P.E. Vickers et al. Carbon 38(2000)675-689 aromatic fragment ions, where the fragments observed tend of 30 ns, and a beam current of 1.0 to be very similar to those observed from organic surfaces ion dose of approxi 4×10 I-analysis that have been damaged by ion doses that are beyond the SIMS spectra were over a ange of m/- of generally accepted static limit of 10 ons cm as a 5-800 in both the positive and negative ion modes. The result of this situation, ToF-SIMS analysis is more readily spectrometer was controlled by a vG Scientific data system applied to the study of the interaction of organic molecules based on a dEC PDP11/73 running the uRSX operating such as epoxy resins(used in the size and matrix material system. Sample preparation has been fully described in CFRP's)adsorbed on carbon fibres [17]. However, the elsewhere [17] surface specificity of SIMs(1-2 nm)is greater than that of KPS (2-5 nm) and its high sensitivity to chemical struc- 24. GC ture make it ideal for the identification of contaminants present on the surface, where its excellent detection limit A Girdel 330 gas chromatograph utilising a fame may be exploited [18, 19 ionisation detector was employed to carry out the IGC characterisation of untreated and electrochemically treated carbon fibres. Teflon columns, with an internal diameter of 2. Experiment 6.25 mm and length of 500 mm were filled with tows of carbon fibres. Three tows of 1000 mm of fibre were pulled 2.. Fibre treatment through the column from the middle of the lengths using a wire drawstring, which led to the column cross-section AKZO Tenax HTA 5000 fibres were obtained that had containing approximately 70 000 fibres along the column been subjected to 0, 25, 50, 100 and 200% of the standard corresponding to a sample weight of approximately 3.6 g (proprietary) manufacturers electrochemical oxidation A slight torque was applied to the tows during the packing procedure, described as the degree of fibre treatment procedure, which helped reduce the number of voids in the DFT). Sample preparation of the fibres for each technique column. The ends of the column were plugged with a small is described below amount of clean glass wool to ensure an even gas flow through the column. 2.2. XPS The carrier gas used was high-purity nitrogen supplied by Air Liquide, and methane (Air Liquide), was used as The system used for all XPs analysis was a VG the non-interacting marker, in order to measure the resist Scientific ESCALAB Mkll spectrometer interfaced to a ance to flow of the column. The flow-rate, measured by PDPll/73 minicomputer utilising DEC HRSX software means of a soap-bubble flowmeter, was approximately 25 AlKa(hv=1486.6 ev)was used in all analyses, at a power cm min in most cases. although it was reduced to of 10 kv at 34 mA. two fibre tows of 30 mm length approximately 15 cm min for the acidic probes as their placed in a specially designed stub ensuring that no signal low retention time meant that the probe signal is observed from the sample holder. Survey scans were resolved from that of the methane marker. The acquired with a pass energy of 50 ev, and the high- temperature was set at 50C, and the injector and resolution spectra with a pass energy of 20 eV. Wagner were both held at 110C. Prior to analysis, the columns sensitivity factors [20] were used for the quantification were conditioned at 120C under a flow of 25 cm min procedures, and, for the C Is peak, a Shirley type of nitrogen for 15 h background was subtracted prior to quantification, because The probes were a range of alkanes, acidic and basic of the increase in the background at molecules. The characteristics of the probes are reported in greater that the energy characteristic of the C Is peak at Table 1. The probes were injected manually with a 284.6 ev. The instrument was operated analyser methane marker by means of a Hamilton gas-tight syringe chamber pressure of 10 mbar or less and spectra were The chromatographs were recorded using a Delsi 21 digital acquired over a period of approximately 45 min recorder, and net retention times calculated by measuring the distance from the non-interacting marker to the centre 23. ToF-SIMS of the peak of the probe. This procedure was deemed satisfactory because there was very little asymmetry ToF-SIMS analysis was carried out using a VG Sci- observed in the peaks ntific Type 23 System equipped with a two-stage reflec- tron type analyser and an Mig300PB pulsed liquid metal 2.5. DCAA ion source, and the spectrometer was run at an operating pressure of 10 mbar. Static SIMS conditions were used Contact angles were measured by a Cahn 322 DCAA with a pulsed 5 kHz, 26 keV, Ga primary ion beam system utilising a 16-speed motor, capable of rastered over a frame area of 0. 4X0.4 mm- at 50 between 19.8 and 264 ums, and a microbalance cycles s. The system was operated using a pulse width resolution of 0. I ug. Fibres were analysed using aP.E. Vickers et al. / Carbon 38 (2000) 675 –689 677 aromatic fragment ions, where the fragments observed tend of 30 ns, and a beam current of 1.0 nA was used giving an 11 22 21 to be very similar to those observed from organic surfaces ion dose of approximately 4310 ions cm analysis . that have been damaged by ion doses that are beyond the SIMS spectra were acquired over a mass range of m/z of 13 22 generally accepted static limit of 10 ions cm . As a 5–800 in both the positive and negative ion modes. The result of this situation, ToF-SIMS analysis is more readily spectrometer was controlled by a VG Scientific data system applied to the study of the interaction of organic molecules based on a DEC PDP11/73 running the mRSX operating such as epoxy resins (used in the size and matrix material system. Sample preparation has been fully described in CFRP’s) adsorbed on carbon fibres [17]. However, the elsewhere [17]. surface specificity of SIMS (1–2 nm) is greater than that of XPS (2–5 nm) and its high sensitivity to chemical struc- 2.4. IGC ture make it ideal for the identification of contaminants present on the surface, where its excellent detection limit A Girdel 330 gas chromatograph utilising a flame may be exploited [18,19]. ionisation detector was employed to carry out the IGC characterisation of untreated and electrochemically treated carbon fibres. Teflon columns, with an internal diameter of 2. Experimental 6.25 mm and length of 500 mm were filled with tows of carbon fibres. Three tows of 1000 mm of fibre were pulled 2.1. Fibre treatment through the column from the middle of the lengths using a wire drawstring, which led to the column cross-section AKZO Tenax HTA 5000 fibres were obtained that had containing approximately 70 000 fibres along the column, been subjected to 0, 25, 50, 100 and 200% of the standard corresponding to a sample weight of approximately 3.6 g. (proprietary) manufacturer’s electrochemical oxidation A slight torque was applied to the tows during the packing procedure, described as the degree of fibre treatment procedure, which helped reduce the number of voids in the (DFT). Sample preparation of the fibres for each technique column. The ends of the column were plugged with a small is described below. amount of clean glass wool to ensure an even gas flow through the column. 2.2. XPS The carrier gas used was high-purity nitrogen supplied by Air Liquide, and methane (Air Liquide), was used as The system used for all XPS analysis was a VG the non-interacting marker, in order to measure the resist￾Scientific ESCALAB MkII spectrometer interfaced to a ance to flow of the column. The flow-rate, measured by PDP11/73 minicomputer utilising DEC mRSX software. means of a soap-bubble flowmeter, was approximately 25 3 21 AlKa (hn51486.6 eV) was used in all analyses, at a power cm min in most cases, although it was reduced to 3 21 of 10 kV at 34 mA. Two fibre tows of 30 mm length are approximately 15 cm min for the acidic probes as their placed in a specially designed stub ensuring that no signal low retention time meant that the probe signal was not is observed from the sample holder. Survey scans were resolved from that of the methane marker. The column acquired with a pass energy of 50 eV, and the high- temperature was set at 508C, and the injector and detector resolution spectra with a pass energy of 20 eV. Wagner were both held at 1108C. Prior to analysis, the columns 3 21 sensitivity factors [20] were used for the quantification were conditioned at 1208C under a flow of 25 cm min procedures, and, for the C 1s peak, a Shirley type of nitrogen for 15 h. background was subtracted prior to quantification, because The probes were a range of alkanes, acidic and basic of the increase in the background at binding energies molecules. The characteristics of the probes are reported in greater that the energy characteristic of the C 1s peak at Table 1. The probes were injected manually with a 284.6 eV. The instrument was operated with an analyser methane marker by means of a Hamilton gas-tight syringe. 29 chamber pressure of 10 mbar or less and spectra were The chromatographs were recorded using a Delsi 21 digital acquired over a period of approximately 45 min. recorder, and net retention times calculated by measuring the distance from the non-interacting marker to the centre 2.3. ToF-SIMS of the peak of the probe. This procedure was deemed satisfactory because there was very little asymmetry ToF-SIMS analysis was carried out using a VG Sci- observed in the peaks. entific Type 23 System equipped with a two-stage reflec￾tron type analyser and an MIG300PB pulsed liquid metal 2.5. DCAA ion source, and the spectrometer was run at an operating 29 pressure of 10 mbar. Static SIMS conditions were used Contact angles were measured by a Cahn 322 DCAA 69 1 with a pulsed 5 kHz, 26 keV, Ga primary ion beam system utilising a 16-speed motor, capable of speeds 2 21 rastered over a frame area of 0.430.4 mm at 50 between 19.8 and 264 mm s , and a microbalance with a 21 cycles s . The system was operated using a pulse width resolution of 0.1 mg. Fibres were analysed using a motor