Precise Synthesis of Acrylate Copolymer via RAFT Polymerization and Its Application

A series of different sequence structure containing stearyl acrylate (SA) and hydroxyethyl acrylate (HEA) copolymer were synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization. The crystallization property of PHEA-b-PSA, PHEA-b-PSA-b-PHEA, PSA-b-PHEA-b-PSA, PHEA-co-PSA, and PHEA-grad-b-PSA were characterized by Differential Scanning Calorimetry (DSC). The condensed structure of different sequence copolymers were investigated using small-angle X-ray scattering (SAXS). A series of copolymers with different sequence structure were coated on the surface of polyester fabric, which can be found that PHEA-b-PSA-b-PHEA block copolymer has good water repellency.

Chiral phenethylamine synergistic tricarboxylic acid modified β-cyclodextrin immobilized on porous silica for enantioseparation

In this work, a series of chiral phenethylamine synergistic tricarboxylic acid modified β-cyclodextrin bonded stationary phase for high performance liquid chromatography(HPLC) were synthesized via a simple one-pot synthesis approach. Various racemates(aryl alcohols, flavanones, triazoles, benzoin, etc.) were well separated on the tricarboxylic acid modified chiral stationary phases in both normal and reversed modes with good reproducibility and stability, and the influence of mobile phase composition on resolution(R_(s)) were deeply investigated. The RSD values of Rsfor repeatability and column-to-column were below 1.28% and 3.05%, respectively. Hence, the fabrication of tricarboxylic acid modified chiral stationary phase(CSPs) is a new efficient strategy to improve the application of β-cyclodextrin as CSPs in the field of chromatography.

Extraction of Eugenol from Essential Oils by In Situ Formation of Deep Eutectic Solvents:A Green Recyclable Process

Eugenol is extensively utilized in chemical industry.In actual production,it is mainly separated from clove essential oils(EOs)through acid-base solutions.In this work,a simple,rapid and effective extraction process was developed for the extraction of eugenol from EOs samples by directly forming deep eutectic solvents(DESs)without using acid-base solutions.The proposed process is designed to dissolve EOs in n-hexane and eugenol was highly selective extracted into DESs with tetrabutylammonium chloride(TBAC).Hydrogen bonds in DESs can be broken by addition of water,resulting in a separation of the two phases,thus obtaining a hydrophobic yellowish eugenol in the upper layer.The quaternary ammonium salt in the lower aqueous solution can be reused after recovery.The most determining influence factors such as the structure of quaternary ammonium salt,the mole ratio of quaternary ammonium salt to eugenol and the amount of n-hexane were investigated.The forming conditions of DESs were studied by Box-Behnken design(BBD).Experiment was carried out under the optimal conditions and good experimental result was demonstrated by the developed process,a high extraction recovery of 92.51% and the purity was about 98.50%,which verifies the excellent performance for the proposed process.

Responsive switchable deep eutectic solvents:A review

Deep eutectic solvents(DESs)have drawn considerable attention as a new type of green solvent since they were reported.Subsequent studies have shown that DESs have the potential to be used as“designable”solvents,which means that the precursors of DESs with different structures and properties can be screened to customize DESs for specific functions.Researchers have found that during the sample preparation process involving DESs,the specific properties of some“smart”DESs can be switched by directing external driving forces,leading to a reversible phase transition of the target solution.These"smart"DESs are called switchable deep eutectic solvents(SDESs).The advent of SDES simplifies the sample pretreatment steps,reduces the use of organic solvents,and makes solvents easy to recycle,which matches the concept of green and sustainable chemistry.Compared with the number of previous experimental studies,the reviews and summaries on SDESs are rare.Therefore,this review made a summary of the concept and research progress of SDESs based on some related works in the past decade,including composition and type,characterization,switching mechanism,etc.It is expected to provide a certain reference and guidance for the subsequent in-depth research of SDESs in the analytical sample pretreatment.

Synthesis and modification of spherical/hollow metal-organic frameworks for efficient extraction of sulfonamides in aqueous environments

In this study,two novel spherical/hollow metal-organic frameworks were successfully synthesized,and further modified by a mild non-covalent modification strategy with dopamine and 1,4-benzenedithiol(BDT)as polymeric monomers to obtain pB DT@PDA-Ni-MOF and p BDT@PDA-Ni/Co-MOF,respectively.The results showed that the above MOFs possessed extremely fast adsorption rates and ideal adsorption capacities for sulfonamides(SAs)and the modified MOFs exhibited enhanced adsorption capacities for SAs owing to a large number of additional functional groups.Then,benefit of their regular morphology and size,a facile syringe-assisted dispersive solid phase extraction(S-DSPE)method was developed for efficient detection of SAs,which will provide a powerful tool for monitoring trace level of SAs in aqueous environment.