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28 October 2023, Volume 43 Issue 5 Previous Issue   
Construction of Multicolor Afterglow Aerogel by Carbon Dots/CNF
Xinzhu HUO, Mengnan CAO, Shouxin LIU, Zhijun CHEN, Jian LI, Shujun LI
2023, 43 (5):  1-7.  doi: 10.3969/j.issn.0253-2417.2023.05.001
Abstract ( 92 )   HTML ( 25 )   PDF (7402KB) ( 72 )  

Citric acid carbon dots(CDs) were prepared by a one-step hydrothermal method using citric acid as carbon source. The afterglow aerogel CDs@CNF was prepared by doping CDs into cellulose nanofibers(CNF) after physical cross-linking. The red afterglow aerogel CDs-RhB@CNF was prepared by triplet-to-singlet Förster resonance energy transfer(TS-FRET) strategy using CDs as donor and rhodamine B(RhB) as acceptor. The photophysical properties and microstructure of the aerogel were characterized by scanning electron microscopy(SEM), transmission electron microscopy(TEM), ultraviolet-visible(UV-Vis) absorption spectrum, steady-state transient fluorescence spectroscopy and International Commission on Illumination(CIE) chromatograms. The results showed that, the phosphorescence lifetime of CDs@CNF at 535 nm was 144.88 ms, the CDs were uniformly distributed in the CNF aerogel, which had a honeycomb porous structure. The phosphorescence lifetime of CDs-RhB@CNF at 600 nm was 102.49 ms, and the Förster transfer efficiency was up to 65.9%. The yellow afterglow aerogel CDs-Rh6G@CNF and CDs-Rh123@CNF were obtained by doping rhodamine 6G(Rh6G) and rhodamine 123(Rh123) with fluorescent dyes, and the aerogel-loaded phosphorescent paper was further applied in the field of aesthetic origami and advanced anti-counterfeiting, extending the strategy and application area of preparing multicolor afterglow materials from natural biomass.

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Synthesis of Sulfonated Lignin Based Chain Transfer Agent and Its Application in Aqueous RAFT Polymerization
Jingyi LIU, Guangbin WANG, Chunpeng WANG, Fuxiang CHU, Yuzhi XU
2023, 43 (5):  8-16.  doi: 10.3969/j.issn.0253-2417.2023.05.002
Abstract ( 63 )   HTML ( 11 )   PDF (876KB) ( 34 )  

The sulfonated lignin-based chain transfer agent(SL-CTA) was synthesized using pre-sulfonated corn stover lignin, followed by the functional modification of xanthate carbon disulfide and methyl bromoacetate. The SL-CTA was used in the aqueous RAFT polymerization of acrylamide to prepare sulfonated lignin-acrylamide copolymer(SL-g-PAM). Various methods were used to characterize the chain transfer agents and copolymers. The results showed that the arylsulfonation modification was more effective than the sulfomethylation modification. The best modification effect was achieved when 1g of lignin was reacted with 2 g of chlorosulfonic acid at 25 ℃ for 4 h, where the S concentration in sulfonated lignin was 1.83%, the ratio of Mw/Mn was 1.19, the amount of total hydroxyl groups was 4.86 mmol/g, and the water solubility was good. The chemical structure of the SL-CTA was then investigated by FT-IR and 13C NMR. The results showed that the stretching vibration absorption peak of C—S bond at 900 cm-1 and the characteristic peak at 1 738 cm-1 relating to C=O group were found in the FT-IR spectrum, and the peak at δ 172 corresponding to carbon atom of the C=S appeared in the 13C NMR spectrum, proving the successful synthesis of the chain transfer agent. In addition, the effects of the ratios of monomer/chain transfer agent/initiator, pH value and reaction temperature on the monomer conversion in the aqueous RAFT polymerization system of acrylamide were investigated. The results showed that the conversion rate was as high as 98.5% when the ratio of monomer/chain transfer agent/initiator was 500∶4∶1, pH value was 5, reaction temperature was 70 ℃ and reaction time was 4 h. Under the experimental conditions, the first-order kinetic curve of the polymerization reaction showed a good linear relationship, and the relative molecular mass of the obtained polymer also presented a linear relationship with the monomer conversion rate. At the same time, its polydispersity index was low and the distribution was relatively narrow(1.13-1.43), which all indicated that the reaction had high controllability.

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HPLC Fingerprint and Content Determination of Two Principal Components in Waste Liquid of Tara Enzymatic Hydrolysis
Qinhao GUAN, Lihua TANG, Liangliang ZHANG, Man XU, Yiwen LIU, Lixin HUANG
2023, 43 (5):  17-24.  doi: 10.3969/j.issn.0253-2417.2023.05.003
Abstract ( 85 )   HTML ( 33 )   PDF (1063KB) ( 43 )  

An HPLC method was developed for the simultaneous analysis of quinic acid(QA) and gallic acid(GA) in tara powder enzymatic digestion waste solution, and the methodological verification was carried out. The HPLC fingerprints were further drawn and the different batches of tara powder enzymatic digestion waste solution were evaluated by combining similarity and cluster analysis. The results showed that the detection wavelength at 215 nm, mobile phase acetonitrile-0.1% aqueous trifluoroacetic acid aqueous solution, acetonitrile gradient of 5%-20%, flow rate of 1.0 mL/min and column temperature of 30 ℃ were selected as the chromatographic analysis conditions for quinic acid and gallic acid. The linear range of quinic acid standard curve was 1.25-20 g/L, and the detection limit was 0.5 g/L. The linear range of gallic acid standard curve was 0.062 5-1 g/L, and the detection limit was 5 mg/L. The RSD of precision, repeatability, stability, and the spiked recovery test were less than 5%.The average spiked recoveries of quinic acid and gallic acid were 100.87% and 99.65%, respectively. The similarity of the fingerprint profiles of the 12 batches of waste samples was greater than 0.95. The samples could be divided into two categories by cluster analysis, with samples No.10 and No.11 were clustered into one category, and the rest samples were clustered into one category. The mass concentrations of quinic acid and gallic acid were calculated to be 482.3 g/L and 35.7 g/L, respectively.

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Rheological Behavior of Chitosan/Polyvinyl Alcohol and Its Spinnability
Wenchao ZENG, Haodong SUN, Zongwei ZHANG, Jianguo LI, Lihui CHEN
2023, 43 (5):  25-31.  doi: 10.3969/j.issn.0253-2417.2023.05.004
Abstract ( 65 )   HTML ( 15 )   PDF (3041KB) ( 43 )  

The chitosan(CS)/polyvinyl alcohol(PVA) spinning solution was prepared using acetic acid(HAc) as solvent. The steady-state rheological and dynamic rheological properties were investigated, and the feasibility of electrospinning was examined. The results showed that with the increase of CS mass fraction, the consistency coefficient, structural viscosity index, apparent viscosity, storage modulus(G′), loss modulus(G″) and composite viscosity(η*) of the spinning solution increased accordingly, while the non-Newtonian index decreased accordingly, which was not conducive to the electrospinning of CS/PVA spinning solution. With the increase of the test temperature, the consistency coefficient, structural viscosity index, apparent viscosity, G′, G″nd η* of the spinning solution decreased correspondingly, whereas the non-Newtonian index increased, the flow performance of the spinning liquid was strengthened and the spinnability was improved. When the mass fraction of CS was 3.0%, the apparent viscosity, consistency coefficient and structural viscosity index of the spinning solution at the test temperature of 30 ℃ were small, which were 1.650 Pa·s, 7.978 1 and 2.16, respectively, and the non-Newtonian index was 0.887 7 close to 1, indicating that the spinning solution had good fluidity and processability. Combined with SEM and rheological behavior analysis, under room temperature the CS/PVA spinning solution with a CS mass fraction of 3.0% exhibited excellent spinnability and could construct continuous, uniform nanofibers without beaded connections.

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Preparation and Properties of Pressure Sensitive Adhesives with Rosin-oil and Furfural-oil Based Semi-interpenetrating Networks
Simai QI, Tong LUO, Meihong LIU, Chunpeng WANG, Fuxiang CHU, Jifu WANG
2023, 43 (5):  32-40.  doi: 10.3969/j.issn.0253-2417.2023.05.005
Abstract ( 65 )   HTML ( 18 )   PDF (1472KB) ( 47 )  

Series polyacrylate copolymers of THFMA-10, THFMA-20 and RGMA-20 were obtained by free radical polymerization using rosin-based glycidyl methacrylate(RGMA) and furfural-based monomer tetrahydrofurfuryl methacrylate(THFMA) as hard monomers and oil-based monomer lauryl methacrylate(LMA) as soft monomers. Semi-interpenetrating crosslinked network photocuring pressure-sensitive adhesive was prepared through photocuring reaction. The structure of the photocurable pressure-sensitive adhesive was characterized by infrared spectroscopy(FT-IR) and gel permeation chromatography(GPC), and its thermal properties, ultraviolet ray(UV) absorption properties, mechanical properties and rheological properties were analyzed. The results showed that the relative molecular weight(Mn) of the three copolymers was between 40 000 and 60 000, and the dispersion index(PDI) was between 2 and 3. The influence of Mn on the adhesion properties of the pressure-sensitive adhesive was negligible. FT-IR analysis indicated that the photocurable pressure-sensitive adhesive was successfully prepared. The DSC analysis results showed that the interpenetrating cross-linked network had good compatibility with the copolymer. Triethylene glycol diacrylate(TPGDA) was used as crosslinking agent, and the elasticity and cohesion of acrylate copolymer were improved significantly after cross-linking photocuring with 5% of TPGDA. Compared to THFMA, the molecular chain rigidity of the pressure sensitive adhesive obtained by RGMA monomers was higher. TG analysis showed that the thermal stability of the pressure sensitive adhesive was obviously improved after photocuring. The UV absorption performance of the pressure-sensitive adhesive prepared with RGMA as the hard monomer was better than that of THFMA, and it had more advantages in the application of UV protection. Compared with the bifunctional TPGDA, the mechanical properties of the photocurable pressure sensitive adhesive prepared by the tri-functional crosslinking agent pentathritol tetraacrylate(PETA) were significantly improved. The RGMA-based copolymer was added with 9% crosslinking agent PETA, which could effectively balance the initial adhesion(12.34 N), 180° peel strength(264 N/m) and adhesion properties(adhesion time 24 h). The energy storage modulus(G′) and loss modulus(G″) of the photocured pressure-sensitive adhesive increased with the increase of frequency. The structure of the photocured semi-interpenetrating network improved the performance of the pressure-sensitive adhesive. The THFMA-10 series of pressure-sensitive adhesive met the Dahlquist critical boundary before and after photocuring, indicating good pressure-sensitive performance.

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The Enhancement of Photocatalytic CO2 Reduction Performance of CuO-ZnO by Cellulose Template Method
Xian HE, Chun SHI, Zhenqiang ZAI, Yahui TIAN, Jinxia MA
2023, 43 (5):  41-48.  doi: 10.3969/j.issn.0253-2417.2023.05.006
Abstract ( 63 )   HTML ( 19 )   PDF (9850KB) ( 46 )  

The cellulose fiber that was first-loaded and then carbonized CuO-ZnO-biochar(CuO-ZnO-CL+C) composites, was prepared using softwood bleached kraft pulp(SBKP) as the carrier and loading CuO-ZnO followed by carbonization. The effects of carrier loading and the sequence of carbonization on the CuO-ZnO loading in the composites were investigated by scanning electron microscope(SEM), inductively coupled plasma mass spectrometry(ICP-MS), X-ray diffraction(XRD), dual constant potential instrumentation, and vacuum photocatalytic reduction of CO2 system. The results showed that the carbonized and then loaded biochar(CC+L) was only physically mixed with CuO and ZnO, and there was no hydroxyl group on its surface to adsorb and immobilize the catalyst. It was very easy to agglomerate, and the CuO content of the resulting CuO-ZnO-CC+L composite was not as high as CuO-ZnO-CL+C. The crystalline shape of the CuO-ZnO-CL+C composite was more complete, with higher photocurrent intensity, smaller resistance, and better photocatalytic reduction of CO2 activity. The effects of the ratio of the amount of Cu2+ to Zn2+, the carbonization temperature of the composites, and the diameter of the cellulose fibers on the prepared CuO-ZnO-CL+C were investigated with CO yield as the index. The results showed that: when SBKP was used as the cellulose template under the condition of the molar ratio of Cu2+ to Zn2+ of 1∶6 and the compositing temperature of 500 ℃, the prepared CuO-ZnO-CL+C contained 64.86% carbon, CuO and ZnO loadings were 10.94% and 26.50%, respectively, and the yield of photocatalytic reduction of CO2 to CO reached a maximum value of 0.22 mmol/(g·h), CH4 yield was 0.043 mmol/(g·h), with a selectivity of CO as high as 83.7%.

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Synthesis, Characterization and Properties of Emulsifiable Isocyanate
Changchun LIU, Zhihao SHEN, Jin CHEN, Bencai DAI, Yang ZHOU
2023, 43 (5):  49-55.  doi: 10.3969/j.issn.0253-2417.2023.05.007
Abstract ( 62 )   HTML ( 11 )   PDF (2120KB) ( 43 )  

Polyaryl polymethylene isocyanates(PAPI) had been gradually attracted attention owing to their extremely high chemical activity, while their high chemical activity and poor water dispersibility limited the use of isocyanates. In this work, MPEG-RA was prepared by reaction of acyl chlorination of ricinoleic acid(RA) with polyethylene glycol monomethyl ether(MPEG), and the as-prepared MPEG-RA was introduced into PAPI as a virtual 'shell' through hydroxyl groups to build a virtual 'core(PAPI)-shell(MPEG-RA)' structure to prepare emulsifiable isocyanate(MPEG-RA-PAPI), which could improve the stability and water dispersibility of isocyanate. Then, the prepared MPEG-RA-PAPI was applied as wood adhesive to prepare plywood. The chemical structure, active group(-NCO) content stability and water dispersibility of the prepared MPEG-RA and MPEG-RA-PAPI were analyzed by Fourier transform infrared spectroscopy, chemical titration analysis, and laser particle size analyzer. The results showed that the prepared MPEG-RA-PAPI was the preset'core-shell' molecular structure. The prepared MPEG-RA-PAPI(R=n-NCO/n-OH=40) contained about 24% -NCO, and the content of -NCO did not decrease after one month of storage. The -NCO content of MPEG-RA-PAPI(R=40) emulsion was about 14% after storage for 8 h, which was significantly higher than that of MPEG-PAPI(about 4%), indicating that the structure improved the stability and water dispersibility of isocyanate. The prepared MPEG-RA-PAPI was applied to plywood. When the addition amount of MPEG-SA-PAPI was 20%, the water resistance of plywood could be significantly improved, the dry bonding strength was 1.80 MPa, the type II wet strength was 0.98 MPa, the type I wet strength was 0.77 MPa, and the working life reached nearly 5 h.

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The Process of Recovering Aleuritic Acid in Lac Saponification Waste Liquid
Shixian WANG, Baoshan TANG, Hong ZHANG, Jinju MA, Lanxiang LIU, Juan XU
2023, 43 (5):  56-62.  doi: 10.3969/j.issn.0253-2417.2023.05.008
Abstract ( 56 )   HTML ( 12 )   PDF (609KB) ( 35 )  

In order to improve the yield of aleuritic acid, the lac saponification waste liquid left in the preparation of aleuritic acid by the factory was used as raw material to recover aleuritic acid by configuration conversion method through salting out, acid analysis, decolorization, recrystallization and other steps. The configuration conversion process of aleuritic acid was optimized by single factor experiment, and the structure of aleuritic acid was analyzed by nuclear magnetic resonance, mass spectrometry, infrared and thermogravimetric analysis. The configuration analysis of aleuritic acid was carried out by differential scanning calorimetry and C18 column resolution by high performance liquid chromatography. The results showed that the recovery of aleuritic acid by configuration conversion method could improve the yield of aleuritic acid. The optimal preparation conditions were determined as the ratio of solid to liquid of raw material and concentrated hydrochloric acid of 3:5(g: mL), reaction temperature of 100℃ and reaction time of 7 h, and the amount of active clay was 10% of the quality of the crude aleuritic acid. After decolorization and recrystallization with 20% ethanol solution for two times, the yield and purity of aleuritic acid were 3.78%±0.5% and 80.65%±0.41% respectively. The results of structure and configuration analysis of the product showed that the product prepared by this method was erythron aleuritic acid. The eleostearic acid prepared by this method came from waste and had fewer impurities after refining, so it could effectively improve the yield of aleuritic acid.

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Difference of Characteristic Components and Bioactivities for Qinan and Traditional Agarwood
Zekun HU, Tingting YAN, Gaiyun LI, Jiahui QIN, Xinwen WU, Yuan CHEN
2023, 43 (5):  63-72.  doi: 10.3969/j.issn.0253-2417.2023.05.009
Abstract ( 58 )   HTML ( 15 )   PDF (616KB) ( 41 )  

The extracts of Qinan(QN) and traditional agarwood(TA) were prepared by cold extraction(CE) and hot extraction(HE) with water and ethanol as solvent, respectively. The chemical constituents of the extracts were analyzed by GC-MS and HPLC, and their antioxidant and antibacterial activities were studied. The results showed that the species of sesquiterpenoids in QN were less than those of TA, while the contents of sesquiterpenoids in both were higher than that of TA. There was almost no tetrahydro-2-(2-phenylethyl) chromones(THPECs) in QN, and Flidersia type 2-(2-phenylethyl) chromones(FTPECs) was contained, where the mass fraction of 2-(2-phenethyl) chromone could reach 10.87%, and the mass fraction of 2-[2-(4-methoxy)phenethyl]chromone was 4.80%. The species and contents of THPECs in TA were rich, and the mass fraction of agartetrol could reach 1.50%. With the increasing ethanol volume fraction(0-55%), the ABTS free radical scavenging ability and iron ion reduction ability of QN and TA extracts increased. Although the antioxidant activity of QN water extracts was lower than that of TA, while its ethanol extracts were higher than that of TA. QN and TA had no significant antibacterial activity against Escherichia coli, but their water extracts had antibacterial activity against Candida albicans.

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Preparation, Structural Characterization and Stability Study of Chinese Quince Seed Peptide-Zinc Chelate
Yejun DENG, Lixin HUANG, Caihong ZHANG, Pujun XIE
2023, 43 (5):  73-80.  doi: 10.3969/j.issn.0253-2417.2023.05.010
Abstract ( 59 )   HTML ( 5 )   PDF (1460KB) ( 39 )  

In order to improve the stability and bioavailability of Zn2+, the Chinese quince seed peptide(CQSP) was prepared by enzymatic hydrolysis using Chinese quince seed as raw material. Five peptide fractions with different molecular weight ranges were obtained by ultrafiltration, and they were applied for preparation of CQSP-Zn chelate. The effects of protease types and peptide molecular weight on the chelation rate of Zn2+ were investigated. The amino acids composition analysis, Fourier transform infrared(FT-IR) spectroscopy, ultraviolet-visible(UV-Vis) spectroscopy and fluorescent spectroscopy were used to identify the structural characteristics of the chelate, and the solubility of CQSP-Zn at different pH values as well as digestion stages were also studied. The results indicated that the CQSP with the molecular weight less than 1 000 u hydrolyzed by alkaline protease presented the highest Zn2+ chelating rate(83.26%). The analysis of FT-IR spectroscopy, UV-Vis spectroscopy and fluorescent spectroscopy revealed the interaction between CQSP and Zn2+, and the -NH, CH2, C=O, C-N, -COOH in CQSP might participate in the chelating of Zn2+. Compared with the inorganic ZnSO4, CQSP-Zn showed higher solubility at pH 2.0-8.0 and simulated gastrointestinal digestion procedure. When the pH value was 8.0, the Zn2+ solubility of CQSP-Zn was 73.85%, which was 11.19 times higher than that of ZnSO4. In the simulated intestinal fluid with a pH value of 7.5, the Zn2+ solubility of CQSP-Zn was 65.86% at 0 minute of digestion, significantly higher than ZnSO4(16.24%), demonstrating potential application of CQSP-Zn as Zn2+ supplement.

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Ethanol Precipitation, Deproteinization and Anti-oxidant Activity of Polysaccharides from Pine Needles of Cedrus deodara
Quhuan MA, Xin WANG, Xiaofeng SHI, Wei SHEN, Bin FAN, Xindi WANG
2023, 43 (5):  81-88.  doi: 10.3969/j.issn.0253-2417.2023.05.011
Abstract ( 62 )   HTML ( 11 )   PDF (629KB) ( 31 )  

The ethanol precipitation, deproteinization process and anti-oxidant activity of polysaccharides from pine needles of Cedrus deodara were studied. On the basis of single factor experiment, the concentration ratio of extraction solution, volume fraction of ethanol, and alcohol settling time were optimized by Box-Behnken design model. The optimum conditions of alcohol precipitation of C. deodara pine needles were determined by comparing the yield of polysaccharides. With the protein removal rate and polysaccharide loss rate as the index, the deproteinization effect of Sevage method and three chloroacetic acid method on polysaccharide of pine needles were compared, and the amount of reagent and the times of deproteinization were investigated. The anti-oxidant ability of the purified polysaccharides was evaluated by DPPH and ABTS free radical methods. The optimum alcohol precipitation conditions for the polysaccharide of pine needles were the concentration ratio(volume of crude extract to dry weight of pine needles) of 3:1(mL: g), the alcohol volume fraction of first order alcohol precipitation of 71%, the temperature of alcohol precipitation of 40℃, and the time of alcohol precipitation of 10 h. Under these conditions, the yield of pine needles polysaccharide was 3.81%, which was close to the predicted value. The supernatant after collecting polysaccharides was concentrated according to the ratio of solution to pine needle dry mass of 1:1(mL: g), and the volume fraction of alcohol precipitate at two level was 80%. The protein removal efficiency of Sevage method was superior to three chloroacetic acid method. Its optimum condition was that the volume ratio of Sevage reagent to polysaccharide solution was 1:1, and the number of protein removal was 3 times. After purification, the contents of primary and secondary alcohol precipitate polysaccharides were calculated by UV method with glucose conversions of 35.36% and 36.62%, respectively. The scavenging activities on DPPH and ABTS radicals were as follows: vitamin C(Vc)>secondary alcohol precipitate polysaccharides>butylated hydroxytoluene(BHT)>primary alcohol precipitates polysaccharides. The purified 80% alcohol precipitation polysaccharides of C. deodara pine needles showed good anti-oxidant activity.

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Preparation of Lignin Micro/Nano Particles by Electrospray
Chen OUYANG, Renjie SHEN, Xinru CHEN, Sijun CHEN, Hao REN
2023, 43 (5):  89-94.  doi: 10.3969/j.issn.0253-2417.2023.05.012
Abstract ( 49 )   HTML ( 3 )   PDF (2360KB) ( 29 )  

Lignin micro/nano particles in collapsed spherical shape with controlled structure and high purity were obtained by electrostatic spraying technique using alkali lignin(ALL) and acetylated lignin(ACL) as raw materials dissolving in chloroform(CF) or tetrahydrofuran(THF) at different mass fractions. The results showed that the morphology and size of lignin micro/nano particles were dependent on the drying rate. As the drying rate increased, the average diameter of lignin microparticles increased from 1.9 μm to 2.6 μm, and the nanoparticle diameters were mainly distributed between 200-500 nm. Furthermore, a comparative study revealed that the hydrophobicity of the lignin coating was mainly influenced by the particle morphology. Using smaller-size particle, the greater degree of slumping, and the higher contact angle of the coating was obtained. By modulating the morphology and size of the micro/nano particles, materials with different hydrophobic properties could be obtained.

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Preparation of Polylactic Acid/Glycolic Acid Magnetic Microspheres and Their Loading of Curcumin
Guifang LI, Lingling KANG, Huatai ZHU, Jingyang ZHAO, Jiandu LEI, Xianliang SONG
2023, 43 (5):  95-101.  doi: 10.3969/j.issn.0253-2417.2023.05.013
Abstract ( 54 )   HTML ( 7 )   PDF (2391KB) ( 35 )  

The curcumin/polylactic acid/glycolic acid(PLGA) magnetic microsphere was innovatively prepared by a stirring-homogenization two-step emulsification method using PLGA copolymer as drug loading material and oleic acid-modified triiron tetraoxide(Fe3O4@OA) nanoparticles as the magnetic functional material. Impacts of the emulsification method, high-speed homogenization speed, water oil volume ratio, PLGA dosage, mass fraction of aqueous polyvinyl alcohol(PVA), the dosage of Fe3O4@OA and curcumin on the particle size of magnetic microspheres were examined. The morphology and physicochemical properties of curcumin/PLGA magnetic microspheres were analyzed by optical microscope, laser particle sizer, ultraviolet spectrophotometer, vibrating sample magnetometer and thermogravimetric analyzer, respectively. The results showed that the optimal preparation process for curcumin/PLGA magnetic microspheres was the stirring homogenization two-step emulsification method, with a high-speed homogenization speed of 15 000 r/min, a water oil phase volume ratio of 10∶1, a PLGA dosage of 100 mg, a water phase PVA mass fraction of 1%, the Fe3O4@OA dosage of 40 mg and the dosage of 10 mg curcumin. Under these conditions, the surface of the microspheres was smooth, the particle size was homogeneous, the polydispersity index(PDI) was 0.38, the average particle size was 3.60 μm, the magnetic induction strength of the microspheres was 14.12 (A·m2)/kg, and the magnetic content was about 27.98%. The encapsulation rate of drug-laden microspheres was 97.09%, and the drug loading was 6.40%, which showed a significant sustained release effect in the in vitro release assay.

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Preparation and Properties of Fluorocarbon Coatings Modified by Hydroabietyl Alcohol
Wen QI, Suyun ZHANG, Xingwei LI, Chun LU
2023, 43 (5):  102-108.  doi: 10.3969/j.issn.0253-2417.2023.05.014
Abstract ( 56 )   HTML ( 17 )   PDF (2263KB) ( 31 )  

Addressing the issue of poor adhesion of fluoroethylene vinyl ether polymer(FEVE) fluorocarbon coatings, the hydroabietyl alcohol was adopted to modify this system. The influence of the mass fraction of hydroabietyl alcohol on the hardness, adhesion and chemical corrosion resistance of the modified FEVE fluorocarbon resin system was investigated. The results showed that the optimal mass ratio of hydroabietyl alcohol to FEVE fluorocarbon coating curing agent hexamethylene diisocyanate(HDI) was 100:24. The addition of hydroabietyl alcohol was beneficial to improve the hardness and adhesion of the modified FEVE fluorocarbon coating film, while it had a negative impact on the acid resistance, alkali resistance and salt water resistance of the paint film. When the mass content of hydroabietyl alcohol was 0.75%, the hardness and adhesion of the coating film increased to the maximum values of 5H and 12.483 MPa, respectively. The alkali resistance was normal for 10 days, and the 3.5% salt water resistance was also normal for 10 days.

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Effects of Sulfuric Acid on Enzymatic Hydrolysis and Fermentation of Hydrogen Peroxide-acetic Acid Pretreated Dendrocalamus sinicus
Gaoyuan LIU, Zhengjun SHI, Ping ZHAO, Haiyan YANG, Jing YANG
2023, 43 (5):  109-116.  doi: 10.3969/j.issn.0253-2417.2023.05.015
Abstract ( 59 )   HTML ( 3 )   PDF (655KB) ( 36 )  

Taking Dendrocalamus sinicus(DS) as the research object, hydrogen peroxide-acetic acid(PA) pretreatment was carried out to investigate the effects of sulfuric acid addition on chemical compositions, enzymatic hydrolysis efficiency and ethanol yield. The results showed that the lignin content of bamboo decreased with the increase of sulfuric acid during PA pretreatment, while the relative contents of cellulose and hemicellulose increased. In addition, adding sulfuric acid as reaction promoter in PA pretreatment could improve the enzymatic hydrolysis efficiency. When the volume fraction of sulfuric acid was 0.5%, the 72 h yields of glucose and xylose were 84.77% and 85.05%, respectively, which were increased by 42.40% and 33.72% compared to that of hydrogen peroxide-acetic acid pretreatment without sulfuric acid. The hydrolysate was fermented by Saccharomyces cerevisiae and the mass concentration of ethanol was 13.52 g/L, which was 73.33% higher than that of the hydrolysate pretreated by hydrogen peroxide-acetic acid without sulfuric acid. During the PA pretreatment of D. sinicus, sulfuric acid was used as an additive, which could reduce the hydrophobicity of substrate and the surface coverage of lignin while the crystallinity and specific surface area were increased. Adding 0.5% sulfuric acid, the accessibility of cellulose increased from 282.15 mg/g (without sulfuric acid) to 500.12 mg/g, as well as further increased the productive adsorption between cellulase and cellulose, resulting in an improvement of the enzymatic hydrolysis efficiency and fermentation yield of D. sinicus.

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Biomass-derived Hydrophilic Porous Carbons for Energy Storage
Huan LIU, Lu JIANG, Yanling YU, Xiuli HUANG, Maodong XU, Yiming REN
2023, 43 (5):  117-124.  doi: 10.3969/j.issn.0253-2417.2023.05.016
Abstract ( 55 )   HTML ( 9 )   PDF (11895KB) ( 51 )  

Using waste disposable bamboo chopsticks as carbon source, bamboo-based porous carbon was prepared by direct pyrolysis followed by washing with deionized water after pretreatment with NaOH and Na2SO3. The surface morphology, specific surface area, pore structure and surface wettability were characterized and analyzed. The results showed that compared with bamboo-based porous carbon(PC-H) pretreated with deionized water, bamboo-based porous carbon(PC-Na) pretreated with NaOH and Na2SO3 mixture possessed high surface area(1 434 m2/g), well-developed porous structure(0.69 cm3/g) and excellent wettability(water contact angle of about 53.5°). Using the produced bamboo-based porous carbon as the positive electrode, the assembled aqueous Zn-ion hybrid supercapacitor(ZIHSC) displayed a high specific capacity of 75.6(mA·h)/g at a current density of 0.2 A/g. When the current density increased to 50 times, the specific capacitance retention rate was 52%, showing excellent rate performance. The maximum energy density was 59.3(W·h)/kg and the maximum power density was up to 7.6 kW/kg. The specific capacitance decays was only 2.7% after 5 000 charge-discharge cycles at a current density of 5 A/g, showing excellent cycle stability.

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Preparation and Performance Evaluation of Hydroxytyrosol Nanoliposome Freeze-dried Powder
Wenjun LI, Chengzhang WANG, Jiandu LEI, Hao ZHOU
2023, 43 (5):  125-132.  doi: 10.3969/j.issn.0253-2417.2023.05.017
Abstract ( 65 )   HTML ( 9 )   PDF (2488KB) ( 44 )  

In order to make hydroxytyrosol(HT) nano-liposomes stored at low temperature for a long time, the freeze-dried powder of HT nano-liposomes was prepared by freeze-drying method based on the preparation of the suspension of HT nano-liposomes. The freeze-drying process conditions were selected based on its appearance, redispersability, particle size and encapsulation rate as the main indexes, and the freeze-drying protective agent was screened by single factor test combined with orthogonal test to evaluate its stability. The results showed that the obtained freeze-dried powder was loose, smooth, flat and full appearance (appearance +++) when the freeze-dried protective agent was m (D-trehalose):m(sucrose): m(mannitol)=4:2:1 and the solution mass fraction was 10% at -50℃ for 8 h and freeze-drying for 72 h. The freeze-dried powder could redissolve into uniform suspension within 1 min of oscillation without soluble particles or clumps(redispersability +++), with water content of 3.28%±0.23%, the average particle size of(125.24±1.58) nm, and the encapsulation rate of 69.74%±0.94%. Transmission electron microscopy showed that the particles were round in appearance, smooth in surface and uniform in size. The stability study found that low temperature was more conducive to the stable storage of freeze-dried powder. When it was stored at 4℃ for 6 months, the freeze-dried powder exhibited better stability and no significant change in performance.

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Research Progress on Oil Content, Fatty Acid Composition and Bioactive Components of Hazelnut
Chenshan SHI, Shuang GAO, Chenyan GUO, Junhua HAN, Jianchun JIANG, Lisong LIANG
2023, 43 (5):  133-144.  doi: 10.3969/j.issn.0253-2417.2023.05.018
Abstract ( 59 )   HTML ( 9 )   PDF (909KB) ( 36 )  

Hazelnut (Corylus), as an important non-wood forest trees in China, is renowned for its abundant unsaturated fatty acids and recognized as a "heart-healthy" food. This paper introduces the oil content and fatty acid composition of hazelnuts, analyzes the potential factors that affect these properties. The research progress on phenolic compounds, tocopherols and phytosterols in hazelnut kernels was reviewed. The protein produced as a by-product of hazelnut processing was briefly introduced, and the impact of processing on hazelnut oil was discussed. Literature analysis suggests that the oil content and fatty acid composition in hazelnuts are influenced by variations in growing environments and cultivars. The high content of linoleic acid in hazelnut oil is the primary cause of its susceptibility to oxidative rancidity during processing and storage. Tocopherols and phytosterols have been identified as the main active compounds naturally existed in hazelnut oil, with α-tocopherol and β-sitosterol being the most abundant. These compounds play a crucial role in preventing oil oxidation. Furthermore, phenolics such as gallic acid, syringic acid, vanillic acid and condensed tannin are primarily concentrated in the hazelnut skin, displaying significant variations among different hazelnut varieties. Future research should explore the application of emerging technologies and the synergistic application of active antioxidant ingredients in hazelnut oil.

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Research Progress of Biomass Based Carbon Materials in the Treatment of Dyeing Wastewater
Shuang JIA, Meijuan HUANG, Bo ZHANG, Zhiyi WEI, Hui CHENG, Shouzhu LI
2023, 43 (5):  145-156.  doi: 10.3969/j.issn.0253-2417.2023.05.019
Abstract ( 63 )   HTML ( 9 )   PDF (2044KB) ( 42 )  

Firstly, the decontamination mechanism of biomass-based carbon materials was summarized, and the selection, preparation and surface modification methods of biomass raw materials were analyzed according to the mechanism. The effects of internal factors, including pore structure and surface functional groups, and external factors such as initial concentration, adsorbent dosage, contact time, solution pH and temperature on the adsorption performance were discussed. In addition, the adsorption characteristics such as adsorption thermodynamics, adsorption isotherm and adsorption kinetics were analyzed. Finally, the problems existed in the practical application of biomass-based carbon materials and the diverse development directions in the future were summarized, hoping to provide reference for the application of biomass based carbon materials in the high-efficiency treatment of dying wastewater.

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