Advanced materials are essential to the quality of modern day life, but the synthesis of these compounds is often inefficient in terms of energy, time and resources; especially when considering the hydrothermal batch methods used to prepare many such compounds – often requiring week-long reaction times with variable yields and product quality. In contrast, Continuous flow synthesis (CFS) provides a more readily scalable means for the efficient, effective and reproducible synthesis of inorganic compounds. This publication demonstrates the novel CFS of several metal ammonium phosphates and compare the effect of synthesis route on particle size, size distribution, and crystallinity.

Genesis of Pure Se(0) Nano- and Micro- structures in Wastewater

Adsorption of methylene blue onto poly(cyclotriphosphazene-co-4,4'-sulfonyldiphenol) nanotubes: kinetics, isotherm and thermodynamics analysis.

Nonconventional luminophores devoid of remarkable conjugates have attracted considerable attention due to their unique luminescence behaviors, updated luminescence mechanism of organics and promising applications in optoelectronic, biological and medical fields. Unlike classic luminogens consisting of molecular segments with greatly extended electron delocalization, these unorthodox luminophores generally possess nonconjugated structures based on subgroups such as ether (–O–), hydroxyl (–OH), halogens, carbonyl (CO), carboxyl (–COOH), cyano (CN), thioether (–S–), sulfoxide (SO), sulfone (OSO), phosphate, and aliphatic amine, as well as their grouped functionalities like amide, imide, anhydride and ureido. They can exhibit intriguing intrinsic luminescence, generally featuring concentration-enhanced emission, aggregation-induced emission, excitation-dependent luminescence and prevailing phosphorescence. Herein, we review the recent progress in exploring these nonconventional luminophores and discuss the current challenges and future perspectives. Notably, different mechanisms are reviewed and the clustering-triggered emission (CTE) mechanism is highlighted, which emphasizes the clustering of the above mentioned electron rich moieties and consequent electron delocalization along with conformation rigidification. The CTE mechanism seems widely applicable for diversified natural, synthetic and supramolecular systems.

Nonconventional luminophores: characteristics, advancements and perspectives.

The use of polyurethane for asphalt pavement engineering applications: A state-of-the-art review

Porous polyurea (PPU) is prepared through a simple protocol by reacting toluene diisocyanate (TDI) with water in a binary solvent of water–acetone, and the process is optimized. Porosimetric tests demonstrate that PPU possesses typical properties of porous materials. The structure of the material is characterized by Fourier transform infrared (FTIR), NMR (1H & 13C) and X-ray diffraction (XRD). FTIR analysis shows that TDI is fully reacted. Microstructure analysis of PPU by NMR reveals that PPU consists of short polyurea chains with a degree of polymerization about 15. The presence of crystallinity in PPU is confirmed by XRD, which shows three diffraction peaks, for which the corresponding chain conformations, based on interplanar spaces owing to different hydrogen-bonds, are depicted. TGA analysis demonstrates that PPU has high thermal stability, and no degradation is seen before 270 °C. The DSC test reveals that no obvious glass transition is observed owing to intensive hydrogen-bonding.

One step preparation of porous polyurea by reaction of toluene diisocyanate with water and its characterization

In contrast to conventional fluorescent polymers featured by large conjugation structures, a new class of fluorescent polymers without any conjugations is gaining great interest in immerging applications beyond the possibility to achieve by the conjugated polymers. Poly(ethylene glycol) (PEG), widely used in biomedical fields for a long time owing to its nontoxicity and nonimmunogenicity, is found to be fluorescence emissive in the solid state and in aqueous solution, though deemed as not fluorescent in numerous reports. Through systematic study under different conditions, the emission is ascribed to the cluster formation of its chains; thereby the blue-shift of the emission with the excitation wavelength was interpreted through the Forster resonance energy transfer. The clusterization was ascertained through size measurements, Fourier transform infrared spectroscopy, NMR analyses, and the dependence on temperature, pH, and nonsolvent presence. Tested in the presence of competitive metal ions, selective emission quenching by Fe³⁺ and Cr⁶⁺ was observed. PEG was used as a sensor for the detection of Cr⁶⁺, Fe³⁺, and H₂O₂, outperforming most of the reported sensors alike. Its uses for data encryption and cell imaging were also presented. This work provides therefore a novel face of PEG with great potential in a variety of emerging applications, in particular, as sensors in the biomedical area.

Fluorescence Behavior and Mechanisms of Poly(ethylene glycol) and Their Applications in Fe3+ and Cr6+ Detections, Data Encryption, and Cell Imaging

Owing to their high specific surface area and low density, porous polymer materials are of great importance in a vast variety of applications, particularly as supports for enzymes and transition metals. Herein, highly uniform and porous polyurea microspheres (PPM), with size between 200 µm and 500 µm, are prepared by interfacial polymerization of toluene diisocyanate (TDI) in water through a simple microfluidic device composed of two tube lines, in one of which TDI is flowing and merged to the other with flowing aqueous phase, generating therefore TDI droplets at merging. The polymerization starts in the tube while flowing to the reactor and completed therein. This is a simple, easy and effective process for preparation of uniform PPM. Results demonstrate that the presence of polyvinyl alcohol in the aqueous flow is necessary to obtain uniform PPM. The size of PPM is readily adjustable by changing the polymerization conditions. In addition, palladium is incorporated in PPM to get the composite microspheres Pd@PPM, which are used as catalyst in degradation of methylene blue and rhodamine B. High performance and good reusability are demonstrated. Monodispersity, efficient dye degradation, easy recovery and remarkable reusability make Pd@PPM a promising catalyst for dye degradation.

/pdf/highly-uniform-and-porous-polyurea-microspheres-clean-and-1jmqxfxfig.pdf

Highly Uniform and Porous Polyurea Microspheres: Clean and Easy Preparation by Interface Polymerization, Palladium Incorporation, and High Catalytic Performance for Dye Degradation.

A novel and simple pathway to synthesis of porous polyurea absorbent and its tests on dye adsorption and desorption

Water–oil separation from their emulsions and mixtures has been a prominent topic in fundamental research and in industries. A superhydrophobic/oleophilic membrane (SHP) was obtained by dipping a cellulose filter paper in an acetonitrile solution of toluene diisocyanate (TDI) and in that of N-(2,4-diaminophenyl) maleimide, alternatively and repeatedly for three times, to make the paper coated by maleimide-containing polyurea (PU), which was then reacted with n-dodecanethiol (DAT) through Michael addition to obtain the superhydrophobic porous membrane (SHP). All the involved reactions were confirmed by different techniques. SHP membrane as prepared was demonstrated to be superhydrophobic and oleophilic and of high performance in separation of oil and water from their emulsions and mixtures. This study provides a new route to the fabrication of new materials of high superhydrophobicity and oleophilicity, featured by ease of fabrication, low-cost and versatile availability of the starting materials, both synthetic and natural.

Fabrication of superhydrophobic/oleophilic membranes by chemical modification of cellulose filter paper and their application trial for oil–water separation

Catalysis of isocyanate reaction with water by DMF and its use for fast preparation of uniform polyurea microspheres through precipitation polymerization

Shusheng Li

Papers

Fluorescence Behavior and Mechanisms of Poly(ethylene glycol) and Their Applications in Fe3+ and Cr6+ Detections, Data Encryption, and Cell Imaging

Highly Uniform and Porous Polyurea Microspheres: Clean and Easy Preparation by Interface Polymerization, Palladium Incorporation, and High Catalytic Performance for Dye Degradation.

A novel and simple pathway to synthesis of porous polyurea absorbent and its tests on dye adsorption and desorption

Fabrication of superhydrophobic/oleophilic membranes by chemical modification of cellulose filter paper and their application trial for oil–water separation

Catalysis of isocyanate reaction with water by DMF and its use for fast preparation of uniform polyurea microspheres through precipitation polymerization