Water Soluble Poly Anilines: Properties and Applications
- PDF / 1,910,788 Bytes
- 6 Pages / 414.72 x 648 pts Page_size
- 67 Downloads / 197 Views
A7 -
y
1A "l-- x
In the last few years considerable interest has focused on these materials as they exhibit a unique combination of properties including conductivity on the order of -_ I ohm- cm- ', electroactivity, clcctrochromism, satisfactory environmental stability, processability and chemical versatility [1-5]. The latter characteristic has already resulted in numerous polyaniline derivatives based upon variations in the degree of oxidation of polymer backbone ((y) and (l-y) in the equation above) [5,6,j, ring substituents (R in the equation above) [5,7] and the nature of the dopant (HA in the equation above) [8-11 ]. Polyaniline has been demonstrated in a wide spectrum of applications which include electrodes for batteries [12] and light-emitting diodes [12], electrochromic devices [1], electrostatic discharge (ESD) protection [14], and welding of plastics [15]. In addition, over the last few years we have shown that polyaniline can be utilized in a number of lithographic processes involved in integrated circuit fabrication [16-20]. The polyanilines that we utilized in this area were processed in organic solvents. More recently, we have developed a series of polyanilines which are water soluble in the conducting form (PanAquasTM)[21]. These polymers eliminate the environmental concerns of organic solvents and thus are more desirable for applicability especially in the electronics industry where the reduction of organic solvents is becoming an issue of increasing importance. This paper will first describe the synthesis and properties of the water soluble polyanilines. This will be followed by a discussion on the applicability of these polymers as removable charge dissipators. It will then be shown that the chemistry 173 Mat. Res. Soc. Symp. Proc. Vol. 328. ©1994 Materials Research Society
of the polymers can be tailored to produce water soluble polyanilines that can undergo cross-linking upon irradiation resulting in systems that can function as permanent (non-soluble) conducting coatings and as water developable conducting resists. EXPERIMENTAL The polyanilines (PanAquasTM) were readily dissolved in water to concentrations between 5 and 20% by weight. The conductivities were measured by a four-point probe method on pressed pellets or spin-applied films of the materials. For the discharge layer experiments, the unsubstituted derivative (R = H in Figure 1) was utilized. A 5% water solution of this polyaniline was spin-applied on the appropriate resists. The samples were evaluated on a 25 KeV e-beam system. For the resist experiments, the polyaniline containing cross-linkable functionality was spin-applied using a 12% by weight water solution onto a silicon oxide wafer. The samples were (1) baked at 80'C on a hot plate for 3 minutes (2) exposed at 50 KeV with an IBM VS-6 gaussian e-beam system and (3) post-expose baked at 80'C on a hot plate for 5 minutes. The samples were dip developed in water at room temperature and rinsed with isopropyl alcohol. RESULTS AND DISCUSSION Water Soluble Polyanilines From a T
Data Loading...
