Various embodiments of the present invention are directed to switchable carboxybetaine-based polymers, hydrogels, and/or elastomers, along with novel related monomers, crosslinkers, and methods. Under acidic conditions, the materials undergo self-cyclization and can catch and kill bacteria. Under neutral/basic conditions, these materials undergo ring-opening and can release killed bacterial cells and resist protein adsorption and bacterial attachment. These smart polymers, hydrogels and elastomers also show excellent mechanical properties making them highly desirable for many biomedical applications.

Process for manufacturing a crystalline alkali metal salt of the general formula (I) [R.sup.1CH(COO)N(CH.sub.2COO).sub.2]M.sup.1.sub.3 (I) wherein M.sup.1 is selected from alkali metal cations, same or different, R.sup.1 is selected from C.sub.1-C.sub.4-alkyl and CH.sub.2CH.sub.2COOM.sup.1, comprising the step of (b) crystallizing said alkali metal salt from an aqueous solution containing in the range of from 5 to 30% by weight of alkali metal hydroxide, referring to said aqueous solution.

Process for manufacturing a crystalline alkali metal salt of the general formula (I) [R.sup.1CH(COO)N(CH.sub.2COO).sub.2]M.sup.1.sub.3 (I) wherein M.sup.1 is selected from alkali metal cations, same or different, R.sup.1 is selected from C.sub.1-C.sub.4-alkyl and CH.sub.2CH.sub.2COOM.sup.1, comprising the step of (b) crystallizing said alkali metal salt from an aqueous solution containing in the range of from 5 to 30% by weight of alkali metal hydroxide, referring to said aqueous solution.

Embodiments of the present invention provide for efficient methods and processes for preparing ionic amino acid esters from a specific synthesis route. The disclosed embodiments consist of a single reaction step: reacting a natural or synthetic unprotected amino acid with an aliphatic, branched or aromatic fatty alcohol of even or odd number of carbon atoms from 6 to 20 with or without unsaturation(s), in stoichiometric amounts, in the presence of an organic acid (HX) like carboxylate, mesylate, tosylate or sulfonate, employed as catalyst and under conventional heating (CC) of 1 to 3 hours at a temperature in the range of approximately 60 to 150 C. and pressure the range of approximately 0 to approximately 250 psi; the product obtained is cooled and recrystallized from ethanol.

Embodiments of the present invention provide for efficient methods and processes for preparing ionic amino acid esters from a specific synthesis route. The disclosed embodiments consist of a single reaction step: reacting a natural or synthetic unprotected amino acid with an aliphatic, branched or aromatic fatty alcohol of even or odd number of carbon atoms from 6 to 20 with or without unsaturation(s), in stoichiometric amounts, in the presence of an organic acid (HX) like carboxylate, mesylate, tosylate or sulfonate, employed as catalyst and under conventional heating (CC) of 1 to 3 hours at a temperature in the range of approximately 60 to 150 C. and pressure the range of approximately 0 to approximately 250 psi; the product obtained is cooled and recrystallized from ethanol.

Embodiments of the present invention provide for efficient methods and processes for preparing ionic amino acid esters from a specific synthesis route. The disclosed embodiments consist of a single reaction step: reacting a natural or synthetic unprotected amino acid with an aliphatic, branched or aromatic fatty alcohol of even or odd number of carbon atoms from 6 to 20 with or without unsaturation(s), in stoichiometric amounts, in the presence of an organic acid (HX) like carboxylate, mesylate, tosylate or sulfonate, employed as catalyst and under conventional heating (CC) of 1 to 3 hours at a temperature in the range of approximately 60 to 150 C. and pressure the range of approximately 0 to approximately 250 psi; the product obtained is cooled and recrystallized from ethanol.

The latex polymer compositions of the present invention exhibit latent crosslinking properties. Latent crosslinking in the polymers takes advantage of the fast interaction between the anionic latex charge and the cationic charge associated with polyfunctional amine crosslinkers. Once the latex is coated onto a substrate, the volatile base evaporates and the groups react to form a crosslinked coating with improved wash-off properties.

The latex polymer compositions of the present invention exhibit latent crosslinking properties. Latent crosslinking in the polymers takes advantage of the fast interaction between the anionic latex charge and the cationic charge associated with polyfunctional amine crosslinkers. Once the latex is coated onto a substrate, the volatile base evaporates and the groups react to form a crosslinked coating with improved wash-off properties.

There is disclosed an improved process for the production of L-carnitine, comprising a step of decolorizing L-carnitinenitrile and removing residual alkali cyanide from a solution of L-carnitinenitrile with an oxidant, wherein the oxidant is preferably hydrogen peroxide or sodium hypochlorite.

There is disclosed an improved process for the production of L-carnitine, comprising a step of decolorizing L-carnitinenitrile and removing residual alkali cyanide from a solution of L-carnitinenitrile with an oxidant, wherein the oxidant is preferably hydrogen peroxide or sodium hypochlorite.