Design of a large Stokes shift ratiometric fluorescent sensor with hypochlorite detection towards the potential application as invisible security ink.

Hypochlorite (ClO-) as a well-known highly reactive oxygen species (ROS), is widely used as preservative and household disinfectant in daily life. Although many fluorescence imaging sensors for ClO- have been reported, the development of ClO- ratio fluorescence sensors with large Stokes shift is still quite limited. This sensor shows obvious benefits including minimizing environmental intervention and improving signal-to-noise ratio. In the present project, we report an innovative conjugated pyrene-based system, 1-B, as a chlorine fluorescence sensor. The detector exhibits ratio detection performance, large Stokes and emission shifts. Furthermore, the system has desired sensitivity as well as selectivity for ClO-. Based on these excellent properties, the sensor 1-B was successfully used as ink to encrypt patterns and anti-counterfeiting information through inkjet printing technology. Compared with the existing probes, the probe shows some superior characteristics, which provides a promising tool for exploring the role of ClO- response sensor in the field of anti-counterfeiting.

Theoretical Investigation of the Hydrolytic Mechanism of α-Functionalized Alkoxysilanes as Effective Crosslinkers and the Difficulty of Deep Vulcanization in RTV Silicone Rubber.

The reactions between α-, γ-ethylenediaminemethyl trimethyl-ketoxime silane (α-, γ-EAMOS) and H2O were investigated on the geometries of stationary points, the reaction pathway (IRC), thermodynamic and kinetic analysis by density functional theory (DFT) at the B3LYP/6-311G (d, p) level. Interestingly, the results showed that the hydrolysis activity of α-EAMOS is higher than that of γ-EAMOS, due to the influence of an amino substituent in position α-C on silicon. α-EAMOS can be used as a superior crosslinker for room temperature vulcanized (RTV) silicone rubber to achieve rapid crosslinking without a toxic catalyst. Besides, compared with the reaction between α-EAMOS and H2O, the reactivity between α-EAMOS and hydroxy siloxane (HO⁻Si(CH3)2⁻OSiH3) was discussed. Particularly, it revealed that the deep vulcanization of RTV silicone rubber is difficult.

Impacts of Different Functional Groups on the Kinetic Rates of α-Amine Ketoximesilanes Hydrolysis in the Preparation of Room Temperature Vulcanized Silicone Rubber.

α-Amine ketoximesilanes are proven to be effective crosslinkers in the preparation of ketone-oxime one-component room temperature vulcanized (RTV) silicone rubber without the use of toxic metal catalyst. This work aimed to investigate the hydrolysis kinetic of α-amine ketoximesilanes, which is vitally important for the preparation of RTV silicone rubber. Five kinds of α-amine ketoximesilanes, namely α-(N,N-diethyl)aminomethyltri(methylethylketoxime)silane (DEMOS), α-(N,N-di-n-butyl)aminomethyltri(methylethylketoxime)silane (DBMOS), α-(N-n-butyl)aminomethyltri(methylethylketoxime)silane (n-BMOS), α-(N-cyclohexyl)aminomethyltri(methylethylketoxime)silane (CMOS) and α-(β-aminomethyl)aminomethyltri(methylethylketoxime)silane (AEMOS), were successfully obtained and confirmed using Fourier transform infrared spectrometer (FT-IR) and hydrogen-1 nuclear magnetic resonance ( ¹H NMR). Kinetics of hydrolysis reactions were measured by FT-IR and conductivity. Our results illustrated that the kinetic constant rates ranged from 12.2 × 10−4 s−1 to 7.6 × 10−4 s−1, with the decreasing order of DEMOS > n-BMOS > DBMOS > CMOS > AEMOS at the given temperature and humidity. Better performances of thermal stability could be achieved when using the α-amine ketoximesilanes as crosslinkers in the preparation of RTV silicon rubber than that of RTV silicone rubber with the use of methyltri(methylethylketoxime)silane (MOS) as a crosslinker and organic tin as a catalyst.

Surface-initiated atom transfer radical polymerization of polyamine grafting from magnetic iron oxide submicroparticles for high adsorption capacity of cadmium in aqueous solution.

Chemical modification of magnetic submicroparticles (MSPs) with functional polymers using controlled/living radical polymerization method has recently gained a great deal of attentions because of the potential applications to water treatment. In this work, we demonstrated an efficient method for poly(glycidyl methacrylate) (pGMA) modification of MSPs, by surface-initiated atom transfer radical polymerization method, and then, the particles were actually modified by triethylenetetramine through epoxy groups of pGMA to form polyamine/MSPs. The material was characterized using infrared spectroscopy, thermo gravimetric analyzer, transmission electron microscopic, gel permeation chromatography, and vibrating sample magnetometer. Sorption of Cd(II) to polyamine/MSPs reached equilibrium in ~100 min and agreed well to the Freundlich isotherm equation with maximum adsorption capacity of 71.3 mg g(-1) for the 500 mg L(-1) Cd(II) aqueous solution at neutral pH.

Poly[[[µ-3,3'-(dimethyl-silanedi-yl)dibenzoato][µ-1,1'-(1,4-phenyl-ene)di-1H-imidazole]-zinc] monohydrate].

The asymmetric unit of the title compound, {[Zn(C16H16O4Si)(C12H10N4)]·H(2)O}(n), consists of one Zn(II) ion, two half 3,3'-(dimethyl-silanedi-yl)dibenzoate ligands and two half 1,1'-(1,4-phenyl-ene)di-1H-imidazole ligands. The Zn(II) ion is four-coordinated by two O atoms from two carboxlate ligands, two N atoms from two imidazole ligands. Two Zn(II) ions are bridged by two carboxyl-ate groups in chelating mode, generating a binuclear secondary building unit (SBU), which is further coordinated by two N atoms from two imidazole ligands in monodentate mode. Thus, the binuclear SBUs are further bridged by imidazole ligands in two different directions, giving rise to a chain. The water solvent mol-ecules are hydrogen bonded within the chain along the c axis.