分子印迹技术制备石油有机硫组分固相萃取剂的研究

用分子印迹技术合成了对石油有机硫组分二苯并噻吩(Dibenzothiophene，DBT)具有高效选择性的分子模板聚合物(Molecularly Imprinted Polymer，MIP)，通过静态吸附的方法研究了不同功能单体和致孔剂及其用量对模板聚合物特异性识别能力的影响．实验表明，以4-乙烯基吡啶(4-VP)为功能单体，在甲苯溶剂中聚合得到的固相萃取剂对DBT具有较大的吸附富集能力和识别特性．其饱和吸附容量达到48．3mg／g．     

烟碱分子烙印聚合物的吸附特性

利用分子烙印技术，以烟碱为烙印分子，甲基丙烯酸(MAA)为功能单体，乙二醇二甲基丙烯酸酯(EDMA)为交联剂，合成了对烟碱具有特异性作用的分子烙印聚合物P(Nic)；通过平衡吸附实验，评价了其对烟碱的亲和力和选择性。与非烙印聚合物相比，P(Nic)对烟碱表现了很高的亲和力；Scatchard分析表明在P(Nic)中存在对烟碱有不同的亲和力的两类作用位点。通过与氨基吡啶类物质在P(Nic)上的吸附行为比较，表明P(Nic)对烟碱具有很好的选择性。本工作证明了用P(Nic)作为固相萃取(SPE)材料选择性地从烟草烟雾中提取烟碱的可能性。     

Ultrathin self-assembled polymeric films on solid surfaces. I. Synthesis and characterization of acrylate copolymers containing alkyl disulfide side chains

Copolymers of 2-hydroxyethyl acrylate and 2-methoxyethyl acrylate with variable compositions were synthesized, fractionated, and characterized by ¹H-NMR, IR, GPC, and viscometry. These copolymers were further modified via polymer analog esterification of copolymer hydroxy groups by a series of disulfide-containing carboxylic acids including lipoic acid and (n-pentyldithio) alkyl carboxylic acids (n-C₅H₁₁SS(CH₂)m? COOH, m = 10, 15, 22) in the presence of 1,3-dicyclohexylcarbodiimide (DCC). Esterification reactions were quantitative for copolymers possessing hydroxy monomer contents ≤ 40% when excess acid and DCC were present for sufficiently long reaction times (2–4 days) at room temperature. Copolymer DSC analysis demonstrates a systematic variation of T_g with copolymer composition in good agreement with ideal mixing theory. These disulfide-bearing copolymers spontaneously yield two-dimensional ultrathin polymer films with side chain-dependent layer thicknesses of 20–45 Å by solution adsorption onto freshly deposited gold surfaces. Such ultrathin polymer films are expected to have diverse applications as bound polymeric surface modification reagents. © 1993 John Wiley & Sons, Inc.     

Polymeric thiols as enzyme activators of serum creatine phosphokinase

Several hydrophilic polymeric thiols were prepared from aminoactivated polymeric supports by reaction with N-acetylhomocysteinethiolactone. Supports include agaroses, cellulose, Glycophase™ controlled-pore glass, and Matrex™ acrylic beads. Thiol content in these polymers was 3–72 μmol SH/g dry polymer. Several were effective solid-phase activators of the sulfhydryl-dependent enzyme creatine phosphokinase at concentrations comparable to that of monomeric thiol required for enzyme activation. The kinetic activation curves for the polymeric and the monomeric (thioglucose) activators were similar, suggesting unhindered interaction of the enzyme with the polymeric activator.     

Preparation and evaluation of uniform-sized molecularly imprinted polymer beads used for the separation of sulfamethazine

Uniform-sized molecularly imprinted polymer (MIP) beads were prepared using a one-step swelling and polymerization method. The obtained sulfamethazine (SMZ)-imprinted polymer showed high affinity and selectivity toward SMZ and other structurally related sulfonamides in acetonitrile or water-acetonitrile mobile phases, particularly in high aqueous systems. The column performance of the MIPs for SMZ and its analogues could be improved by elevating the column temperature and optimizing the flow rate. The hydrogen-bonding effect plays a significant role in the recognition process of SMZ-imprinted polymer systems in organic media, while the ion-exchange effect, as well as hydrophobic effect, dominates the retention mechanism in aqueous-rich media, in addition to shape recognition.     

Soluble polymers with pendant thionine groups: Synthesis and evaluation as singlet oxygen photosensitizers

Thionine ( 1 ) has been covalently bound to linear copoly(styrene-p-vinylbenzyl chloride) and to linear copoly(acrylic acid-2-ethylhexyl acrylate). The resulting polymeric dyes, purified by ultrafiltration, present quantum yields of singlet oxygen generation in dimethylformamide solution lower than their corresponding low-molecular-weight models thionine hydrochloride ( 1.HCl ) and N(3)-acetylthionine ( Ac-1 ), the decrease being more pronounced in the case of the polystyrene-dye photosensitizer. High chromophore concentrations within the volume encompassed by each macromolecule in the solution can explain this fall in efficiency. The free dyes thionine hydrochloride and its hydrolysis products thionoline ( 2 ) and thionol ( 3 ) behave as good singlet oxygen generators, with quantum yields of 0.71, 0.62, and 0.63, respectively. © 1993 John Wiley & Sons, Inc.     

Radiation formation of polymeric nanogels

An alternative method of synthesis of polymeric nanogels is proposed, based not on polymerization, but on intramolecular crosslinking of polymer chains, initiated by pulse irradiation in dilute aqueous solutions. Kinetic data show that for many water-soluble polymers irradiation under these conditions result in intramolecular crosslinking. Preliminary product studies on poly(vinyl alcohol) indicate that in fact internally crosslinked macromolecules can be obtained by this technique.     

Synthesis of Molecularly Imprinted Polymer Particles by Suspension Polymerization in Silicon Oil

Molecular imprinting is a method to prepare polymers with recognition site of desired and predetermined selectivity1. Molecularly imprinted polymers (MIP) are prepared by copolymerizing functional and cross-linking monomers in the presence of a molecular …     

A deuteron NMR study of axial motion and side chain conformation in the mesophase of discotic liquid crystal main-chain polymers

Pulsed deuteron NMR spectroscopy has been used to examine the axial motion and the side-chain conformation in both oriented and unoriented mesophases of discotic liquid crystal main-chain polymers based on pentyloxy or heptyloxy substituted triphenylenes. Lineshape simulations show that the rotational motion of the triphenylene rings about the column axes can be described by an inhomogeneous distribution of reorientation angles around 45°. However, only about 60% of the discs are involved in such large amplitude motions; the remaining 40% have reorientation angles below 10°. This illustrates the severe restrictions imposed on the rotation of the discs by the interlinkage of the columns via the alkylene spacers. Furthermore, the simulations demonstrate that, at the -carbon, the side chains show very little fast internal motion, but have a relatively complex conformation involving a disorder which does not change on the microsecond timescale. Since such a disorder is not present in the corresponding monomeric samples it is ascribed to the presence of the spacers. These results are also consistent with the presence of large sterical hindrances between the first side chains segments of adjacent discs, and they indicate a correlated reorientation of the discotic units within a column.     

Synthesis and X-Ray Crystal Structure Study of ]2-Methyl-4-(2-methylbenzoyl)-phenoxy] Acetic Acid Hydrazide

Benzophenone analog 3 has been synthesized and characterized by the X-ray diffraction (XRD) method. The compound crystallizes in a monoclinic space group P2₁/c with cell parameters a = 7.701(8) Å, b = 7.151(5) Å, c= 28.323(3) Å, = 104.639(4)°, Z = 4. The structure exhibits intra- and intermolecular hydrogen bonding of the type N–HO, C–HO, and N–HN. The molecules are interlinked through hydrogen bonds forming an infinite chain. This polymeric-like structure may play an important role in biological activity.