环境友好海洋防污体系的研究进展

海洋污损是海洋资源开发与利用中遇到的一个国际性难题,发展环境友好海洋防污体系是该领域最重要的方向。本文综述了近年来环境友好海洋防污体系的研究进展,并探讨了未来的发展方向。     

Novel semi‐IPN through vinyl silane polymerization and crosslinking within PVC films

Novel semi‐IPN (interpenetrating polymer networks) were synthesized through vinyl silane modification of unplasticized poly(vinyl chloride) (PVC) films using relatively low temperatures, relatively high vinyl silane contents, and several different processing routes. A free‐radical initiator was used to promote reaction of the vinyl groups, and an aqueous acetic acid solution was used to promote the methoxysilane hydrolysis and condensation (HC) reactions for siloxane crosslink formation. A gel consisting of silane alone was formed prior to the HC process, indicating the formation of a semi‐IPN. The gel content following the HC process far exceeded the silane content, indicating a significant amount of PVC was entrapped by the silane network. This conclusion is supported by the homogeneous molecular structure and morphology of the films. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 8–22, 2001     

End‐capped AB3‐type hyperbranched carbosilane macromolecules

End‐capped carbosilane macromolecules were prepared via the hydrosilation and continual addition of phenylethynyl, amine, bis(trimethylsilyl)amine, and cholesterol groups on the AB₃‐type hyperbranched carbosilane polymer. The matrix‐assisted laser desorption/ionization time‐of‐flight mass spectroscopic views of the end‐capped hyperbranched carbosilanes agreed with the expected mass distribution, in close regularity. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3287–3293, 2001     

A ferrocene‐containing porous organic polymer linked by tetrahedral silicon‐centered units for gas sorption

A novel ferrocene‐containing porous organic polymer (FPOP) has been prepared by Sonogashira‐Hagihara coupling reaction of 1,1′‐dibromoferrocene and tetrakis(4‐ethynylphenyl)silane. Compared with other polymers, the resulting polymer possesses excellent thermal stability with the decomposition temperature of 415°C and high porosity with Brunauer–Emmett–Teller (BET) surface area of 542 m² g^?1 as measured by nitrogen adsorption‐desoprtion isotherm at 77 K. For applications, it shows moderate carbon dioxide uptakes of up to 1.42 mmol g^?1 (6.26 wt%) at 273 K/1.0 bar and 0.82 mmol g^?1 (3.62 wt%) at 298 K/1.0 bar, and hydrogen capacity of up to 0.45 mmol g^?1 (0.91 wt%) at 77 K/1.0 bar, indicating that FPOP might be utilized as a promising candidate for storing carbon dioxide and hydrogen. Although FPOP possesses lower porosity than many porous polymers, the gas capacities are higher or comparable to them, thereby revealing that the incorporation of ferrocene units into the network is an effective strategy to enhance the affinity between the framework and gas.     

Ab initio chemical kinetics for reactions of H atoms with SiHx (x = 1–3) radicals and related unimolecular decomposition processes

Hydrogen atoms and SiH_x (x = 1–3) radicals coexist during the chemical vapor deposition (CVD) of hydrogenated amorphous silicon (a‐Si:H) thin films for Si‐solar cell fabrication, a technology necessitated recently by the need for energy and material conservation. The kinetics and mechanisms for H‐atom reactions with SiH_x radicals and the thermal decomposition of their intermediates have been investigated by using a high high‐level ab initio molecular‐orbital CCSD (Coupled Cluster with Single and Double)(T)/CBS (complete basis set extrapolation) method. These reactions occurring primarily by association producing excited intermediates, ¹SiH₂, ³SiH₂, SiH₃, and SiH₄, with no intrinsic barriers were computed to have 75.6, 55.0, 68.5, and 90.2 kcal/mol association energies for x = 1–3, respectively, based on the computed heats of formation of these radicals. The excited intermediates can further fragment by H₂ elimination with 62.5, 44.3, 47.5, and 56.7 kcal/mol barriers giving ¹Si, ³Si, SiH, and ¹SiH₂ from the above respective intermediates. The predicted heats of reaction and enthalpies of formation of the radicals at 0 K, including the latter evaluated by the isodesmic reactions, SiH_x + CH₄ = SiH₄ + CH_x, are in good agreement with available experimental data within reported errors. Furthermore, the rate constants for the forward and unimolecular reactions have been predicted with tunneling corrections using transition state theory (for direct abstraction) and variational Rice–Ramsperger–Kassel–Marcus theory (for association/decomposition) by solving the master equation covering the P,T‐conditions commonly employed used in industrial CVD processes. The predicted results compare well experimental and/or computational data available in the literature. © 2013 Wiley Periodicals, Inc.     

Square‐Wave Voltammetric Detection of Dopamine at a Copper‐(3‐Mercaptopropyl) Trimethoxy Silane Complex Modified Electrode

Square‐wave voltammetric detection of dopamine was studied at a copper (Cu)‐(3‐mercaptopropyl) trimethoxy silane (MPS)‐complex modified electrode (Cu‐MPS). The modification of the electrode was based on the attachment of MPS onto an electrochemically activated glassy carbon electrode (GCE) by the interaction between methoxy silane groups of MPS and surface hydroxyl groups and followed by the complexation of copper with the thiol groups of MPS. The surface of the modified electrode was further coated by a thin layer of Nafion film. The surface of the Nafion coated MPS‐Cu complex modified electrode (Nafion/Cu‐MPS) was characterized using cyclic voltammetry, electrochemical quartz crystal microbalance (EQCM), scanning electron microscope (SEM), X‐ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FT‐IR) spectrometry. The modified electrode exhibited an excellent electrocatalytic activity towards the oxidation of dopamine, which was oxidized at a reduced potential of +0.35 V (vs. Ag/AgCl) at a wider pH range. Various experimental parameters, such as the amount of copper, the pH, and the temperature were optimized. A linear calibration plot was obtained in the concentration range between 8.0×10^?8 M and 5.0×10^?6 M and the detection limit was determined to be 5.0×10^?8 M. The other common biological compounds including ascorbic acid did not interfere and the modified electrode showed an excellent specificity to the detection of dopamine. The Nafion/Cu‐MPS modified electrode can be used for about 2 months without any significant loss in sensitivity.     

氨基硅烷偶联剂改性凹凸棒土的制备及其吸附性能

采用双氨基硅烷偶联剂KH-792对盐酸改性凹凸棒土(HATT)进行改性,使用FTIR、TGA、DSC、XRD和BET等对目标产物(KHATT)进行了表征。 研究了KHATT对模拟水样中Cr(Ⅵ)的吸附性能,系统考察了模拟水样中Cr(Ⅵ)的初始浓度、pH值、吸附时间及KHATT用量等因素对Cr(Ⅳ)去除率的影响。 结果表明,在KHATT用量为3 g/L、吸附时间为40 min、pH值为5.5的条件下,KHATT对Cr(Ⅵ)的去除率最高,达85.15%;且KHATT经再生后第4次的吸附量仍可达到第1次吸附量的90%以上。 对吸附的过程和机理进行了初步探讨。     

ATR‐FTIR Kretschmann spectroscopy for interfacial studies of a hidden aluminum surface coated with a silane film and epoxy I. Characterization by IRRAS and ATR‐FTIR

Interfacial analysis is essential in many areas of interest, for instance within the ongoing research on environmentally friendly pretreatments of metal surfaces. While studies of the hidden interface between a metal and polymer top‐coat are of great importance, properties of a surface confined between two media are difficult to analyze in detail. Within the two parts of this study, ATR‐FTIR spectroscopy in the Kretschmann geometry is employed as the main analytical tool to study the interface between a thermo‐cured epoxy and aluminum pretreated with a silane film. The technique requires model systems based on thin metal films, but in contrast to most analytical techniques it permits the analysis of a hidden interface. Initial characterization of the silane film formed from a pH‐regulated γ‐APS and BTSE solution was conducted by both ATR‐FTIR Kretschmann and IRRAS spectroscopy. Absorption bands were obtained at 1250–900 cm^?1, assigned to Si? O functionalities, and at ～1570 and ～1410 cm^?1 assigned to acetate existing as a counter‐ion to γ‐APS. After application of the epoxy film, interfacial alterations were detected upon thermal curing including the densification of the epoxy film, the dehydration of aluminum and the formation of molecular epoxy reaction products. Few alterations could be assigned to the silane film. Calculated spectra derived from optical data can verify experimental results and aid data interpretation, and effects of metal oxidation of aluminum were confirmed by introducing gold as an additional substrate. The results showed that ATR‐FTIR Kretschmann spectroscopy is clearly a valuable tool for the study of hidden interfaces of stratified media. Copyright © 2011 John Wiley & Sons, Ltd.     

ATR‐FTIR Kretschmann spectroscopy for interfacial studies of a hidden aluminum surface coated with a silane film and epoxy II. Analysis by integrated ATR‐FTIR and EIS during exposure to electrolyte with complementary studies by in situ ATR‐FTIR and in situ IRRAS

The destabilization of the interface between a polymer and a metal surface is of considerable interest in several application areas, including the ongoing research on environmentally friendly pretreatments as a replacement for the Cr(VI)‐containing systems where the understanding of mechanisms and performance of a confined metal/polymer interface is of utmost importance. Processes at hidden interfaces are, however, difficult to analyze in detail and at relevant climatic conditions. This study has been divided in two parts, where the subject of Part I is the surface characterization by ATR‐FTIR Kretschmann and IRRAS spectroscopy of aluminum coated with an amino‐functional silane, and the interfacial analysis by ATR‐FTIR Kretschmann after further application of an epoxy film. This second part describes the interaction between the coated sample and an electrolyte. The analysis is performed by integrated in situ ATR‐FTIR Kretschmann and EIS, which requires model systems with evaporated metal films on an internal reflection element. Complementary analyses were also conducted on substrates in the absence of the metal film, and or in the absence of an epoxy top‐coat, respectively. Changes in the interfacial region were observed and assigned to the water uptake including swelling of the epoxy, and the formation of aluminium oxidation and hydration products. Complementary studies allowed the distinction between water uptake in the silane film and the epoxy, respectively, as well as reformations of the siloxane network. Copyright © 2011 John Wiley & Sons, Ltd.     

Recent advances in the development of activatable multifunctional probes for in vivo imaging of caspase-3

Caspases are a family of proteases that play critical roles in controlling inflammation and cell death.Apoptosis is a caspase-3 mainly controlled behavior to avoid inflammation and damage to surrounding cells,whereas anomalistic cell apoptosis may be associated with many diseases.The detection and imaging of caspase-3 will be of great significance in evaluating the early therapeutic effect of tumors.Developing smart fluorescent probes may be helpful for the visualization of the rapeutic effect compared with "always on" probes.Thus,more and more works toward activatable fluorescent probes for caspase-3 imaging have been reported.In addition,multifunctional probes have also been designed to further improve the imaging of caspase-3.Herein,this review systematically summarized the representative wo rk of caspase-3 from the perspective of molecular design that it will play a guiding role in the design of probes that respond to caspase-3.Also,challenges and perspectives toward the field for imaging of cell apoptosis(caspase-3) are also discussed.