Photophysical Properties of Sol-gel derived Luminescent Silicone Hybrids SynthesizedviaFacile Amino-Ene Reaction

Preparation of Agarose Fluorescent Hydrogel Inserted by POSS and Its Application for the Identification and Adsorption of Fe3

After entering in water, Fe3+ is enriched in the human body and along the food chain, causing chronic poisoning and irreversible harm to human health. In order to solve this problem, we synthesized citric acid POSS (CAP) from aminopropyl POSS (OAP) and citric acid. Then, we synthesized fluorescent hydrogels (CAP-agarose hydrogel, CAHG) with CAP and agarose. The luminescence mechanism of CAP was investigated by theoretical calculation. CAP plays a dual role in composite hydrogels: one is to give the gels good fluorescence properties and detect Fe3+; the second is that the surface of CAP has a large content of carbonyl and amide groups, so it can coordinate with Fe3+ to enhance the adsorption properties of hydrogels. The experimental results show that the lowest Fe3+ concentration that CAHG can detect is 5 μmol/L, and the adsorption capacity for Fe3+ is about 26.75 mg/g. In a certain range, the fluorescence intensity of CAHG had an exponential relation with Fe3+ concentration, which is expected to be applied to fluorescence sensors. Even at a lower concentration, CAHG can effectively remove Fe3+ from the solution. The prepared fluorescent hydrogel has great potential in the field of fluorescent probes, fluorescent sensors, and ion adsorption. Besides, CAHG can be used as photothermal material after adsorbing Fe3+, allowing for material recycling and reducing material waste.

Structure-Dependent Photoluminescence of Europium(III) Coordination Oligomeric Silsesquioxane: Synthesis and Mechanism

The coordination environment of Eu3+ is a crucial factor in the optical performance of the complex. Herein, a new kind of oligomeric silsesquioxane was employed to improve the coordination environment of central ions, the luminescence intensity of which was greatly enhanced with an efficient emission peak at 619 nm. More importantly, the photoluminescent properties of the product will be altered because of the formation of the Si-O-Si structure. The relevant mechanism has also been investigated and proposed by a series of characterization analyses. Additionally, the fluorescence lifetime, intrinsic quantum yield, and energy transfer efficiency were calculated. In addition, the observed trend of Judd-Ofelt intensity parameters was used to justify the coordination environment of Eu3+ ions. The experimental results reveal that the sol-gel reaction of the ligands can effectively promote intramolecular energy transfer. In addition, we introduced four theory modules of ligands (LSi, LSi-1, LSi-2, and LSi-3) with certain rules of formation of Si-O-Si, and density functional theory (DFT) and time-dependent DFT (TD-DFT) were used to explore their excited electron transfer process and their electronic absorption spectra, combined with Marcus theory. The calculated results show that the sol-gel reaction will induce the separation of the distribution of excited holes and electrons, leading to an efficient charge-transfer (CT) process. The predictable results were in good accordance with the experimental findings. Consequently, the sol-gel reaction occurring among ligands will be attributed to an efficient CT process, leading to a strong luminescence intensity, as observed experimentally.

Light- and heat-triggered reversible luminescent materials based on polysiloxanes with anthracene groups

Reversible silicone elastomers were successfully developed by light-triggered dimerization and heat depolymerization which happened to the anthryl groups.

A new approach for the synthesis of sulfur-bridged polysiloxanes via thiol–ene “click” reaction and their post-functionalization to obtain luminescent materials

A novel polymerization method for preparing well defined sulfur containing siloxane polymers.

Highly luminescent lanthanide CPs based on dinuclear cluster: crystal structure and sensitive Trp sensor

A lanthanide coordination polymer is explored as Trp sensor. The possible sensing mechanism is the combination between Trp and Tb³⁺, which improves the antenna effect.

Multifunctional alkoxysilanes prepared by thiol–yne “click” chemistry: their luminescence properties and modification on a silicon surface

Novel multifunctional alkoxysilanes were prepared by facile thiol–yne “click” chemistry without heavy metal catalyst or solvent. These are used to modify the Si surface, which can then be used for further functionalization or the immobilization of polymers or biomolecules.