Nowadays,the production of consumer goods is based on the use of non-renewable raw materials,which in recent years has been performing as a problem for the environment.Considering the large number of available biofibe...Nowadays,the production of consumer goods is based on the use of non-renewable raw materials,which in recent years has been performing as a problem for the environment.Considering the large number of available biofibers in nature,their use in the development of polymeric composites has inevitably emerged,it is also necessary to take into account the countless discarded plastics that still have the potential to be reused.In this work,fibers were extracted from pineapple crown residues and utilized to compose sustainable composites using recycled polypropylene from cups discarded in the trash as a matrix.However,it is known that for good performance,it is necessary to achieve a good chemical interaction between the fiber and the matrix.In order to improve this interaction,alkaline mercerization treatment was carried out on the surface of the fibers removing some components incompatible with the polymer.In this work,the effect of the mercerization treatment on the properties of the fibers was studied,as well as their interaction with the matrix.The effect of fiber concentration on the mechanical and thermal properties of composites was also evaluated.Levels of 5 and 7 wt%were used for both natural and mercerized fibers.A decrease in the number of degradation stages was observed through thermogravimetry analyses(from four in natural fiber to two in mercerized fibers),showing that the mercerization performed on the fibers was effective.An increase in the degree of crystallinity of mercerized fibers was also observed through the results of X-ray diffraction.Both techniques indicate that amorphous compounds,such as hemicellulose and lignin,were partially removed.Through the tensile test,it could be noted that all composites presented higher values of de elastic modulus than recycled polypropylene without added load;however,there were no differences in the elastic modulus between the different types of fibers and load levels.Therefore,it is interesting to use fibers as reinforcing agents in polymers;however,the treatment did not increase the mechanical properties of the composites.In parallel,other factors,such as the dispersion of the components,must be taken into account to justify this result.展开更多
Integrating functional nanomaterials on nonplanar organisms has emerged as a rising technology,while significant mismatch would cause interface failure and poor durability.Herein,we demonstrate a facile strategy to as...Integrating functional nanomaterials on nonplanar organisms has emerged as a rising technology,while significant mismatch would cause interface failure and poor durability.Herein,we demonstrate a facile strategy to assemble crystalline catecholate frameworks with honeycomb lattice on seaweed-derived polysaccharide microfibers,which is expected to form biomimetic connections and maintain durable stability.By physiological coagulation,well-aligned ZnO nanoarrays are tightly attached on alginate fibers,which is fractionally adopted as sacrifice for heteroepitaxial growth of zinc-catecholate frameworks(Zn3(HHTP)2).Benefiting from amplification effect of in-situ formed heterojunctions,promoted interfacial charge transfer is achieved,which allows for fabricating broadband photodetectors.Combined with high porosity for gas adsorption,the heteroepitaxial catecholate framework further enables its use as highly selective ppb-level triethylamine sensors.This work provides a promising strategy for heteroepitaxial growth of catecholate frameworks on organo-substrates and opens new applications in wearable sensor platform based on comfortable biofibers.展开更多
The objective of the current study was the fabrication and characterization of electrospun zein-ZnO fibers containing various concentrations of cumin essential oil(CEO)(0,1,2,and 3%(v/v)).The electrospinning solution...The objective of the current study was the fabrication and characterization of electrospun zein-ZnO fibers containing various concentrations of cumin essential oil(CEO)(0,1,2,and 3%(v/v)).The electrospinning solution’s apparent viscosity,conductivity,and surface tension were measured.Also,the electrospun’s morphological,color,encapsulation efficiency,antioxidant and antimicrobial properties,thermal stability,and release kinetic were investigated.The results represented that following the increase in CEO concentration,the conductivity and surface tension of the electrospinning solution changed from 182.92μS/cm to 145.22μS/cm and 19.52 mN/m to 22.35 mN/m,respectively.The scanning electron microscope(SEM)revealed the homogenous and free-bead structure of electrospun fibers.Besides,the diameter of fibers enhanced with a rise in CEO concentration from 217.13 nm to 321.67 nm.The finding estimated the maximum encapsulation efficiency and loading capacity at about 95.09% and 25.65%,respectively in electrospun containing the highest concentration of CEO(3%).CEO inclusion in electrospinning fibers augmented the value of contact angle,color difference,TPC,antioxidant,and antimicrobial properties.The favorable interaction between the CEO ingredients and electrospinning fibers was confirmed through FTIR and XRD analysis.Furthermore,the incorption of CEO enhanced the thermal stability of fibers.Release kinetic in different simulant(aqueous,acidic,alkaline,and fatty)revealed that Fick’s diffusion was the main release mechanism.The highest diffusion coefficient was observed in electrospun fibers containing 3%CEO in the fatty media simulant.These findings could present a new horizon into electrospinning fiber’s application in various fields of medicine,tissue engineering,food,and pharmaceutical industry.展开更多
基金The authors would like to thank CAPES(Finance Code 001 and Process PNPD20131474-33001014004P9)and CNPq for financial support.
文摘Nowadays,the production of consumer goods is based on the use of non-renewable raw materials,which in recent years has been performing as a problem for the environment.Considering the large number of available biofibers in nature,their use in the development of polymeric composites has inevitably emerged,it is also necessary to take into account the countless discarded plastics that still have the potential to be reused.In this work,fibers were extracted from pineapple crown residues and utilized to compose sustainable composites using recycled polypropylene from cups discarded in the trash as a matrix.However,it is known that for good performance,it is necessary to achieve a good chemical interaction between the fiber and the matrix.In order to improve this interaction,alkaline mercerization treatment was carried out on the surface of the fibers removing some components incompatible with the polymer.In this work,the effect of the mercerization treatment on the properties of the fibers was studied,as well as their interaction with the matrix.The effect of fiber concentration on the mechanical and thermal properties of composites was also evaluated.Levels of 5 and 7 wt%were used for both natural and mercerized fibers.A decrease in the number of degradation stages was observed through thermogravimetry analyses(from four in natural fiber to two in mercerized fibers),showing that the mercerization performed on the fibers was effective.An increase in the degree of crystallinity of mercerized fibers was also observed through the results of X-ray diffraction.Both techniques indicate that amorphous compounds,such as hemicellulose and lignin,were partially removed.Through the tensile test,it could be noted that all composites presented higher values of de elastic modulus than recycled polypropylene without added load;however,there were no differences in the elastic modulus between the different types of fibers and load levels.Therefore,it is interesting to use fibers as reinforcing agents in polymers;however,the treatment did not increase the mechanical properties of the composites.In parallel,other factors,such as the dispersion of the components,must be taken into account to justify this result.
基金This work was supported by the National Natural Science Foundation of China(No.51973099)Taishan Scholar Program of Shandong Province(Nos.tsqn201812055 and tspd20181208)the State Key Laboratory of Bio-Fibers and Eco-Textiles(Qingdao University)(Nos.ZKT04 and GZRC202007).
文摘Integrating functional nanomaterials on nonplanar organisms has emerged as a rising technology,while significant mismatch would cause interface failure and poor durability.Herein,we demonstrate a facile strategy to assemble crystalline catecholate frameworks with honeycomb lattice on seaweed-derived polysaccharide microfibers,which is expected to form biomimetic connections and maintain durable stability.By physiological coagulation,well-aligned ZnO nanoarrays are tightly attached on alginate fibers,which is fractionally adopted as sacrifice for heteroepitaxial growth of zinc-catecholate frameworks(Zn3(HHTP)2).Benefiting from amplification effect of in-situ formed heterojunctions,promoted interfacial charge transfer is achieved,which allows for fabricating broadband photodetectors.Combined with high porosity for gas adsorption,the heteroepitaxial catecholate framework further enables its use as highly selective ppb-level triethylamine sensors.This work provides a promising strategy for heteroepitaxial growth of catecholate frameworks on organo-substrates and opens new applications in wearable sensor platform based on comfortable biofibers.
文摘The objective of the current study was the fabrication and characterization of electrospun zein-ZnO fibers containing various concentrations of cumin essential oil(CEO)(0,1,2,and 3%(v/v)).The electrospinning solution’s apparent viscosity,conductivity,and surface tension were measured.Also,the electrospun’s morphological,color,encapsulation efficiency,antioxidant and antimicrobial properties,thermal stability,and release kinetic were investigated.The results represented that following the increase in CEO concentration,the conductivity and surface tension of the electrospinning solution changed from 182.92μS/cm to 145.22μS/cm and 19.52 mN/m to 22.35 mN/m,respectively.The scanning electron microscope(SEM)revealed the homogenous and free-bead structure of electrospun fibers.Besides,the diameter of fibers enhanced with a rise in CEO concentration from 217.13 nm to 321.67 nm.The finding estimated the maximum encapsulation efficiency and loading capacity at about 95.09% and 25.65%,respectively in electrospun containing the highest concentration of CEO(3%).CEO inclusion in electrospinning fibers augmented the value of contact angle,color difference,TPC,antioxidant,and antimicrobial properties.The favorable interaction between the CEO ingredients and electrospinning fibers was confirmed through FTIR and XRD analysis.Furthermore,the incorption of CEO enhanced the thermal stability of fibers.Release kinetic in different simulant(aqueous,acidic,alkaline,and fatty)revealed that Fick’s diffusion was the main release mechanism.The highest diffusion coefficient was observed in electrospun fibers containing 3%CEO in the fatty media simulant.These findings could present a new horizon into electrospinning fiber’s application in various fields of medicine,tissue engineering,food,and pharmaceutical industry.
