Starch nanoparticles are used as a matrix with natural rubber for tire making, alternative adsorbents for wastewater treatment, drug carriers, packaging materials, emulsion stabilizers and fat replacers. The objective...Starch nanoparticles are used as a matrix with natural rubber for tire making, alternative adsorbents for wastewater treatment, drug carriers, packaging materials, emulsion stabilizers and fat replacers. The objective of this study is to prepare the starch nanoparticles from cassava peel by mineral acid hydrolysis using hydrochloric and sulfuric acids and perform the characterization of starch nanoparticles with Fourier transform infrared (FTIR),X-ray diffraction (XRD) and scanning electron microscope (SEM)It was found that the obtained yield of starch nanoparticles by H2SO4was higher than that by HCl.展开更多
A facile and green synthetic approach for fabrication of starch-stabilized magnetite nanoparticles was implemented at moderate temperature. This synthesis involved the use of iron salts, potato starch,sodium hydroxide...A facile and green synthetic approach for fabrication of starch-stabilized magnetite nanoparticles was implemented at moderate temperature. This synthesis involved the use of iron salts, potato starch,sodium hydroxide and deionized water as iron precursors, stabilizer, reducing agent and solvent respectively. The nanoparticles（NPs） were characterized by UV-vis, PXRD, HR-TEM, FESEM, EDX, VSM and FT-IR spectroscopy. The ultrasonic assisted co-precipitation technique provides well formation of highly distributed starch/Fe3O4-NPs. Based on UV–vis analysis, the sample showed the characteristic of surface plasmon resonance in the presence of Fe3O4-NPs. The PXRD pattern depicted the characteristic of the cubic lattice structure of Fe3O4-NPs. HR-TEM analysis showed the good dispersion of NPs with a mean diameter and standard deviation of 10.68 4.207 nm. The d spacing measured from the lattice images were found to be around 0.30 nm and 0.52 nm attributed to the Fe3O4 and starch, respectively. FESEM analysis confirmed the formation of spherical starch/Fe3O4-NPs with the emission of elements of C, O and Fe by EDX analysis. The magnetic properties illustrated by VSM analysis indicated that the as synthesized sample has a saturation magnetization and coercivity of 5.30 emu/g and 22.898 G respectively.Additionally, the FTIR analysis confirmed the binding of starch with Fe3O4-NPs. This method was cost effective, facile and eco-friendly alternative for preparation of NPs.展开更多
The present study evaluated commercial starch behavior and tapioca starch nanoparticles(TsNP)with 100 ppm ultralow salinity formation water as a potential alternative for enhanced oil recovery(EOR).Generally,starch ex...The present study evaluated commercial starch behavior and tapioca starch nanoparticles(TsNP)with 100 ppm ultralow salinity formation water as a potential alternative for enhanced oil recovery(EOR).Generally,starch exhibits excellent properties as a conventional viscosifier substitute in the petroleum industry.This study proposed a conventional polymer substitute,which is typically hydrolyzed polyacrylamide(HPAM)or oxide nanoparticles,for chemical flooding EOR employment.The TSNP was successfully synthesized via nanoprecipitation with ethanol as the precipitant medium.Two TsNp of different sizes,1%and 3%,are successfully synthesized,which demonstrated chemical and physical attributes almost identical to raw tapioca starch(TS),corroborating their composition similarities.The 1%TSNP was significantly smaller compared to the 3%TsNP,but both samples possessed distinct angular,polygonal,andtruncated shapes with sharp edges.Although the structure of the TSNP synthesized was a C-type crystal,their crystallinity was slightly lower.Fourier-transform infrared(FTR)and energy dispersive X-ray(EDx)analyses confirmed similar chemical compositions of the raw TS and TSNP assessed.The EOR formulations employed in the study were prepared with various TS and TSNP concentrations,ranging from 0 ppm to 2000 ppm.The formulations were assessed at various temperatures between 25℃ and 75C.Rheological results indicated that TS and TSNP formulations coupled with low salinity formation water yielded non-Newtonian shear thickening behavior with respect to starch types,concentrations,temperatures,and shear rates.The 1%TsNp formulation exhibited favorable solution viscosifying criteria than the 3%TSNP sample within evaluated parameters.Surface tension,IFT,and wettability alteration measurements revealed indirect and inconclusive trend regarding TSNp concentrations and temperatures.Nonetheless,adding 1%and 3%TSNP considerably influenced IFT reduction and wettability alteration in several favorable combinations,indicating feasibility for EOR applications.展开更多
The increasing demand for sustainable energy storage solutions has intensified the focus on high-performance supercapaci-tors,known for their rapid charge/discharge capabilities,high power density,and long cycle life....The increasing demand for sustainable energy storage solutions has intensified the focus on high-performance supercapaci-tors,known for their rapid charge/discharge capabilities,high power density,and long cycle life.Polyurethane(PU)-based materials have gained attention as promising candidates for supercapacitor electrodes,due to their flexibility,mechanical robustness,and tunable properties.It is important to clarify that PU typically does not contribute directly to charge storage via adsorption or pseudocapacitive mechanisms.Instead,PU serves as a flexible scaffold,a binder,or a precursor for the preparation of heteroatom-doped carbon materials upon thermal treatment.Thus,the term'PU-based'in this review refers to PU-supported or PU-derived composites,where PU enables structural or functional integration of active electrode Materi-als.Polyurethane composites incorporating graphene oxide have demonstrated a specific capacitance of 758.8 mF/cm^(2)with capacitance retention of 92%over 5,000 cycles.Other PU-based electrodes have achieved energy densities up to 22.5 Wh/kg and power densities of 1472.7 W/kg,reflecting their potential for high-performance energy storage applications.Despite these advantages,challenges,such as low intrinsic conductivity and the environmental impact of traditional synthesis methods,limit their widespread adoption.Conventional PU composites often incorporate conductive additives like carbon materi-als,metal oxides,or conductive polymers to enhance their electrochemical performance,yet these approaches may involve non-renewable or toxic components.Developing green energy materials that adhere to sustainability and green chemistry principles is crucial to address these limitations.This includes using renewable resources,environmentally friendly process-ing techniques,and recyclable materials to reduce the ecological footprint and meet the growing need for sustainable energy storage technologies.This review highlights current trends in developing eco-friendly supercapacitor materials,addressing key challenges such as limited conductivity and complex processing.It uniquely integrates green chemistry principles with advances in polyurethane composites,emphasizing sustainable feedstocks,heteroatom doping,and functional nanomateri-als.By combining these aspects,this review provides a comprehensive perspective not fully covered in existing literature.展开更多
Biopolymer based hydrogels are highly adaptable, compatible and have shown great potential in biological tissues in biomedical applications. However, the development of bio-based hydrogels with high strength and effec...Biopolymer based hydrogels are highly adaptable, compatible and have shown great potential in biological tissues in biomedical applications. However, the development of bio-based hydrogels with high strength and effective antibacterial activity remains challenging. Herein, a series of vanillin-cross-linked chitosan nanocomposite hydrogel interfacially reinforced by g-C_(3)N_(4)nanosheet carrying starch-caped Ag NPs were prepared for wound healing applications. The study aimed to enhance the strength, sustainability and control release ability of the fabricated membranes. Starch-caped silver nanoparticles were incorporated to enhance the anti-bacterial activities The fabricated membranes were assessed using various characterization techniques such as FT-IR, XRD, SEM, mechanical testing, Gel fraction and porosity alongside traditional biomedical tests i.e., swelling percentage, moisture retention ability, water vapor transmission rate, oxygen permeability, anti-bacterial activity and drug-release of the fabricated membranes. The mechanical strength reached as high as 25.9 ± 0.24 MPa for the best optimized sample. The moisture retention lied between 87%–89%, gel fraction 80%–85%, and water vapor transmission up to 104 ± 1.9g m^(-2)h^(-1)showing great properties of the fabricated membrane. Swelling percentage surged to 225% for blood while porosity fluctuated between 44% ± 2.1% and 52.5% ± 2.3%. Oxygen permeability reached up to 8.02 mg/L showing the breathable nature of fabricated membranes. The nanocomposite membrane shown excellent antibacterial activity for both gram-positive and gram-negative bacteria with a maximum zone of inhibition 30 ± 0.25 mm and 36.23 ± 0.23 mm respectively. Furthermore, nanoparticles maintained sustainable release following non-fickian diffusion. The fabricated membrane demonstrated the application of inorganic filler to enhance the strength of biopolymer hydrogel with superior properties.These results envisage the potential of synthesized membrane to be used as wound dressing, artificial skin and load-bearing scaffolds.展开更多
This work aims to understand the effect of nanoparticle-enzyme interactions and how such interactions affect starch based soil removal. Silica and laponite are used as the model nanoparticles, and s-amylase is employe...This work aims to understand the effect of nanoparticle-enzyme interactions and how such interactions affect starch based soil removal. Silica and laponite are used as the model nanoparticles, and s-amylase is employed as the model enzyme. The results show that, if the nanoparticles and enzyme are added simultaneously, laponite enhances the enzyme performance toward starch soil removal, whereas silica imposes a small effect on the enzymatic activity towards the same soil substrates. However, when nanoparticles are added first, the enzyme activity is not affected much by laponite but is hindered significantly by silica nanoparticles. Furthermore, sequential addition of the enzyme followed by silica nanoparticles improves soil removal. Electron microscopic analyses, measurements of the enzyme activity in suspen- sions of nanoparticles, and particle size characterisation suggest that dense coverage of soil surface by the silica nanoparticles be likely a mechanism for the experimentally observed hindrance of soil removal when silica nanoparticles are added before enzyme.展开更多
文摘Starch nanoparticles are used as a matrix with natural rubber for tire making, alternative adsorbents for wastewater treatment, drug carriers, packaging materials, emulsion stabilizers and fat replacers. The objective of this study is to prepare the starch nanoparticles from cassava peel by mineral acid hydrolysis using hydrochloric and sulfuric acids and perform the characterization of starch nanoparticles with Fourier transform infrared (FTIR),X-ray diffraction (XRD) and scanning electron microscope (SEM)It was found that the obtained yield of starch nanoparticles by H2SO4was higher than that by HCl.
基金supported by the Malaysian Ministry of High Education and Universiti Teknologi Malaysia (UTM) under Tier 1 grant (No. Q.K130000.2543.12H95)
文摘A facile and green synthetic approach for fabrication of starch-stabilized magnetite nanoparticles was implemented at moderate temperature. This synthesis involved the use of iron salts, potato starch,sodium hydroxide and deionized water as iron precursors, stabilizer, reducing agent and solvent respectively. The nanoparticles（NPs） were characterized by UV-vis, PXRD, HR-TEM, FESEM, EDX, VSM and FT-IR spectroscopy. The ultrasonic assisted co-precipitation technique provides well formation of highly distributed starch/Fe3O4-NPs. Based on UV–vis analysis, the sample showed the characteristic of surface plasmon resonance in the presence of Fe3O4-NPs. The PXRD pattern depicted the characteristic of the cubic lattice structure of Fe3O4-NPs. HR-TEM analysis showed the good dispersion of NPs with a mean diameter and standard deviation of 10.68 4.207 nm. The d spacing measured from the lattice images were found to be around 0.30 nm and 0.52 nm attributed to the Fe3O4 and starch, respectively. FESEM analysis confirmed the formation of spherical starch/Fe3O4-NPs with the emission of elements of C, O and Fe by EDX analysis. The magnetic properties illustrated by VSM analysis indicated that the as synthesized sample has a saturation magnetization and coercivity of 5.30 emu/g and 22.898 G respectively.Additionally, the FTIR analysis confirmed the binding of starch with Fe3O4-NPs. This method was cost effective, facile and eco-friendly alternative for preparation of NPs.
基金express gratitude to Universiti Teknologi Malaysia Johor Bahru(Grant number:R.J130000.7651.4C318)the Malaysian Ministry of Higher Education(MOHE)for funding this study.
文摘The present study evaluated commercial starch behavior and tapioca starch nanoparticles(TsNP)with 100 ppm ultralow salinity formation water as a potential alternative for enhanced oil recovery(EOR).Generally,starch exhibits excellent properties as a conventional viscosifier substitute in the petroleum industry.This study proposed a conventional polymer substitute,which is typically hydrolyzed polyacrylamide(HPAM)or oxide nanoparticles,for chemical flooding EOR employment.The TSNP was successfully synthesized via nanoprecipitation with ethanol as the precipitant medium.Two TsNp of different sizes,1%and 3%,are successfully synthesized,which demonstrated chemical and physical attributes almost identical to raw tapioca starch(TS),corroborating their composition similarities.The 1%TSNP was significantly smaller compared to the 3%TsNP,but both samples possessed distinct angular,polygonal,andtruncated shapes with sharp edges.Although the structure of the TSNP synthesized was a C-type crystal,their crystallinity was slightly lower.Fourier-transform infrared(FTR)and energy dispersive X-ray(EDx)analyses confirmed similar chemical compositions of the raw TS and TSNP assessed.The EOR formulations employed in the study were prepared with various TS and TSNP concentrations,ranging from 0 ppm to 2000 ppm.The formulations were assessed at various temperatures between 25℃ and 75C.Rheological results indicated that TS and TSNP formulations coupled with low salinity formation water yielded non-Newtonian shear thickening behavior with respect to starch types,concentrations,temperatures,and shear rates.The 1%TsNp formulation exhibited favorable solution viscosifying criteria than the 3%TSNP sample within evaluated parameters.Surface tension,IFT,and wettability alteration measurements revealed indirect and inconclusive trend regarding TSNp concentrations and temperatures.Nonetheless,adding 1%and 3%TSNP considerably influenced IFT reduction and wettability alteration in several favorable combinations,indicating feasibility for EOR applications.
基金Open access funding provided by The Science,Technology&Innovation Funding Authority(STDF)in cooperation with The Egyp-tian Knowledge Bank(EKB).
文摘The increasing demand for sustainable energy storage solutions has intensified the focus on high-performance supercapaci-tors,known for their rapid charge/discharge capabilities,high power density,and long cycle life.Polyurethane(PU)-based materials have gained attention as promising candidates for supercapacitor electrodes,due to their flexibility,mechanical robustness,and tunable properties.It is important to clarify that PU typically does not contribute directly to charge storage via adsorption or pseudocapacitive mechanisms.Instead,PU serves as a flexible scaffold,a binder,or a precursor for the preparation of heteroatom-doped carbon materials upon thermal treatment.Thus,the term'PU-based'in this review refers to PU-supported or PU-derived composites,where PU enables structural or functional integration of active electrode Materi-als.Polyurethane composites incorporating graphene oxide have demonstrated a specific capacitance of 758.8 mF/cm^(2)with capacitance retention of 92%over 5,000 cycles.Other PU-based electrodes have achieved energy densities up to 22.5 Wh/kg and power densities of 1472.7 W/kg,reflecting their potential for high-performance energy storage applications.Despite these advantages,challenges,such as low intrinsic conductivity and the environmental impact of traditional synthesis methods,limit their widespread adoption.Conventional PU composites often incorporate conductive additives like carbon materi-als,metal oxides,or conductive polymers to enhance their electrochemical performance,yet these approaches may involve non-renewable or toxic components.Developing green energy materials that adhere to sustainability and green chemistry principles is crucial to address these limitations.This includes using renewable resources,environmentally friendly process-ing techniques,and recyclable materials to reduce the ecological footprint and meet the growing need for sustainable energy storage technologies.This review highlights current trends in developing eco-friendly supercapacitor materials,addressing key challenges such as limited conductivity and complex processing.It uniquely integrates green chemistry principles with advances in polyurethane composites,emphasizing sustainable feedstocks,heteroatom doping,and functional nanomateri-als.By combining these aspects,this review provides a comprehensive perspective not fully covered in existing literature.
基金supported by the National Natural Science Foundation of China (No. 52003113)Guangdong Basic and Applied Basic Research Foundation (Nos. 2021A1515010745,2020A1515110356)+1 种基金Science and Technology Projects of Guangzhou City (No. 202102020359)the financial support from the China Postdoctoral Science Foundation (No.F121280003)。
文摘Biopolymer based hydrogels are highly adaptable, compatible and have shown great potential in biological tissues in biomedical applications. However, the development of bio-based hydrogels with high strength and effective antibacterial activity remains challenging. Herein, a series of vanillin-cross-linked chitosan nanocomposite hydrogel interfacially reinforced by g-C_(3)N_(4)nanosheet carrying starch-caped Ag NPs were prepared for wound healing applications. The study aimed to enhance the strength, sustainability and control release ability of the fabricated membranes. Starch-caped silver nanoparticles were incorporated to enhance the anti-bacterial activities The fabricated membranes were assessed using various characterization techniques such as FT-IR, XRD, SEM, mechanical testing, Gel fraction and porosity alongside traditional biomedical tests i.e., swelling percentage, moisture retention ability, water vapor transmission rate, oxygen permeability, anti-bacterial activity and drug-release of the fabricated membranes. The mechanical strength reached as high as 25.9 ± 0.24 MPa for the best optimized sample. The moisture retention lied between 87%–89%, gel fraction 80%–85%, and water vapor transmission up to 104 ± 1.9g m^(-2)h^(-1)showing great properties of the fabricated membrane. Swelling percentage surged to 225% for blood while porosity fluctuated between 44% ± 2.1% and 52.5% ± 2.3%. Oxygen permeability reached up to 8.02 mg/L showing the breathable nature of fabricated membranes. The nanocomposite membrane shown excellent antibacterial activity for both gram-positive and gram-negative bacteria with a maximum zone of inhibition 30 ± 0.25 mm and 36.23 ± 0.23 mm respectively. Furthermore, nanoparticles maintained sustainable release following non-fickian diffusion. The fabricated membrane demonstrated the application of inorganic filler to enhance the strength of biopolymer hydrogel with superior properties.These results envisage the potential of synthesized membrane to be used as wound dressing, artificial skin and load-bearing scaffolds.
基金UK EPSRC for funding this project under Grants EP EP/F027389/1,EP/F023014/1,EP/D000645/1 and EP/F000464/1
文摘This work aims to understand the effect of nanoparticle-enzyme interactions and how such interactions affect starch based soil removal. Silica and laponite are used as the model nanoparticles, and s-amylase is employed as the model enzyme. The results show that, if the nanoparticles and enzyme are added simultaneously, laponite enhances the enzyme performance toward starch soil removal, whereas silica imposes a small effect on the enzymatic activity towards the same soil substrates. However, when nanoparticles are added first, the enzyme activity is not affected much by laponite but is hindered significantly by silica nanoparticles. Furthermore, sequential addition of the enzyme followed by silica nanoparticles improves soil removal. Electron microscopic analyses, measurements of the enzyme activity in suspen- sions of nanoparticles, and particle size characterisation suggest that dense coverage of soil surface by the silica nanoparticles be likely a mechanism for the experimentally observed hindrance of soil removal when silica nanoparticles are added before enzyme.
