Tridodecyl methylammonium chloride

Sol-gel methods have been used to form membranes on sensor surfaces by the mixing of the ion-sensitive molecule with alkoxysilanes which then crosslink to form a hard, transparent coating on the sensor. For example, tridodecyl-methylammonium chloride-doped films were used as a chloride sensor and showed Hofmeister-type selectivity [91]. Long cure times (several days), however, represent a disadvantage in this process [91]. 

Wettability, surface free energy, surface charge and compliance have been studied. Heparinized surfaces have exhibited considerable compatibility with blood. Typically, heparin is surface bound using cationic materials including tridodecyl methylammonium chloride, benzalkonium chloride, octadecylamine and quaternary ammonium polymers. Since polyelectrolyte complexes of heparin and chitosan have been prepared and exhibit either thrombogenic or non thrombogenic properties chitosan can be coated onto artificial polymeric supports and then reacted with heparin or with heparin-like substances... 

The catheters were inplanted for 30 min in carotid and femoral arteries. I-Fibrinogen was injected prior to implantation the radioactivity of the entire catheter and extruded thrombus was determined by y-ray spectrometry. Table I presents the data on chitosan--heparin coated polyethylene catheters. The tridodecyl methylammonium chloride-heparin surface performs poorly in comparison to the chitosan--heparin cyanoborohydride surface. 

The solvent polymeric membranes used for EMF measurements typic ly consisted of 1 wt.% metalloporphyrin, 33 wt. % poly-(vinyl chloride) (PVC) and 66 wt % plasticizer (dibutylsebacate). If the porphyrin complex central metal oxidation state was (-I- 2) or (-t- 4), addition of lipophilic cationic sites or anionic sites respectively was required to achieve optimal anion response and selectivity. Tridodecyl-methylammonium cation (TDMAC) or teti s[bis (3,5-trifluoromethyl) phenyl] anion (at a concentration 10-20% mol relative to the metalloporphyrin) are used for this purpose. The total weight of the components varies according to the desired memln ane thickness (typically 150-250 pm) and diameter (7-10 mm). 

---