In this study, we developed the manufacturing pathways of carbon nanofibers (CNF) and activated carbon nanofibers (ACNF) via the ¡§melt-spinning¡¨ method. A novel route based on the solvent-free core/sheath melt-spinning of polypropylene/ (phenol formaldehyde-polyethylene) (PP/(PF-PE)) to prepare CNF. The approach consists of three main steps: co-extrusion of PP (core) and a polymer blend of PF and PE (sheath), followed by melt-spinning, to form the core/sheath fibers; stabilization of core/sheath fibers to form the carbon fiber precursors; and carbonization of carbon fiber precursors to form the final CNF. Both scanning electron microscopy and transmission electron microscopy images reveal long and winding CNF with diameter 100 - 600 nm and length greater than 80 £gm. With a yield of ~ 45 % based on its raw material PF, the CNF exhibits regularly oriented bundles which curl up to become rolls of wavy long fibers with clean and smooth surface. Results from X-ray diffractometry, energy dispersive X-ray, Raman spectroscopy, and selected area electron diffraction patterns further reveal that the CNF exhibits a mixed phase of carbon with graphitic particles embedded homogeneously in an amorphous carbon matrix. The carbon atoms in CNF are evenly distributed in a matrix having a composition of 90 % carbon element and 10 % in oxygen element. A series of ACNF have also been prepared based on the chemical activation on the thus-prepared CNF; their morphological and microstructure characteristics were analyzed by scanning electron microscopy, atomic force microscopy (AFM), Raman spectroscopy, and X-ray diffractometry, with particular emphasis on the qualitative and quantitative AFM analysis. The effect of activating agent, potassium hydroxide and phosphorous acid, is compared; factors affecting the surface morphology and microstructure of ACNF are analyzed. The ACNF also exhibits a mixed phase of carbon with graphitic particles embedded homogeneously in an amorphous carbon matrix. The resulting ACNF consists of 73 % C element and 27 % O element. The total pore volume of the all activated ACNF is larger than that of un-activated CNF. It can be inferred that chemical activation by KOH results in increased micropore volume in carbon nanofibers; while the micropores produced by the chemical activation of H3PO4 may further be activated and then enlarged to become the mesopores at the expense of micropore volume. For the concentration effect of KOH on ACNF, it can be inferred that high concentration KOH activation results in increased SBET and micropore volume in carbon nanofibers. The average pore diameter of ACNF gradually decreases as the KOH concentration increases.

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Putting on or taking off clothes helps the body to stay within the comfortable temperature range (toavoid shivering or sweating) at different activity levels and ambient conditions. Clothes with built-inthermo-regulating properties would mean maintained comfort without putting on or taking off clothesthat frequently. Integration of phase change materials (PCMs) in clothes is one way of achievingthermo-regulating properties. When the body temperature goes up, the PCM melts and absorbs theheat from the body in the form of latent heat (cooling effect). When the temperature drops, the PCMcrystallizes and the stored heat is released again (warming effect).Research on thermo regulating fibres of the bi-component type containing PCM in the core has beenconducted at Swerea IVF in Mölndal, Sweden, for some time. It has been found that high molecularweight HDPE is a suitable viscosity modifier for hydrocarbon waxes used as PCM. The preparation ofcore materials has so far been done in a batch wise fashion in the way that molten wax has beensoaked into pelletized HDPE at around 180°C during prolonged times followed by melt compoundingin a Brabender batch kneader (0.3 kg per batch). Besides being very impractical for larger productionvolumes the method involves long residence times at high temperatures which may induce thermaldegradation reactions. The objective of the present diploma (master’s thesis) work was to develop acontinuous mixing method to produce PCM/HDPE blends and to test the resulting material in bicomponentfibers with a Nylon (PA6) sheath and to characterize the resulting fiber properties in termsof strength and latent heat.It was proven possible to compound HDPE with large amounts (70%) of octadecane (PCM) on aBrabender twin screw extruder. HDPE was metered to the extruder hoper by means of a screw feederand wax was continuously fed to the hoper in the liquid state by means of a heated membrane pump.To facilitate mixing HDPE in form of powder instead of pellets was used. The extruded threads weresolidified in a water bath followed by granulation. Bi-component fibers were successfully producedfrom such materials. Fibers containing 15 to 42% Octadecane were produced showing heat of fusionsin the range 26 to 86 J/g and tenacities in the range 33 to 16 cN/tex. The heat of fusion of the fiberscompares favorable with existing commercial products showing values in the range 5-15 J/g (acrylicand cellulosic fibres containing microencapsulated hydrocarbon waxes). The peak melting point ofoctadecane measured by DSC was found to be depressed some 4-5°C in the fibers compared to pureoctadecane (28°C). Such a melting point depression is important to consider when choosing type ofhydrocarbon wax. / Program: Magisterutbildning i textilteknologi

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