Surface properties of PAN-based carbon fibers tuned by anodic oxidation in different alkaline electrolyte systems

Study on surface- and mechanical fiber characteristics and their effect on epoxy composite properties tuned by continuous anodic carbon fiber oxidation

“…It was observed that the adjusted pH of the electrolyte solution after measuring the -potential (averaged over six single measurements) increases in the acidic range, while it decreases in the alkaline pH range. As described in our previous work [22], the carbon bers (HT as well as HM) oxidized in KNO 3 /KOH electrolyte contained oxygen, potassium, and sodium (possibly dissolved from the glass beaker) at their surface. These changes in the -curves can be explained if one assumes that the carbon ber surface contains carboxylate-type (the alkali salt of the 'free' surface carboxylic groups, COO ¡ K C or COO ¡ Na C ) surface functionalities.…”

“…The formation of covalently bonded surface oxides is favored only in diluted alkaline solutions, whereas colloidal and gaseous oxidation products are mainly formed in concentrated alkaline electrolytes. Therefore, some preliminary investigations in several alkaline electrolyte systems were carried out to nd an appropriate electrolyte system [22]. Unmodi ed carbon bers were continuously anodically oxidized (galvanostatic mode with current per ber mass I =m D 10 mA/mg [21]), using a mixture of 0.01 M KOH /0.5 M K 2 CO 3 or KNO 3 electrolyte solution.…”

“…Unmodi ed carbon bers were continuously anodically oxidized (galvanostatic mode with current per ber mass I =m D 10 mA/mg [21]), using a mixture of 0.01 M KOH /0.5 M K 2 CO 3 or KNO 3 electrolyte solution. We chose these two electrolyte solutions in expectation of different functionalized carbon ber surfaces [22,23]. The treatment time was varied (2.5, 5, and 10 min) to obtain carbon bers with different oxidation levels.…”

Behavior of CFRP Plate in Simulated ICCP System of Concrete Structures

“…Figure 6 shows surface conditions of CFRP strips subjected to a current density of 40 A/m 2 after 84 h of anodic polarization in three different solutions. The black sediment may be attributed to electrochemical oxidation (Bismarck et al, 1999a(Bismarck et al, , 1999bFukunaga & Ueda, 2000). The other obvious change was the thickness of the CFRP strips.…”

Substrate Independent Dyeing of Synthetic Textiles Treated with Low-Pressure Plasmas

“…Structural preservation and gradients, with increasing degree of crosslinking over film thickness, can be controlled through process parameters, such as gas pressure, gas flow, and applied electric voltage, so that one can also construct so-called gradient layers. It is thus possible to obtain ultra-thin films with very useful properties for technological applications (Bismarck et al, 1999). A combination of polymerizable gases with non-polymerizable gases allows for the deposition of a variety of plasma polymer layers with many different functional groups possible.…”