| Phellodendron amurense Rupr.is the main medicinal plant in Northeast China and its bark,leaves,and fruits are rich in biologically active components,which have a significant research value.At present,researches on P.amurense are major focused on the extraction of alkaloids in the bark and essential oils in leaves and fruits,and these extraction methods have problems such as low extraction efficiency and environmental pollution that need to be solved urgently.In this work,P.amurense is selected as a raw material to design an ionic liquid solvent system[C4C1Im][OOCCH3]/DMSO to achieve the full-component dissolution of P.amurense plant materials under mild conditions and separate the alkaloid compounds,essential oils,seed oils,cellulose,hemicellulose,and lignin in the dissolving solution,and studied their applications in the fields of flexible sensors,industrial chemicals,and ultraviolet protection,which establishes a technical route for the comprehensive utilization of P.amurense resources under the[C4C1Im][OOCCH3]/DMSO solvent system.Firstly,the ionic liquid solvent system[C4C1Im][OOCCH3]/DMSO was designed to achieve the full component dissolution of P.amurense xylem under mild conditions.The possible influencing factors of plant materials dissolution in an ionic liquid solvent system,such as anion type,length of cation alkyl side chain,type of diluent solvent,and molar concentration of ionic liquid,were compared and analyzed by Kamlet-Taft solvation parameters,with the aid of technical means such as dynamic rheology,the possible dissolution mechanism of plant materials in the ionic liquid solvent system is explained.The results show that the optimal ionic liquid solvent system is 2.0 mol/L[C4C1Im][OOCCH3]/DMSO,the maximum loading of wood powder is 4%,the dissolution reaction temperature is 70? and the dissolution reaction time is 60 min.In the ionic liquid solvent system,new hydrogen bonds are formed between anions and cellulose molecules to break the intramolecular and intermolecular hydrogen bonds of cellulose in raw plant materials to complete the dissociation of cellulose molecular chains.The cation of ionic liquid reacts with acetyl group of hemicellulose and ether bonds between lignin molecular chains to complete the dissolution.The dissolution of the three main components of plant cell walls leads to the collapse of the plant cell wall structure,which in turn creates conditions for the outflow of plant cell contents.Secondly,the ionic liquid solvent system[C4C1Im][OOCCH3]/DMSO was applied to separate the alkaloids from the bark and leaves of P.amurense,and the efficiency and safety of the ionic liquid solvent system used in the separation of alkaloids were analyzed and compared.Through single factor optimization,the PBD model and BBD model optimize and screen the factors that may affect the separation of alkaloids from bark and leaves of P.amurense and determine the optimal conditions for the separation of alkaloids through the ionic liquid solvent system.The optimal conditions for the separation of alkaloids from bark are ionic liquid molar concentration 1.99 mol/L,liquid-solid ratio 26 mL/g,ultrasonic irradiation temperature 75?,ultrasonic irradiation time 40 min,ultrasonic irradiation power 80 W,and particle size 250 ?m.The optimal conditions for the separation of alkaloids from leaves are ionic liquid molar concentration 2.01 mol/L,liquid-solid ratio 25 mL/g,ultrasonic irradiation temperature 79?,ultrasonic irradiation time 30 min,ultrasonic irradiation power 80 W,and particle size 250 ?m.Under the optimal conditions,the average yields of alkaloids from bark and leaves were 4.22±0.20 mg/g and 2.47±0.12 mg/g,respectively.Moreover,by comparing with other alkaloid separation methods and evaluating the stability,recoverability,and repeatability of alkaloids in ionic liquid solvent system,the efficiency and safety of ionic liquid solvent system for alkaloid separation were fully proved.The ionic liquid solvent system[C4C1Im][OOCCH3]/DMSO was applied to separate the essential oil and seed oil from P.amurense seeds and evaluate the main components and physical and chemical properties of the essential oils and seed oil products.After single factor optimization,significant screening of PBD,and optimization of BBD,the optimal conditions for the separation of essential oil and seed oil from P.amurense seeds by ultrasonic-assisted in ionic liquid solvent system were obtained.The optimal conditions for the separation of essential oil are ionic liquid molar concentration 2.16 mol/L,liquid-solid ratio 24.90 mL/g,ultrasonic irradiation time 23.46 min,ultrasonic irradiation temperature 70?,ultrasonic irradiation power 70 W,and particle size 250 ?m.The optimal separation conditions for seed oil are ionic liquid molar concentration 2.17 mol/L,liquid-solid ratio 25.15 mL/g,ultrasonic irradiation time 57.86 min,ultrasonic irradiation temperature 60?,ultrasonic irradiation power 70 W,and particle size 250 ?m.Under the optimal conditions,the isolated essential oil and seed oil yields were 15.38± 0.76 mg/g and 393.57± 19.03 mg/g,respectively,which were highly consistent with the BBD model predicted essential oil and seed oil yields of 15.50 mg/g and 401.13 mg/g.Meanwhile,the difference between the essential oils and seed oils obtained by this method and the essential oils and seed oils obtained by other separation and extraction methods were compared and analyzed.The results show that the ionic liquid solvent system effectively promotes the increase in the yield of essential oils and seed oils without negatively affecting the components of essential oils and seed oils,which is a safe and efficient extraction solvent for the separation of essential oils and seed oils.With the help of the ionic liquid solvent system[C4C1Im][OOCCH3]/DMSO to separate the cellulose,hemicellulose,and lignin components in the xylem of P.amurense and the traditional benzene-alcohol method to prepare homologous cellulose,?-cellulose,and lignin as standard reference materials,which effectively improve the recognizability of recycled materials.According to the differences in the solubility of cellulose,hemicellulose,and lignin in different solvents,acetone/water(1:1,v:v),95%ethanol,and water are added to the ionic liquid solution of the xylem of P.amurense in sequence,which achieves the maximum separation of cellulose,hemicellulose,and lignin in the ionic liquid dissolution of P.amurense powder,and the mass percentage of cellulose in the regenerated cellulose material is 85.96%,the mass percentage of hemicellulose in the regenerated hemicellulose material is 79.16%,and the mass percentage of lignin in the regenerated lignin component is 97.35%.Moreover,in the process of dissolving,regenerating,and separating plant materials,the crystalline type of cellulose changes from cellulose type I to cellulose type II,and the thermal stability of the regenerated materials decreases to varying degrees,which significantly reduces the difficulty of high-value utilization of biomass materials.Finally,using the regenerated cellulose,regenerated hemicellulose,and regenerated lignin as raw materials,the application of regenerated materials in the fields of flexible sensors,industrial chemicals,and ultraviolet protection is studied.Regenerated cellulose applies as a matrix,the construction of a double-layer conductive network on the surface of regenerated cellulose was completed by adding conductive fillers such as multi-walled carbon nanotubes and reduced graphene oxide,which promotes the application of regenerated cellulose materials in the field of flexible sensors.In the regenerated cellulose/multi-wall carbon nanotube/graphene composite material,the connection between the regenerated cellulose and the multi-wall carbon nanotubes through hydrogen bonds effectively weakens the agglomeration effect between the multi-wall carbon nanotubes,and the graphene is connected to the surface of multi-walled carbon nanotubes through?-? interaction to promote its uniform dispersion in the composite material.The results show that the composite material with the mass ratio of regenerated cellulose,multi-walled carbon nanotubes,and graphene of 15:3:2 has the best electrical conductivity and tensile strength.And the standardized resistance of the composite material maintains good stability under periodic deformation,which proves that the regenerated cellulose/multi-wall carbon nanotube/graphene composite material is a very promising flexible strain sensor.Regenerated hemicellulose material as the matrix,the furfural prepared by the catalysis of a homogeneous catalyst strongly acidic ionic liquid[HO3S(CH2)4C1Im]HSO4 in the methyl isobutyl methanol/water biphasic system,which effectively improves the yield and conversion rate of furfural.The methyl isobutyl methanol/water two-phase system realizes the simultaneous preparation and extraction of furfural,which effectively avoids the degradation of furfural in the water phase,and the introduction of homogeneous catalyst strongly acidic ionic liquid[HO3S(CH2)4Cilm]HSO4 provides enough acid sites for the system,which accelerates the degradation of regenerated hemicellulose.The optimal conditions for preparing furfural were obtained through optimization:methyl isobutyl methanol/water two-phase system,strong acidic ionic liquid[HO3S(CH2)4C1Im]HSO4 catalyst,two-phase system composition(methyl isobutyl methanol:water?1:1,v:v),the liquid-solid ratio is 40 mL/g,the molar concentration of the acid catalyst is 0.10 mol/L,the microwave irradiation time is 40 min,and the microwave irradiation power is 385 W,and the furfural yield and conversion rate under optimal conditions were 332.85±16.64 mg/g and 51.36%,respectively.Through kinetic fitting and Arrhenius equation,the apparent catalytic energy of regenerated hemicellulose catalyzed to prepare furfural was compared and analyzed,the results show that the strong acid homogeneous catalyst[HO3S(CH2)4C1Im]HSO4 reduces the activation energy of the depolymerization of regenerated hemicellulose to furfural in an acidic environment by 30.36%,which promotes the final furfural in the two-phase system Increase in yield.Regenerated lignin material as the matrix,combined with the physical sunscreen titanium dioxide,regenerated lignin@TiO2 nanospheres were prepared through quaternization reaction and chromophore inclusion,and evaluate its ultraviolet protection performance.The inclusion of regenerated lignin significantly reduces the number of free radicals generated by titanium dioxide photocatalysis,the spherical structure with titanium dioxide as the core connects to the phenolic hydroxyl group of the chromophore group of regenerated lignin through hydrogen bonds,which effectively reduces the color of nano-microspheres and promotes its use in the field of ultraviolet protective cosmetics.Taking the sun protection index and photocatalytic activity as the optimization goals to optimize the quality composition of regenerated lignin and titanium dioxide in the regenerated lignin@TiO2 nanospheres,the optimized result of the optimal quality is regenerated lignin:TiO2?1:2.The sun protection factor of the regenerated lignin@TiO2 nano-microspheres is 37.92,which has strong ultraviolet protection ability and is a very potential UV sunscreen agent.In this research,the green solvent ionic liquid solvent system[C4C1Im][OOCCH3]/DMSO has realized the effective dissolution of P.amurense and completed the separation and application of biologically active components in various parts of the plant,which provides a theoretical basis and technical support for the comprehensive utilization of P.amurense plants. |
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