB molecules and PMMA nanofiber structures decreased the enthalpy of exothermic decomposition, from -21.00 to -10.66 kJ/mol H2, suggesting that this type of AB nanofiber composite can provide a convenient reversible hydrogen storage material. Based on the thermogravimetric analysis curves, the use of PMMA to support AB in composite structures resulted in a decrease in AB weight loss from 60.00 to 11.10 wt.% which, in turn, could vigorously reduce the emission of by-product impurities. Based on the obtained results, the strategy of supporting AB in nanofiber structures can be presented as a practical solution to maintain lower operational temperatures and to reduce undesirable volatile products in the dehydrogenation process of AB.

In this study, an effective approach for enhancing the glass transition and mechanical properties of poly(methyl methacrylate)(PMMA) composite nanofibers by incorporation of MgCl 2 in the electrospun solutions has been presented. Pure PMMA and various compositions of MgCl 2 /PMMA nanofibers were successfully fabricated by electrospinning process under optimized conditions. SEM images indicated that the nanocomposite sample containing 1 wt% MgCl 2 has the lowest average diameter with narrow distribution. According to FTIR spectra of the fabricated composites, considerable increase in absorption intensity of most bands were indicated while clear shift from 1728 cm -1 to 1735 cm -1 related to carbonyl group has been identified. DSC thermograms demonstrated 10 o C to 25 o C enhancement in the glass transition temperature for various nanocomposite samples. The results of the mechanical properties of the composite nanofibers sample with 1 wt% MgCl 2 revealed an enhancement in the tensile strength of ~151 % from 0.78±0.08 MPa to 1.96±0.10 MPa, and an increase in the modulus has been seen by ~236 % from 27.48±4.20 MPa to 92.25±8.50 MPa, as compared to the pure PMMA nanofibers.