Graft photopolymerization

In this photopolymerization, various molar ratios of polysilane MMA are used 1 1, 1 5, 1 10, 1 20, 1 50. Similarly, in the graft photopolymerization, while the polymer molecular weights and the polymerization yields decrease, the relative... 

Wen, J., Guillo, C., Ferrance, J. R, and Landers, J. P, DNA extraction using a tetramethyl orthosihcate-grafted photopolymerized monohthic sohd phase. Anal. Chem., 78,1673-1681, 2006. 

Gam-Derouich S., M. Jouini, D. Ben Hassen-Chehimi, M. M. Chehimi. Aryl diazonium salt surface chemistry and graft photopolymerization for the preparation of molecularly imprinted polymer biomimetic sensor layers. Electrochim. Acta 73, 2012 45-52. 

Bakas, I., Z. Salmi, M. Jouini, F. Geneste, I. Mazerie, D. Floner, B. Carbonnier, Y. Yagci, and M. M. Chehimi. Picomolar detection of melamine using molecularly imprinted polymer-based electrochemical sensors prepared by UV-graft photopolymerization. Electroanalysis 27, 2015 429-439. 

Wang ZH, Li JS, Liu XL et al (2013) Preparation of an amperometric sensor for norfloxacin based on molecularly imprinted grafting photopolymerization. Anal Bioanal Chem 405 2525-2533... 

After photopolymerization of a certain monomer for a given time, the polymerization mixture was poured into excess precipitant to isolate the polymer, which was then extracted with a solvent to separate the polymer grafted onto the PSG from the homopolymer. 

The photopolymerization of St with catalytic amount of 52 as the pho-toiniferter gave a benzene-soluble polymer that contains a styryl double bond and a DC group at the polymer chain ends. When this macromonomer-iniferter 54 was copolymerized with a second monomer in the presence of an azo initiator, the formation of a high molecular weight graft copolymer was confirmed by GPC data. The monomer iniferter 52 was also used for the preparation of photoresist polymers [189]. 

Fig. 20 Phosphorylcholine-containing iniferter derivatized on glass through silane coupling agent (upper) and graft chain photopolymerized with poly(dimethylacrylamide) (lower)...

MIP films, applied to a QCM transducer, have been employed for chiral recognition of the R- and 5-propranolol enantiomers [107]. MIP films were prepared for that purpose by surface grafted photo-radical polymerization. First, a monolayer of 11-mercaptoundecanoic acid was self-assembled on a gold electrode of the quartz resonator. Then, a 2,2 -azobis(2-amidinopropane) hydrochloride initiator (AAPH), was attached to this monolayer. Subsequently, this surface-modified resonator was immersed in an ACN solution containing the MAA functional monomer, enantiomer template and trimethylolpropane trimethacrylate (TRIM) cross-linker. Next, the solution was irradiated with UV light for photopolymerization. The resulting MIP-coated resonator was used for enantioselective determination of the propranolol enantiomers under the batch [107] conditions and the FIA [107] conditions with an aqueous-ACN mixed solvent solution as the carrier. The MIP-QCM chemosensor was enantioselective to 5-propranolol at concentrations exceeding 0.38 mM [107]. 

Graft polymerization on PDMS channel surface (not channel lumen) in enclosed channels was carried out by first adsorbing the photoinitiator (benzophe-none) on the PDMS surface, followed by UV-mediated photopolymerization. In this manner, the EOF stability of the PDMS channels lasts for 45 h [254]. Besides PDMS chips, PC chips have also been chemically modified by sulfonation (using S03 gas) to produce hydrophilic surfaces [255]. 

Other than beads, porous polymer monoliths, which were photopolymerized in a COC chip, were used for solid-phase extraction. It is known that priming polymeric surfaces is not as simple as priming silica surfaces, which use a common surface primer agent, TMPM. Therefore, the grafting method as initiated by UV should be used to attach the polymer monoliths [588]. A similar strategy was used for sample pre-concentration of PAHs (e.g., pyrene). Pyrene (900 nM) was first concentrated by 400-fold in 24% ACN before switching to 56% ACN for CEC separation (see Figure 5.5) [148]. 

Although benzophenone derivatives have found application in a number of photopolymerization processes (10), these have usually involved cross-linking reactions induced by energy transfer from photo-exdted benzophenones to groups (e.g. cinnamate) attached to the polymer chains. In such cases, the benzophenones act as sensitisers and not as photoinitiators. An e>fample in which hydrogen abstraction by photoexdted benzophenone has been utilized for photoinitiation is the ultra-violet induced grafting of styrene on to polyethylene (8,45). Recently, extensive studies concerned with photoinitiation of vinyl polymerization by benzophenone derivatives in homogeneous media have been carried out, and are described in detail below. 

Photosensltlzatlon of polymers has been found to be Important for a variety of purposes such as 1) Photopolymerization, 2) PhotomodlfIcatlon (photo-grafting), 3) Photodegradation, and 4) Photostablllzatlon (13 In commercial polymers photodegradation reactions are usually photosensitized by the presence of alien groups In the chain or by the presence of trace Impurities (2,3). 

Smets, DeWinter and Delzenne attached eosin units to polyvinyl-amine) through the amino groups. Photopolymerization was initiated at the eosin sites, yielding grafts of poly(vinylamine-eosin-poly-(acryla-mide) where X is —CONH2. 

---