To combine the high elasticity and good mechanical performance of isoprene rubber(IR)with excellent fatigue resistance and low heat build-up of Eucommia ulmoides gum(EUG),the present study employed a chemical method t...To combine the high elasticity and good mechanical performance of isoprene rubber(IR)with excellent fatigue resistance and low heat build-up of Eucommia ulmoides gum(EUG),the present study employed a chemical method to graft 4-amino pyridine(AP)onto epoxidized IR and EUG,thereby creating a chemical assembly rubber of amino-pyridine-grafted epoxidized IR(AP-EIR)and amino pyridine-grafted epoxidized EUG(AP-EEUG)via a dynamic hydrogen bonding network.The presence of hydrogen bonds between AP-EIR and AP-EEUG was confirmed by variable temperature infrared spectroscopy,whereas scanning electron microscopy-energy dispersive spectroscopy revealed a uniform dispersion of zinc oxide and nano-fillers.Hydrogen bonds significantly facilitate strain-induced crystallization between the AP-EIR and AP-EEUG molecules,thereby strengthening their intermolecular interactions.During mechanical deformation,the material primarily dissipates energy through the breaking of hydrogen bonds,which effectively improves the mechanical strength of the material,and the introduction of amino groups in this chemical assembly rubber improves the uniform dispersion of nano-fillers,as well as the interface interaction between rubber and nano-fillers.Consequently,the chemically assembled rubber exhibited superior modulus,tensile strength,and tear strength compared to IR and its physical blend,while also demonstrating reduced heat build-up during dynamic loading.展开更多
The biodegradable polybutylene succinate(PBS)material offers a sustainable solution for a circular economy to address the global issue of marine plastic waste.Its cross-linkage with non-biodegradable xanthan gum(XG)bi...The biodegradable polybutylene succinate(PBS)material offers a sustainable solution for a circular economy to address the global issue of marine plastic waste.Its cross-linkage with non-biodegradable xanthan gum(XG)biopolymer to ameliorate residual granitic soil(RGS)in arid and semiarid regions can significantly mitigate soil erosion.This study investigates the enhancement of RGS by cross-linking the PBS and XG biopolymers.Employing a multitude of geotechnical tests(liquid limit,linear shrinkage,specific gravity,compaction,and UCS tests)at 3 d,28 d,and 90 d of steam-curing at a controlled temperature of 16℃,the outcomes were validated through scanning electron microscopy(SEM),thermogravimetric analysis(TGA),Fourier transform infrared spectroscopy(FTIR),and Brunauer-Emmett-Teller(BET)analyses.In addition,a comprehensive experimental database of 150 tests and nine parameters from the current study was utilized to model the UCS90-d(i.e.unconfined compressive strength after 90 d of curing)of the PBS-XG-treated RGS mixtures by deploying the random forest(RF)and eXtreme Gradient Boost(XGBoost)methods.The results found that the two biopolymers significantly improve the mechanical properties of RGS,with optimal UCS achieved at specific dosages(0.4PBS,1.5XG,and 0.2PBS+1.5XG dosage levels)and curing times.The UCS of PBS-XG-treated RGS showed up to a 57%increase after 90 d of curing.Furthermore,SEM and FTIR analyses revealed the formation of stronger microstructures and chemical bonds,respectively,whereas BET analysis indicated that pore volume and diameter are critical in affecting UCS.The proposed RF model outperformed XGBoost in predictive accuracy and generalization,demonstrating robustness and versatility.Moreover,SHAP values highlighted the significant impact of input parameters on UCS90-d,with curing time and specific material properties being key determinants.The study concludes with the proposal of a novel PyCharm intuitive graphical user interface as a"UCS Prediction App"for engineers and practitioners to forecast the UCS90-d of granitic residual soil.展开更多
Loess slopes in cold and arid regions are susceptible to shallow soil degradation,which may trigger severe environmental problems related to soil erosion.To address this environmental challenge,this study selected a c...Loess slopes in cold and arid regions are susceptible to shallow soil degradation,which may trigger severe environmental problems related to soil erosion.To address this environmental challenge,this study selected a compound ecological curing agent composed of gellan gum and guar gum for stabilizing shallow loess slopes.Triaxial compression and disintegration tests were employed to comparatively analyze the effects of compound gum content,mass mix ratio,and curing age on the mechanical and disintegration properties of solidified loess.The curing mechanism was analyzed using scanning electron microscopy(SEM),and the ecological protection effect was monitored for a 60-day period.The results indicate that gellan gum,guar gum,and the compound gum can enhance the mechanical and disintegration properties of loess,promote plant growth,and optimize the ecological environment.However,the combination of gellan gum and guar gum proves more effective than using either gellan gum or guar gum alone.Considering the effects on mechanical properties,disintegration performance,and material economy,the disintegration rate of loess decreases by 75.72%compared to plain loess when the compound glue content is 0.5%,the mixing ratio of gellan gum to guar gum is 3:7 and the curing age is 7 days.Meanwhile,the cohesion and internal friction angle increase by 118.06%and 10.97%,respectively.Moreover,the disintegration performance and mechanical properties of the samples first increase and then decrease with the increase in compound glue and the mix ratio and are basically stabilized after the curing age reaches 7d.展开更多
The deformation characteristics of silty soils under vibrational loads can easily change due to the wetting process,leading to the failure of roadbed structures.Commonly used methods for improving silty soils in engin...The deformation characteristics of silty soils under vibrational loads can easily change due to the wetting process,leading to the failure of roadbed structures.Commonly used methods for improving silty soils in engineering often yield unsatisfactory economic and ecological outcomes.As an environment-friendly soil improvement material,Xanthan gum has broad application prospects and is therefore considered a solidifying agent for enhancing silty soil properties in the Yellow River Basin.In this study,a series of tests is conducted using a scanning electron microscope and a dynamic triaxial testing apparatus to investigate the microstructure and dynamic deformation characteristics of unsaturated silty soil with varying xanthan gum contents during the wetting process.The results show that xanthan gum effectively fills voids between soil particles and adheres to their surfaces,forming fibrous and network structures.This modification enhances the inherent properties of the silty soil and significantly improves its stability under dynamic loading.Specifically,with increasing xanthan gum content,the dynamic shear modulus increases while the damping ratio decreases.During the wetting process,as suction decreases,the dynamic shear modulus decreases while the damping ratio increases.Xanthan gum reduces the sensitivity of the dynamic deformation characteristics of the treated silty soil to changes in suction levels.Finally,based on the modified Hardin-Drnevich hyperbolic model,a predictive model for the dynamic shear modulus and damping ratio of treated silty soil is proposed,considering the xanthan gum content.These research findings provide a theoretical basis for the construction and maintenance of water conservancy,slope stabilization,and roadbed projects in the Yellow River Basin.展开更多
Protein-energy malnutrition (PEM) as a result of poor nutrition, especially for deprived resourced households, is a big health concern in the world. According to the World Health Organisation, PEM accounts for 49% of ...Protein-energy malnutrition (PEM) as a result of poor nutrition, especially for deprived resourced households, is a big health concern in the world. According to the World Health Organisation, PEM accounts for 49% of the 10.4 million deaths of children under five that take place in developing countries. The aim of this study was to evaluate the influence of gum Arabic (GA) and texturized soy protein (TSP) and their interactive effect on proximate, functional, and textural properties of the protein-rich snack stick produced from ground green maize, GA powder, and ground TSP. GA varied at 0%, 4%, 8%, and 12%, while TSP varied at 0%, 12%, 24% and 36%. The 5 cm long protein-rich snack sticks were made using a sausage stuffer and baked in an oven at 110˚C for 1 hr 30 minutes. The snack sticks were subjected to proximate, functional and textural analysis using the standard methods. Increasing GA resulted in a significant (p p < 0.05) increased the protein content (32.46%), Ash content (3.6%), fat (11.96%), and moisture content (16.25%) of protein-rich snack sticks. The interactive effect between GA and TSP led to a decrease in fibre and carbohydrates. Results from this study show GA and TSP significantly enhanced the physico-chemical properties of protein-rich snack sticks. A sample with 4% GA and 36% TSP is recommended for the best physico-chemical attributes of the protein-rich snack stick.展开更多
Understanding the sedimentation and simultaneous consolidation behavior of xanthan gum(XG)-biopolymer-treated soils remains a significant research gap in developing environmentally friendly ground-improvement techniqu...Understanding the sedimentation and simultaneous consolidation behavior of xanthan gum(XG)-biopolymer-treated soils remains a significant research gap in developing environmentally friendly ground-improvement techniques for geotechnical applications.This study addresses this gap by conducting laboratory experiments on kaolinite suspensions with varying XG-to-kaolinite mass ratios(mb/ms).The results showed that the XG treatment modified the sedimentation patterns by promoting larger floc formation and accelerated settling.Additionally,the XG treatment enhanced the shear stiffness and shear strength,particularly at shallow depths.At mb/ms ratios less than 1%,the volume compression was reduced by the XG;the coefficient of compressibility decreased by 49%at 1%mb/ms,and the consolidation was accelerated,as indicated by a 387%increase in the hydraulic conductivity at 0.5%mb/ms under the vertical effective stress of 40 kPa.Contrastingly,at mb/ms ratios greater than 1%,viscous XG hydrogels clogged pores,resulting in a 45%reduction in the coefficient of consolidation at 2%mb/ms under a vertical effective stress of 15 kPa and a 35%decrease in the hydraulic conductivity at 2%mb/ms under a vertical effective stress of 40 kPa.These findings underscore the potential of XG treatment in improving the sedimentation and consolidation processes,highlighting its applicability in geotechnical projects,such as dredging,landfilling,and artificial island construction.展开更多
This study aims to enhance the mechanical properties,disintegration,and dissolution rates of crosslinked carrageenan(CRG)capsule shells by shortening the long chains of CRG through a hydrolysis reaction with citric ac...This study aims to enhance the mechanical properties,disintegration,and dissolution rates of crosslinked carrageenan(CRG)capsule shells by shortening the long chains of CRG through a hydrolysis reaction with citric acid(CA).The hydrolysis of CRG was carried out using varying concentrations of CA,resulting in hydrolyzed CRG(HCRG).This was followed by cross-linking with xanthan gum(XG)and the addition of sorbitol(SOR)as a plasticizer.The results indicated that the optimal swelling capacity of HCRG-XG/SOR hard-shell capsules occurred at a CA concentration of 0.5%,achieving a maximum swelling rate of 445.39%after 15 min.Additionally,the best capsule hardness was alsomeasured at this CA concentration,reaching a hardness level of 480.157 g(F=4.67 N).FTIR analysis demonstrated that the presence of the acid group from CA altered the composition of the CRG chains.Furthermore,SEM-EDX mapping analysis revealed that the surface morphology of the synthesized capsules exhibited a relatively smooth texture with a limited number and size of pores,resulting in good capsule stability for drug delivery.Thein vitro disintegration and dissolution rates of theHCRG-XG/SOR capsuleswere observed to be the fastest and highest atpH1.2,respectively.The disintegration time was recorded at 20 min and 46 s,while the dissolution test indicated a drug release of 78.08%after 5min and 100%after 120 min.The drug delivery kinetics ofHCRG-XG/SOR followed the Ritger-Peppas model,indicating a complex release mechanism that involved swelling,diffusion,erosion,and capsule disintegration.展开更多
Finding appropriate flotation reagents to separate copper-nickel sulfide ores from various magnesium silicate gangue minerals has always been a challenge in the mineral processing industry.This study introduced xantha...Finding appropriate flotation reagents to separate copper-nickel sulfide ores from various magnesium silicate gangue minerals has always been a challenge in the mineral processing industry.This study introduced xanthan gum(XG)as a non-toxic and environmentally friendly depressant of talc,olivine,and serpentine.The effects and mechanisms of XG on the aggregation and flotation behavior of talc,olivine and serpentine were investigated by flotation tests,sedimentation tests,IC-FBRM particle size analysis tests,adsorption quantity tests,Fourier transform infrared spectroscopy(FTIR)tests,X-ray photoelectron spectroscopy(XPS)analysis tests and Zeta potential tests.The flotation results indicated that when the three minerals were mixed,XG caused the talc-serpentine aggregation in the solution to shift to olivine-serpentine aggregation,with the remaining XG adsorbing on talc to depress its flotation.In addition,combining XPS and zeta potential tests,the-OH(hydroxyl)groups in XG molecules preferentially adsorbed on Mg sites on the surface of olivine through chemical bonding.The surface potential of olivine significantly shifted to a more negative value,with the negative charge on the olivine surface far exceeding that on the talc surface.This resulted in an increased aggregation effect between positively charged serpentine and negatively charged olivine due to enhanced electrostatic forces.展开更多
The environment-friendly and efficient selective separation of chalcopyrite and molybdenite poses a challenge in mineral pro-cessing.In this study,gum Arabic(GA)was initially proposed as a novel depressant for the sel...The environment-friendly and efficient selective separation of chalcopyrite and molybdenite poses a challenge in mineral pro-cessing.In this study,gum Arabic(GA)was initially proposed as a novel depressant for the selective separation of molybdenite from chalcopyrite during flotation.Microflotation results indicated that the inhibitory capacity of GA was stronger toward molybdenite than chalcopyrite.At pH 8.0 with 20 mg/L GA addition,the recovery rate of chalcopyrite in the concentrate obtained from mixed mineral flota-tion was 67.49%higher than that of molybdenite.Furthermore,the mechanism of GA was systematically investigated by various surface characterization techniques.Contact angle tests indicated that after GA treatment,the hydrophobicity of the molybdenite surface signifi-cantly decreased,but that of the chalcopyrite surface showed no apparent change.Fourier transform-infrared spectroscopy and X-ray photoelectron spectroscopy revealed a weak interaction force between GA and chalcopyrite.By contrast,GA was primarily adsorbed onto the molybdenite surface through chemical chelation,with possible contributions from hydrogen bonding and hydrophobic interactions.Pre-adsorbed GA could prevent butyl xanthate from being adsorbed onto molybdenite.Scanning electron microscopy–energy-dispersive spectrometry further indicated that GA was primarily adsorbed onto the“face”of molybdenite rather than the“edge.”Therefore,GA could be a promising molybdenite depressant for the flotation separation of Cu–Mo.展开更多
An inverse vulcanized polymer,SZIM combining Zn2+-imidazole coordination bonds and polysulfide bonds was synthesized and incorporated into bio-based Eucommia ulmoides gum (EUG) to generate EUG-SZIM-xs.The residual cry...An inverse vulcanized polymer,SZIM combining Zn2+-imidazole coordination bonds and polysulfide bonds was synthesized and incorporated into bio-based Eucommia ulmoides gum (EUG) to generate EUG-SZIM-xs.The residual crystallinity of the EUG matrix synergistically interacted with the dual cross-linking networks to establish reversible deformation domains,providing EUG-SZIM-xs with quick shape memory capability at moderate temperatures.The damping properties were also investigated,and EUG-SZIM-xs displayed high tanδ values (>0.3) when the SZIM dosage was higher than 5.5 phr,which showed a positive correlation with SZIM concentration.Such good damping performance endowed the EUG-SZIM-xs with broadband low-frequency sound absorption.In addition,the dual cross-linking networks endowed the materials with reprocessability under different catalytic systems,and the 1,8-diazobicyclic[5.4.0]undeca-7-ene (DBU)-catalyzed samples exhibited better mechanical properties than EUG-SZIM-xs.展开更多
Peach gum polysaccharide(PGP),a readily available natural polysaccharide,boasts substantial potential across diverse applications,yet its practical utility is severely limited by its vulnerability to bacterial growth ...Peach gum polysaccharide(PGP),a readily available natural polysaccharide,boasts substantial potential across diverse applications,yet its practical utility is severely limited by its vulnerability to bacterial growth and limited antioxidant activity.Herein,we introduced a simple and effective method to enhance the antibacterial and antioxidant properties of PGP by conjugating it with salicylic acid(SA).Cytotoxicity evaluation results confirmed that the resulting PGP-SA retains the excellent biocompatibility of PGP.Notably,PGP-SA demonstrates outstanding antibacterial activity against both Gram-positive(S.aureus)and Gram-negative(E.coli)bacteria,outperforming non-modified PGP.Its antibacterial mechanism is hypothesized to stem from disrupting bacterial cell membranes and proteins,targeting structures vital to microbial survival.Beyond fighting bacteria,PGP-SA also delivers robust antioxidant activity,efficiently scavenging ABTS radicals.Harnessing these dual enhancements,PGP-SA proves highly effective as a fruit preservation coating.Most impressively,it extends the post-harvest shelf life of mangoes:under identical storage conditions,PGP-SA-coatedmangoes stay fresh for seven extra days compared to uncoated fruit.With its simple synthesis process and standout performance,this work not only overcomes PGP’s key limitations but also opens new avenues for its application in food preservation and related industries.展开更多
基金financially supported by the National Natural Science Foundation of China(No.52341301)Liaoning Provincial Department of Education Basic Research Project,China(Nos.LJKZZ20220055 and JYTMS20231498)Shenyang Natural Science Foundation Special,China(No.23-503-6-06).
文摘To combine the high elasticity and good mechanical performance of isoprene rubber(IR)with excellent fatigue resistance and low heat build-up of Eucommia ulmoides gum(EUG),the present study employed a chemical method to graft 4-amino pyridine(AP)onto epoxidized IR and EUG,thereby creating a chemical assembly rubber of amino-pyridine-grafted epoxidized IR(AP-EIR)and amino pyridine-grafted epoxidized EUG(AP-EEUG)via a dynamic hydrogen bonding network.The presence of hydrogen bonds between AP-EIR and AP-EEUG was confirmed by variable temperature infrared spectroscopy,whereas scanning electron microscopy-energy dispersive spectroscopy revealed a uniform dispersion of zinc oxide and nano-fillers.Hydrogen bonds significantly facilitate strain-induced crystallization between the AP-EIR and AP-EEUG molecules,thereby strengthening their intermolecular interactions.During mechanical deformation,the material primarily dissipates energy through the breaking of hydrogen bonds,which effectively improves the mechanical strength of the material,and the introduction of amino groups in this chemical assembly rubber improves the uniform dispersion of nano-fillers,as well as the interface interaction between rubber and nano-fillers.Consequently,the chemically assembled rubber exhibited superior modulus,tensile strength,and tear strength compared to IR and its physical blend,while also demonstrating reduced heat build-up during dynamic loading.
基金supported by the National Natural Science Foundation of China(Grant Nos.52379104 and 52090084).
文摘The biodegradable polybutylene succinate(PBS)material offers a sustainable solution for a circular economy to address the global issue of marine plastic waste.Its cross-linkage with non-biodegradable xanthan gum(XG)biopolymer to ameliorate residual granitic soil(RGS)in arid and semiarid regions can significantly mitigate soil erosion.This study investigates the enhancement of RGS by cross-linking the PBS and XG biopolymers.Employing a multitude of geotechnical tests(liquid limit,linear shrinkage,specific gravity,compaction,and UCS tests)at 3 d,28 d,and 90 d of steam-curing at a controlled temperature of 16℃,the outcomes were validated through scanning electron microscopy(SEM),thermogravimetric analysis(TGA),Fourier transform infrared spectroscopy(FTIR),and Brunauer-Emmett-Teller(BET)analyses.In addition,a comprehensive experimental database of 150 tests and nine parameters from the current study was utilized to model the UCS90-d(i.e.unconfined compressive strength after 90 d of curing)of the PBS-XG-treated RGS mixtures by deploying the random forest(RF)and eXtreme Gradient Boost(XGBoost)methods.The results found that the two biopolymers significantly improve the mechanical properties of RGS,with optimal UCS achieved at specific dosages(0.4PBS,1.5XG,and 0.2PBS+1.5XG dosage levels)and curing times.The UCS of PBS-XG-treated RGS showed up to a 57%increase after 90 d of curing.Furthermore,SEM and FTIR analyses revealed the formation of stronger microstructures and chemical bonds,respectively,whereas BET analysis indicated that pore volume and diameter are critical in affecting UCS.The proposed RF model outperformed XGBoost in predictive accuracy and generalization,demonstrating robustness and versatility.Moreover,SHAP values highlighted the significant impact of input parameters on UCS90-d,with curing time and specific material properties being key determinants.The study concludes with the proposal of a novel PyCharm intuitive graphical user interface as a"UCS Prediction App"for engineers and practitioners to forecast the UCS90-d of granitic residual soil.
基金funded by the Natural Science Foundation of Inner Mongolia Autonomous Region(2023JQ03,2023QN05014)the Youth Science and Technology Talents Project of Autonomous Region Colleges and Universities(NJYT22108)。
文摘Loess slopes in cold and arid regions are susceptible to shallow soil degradation,which may trigger severe environmental problems related to soil erosion.To address this environmental challenge,this study selected a compound ecological curing agent composed of gellan gum and guar gum for stabilizing shallow loess slopes.Triaxial compression and disintegration tests were employed to comparatively analyze the effects of compound gum content,mass mix ratio,and curing age on the mechanical and disintegration properties of solidified loess.The curing mechanism was analyzed using scanning electron microscopy(SEM),and the ecological protection effect was monitored for a 60-day period.The results indicate that gellan gum,guar gum,and the compound gum can enhance the mechanical and disintegration properties of loess,promote plant growth,and optimize the ecological environment.However,the combination of gellan gum and guar gum proves more effective than using either gellan gum or guar gum alone.Considering the effects on mechanical properties,disintegration performance,and material economy,the disintegration rate of loess decreases by 75.72%compared to plain loess when the compound glue content is 0.5%,the mixing ratio of gellan gum to guar gum is 3:7 and the curing age is 7 days.Meanwhile,the cohesion and internal friction angle increase by 118.06%and 10.97%,respectively.Moreover,the disintegration performance and mechanical properties of the samples first increase and then decrease with the increase in compound glue and the mix ratio and are basically stabilized after the curing age reaches 7d.
基金supported by the Postgraduate Education Reform and Quality Improvement Project of Henan Province,China(Grant No.YJS2023AL004)the Graduate Innovation Project of North China University of Water Resources and Electric Power(Grant No.NCWUYC-202315069)the China National Scholarship Fund organized by the China Scholarship Council(Grant No.202208410337).
文摘The deformation characteristics of silty soils under vibrational loads can easily change due to the wetting process,leading to the failure of roadbed structures.Commonly used methods for improving silty soils in engineering often yield unsatisfactory economic and ecological outcomes.As an environment-friendly soil improvement material,Xanthan gum has broad application prospects and is therefore considered a solidifying agent for enhancing silty soil properties in the Yellow River Basin.In this study,a series of tests is conducted using a scanning electron microscope and a dynamic triaxial testing apparatus to investigate the microstructure and dynamic deformation characteristics of unsaturated silty soil with varying xanthan gum contents during the wetting process.The results show that xanthan gum effectively fills voids between soil particles and adheres to their surfaces,forming fibrous and network structures.This modification enhances the inherent properties of the silty soil and significantly improves its stability under dynamic loading.Specifically,with increasing xanthan gum content,the dynamic shear modulus increases while the damping ratio decreases.During the wetting process,as suction decreases,the dynamic shear modulus decreases while the damping ratio increases.Xanthan gum reduces the sensitivity of the dynamic deformation characteristics of the treated silty soil to changes in suction levels.Finally,based on the modified Hardin-Drnevich hyperbolic model,a predictive model for the dynamic shear modulus and damping ratio of treated silty soil is proposed,considering the xanthan gum content.These research findings provide a theoretical basis for the construction and maintenance of water conservancy,slope stabilization,and roadbed projects in the Yellow River Basin.
文摘Protein-energy malnutrition (PEM) as a result of poor nutrition, especially for deprived resourced households, is a big health concern in the world. According to the World Health Organisation, PEM accounts for 49% of the 10.4 million deaths of children under five that take place in developing countries. The aim of this study was to evaluate the influence of gum Arabic (GA) and texturized soy protein (TSP) and their interactive effect on proximate, functional, and textural properties of the protein-rich snack stick produced from ground green maize, GA powder, and ground TSP. GA varied at 0%, 4%, 8%, and 12%, while TSP varied at 0%, 12%, 24% and 36%. The 5 cm long protein-rich snack sticks were made using a sausage stuffer and baked in an oven at 110˚C for 1 hr 30 minutes. The snack sticks were subjected to proximate, functional and textural analysis using the standard methods. Increasing GA resulted in a significant (p p < 0.05) increased the protein content (32.46%), Ash content (3.6%), fat (11.96%), and moisture content (16.25%) of protein-rich snack sticks. The interactive effect between GA and TSP led to a decrease in fibre and carbohydrates. Results from this study show GA and TSP significantly enhanced the physico-chemical properties of protein-rich snack sticks. A sample with 4% GA and 36% TSP is recommended for the best physico-chemical attributes of the protein-rich snack stick.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(Grant No.2022R1A2C2091517).
文摘Understanding the sedimentation and simultaneous consolidation behavior of xanthan gum(XG)-biopolymer-treated soils remains a significant research gap in developing environmentally friendly ground-improvement techniques for geotechnical applications.This study addresses this gap by conducting laboratory experiments on kaolinite suspensions with varying XG-to-kaolinite mass ratios(mb/ms).The results showed that the XG treatment modified the sedimentation patterns by promoting larger floc formation and accelerated settling.Additionally,the XG treatment enhanced the shear stiffness and shear strength,particularly at shallow depths.At mb/ms ratios less than 1%,the volume compression was reduced by the XG;the coefficient of compressibility decreased by 49%at 1%mb/ms,and the consolidation was accelerated,as indicated by a 387%increase in the hydraulic conductivity at 0.5%mb/ms under the vertical effective stress of 40 kPa.Contrastingly,at mb/ms ratios greater than 1%,viscous XG hydrogels clogged pores,resulting in a 45%reduction in the coefficient of consolidation at 2%mb/ms under a vertical effective stress of 15 kPa and a 35%decrease in the hydraulic conductivity at 2%mb/ms under a vertical effective stress of 40 kPa.These findings underscore the potential of XG treatment in improving the sedimentation and consolidation processes,highlighting its applicability in geotechnical projects,such as dredging,landfilling,and artificial island construction.
基金funded through the Penelitian Unggulan Halal,Airlangga University FY 2024 grant number:987/UN3/2024.
文摘This study aims to enhance the mechanical properties,disintegration,and dissolution rates of crosslinked carrageenan(CRG)capsule shells by shortening the long chains of CRG through a hydrolysis reaction with citric acid(CA).The hydrolysis of CRG was carried out using varying concentrations of CA,resulting in hydrolyzed CRG(HCRG).This was followed by cross-linking with xanthan gum(XG)and the addition of sorbitol(SOR)as a plasticizer.The results indicated that the optimal swelling capacity of HCRG-XG/SOR hard-shell capsules occurred at a CA concentration of 0.5%,achieving a maximum swelling rate of 445.39%after 15 min.Additionally,the best capsule hardness was alsomeasured at this CA concentration,reaching a hardness level of 480.157 g(F=4.67 N).FTIR analysis demonstrated that the presence of the acid group from CA altered the composition of the CRG chains.Furthermore,SEM-EDX mapping analysis revealed that the surface morphology of the synthesized capsules exhibited a relatively smooth texture with a limited number and size of pores,resulting in good capsule stability for drug delivery.Thein vitro disintegration and dissolution rates of theHCRG-XG/SOR capsuleswere observed to be the fastest and highest atpH1.2,respectively.The disintegration time was recorded at 20 min and 46 s,while the dissolution test indicated a drug release of 78.08%after 5min and 100%after 120 min.The drug delivery kinetics ofHCRG-XG/SOR followed the Ritger-Peppas model,indicating a complex release mechanism that involved swelling,diffusion,erosion,and capsule disintegration.
基金Project(52264022)supported by the National Natural Science Foundation of ChinaProject(BGRIMM-KJSKL-2025-17)supported by the Open Foundation of State Key Laboratory of Mineral Processing,China。
文摘Finding appropriate flotation reagents to separate copper-nickel sulfide ores from various magnesium silicate gangue minerals has always been a challenge in the mineral processing industry.This study introduced xanthan gum(XG)as a non-toxic and environmentally friendly depressant of talc,olivine,and serpentine.The effects and mechanisms of XG on the aggregation and flotation behavior of talc,olivine and serpentine were investigated by flotation tests,sedimentation tests,IC-FBRM particle size analysis tests,adsorption quantity tests,Fourier transform infrared spectroscopy(FTIR)tests,X-ray photoelectron spectroscopy(XPS)analysis tests and Zeta potential tests.The flotation results indicated that when the three minerals were mixed,XG caused the talc-serpentine aggregation in the solution to shift to olivine-serpentine aggregation,with the remaining XG adsorbing on talc to depress its flotation.In addition,combining XPS and zeta potential tests,the-OH(hydroxyl)groups in XG molecules preferentially adsorbed on Mg sites on the surface of olivine through chemical bonding.The surface potential of olivine significantly shifted to a more negative value,with the negative charge on the olivine surface far exceeding that on the talc surface.This resulted in an increased aggregation effect between positively charged serpentine and negatively charged olivine due to enhanced electrostatic forces.
基金supported by the National Key Research and Development Program of China(Nos.2022YFC2904502 and 2022YFC2904501)the Major Science and Technology Projects in Yunnan Province,China(No.202202AB080012).
文摘The environment-friendly and efficient selective separation of chalcopyrite and molybdenite poses a challenge in mineral pro-cessing.In this study,gum Arabic(GA)was initially proposed as a novel depressant for the selective separation of molybdenite from chalcopyrite during flotation.Microflotation results indicated that the inhibitory capacity of GA was stronger toward molybdenite than chalcopyrite.At pH 8.0 with 20 mg/L GA addition,the recovery rate of chalcopyrite in the concentrate obtained from mixed mineral flota-tion was 67.49%higher than that of molybdenite.Furthermore,the mechanism of GA was systematically investigated by various surface characterization techniques.Contact angle tests indicated that after GA treatment,the hydrophobicity of the molybdenite surface signifi-cantly decreased,but that of the chalcopyrite surface showed no apparent change.Fourier transform-infrared spectroscopy and X-ray photoelectron spectroscopy revealed a weak interaction force between GA and chalcopyrite.By contrast,GA was primarily adsorbed onto the molybdenite surface through chemical chelation,with possible contributions from hydrogen bonding and hydrophobic interactions.Pre-adsorbed GA could prevent butyl xanthate from being adsorbed onto molybdenite.Scanning electron microscopy–energy-dispersive spectrometry further indicated that GA was primarily adsorbed onto the“face”of molybdenite rather than the“edge.”Therefore,GA could be a promising molybdenite depressant for the flotation separation of Cu–Mo.
基金supported by the Natural Science Foundation of Hunan Province(No.2024JJ7392)the National Natural Science Foundation of China(No.52463002)+1 种基金Educational Commission of Hunan Province(No.22A0383)Special Funds for Construction of Innovative Provinces in Hunan Province(No.2020SK2028).
文摘An inverse vulcanized polymer,SZIM combining Zn2+-imidazole coordination bonds and polysulfide bonds was synthesized and incorporated into bio-based Eucommia ulmoides gum (EUG) to generate EUG-SZIM-xs.The residual crystallinity of the EUG matrix synergistically interacted with the dual cross-linking networks to establish reversible deformation domains,providing EUG-SZIM-xs with quick shape memory capability at moderate temperatures.The damping properties were also investigated,and EUG-SZIM-xs displayed high tanδ values (>0.3) when the SZIM dosage was higher than 5.5 phr,which showed a positive correlation with SZIM concentration.Such good damping performance endowed the EUG-SZIM-xs with broadband low-frequency sound absorption.In addition,the dual cross-linking networks endowed the materials with reprocessability under different catalytic systems,and the 1,8-diazobicyclic[5.4.0]undeca-7-ene (DBU)-catalyzed samples exhibited better mechanical properties than EUG-SZIM-xs.
基金supported by Guangxi Science and Technology Plan Project(No.Guike AA25069007)Guilin Scientific Research and Technology Development Plan(No.20220103-2).
文摘Peach gum polysaccharide(PGP),a readily available natural polysaccharide,boasts substantial potential across diverse applications,yet its practical utility is severely limited by its vulnerability to bacterial growth and limited antioxidant activity.Herein,we introduced a simple and effective method to enhance the antibacterial and antioxidant properties of PGP by conjugating it with salicylic acid(SA).Cytotoxicity evaluation results confirmed that the resulting PGP-SA retains the excellent biocompatibility of PGP.Notably,PGP-SA demonstrates outstanding antibacterial activity against both Gram-positive(S.aureus)and Gram-negative(E.coli)bacteria,outperforming non-modified PGP.Its antibacterial mechanism is hypothesized to stem from disrupting bacterial cell membranes and proteins,targeting structures vital to microbial survival.Beyond fighting bacteria,PGP-SA also delivers robust antioxidant activity,efficiently scavenging ABTS radicals.Harnessing these dual enhancements,PGP-SA proves highly effective as a fruit preservation coating.Most impressively,it extends the post-harvest shelf life of mangoes:under identical storage conditions,PGP-SA-coatedmangoes stay fresh for seven extra days compared to uncoated fruit.With its simple synthesis process and standout performance,this work not only overcomes PGP’s key limitations but also opens new avenues for its application in food preservation and related industries.
