Reverse micellar polymerization

Particles of the enzymatically synthesized phenolic polymers were also formed by reverse micellar polymerization. A thiol-containing polymer was synthesized by peroxidase-catalyzed copolymerization of p-hydroxythiophenol and p-ethylphenol in reverse micelles [70], CdS nanoparticles were attached to the copolymer to give polymer-CdS nanocomposites. The reverse micellar system was also effective for the enzymatic synthesis of poly(2-naphthol) consisting of qui-nonoid structure [71], which showed a fluorescence characteristic of the naphthol chromophore. Amphiphilic higher alkyl ester derivatives were enzymatically polymerized in a micellar solution to give surface-active polymers at the air-water interface [72, 73]. 

In addition to solubilization, entrapment of polymers inside reversed micelles can be achieved by performing in situ suitable polymerization reactions. This methodology has some specific peculiarities, such as easy control of the polymerization degree and synthesis of a distinct variety of polymeric structures. The size and shape of polymers could be modulated by the appropriate selection of the reversed micellar system and of synthesis conditions [31,191]. This kind of control of polymerization could model and/or mimic some aspects of that occurring in biological systems. 

Reverse micellar systems were used for the polymerization of phenol derivatives. HRP-catalyzed polymerization of p-ethylphenol in the ternary system composed of a bis(2-ethylhexyl) sodium sulfosuccinate (AOT)—water—isooctane system produced spherical polyphenol particles having 0.1—2 /tm diameters quantitatively.21 Similar particles were obtained by pouring the solution of enzymatically prepared polyphenol into a nonsolvent containing AOT.22... 

Fluorescent naphthol-based polymers were prepared by HRP-catalyzed polymerization of 2-naphthol in AOT/isooctane reverse micelles to give the polymer microspheres.31 The precipitated polymer was soluble in a range of polar and nonpolar organic solvents and possessed quinonoid structure. The reverse micellar system induced the peroxidase-catalyzed copolymerization of p-hydroxythiophenol and />ethylphenol, yielding the thiol-containing polyphenol particles.32 The attachment of CdS to the particles gave the CdS—polymer nanocomposite showing fluorescence characteristics. 

Peroxidase-catalyzed grafting of polyphenols on lignin was performed by HRP-catalyzed polymerization of />cresol with lignin in the aqueous 1,4-dioxane or reverse micellar system.57 Phenol moiety in lignin was reacted with />cresol to produce a lignin—phenol copolymer with a branched and/or cross-linked structure. The product was highly insoluble in common organic solvents. 

Solvent displacement Salting out Emulsion diffusion Emulsion-solvent evaporation SCF technology Complexation/coacervation Reverse micellar methods In situ polymerization... 

We focus on the enzymic polymerization of nucleotides in a reversed micellar system utilizing the liquid/solid interface. 

IV. STUDY OF ENZYMIC POLYMERIZATION OF NUCLEOTIDES IN A REVERSED MICELLAR SYSTEM AS A DEVELOPMENT OF BIOPOLYMER SYNTHESIS UTILIZING THE LIQUID-SOLID INTERFACE... 

Oparin and coworkers [125,126] have studied the enzymic polymerization of ADP by polynucleotide phosphorylase (PNPase) and Mg ions in coacervates in an attempt to construct primitive forms of precellular structures. Walde et al. [127] have investigated this enzymic ADP polymerization in AOT reversed micellar solutions instead of coacervates. The PNPase-catalyzed synthesis of poly(A) (polyadenylic acid) in the AOT reversed micelles was carried out by mixing two reversed micellar solutions, one containing ADP and the other containing the enzyme. 

It was found by HPLC that the poly(A) precipitated out at = 10, 20, and 30, of which the highest polymerization proceeded at IEq = 20, but every supernatant included hardly any poly(A). No precipitation occurred at Wg = 40 [85]. The polymerization in the AOT reversed micelles seems to need an appropriate size of water pool, and the greater the fPo and the closer it approaches an emulsion, the lesser the tendency to precipitate. This means that the small amount of water in the reversed micellar system has an important role in the precipitation. No poly(A) precipitated out of the HTAC reversed micellar solution, but a small amount of poly(A) did out of the Ci2Eg reversed micellar solution, [85]. The electrostatic repulsion between poly (A) and AOT must play an important role in the precipitation. 

Gel electrophoresis of poly(A) in the AOT reversed micellar system revealed that the size of poly(A) in the precipitate (4.0 kb, 1.6 kb -0.6 kb) was nearly the same as that in the supernatant (2.5 kb-1.0 kb, 0.4 kb), in which the asterisk denotes the highest distribution of poly(A) [85]. A similar tendency was observed in the Ci2Eg reversed micelles. In the case of HTAC reversed micelles, the size of poly(A) (7.4 kb-5.3 kb -1.0 kb) in the supernatant was larger than that in the AOT reversed micelles. ADP molecules are strongly adsorbed at the cationic charged interface of the water pool of HTAC, resulting in enhancement of the polymerization in the water pool due to the entropy effect. 

Surfactant-polymer interactions in an aqueous solution have been studied by many researchers [132], and the adsorption and surface-induced self-assembly of the surfactant at the solid-aqueous interface have been recently studied [133]. On the other hand, these subjects have been rarely studied for oil solutions. The surfactant-polymer interaction in oil and the surface-induced self-assembly of surfactants at the oil-solid interface are important for further research studies to enhance the polymerization at the interface of the liquid/solid in reversed micellar solutions. 

Another subject is concerned with biopolymer synthesis utilizing the liquid/solid interface in a reversed micellar system. The enzymic polymerization of ADP in AOT reversed micellar solution containing a Mg ions resulted in the precipitation of poly(A) together with the PNPase. Further polymerization could proceed by the enzyme in the precipitate by feeding ADP through the dynamic AOT monolayer on a glass surface. This is concluded to be a kind of solid polymerization in a reversed micellar solution. This process of polymerization provides a simple isolation of both the product and enzyme the maintenance of the enzyme activity for a long time and a novel solid polymerization on the oil/solid interface. This polymerization at the interfaces in the reversed micellar solution could be applied to other biopolymer syntheses. 

Abstract The enzymatic polymerization of ADP was carried out in sodium bis(2-ethylhexyl)sulfosuccinate (AOT)-reversed micellar solutions. The poly (adenylic acid), poly(A), being formed in the water pools precipitated out of the AOT solution together with the enzyme, whose activity was maintained for a long time. The process of the precipitation was studied in comparison with the polymerization in cationic surfactant reversed micelles and the precipitate aggregates were observed by atomic force microscopy (AFM). 

We have studied the enzymatic polymerization of ADP in a sodium bis(2-ethylhexyl) sulfosuccinate, AOT, reversed micellar system [3]. This enzymatic polymerization by polynucleotide phosphorylase(PNPase) and Mg ion was greatly different from the general aspect of the enzy-... 

The addition of a fresh AOT-reversed micellar solution containing ADP to the precipitate resulted in a new start to the reaction, showing that the PNPase precipitated with the poly(A), as shown in Fig. lb. Interestingly, each repeated addition of a fresh reversed micellar solution to the precipitates resulted in a new polymerization of ADP. The activity of the PNPase on the interface of the glass sur-face/0.2 M AOT solution was then examined, as shown in Fig. 4. The ca. 500 nmol of ADP was consumed per 72 pg PNPase, in which 720 nmol of the ADP was contained as a substrate in 1 ml of 0.2 M AOT reaction solution. This... 

Fluorescent polymers have been realized by the oxidative polymerization of 2-naphthol (94) [143]. The polymerization was carried out in a reverse micellar system using AOT/isooctane to give the polymer in single and interconnected microspheres. The frequency of the AOT carbonyl IR vibrations was shifted as a function of the monomer concentration, thus proving the penetration of the monomers into the interfacial region of the reversed mi-... 

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