A Study Based On The Adsorption,Detection And Solubility Of Three Phenolic Compounds

Phenolic compounds are common organic compounds that can be classified as endogenous and exogenous phenols.Endogenous phenols are naturally occurring compounds found in plants,such as flavonoids and catechins,which have various pharmacological activities,including antioxidant,anti-inflammatory,and antibacterial effects,and are widely used in traditional Chinese medicine and health products.Exogenous phenols,on the other hand,are usually pollutants,such as hydroxypyrene and naphthol,which are mainly generated from human activities,such as the combustion of fossil fuels and industrial production processes,resulting in emissions of waste gas,wastewater,and solid waste.These compounds are toxic,carcinogenic,and reproductively hazardous,posing serious threats to the environment and human health.Endogenous phenols can be extracted from natural plants or synthesized,but stability and bioavailability issues need to be considered.The control of exogenous phenols requires enhanced monitoring and detection capabilities,as well as the use of physical,chemical,and biological methods for treatment and removal to reduce their hazards.In this article,we prepared three materials for endogenous salicin and exogenous hydroxypyrene and naphthol,and investigated their properties in terms of controlled release,adsorption,and detection.(1)Synthesis,characterization and solubility studies of chrysin co-crystalsTwo novel co-crystals,HNU-65 and HNU-66,were assembled using BPY(4,4’-bipyridine)and R1(1,4-bis(4-pyridylmethoxy)benzene)with chrysin.Structural analysis showed that in HNU-65,the-OH of chrysin formed intermolecular hydrogen bonds with the-N of BPY,constructing a tetragonal structure.In HNU-66,a layered structure was constructed through intermolecular hydrogen bonds between the-OH of chrysin and the-N of BPY.The structures of these two co-crystals were characterized by infrared spectroscopy,PXRD,and DSC.Importantly,the solubility of these two co-crystals was greatly improved in phosphate-buffered chrysin at p H = 7.4.In addition,toxicity experiments confirmed that the two co-crystals were biocompatible and could exist in cells,demonstrating their potential for biological applications.(2)Functional melamine sponge for the adsorption/ detection of 1-hydroxypyrene in waterThe preceding discussion highlighted the efficient utilization of endogenous phenolic compounds and the successful synthesis of two novel eutectics.In this chapter,our focus shifted to the investigation of exogenous phenolic compounds,with particular emphasis on 1-hydroxypyrene(1-HP)as a representative compound,aiming to mitigate its potential environmental and human health risks.To achieve effective detection and adsorption of exogenous phenolic compound 1-HP in water,we synthesized a functional material(referred to as MNT)by modifying melamine sponge.The modification agents employed were 3-aminopropyltrimethoxysilane(ATMS)and 4-diphenylaminobenzaldehyde(TPACHO).MNT exhibited a detection limit(LOD)of 0.159 ppb for 1-HP in water,surpassing the international standard for 1-HP content(1 ppb).Due to the hydrophobic nature(contact angle of 142°)and π-π interactions,MNT demonstrated remarkable adsorption capability for 1-HP in water.Within a mere 2-hour adsorption period,MNT was capable of removing 90% of 1-HP(at a concentration of 10 ppm)from water.Furthermore,we performed testing on actual urine samples using MNT to determine the 1-HP content,and the results were consistent with those obtained through high-performance liquid chromatography(HPLC).(3)Chitosan-modified melamine sponge for the adsorption/detection of naphthol in waterNaphthol is a common exogenous phenolic compound that is widely present in industrial processes.Compared to hydroxypyrene,naphthol exhibits higher toxicity and environmental impact at certain concentrations.Therefore,studying the adsorption and detection of naphthol can effectively assess and monitor its potential hazards to the environment and human health.In this chapter,to enable real-time monitoring of the concentration of exogenous phenolic compound naphthol in water and facilitate its adsorption in water,we successfully synthesized a functional material called TCM composite sponge by grafting 4-diphenylamino benzaldehyde onto chitosan-loaded sponge.The TCM composite sponge not only possesses fluorescence detection capabilities but also exhibits high adsorption capacity.With the introduction of chitosan and 4-diphenylamino benzaldehyde,the TCM sponge exhibits distinctive blue-yellow fluorescence and shows significant fluorescence quenching in the presence of naphthol solution(LOD = 6.629 ppb),enabling fluorescence detection.Furthermore,the introduction of chitosan and 4-diphenylamino benzaldehyde imparts the sponge with hydrophobicity and efficient adsorption capability for naphthol.In aqueous solutions,the adsorption rate reaches 86% when the naphthol concentration is equal to or less than 10 ppm.