Antifouling additives

Koszman, I., Antifoulant Additive for Steam-Cracking Process, U.S. Patent 3,531,394, Sept. 29, 1970. Hochman, R. F, Fundamentals of the Metal Dusting Reaction, Proceedings, Fourth International Congress on Metallic Corrosion, NACF (1971). 

Pendant quaternary amine salts prepared by Price [3] were effective as antifouling additives in marine paint. 

The use of additives to eliminate or reduce the effects of fouling has already been mentioned. An example of the effectiveness of an antifoulant on the preheat stream of a crude oil distillation unit has been described [van Nostrand etal 9Zl. These data show that considerable mitigation of the fouling can be achieved by this method. Fig. 3.1 demonstrates the fall off in heat duty with and without antifouling additives. At the time of publication (1981) the annual cost of these chemicals was 1.55 x 10 for a crude unit handling 100,000 barrels per day. 

Uses Biocide, antifoulant additive for commercial ship bottom paints Manuf./Dlstrlb. Aldrich... 

Hazardous Decomp. Prods. Heated to decomp., emits toxic vapors of Cr and fumes of tin Uses Biocide, antifoulant additive for commercial ship bottom paints Manuf./Distrib. Aldrich http //www.sigma-aidrich.com... 

Disinfectant Formulations and Sterilization. Hundreds of appHcations covering disinfectant compositions using sodium chlorite have been described in U.S. and foreign patents. Some examples of these are as antimicrobial additives for latexes (166), marine antifouling agents (see Coatings, marine) (167,168), antimildew detergent compositions (169), toothpaste and solution compositions for prevention and treatment of periodontal oral disease (see Dentifrices) (170—172), and compositions for the disinfection of contact lenses (qv) (173). 

As an additional antifoulant measure, SHEs have been coated with a phenolic hning. This provides some degree of corrosion protection as well, but this is not guaranteed due to pinholes in the lining process. 

Cathodic protection of an uncoated ship is practically not possible or is uneconomic due to the protection current requirement and current distribution. In addition, there must be an electrically insulating layer between the steel wall and the antifouling coating in order to stifle the electrochemical reduction of toxic metal compounds. Products of cathodic electrolysis cannot prevent marine growths. On the contrary, in free corrosion, growths on inert copper can occur if cathodic protection is applied [23]. 

Stannic Oxide (White Tin Oxide, Tin Dioxide, Stannic Anhydride, Flowers of Tin Stannic Acid, Cassiterite). Sn02, mw 150.69, white powd, mp 1127°, bp 1800-1900° (subl), d 6.95 g/cc. Sol in coned sulfuric and coned hydrochloric acids, si sol in hot coned aq KOH or NaOH. Prepn is by reacting Sn with coned nitric acid (d 1.41 g/cc) on a w bath forming 0-stannic acid. The 0-stannic acid is then heated to a red heat and converted to Sn02. It is used as a chemical reagent and (see above) as an antifouling, flash and barrel wear reducing additive in propints... 

There is a current control system for certain types of biocidal products (known as non-agricultural pesticides) operated by HSE under the Control of Pesticides Regulations (CoPR). These are antifouling products, insecticides, wood preservatives and surface biocides. Additionally agricultural pesticides are controlled under CoPR but these are administered by the Pesticides Safety Directorate (PSD), an executive agency of the Ministry of Agriculture, Fisheries and Food (MAFF). 

In addition to the use of antifouling chemical agents to mitigate the effect of fouling on the tube-side, twisted tubes can be used rather than plain tubes. These have surface irregularities. Plain tubes can also be fitted on the inside with tube inserts. Twisted tubes and tube inserts promote additional turbulence and pressure drop and reduce the surface temperature of the tube to mitigate fouling. Tube inserts will be dealt with in more detail later. 

Pohshing agents, as food additives, 22 57 Pohshing antifouling coatings, 7 158 Pohshing compounds... 

In addition to bacterial inhibition, furanones from D. pulchra directly inhibit settlement and attachment of some species of biofouling larvae and zoospores (de Nys et al. 1995 Dwoijanyn et al. 2006), demonstrating the broad-spectrum antifouling activity of these molecules. However, the molecular mechanisms by which furanones deter larvae and zoospores are not known. 

The average effective diffusivity calculated for the 44 compositions is 1.7 x 10"13 cm2/sec and the loss of tin 2.2%. These are in qualitative agreement with the results of laboratory testing. Cardarelli has also reported that antifouling rubber retains a considerable amount of organotin additives even after complete fouling (11). 

Note At present, there are no cost-effective alternatives or alternative technologies for cholordane and mirex as termiticide, and DDT as the additive of antifouling paint in China. China reportedly plans to eliminate the use and production of chlordane and mirex before 2009 and to elimate the use of DDT as the additive of antifouling paint and as an intermediary in the production of dicofol between 2008 and 2014. (Press release Embassy of the People s Republic of China in the United States, June 22,2006.)... 

These types of switchable electrode surfaces have been used to selectively pattern two different cell populations onto a surface [151] and additionally these surfaces can selectively release different cells at different applied potentials [152]. However, it is important to recognize that electrochemically switching a surface from inactive to conjugation and active to conjugation has been well explored with nitro-terminated aryl diazonium salts. In such studies, the application where very anodic potential resulted in a six-electron reduction to an amine [139], to which proteins could be attached [153-155]. The key difference is that the interaction of the biological medium with the surface is controlled by the presence of the antifouling layer. In many ways these electrode surfaces developed by Mrksich and coworkers [150-152, 156] are very similar to the antifouling surfaces with molecular wires discussed in Section 1.4.2 [131, 132, 138, 142]. In both cases the electrode is... 

---