1.Semi-online nanoflow liquid chromatography/matrix-assisted laser desorption ionization mass spectrometry of synthetic polymers using an octadecylsilyl-modified monolithic silica capillary column.
Watanabe T1, Nakanishi K, Ozawa T, Kawasaki H, Ute K, Arakawa R. Rapid Commun Mass Spectrom. 2010 Jul 15;24(13):1835-41. doi: 10.1002/rcm.4584.
We have designed a semi-online liquid chromatography/matrix-assisted laser desorption/ionization mass spectrometry (LC/MALDI-MS) system to introduce eluent from a octadecylsilyl (ODS) group modified monolithic silica capillary chromatographic column directly onto a sample plate for MALDI-MS analysis. Our novel semi-online system is useful for rapidly and sensitively examining the performance of a monolithic capillary column. An additional advantage is the small elution volume of a monolithic capillary column, which allows delicate eluents, such as 1,1,1,3,3,3,-hexafluoroisopropyl alcohol (HFIP), to be used to achieve cost-effective analysis. Using the semi-online LC/MALDI-MS system, chromatographic separation of polymers by the monolithic column with different eluents was studied. Separation of poly(methyl methacrylate) and Nylon 6/6 showed that the column functioned via size-exclusion separation when tetrahydrofuran or HFIP eluent was used.
2.Kinetic polymerization behavior of fluorinated monomers for dental use.
Kadoma Y1. Dent Mater J. 2010 Oct;29(5):602-8. Epub 2010 Sep 4.
The kinetic polymerization behavior of 2,2,2-trifluoroethyl methacrylate (TFEMA), 1,1,1,3,3,3-hexafluoroisopropyl methacrylate (HFIPMA), 2,2,2-trifluoroethyl acrylate (TFEA) and 1,1,1,3,3,3-hexafluoroisopropyl acrylate (HFIPA) was determined by isothermal differential scanning calorimetry (DSC) and high-performance liquid chromatography (HPLC) in order to improve the properties of fluorinated powder-liquid adhesive resins. Conversion and heat of polymerization were calculated, and the solubility of the homopolymers in common solvents was examined. Comparison of their polymerization reactivity with that of MMA revealed that the overall rate of polymerization initiated by benzoyl peroxide (BPO) decreased in the order TFEA>MMA>TFEMA>HFIPA>HFIPMA. Based on the retention time of the monomer determined by HPLC, the hydrophobicity of the monomers was found to increase in the order MMA<TFEA<TFEMA<HFIPA<HFIPMA. The overall research results suggested that TFEA and HFIPA would be potentially promising candidates for the monomer liquid component of fluorinated powder-liquid adhesive resins.
3.Thermodynamic characterization of poly(1,1,1,3,3,3-hexafluoroisopropyl methacrylate) by inverse gas chromatography.
Papadopoulou SK1, Panayiotou C. J Chromatogr A. 2012 Mar 16;1229:230-6. doi: 10.1016/j.chroma.2012.01.055. Epub 2012 Jan 25.
The thermodynamic characterization of a fluorinated methacrylic homopolymer was conducted by means of inverse gas chromatography (IGC) at infinite dilution. The polymer under study, poly(1,1,1,3,3,3-hexafluoroisopropyl methacrylate) (PHFIMA) was synthesized via a free radical polymerization reaction and was properly characterized prior to IGC measurements. The IGC characterization encompassed the calculation of the thermodynamic sorption parameters, the parameters of mixing at infinite dilution, the weight fraction activity coefficients and the Flory-Huggins interaction parameters of 15 probes. Moreover, the total and partial solubility parameters of the polymer were determined. The impact of the temperature and the chemical nature of the probes on the aforementioned thermodynamic parameters are discussed. Results demonstrate that PHFIMA is insoluble in almost every tested solvent, with the exception of chloroform, due to its proton donor character which is favorable for the formation of hydrogen bonds with the fluorine groups and the oxygen atoms of the carbonyl groups (proton acceptors) of the polymer.
4.The influence of the surface properties of silicon-fluorine hydrogel on protein adsorption.
Xie H1, Zhao Z1, An S1, Jiang Y2. Colloids Surf B Biointerfaces. 2015 Dec 1;136:1113-9. doi: 10.1016/j.colsurfb.2015.11.027. Epub 2015 Nov 21.
A range of fluorinated hydrogels were synthesized using the copolymerization of 1, 1, 1, 3, 3, 3-hexafluoroisopropyl methacrylate (HFMA) or 1H, 1H, 7H-dodecafluoroheptyl methacrylate (DFMA) with hydrophilic monomers. Bovine serum albumin (BSA) and Lysozyme (LZM) were chosen as model proteins to investigate the performance of protein adsorption on the surface of these fluorinated hydrogels. It was found that the performance of the fluorinated hydrogels toward protein adsorption was different for different proteins; simultaneously, the amount of protein adsorption was related to but not linear with the fluorine content on the hydrogel surface. With increasing HFMA content, the mass of BSA adsorption increased in the first stage and then decreased, meanwhile the mass of LZM adsorption exhibited an upward trend in general. In addition, the amount of protein adsorption was also related to the type and length of the fluorinated groups. The hydrogels made from DFMA behaved better than HFMA hydrogels in terms of reducing protein adsorption.