In this work,polyethylene terephthalate(PET) fibers were continuously treated by atmospheric dielectric barrier discharge(DBD) in Ar mixed O2 plasma,and the discharge was characterized by electrical function and optic...In this work,polyethylene terephthalate(PET) fibers were continuously treated by atmospheric dielectric barrier discharge(DBD) in Ar mixed O2 plasma,and the discharge was characterized by electrical function and optical diagnostics.It is found that the interfacial adhesion strength between treated PET fiber and resorcinol formaldehyde latex(RFL)(little)-rubber was improved(about 50%) by the measurement of interfacial shear strength(IFSS) and peel test.The wettability was improved rapidly in the initial treatment time.It is considered that oxidation chemical reaction as the major role of PET fiber surface modification is ahead of the physical etching effect.The high density of atomic oxygen in the plasma by optical emission spectroscopy supports the purpose.According to the scanning electron micrograph(SEM) image in the work,the longer treatment time obviously caused physical etching effect,which shall be less responsible for the improvement of the wettability.展开更多
This paper presents a method to measure the spontaneous extension of oriented PET fibredirectly during crystallization by twice annealing (constant-length and free-length). Samples be-fore and after the treatment were...This paper presents a method to measure the spontaneous extension of oriented PET fibredirectly during crystallization by twice annealing (constant-length and free-length). Samples be-fore and after the treatment were collected and examined by X-ray diffraction, DSC andbirefringence. The crystallinity, crystallite size, and orientation of both crystalline and amorphousparts between these samples are changed greatly which show that the extension is a consequence ofcrystallization and reorientation of uncrystallized segments along the fibre direction. The results ofthis study are not only important to understand the mechanism of supermolecular structurechanges during crystallization, but also useful to the industrial technology of crystallization spin-ning.展开更多
Production of fuel and chemicals from plastic waste is one of the effective ways to upcycle spent plastics,which is an interesting topic and of significance for green and sustainable development.Herein,we demonstrate ...Production of fuel and chemicals from plastic waste is one of the effective ways to upcycle spent plastics,which is an interesting topic and of significance for green and sustainable development.Herein,we demonstrate a highly efficient catalyst,TiO_(2)nanoparticle supported Ru nanocatalyst(Ru/TiO_(2)),for upcycling polyethylene terephthalate(PET)to alkanes in the presence of H_(2) and water.Under the optimal conditions(200℃,60 bar H_(2),and small amount of H_(2)O),PET could completely convert into alkanes,dominated with cyclohexane and methane.It was indicated that the strong interaction between the TiO_(2)support and Ru nanoparticles made electrons flow from the TiO_(2)support to the Ru nanoparticles,which thus rendered Ru/TiO_(2)to have ability to simultaneously catalyze PET hydrolysis and intermediate hydrogenation.This work realizes the transformation of PET to alkanes,which provides a promising way to chemically upcycle PET.展开更多
Synthetic plastics are often considered to be materials that cannot be broken down by natural processes.One such plastic,polyethylene terephthalate(PET),is commonly used in everyday items but when these products are d...Synthetic plastics are often considered to be materials that cannot be broken down by natural processes.One such plastic,polyethylene terephthalate(PET),is commonly used in everyday items but when these products are discarded,they can cause serious harm to the environment and human health.In this study,PET plastic waste was used to create activated carbon using a physical activation process that involved using CO2 gas.The researchers investigated the effects of different temperatures,carbonization,and activation times on the resulting activated carbon’s surface area.The activated carbon was then analyzed using scanning electron microscopy(SEM),X-ray diffraction(XRD),FTIR,and BET.The activated carbon created from PET plastic waste showed excellent absorption properties for methylene blue in aqueous solutions across a wide range of pH levels.By creating activated carbon from plastic waste,not only are environmental issues addressed,but high-value activated carbon is produced for environmental remediation purposes.展开更多
The implantable artificial hair was prepared by grafting collagen on the surface of poly(ethylene terephthalate)(PET)to improve its biocompatibility.Acrylic acid(AAc)was used to modify the surface properties of PET fi...The implantable artificial hair was prepared by grafting collagen on the surface of poly(ethylene terephthalate)(PET)to improve its biocompatibility.Acrylic acid(AAc)was used to modify the surface properties of PET firstly,and then collagen was grafted on the PET-AAc surface.The concentration of collagen solution was discussed to graft more collagen on PET surface.Composites were well characterized by scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FTIR)and X-ray photoelectron spectroscopy(XPS).SEM indicated that collagen with about 3.07μm thickness was coated on PET surface when the concentration of collagen solution was 1.0 mg/m L.FTIR and XPS showed AAc and collagen were both on the surface of PET monofilaments.The optimized concentration of collagen solution was 1.0 mg/m L,resulting in the most grafting density of 3.46μg/cm^(2).It can be concluded that a large amount of collagen is coated on PET surface.展开更多
Non-thermal plasmas under atmospheric pressure are of great interest in polymer surface processing because of their convenience, effectiveness and low cost. In this paper, the treatment of Polyethylene terephthalate (...Non-thermal plasmas under atmospheric pressure are of great interest in polymer surface processing because of their convenience, effectiveness and low cost. In this paper, the treatment of Polyethylene terephthalate (PET) film surface for improving hydrophilicity using the non-thermal plasma generated by atmospheric pressure glow discharge (APGD) in air is conducted. The discharge characteristics of APGD are shown by measurement of their electrical discharge parameters and observation of light-emission phenomena, and the surface properties of PET before and after the APGD treatment are studied using contact angle measurement, x-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). It is found that the APGD is homogeneous and stable in the whole gas gap, which differs from the commonly filamentary dielectric barrier discharge (DBD). A short time (several seconds) APGD treatment can modify the surface characteristics of PET film markedly and uniformly. After 10 s APGD treatment, the展开更多
Polyethylene terephthalate(PET) resin was hydrolyzed to terephthalate acid(TPA) and ethylene glycol(EG) under microwave irradiation.The effects of crystallinity on the depolymerization of PET was investigated.PET resi...Polyethylene terephthalate(PET) resin was hydrolyzed to terephthalate acid(TPA) and ethylene glycol(EG) under microwave irradiation.The effects of crystallinity on the depolymerization of PET was investigated.PET resin was isothermal crystallized at temperature of 140,170,200 and 230 ℃ for 5 hours,the crystallinity of the resin was 25.7%,29.5%,33.9% and 40.6%,respectively,then the resin with different crystallinity was hydrolyzed under microwave irriadition. Under the same conditions of hydrolytic depolymerization, the degree of PET depolymerization decreased from 72.8% to 69.34% with the increase of crystallinity of PET resin,the rate of depolymerization varied little with the increasing of crystallinity of PET,this indicated that the crystallinity of PET has little effect on the hydrolytic depolymerization.The crystallinity of PET was increased during the temperature elevating process of the hydrolytic depolymerization.Investigation by DSC proved that the crystallinity of PET resin increased notability during the same temperature elevating process as the hydrolyzed depolymerization.According to the theory that depolymerization was firstly proceed in the amorphous phase,the crystallinity should increase during the reaction.However,the crystallinity of PET residue was decreased during all the reaction process,this indicates that the hydrolysis did not preferentially occur in the amorphous phase.展开更多
文摘In this work,polyethylene terephthalate(PET) fibers were continuously treated by atmospheric dielectric barrier discharge(DBD) in Ar mixed O2 plasma,and the discharge was characterized by electrical function and optical diagnostics.It is found that the interfacial adhesion strength between treated PET fiber and resorcinol formaldehyde latex(RFL)(little)-rubber was improved(about 50%) by the measurement of interfacial shear strength(IFSS) and peel test.The wettability was improved rapidly in the initial treatment time.It is considered that oxidation chemical reaction as the major role of PET fiber surface modification is ahead of the physical etching effect.The high density of atomic oxygen in the plasma by optical emission spectroscopy supports the purpose.According to the scanning electron micrograph(SEM) image in the work,the longer treatment time obviously caused physical etching effect,which shall be less responsible for the improvement of the wettability.
文摘This paper presents a method to measure the spontaneous extension of oriented PET fibredirectly during crystallization by twice annealing (constant-length and free-length). Samples be-fore and after the treatment were collected and examined by X-ray diffraction, DSC andbirefringence. The crystallinity, crystallite size, and orientation of both crystalline and amorphousparts between these samples are changed greatly which show that the extension is a consequence ofcrystallization and reorientation of uncrystallized segments along the fibre direction. The results ofthis study are not only important to understand the mechanism of supermolecular structurechanges during crystallization, but also useful to the industrial technology of crystallization spin-ning.
基金the National Natural Science Foundation of China(Nos.22233006,21890761,and 22121002).
文摘Production of fuel and chemicals from plastic waste is one of the effective ways to upcycle spent plastics,which is an interesting topic and of significance for green and sustainable development.Herein,we demonstrate a highly efficient catalyst,TiO_(2)nanoparticle supported Ru nanocatalyst(Ru/TiO_(2)),for upcycling polyethylene terephthalate(PET)to alkanes in the presence of H_(2) and water.Under the optimal conditions(200℃,60 bar H_(2),and small amount of H_(2)O),PET could completely convert into alkanes,dominated with cyclohexane and methane.It was indicated that the strong interaction between the TiO_(2)support and Ru nanoparticles made electrons flow from the TiO_(2)support to the Ru nanoparticles,which thus rendered Ru/TiO_(2)to have ability to simultaneously catalyze PET hydrolysis and intermediate hydrogenation.This work realizes the transformation of PET to alkanes,which provides a promising way to chemically upcycle PET.
基金The Ministry of Natural Resources and Environment(No.TNMT.2022.05.04).
文摘Synthetic plastics are often considered to be materials that cannot be broken down by natural processes.One such plastic,polyethylene terephthalate(PET),is commonly used in everyday items but when these products are discarded,they can cause serious harm to the environment and human health.In this study,PET plastic waste was used to create activated carbon using a physical activation process that involved using CO2 gas.The researchers investigated the effects of different temperatures,carbonization,and activation times on the resulting activated carbon’s surface area.The activated carbon was then analyzed using scanning electron microscopy(SEM),X-ray diffraction(XRD),FTIR,and BET.The activated carbon created from PET plastic waste showed excellent absorption properties for methylene blue in aqueous solutions across a wide range of pH levels.By creating activated carbon from plastic waste,not only are environmental issues addressed,but high-value activated carbon is produced for environmental remediation purposes.
基金Beijing Municipal Commission of Science and Technology Plan Projects,China(No.KYTG02170206/016)Open Project of Beijing Key Laboratory of Clothing Materials R&D and Assessment,China(No.KYTG02170205)
文摘The implantable artificial hair was prepared by grafting collagen on the surface of poly(ethylene terephthalate)(PET)to improve its biocompatibility.Acrylic acid(AAc)was used to modify the surface properties of PET firstly,and then collagen was grafted on the PET-AAc surface.The concentration of collagen solution was discussed to graft more collagen on PET surface.Composites were well characterized by scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FTIR)and X-ray photoelectron spectroscopy(XPS).SEM indicated that collagen with about 3.07μm thickness was coated on PET surface when the concentration of collagen solution was 1.0 mg/m L.FTIR and XPS showed AAc and collagen were both on the surface of PET monofilaments.The optimized concentration of collagen solution was 1.0 mg/m L,resulting in the most grafting density of 3.46μg/cm^(2).It can be concluded that a large amount of collagen is coated on PET surface.
文摘Non-thermal plasmas under atmospheric pressure are of great interest in polymer surface processing because of their convenience, effectiveness and low cost. In this paper, the treatment of Polyethylene terephthalate (PET) film surface for improving hydrophilicity using the non-thermal plasma generated by atmospheric pressure glow discharge (APGD) in air is conducted. The discharge characteristics of APGD are shown by measurement of their electrical discharge parameters and observation of light-emission phenomena, and the surface properties of PET before and after the APGD treatment are studied using contact angle measurement, x-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). It is found that the APGD is homogeneous and stable in the whole gas gap, which differs from the commonly filamentary dielectric barrier discharge (DBD). A short time (several seconds) APGD treatment can modify the surface characteristics of PET film markedly and uniformly. After 10 s APGD treatment, the
文摘Polyethylene terephthalate(PET) resin was hydrolyzed to terephthalate acid(TPA) and ethylene glycol(EG) under microwave irradiation.The effects of crystallinity on the depolymerization of PET was investigated.PET resin was isothermal crystallized at temperature of 140,170,200 and 230 ℃ for 5 hours,the crystallinity of the resin was 25.7%,29.5%,33.9% and 40.6%,respectively,then the resin with different crystallinity was hydrolyzed under microwave irriadition. Under the same conditions of hydrolytic depolymerization, the degree of PET depolymerization decreased from 72.8% to 69.34% with the increase of crystallinity of PET resin,the rate of depolymerization varied little with the increasing of crystallinity of PET,this indicated that the crystallinity of PET has little effect on the hydrolytic depolymerization.The crystallinity of PET was increased during the temperature elevating process of the hydrolytic depolymerization.Investigation by DSC proved that the crystallinity of PET resin increased notability during the same temperature elevating process as the hydrolyzed depolymerization.According to the theory that depolymerization was firstly proceed in the amorphous phase,the crystallinity should increase during the reaction.However,the crystallinity of PET residue was decreased during all the reaction process,this indicates that the hydrolysis did not preferentially occur in the amorphous phase.
