As the world's population exponentially grows,so does the need for the production of food,with cereal production growing annually from an estimated 1.0 billion to 2.5 billion tons within the last few decades.This ...As the world's population exponentially grows,so does the need for the production of food,with cereal production growing annually from an estimated 1.0 billion to 2.5 billion tons within the last few decades.This rapid growth in food production results in an ever increasing amount of agricultural wastes,of which already occupies nearly 50%of the total landfill area.For example,is the billions of dry tons of cellulose-containing spent coffee grounds disposed in landfills annually.This paper seeks to provide a method for isolating cellulose nanocrystals(CNCs)from spent coffee grounds,in order to recycle and utilize the cellulosic waste material which would otherwise have no applications.CNCs have already been shown to have vast applications in the polymer engineering field,mainly utilized for their high strength to weight ratio for reinforcement of polymer-based nanocomposites.A successful method of purifying and hydrolyzing the spent coffee grounds in order to isolate usable CNCs was established.The CNCs were then characterized using current techniques to determine important chemical and physical properties.A few crucial properties determined were aspect ratio of 12±3,crystallinity of 74.2%,surface charge density of(48.4±6.2)mM/kg cellulose,and the ability to successfully reinforce a polymer based nanocomposite.These characteristics compare well to other literature data and common commercial sources of CNCs.展开更多
Spent Coffee Ground (SCG) is characterized by high organic content, in the form of insoluble polysaccharides bound and phenol compounds. Phenol compounds are toxic to nature and <span style="font-family:Verdan...Spent Coffee Ground (SCG) is characterized by high organic content, in the form of insoluble polysaccharides bound and phenol compounds. Phenol compounds are toxic to nature and <span style="font-family:Verdana;">are</span><span style="font-family:Verdana;"> a cause of environmental pollution. Composting method of this study is aerobic static batch composting with temperature control with adding activators of some fungi such as </span><i><span style="font-family:Verdana;">Aspergillus sp</span></i><span style="font-family:Verdana;">, and </span><i><span style="font-family:Verdana;">Penicillium sp. </span></i><span style="font-family:Verdana;">The purpose of the research is to fill the research gap from previous studies of spent coffee grounds compost, which requires a long time in composting, so that if it is used directly on the soil and plants, the positive effect also requires a long time. The result of composting for 28 days with this method is that mature compost has black crumb and normal pH, with characteristics of C/N ratio below 10: C1 (7.06), C2 (6.99). This value is far from the control with a C/N ratio of 8.33. Decompose rate of macromolecule are above 40% for lignin and 70% for cellulose. Implementation of compost in radish plants, resulting Germination Index above 80% which indicates that the compost is ripe: control (92.39%), C1 (183.88%), C2 (191.86%). The results of the analysis with FTIR also showed that the compost was mature and stable, and rich in minerals. So, it can be concluded </span><span style="font-family:Verdana;">that</span><span style="font-family:Verdana;"> this composting method can speed up composting time and optimize the results of compost produced.</span>展开更多
Phosphate (PO<sub>4</sub><sup style="margin-left:-9px;">3-</sup><span style="font-family:Verdana;">) and Nitrate (NO<sub>3</sub><sup style="margin-...Phosphate (PO<sub>4</sub><sup style="margin-left:-9px;">3-</sup><span style="font-family:Verdana;">) and Nitrate (NO<sub>3</sub><sup style="margin-left:-9px;">-</sup></span><span style="font-family:Verdana;">) are two main nutrients that cause wa</span><span style="font-family:Verdana;">ter eutrophication. In the other hand, the presence of PO<sub>4</sub><sup style="margin-left:-9px;">3-</sup></span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">and NO<sub>3</sub><sup style="margin-left:-9px;">-</sup></span><span style="font-family:Verdana;"> is </span><span style="font-family:Verdana;">needed for plant growth. The aims of this study </span><span style="font-family:Verdana;">are </span><span style="font-family:Verdana;">to recycl</span><span style="font-family:Verdana;">e</span><span style="font-family:Verdana;"> Spent Coffee Ground (SCG) modified with calcium hydroxide for adsorption PO<sub>4</sub><sup style="margin-left:-9px;">3-</sup></span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">and NO<sub>3</sub><sup style="margin-left:-9px;">-</sup></span><span style="font-family:Verdana;">. The optimum adsorption capacity for PO<sub>4</sub><sup style="margin-left:-9px;">3-</sup></span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">and NO<sub>3</sub><sup style="margin-left:-9px;">-</sup></span><span style="font-family:Verdana;"> is 36.74 mg/L and 20.21 mg/L, respectively. The Freundlich isotherm model was suitable for PO<sub>4</sub><sup style="margin-left:-9px;">3-</sup></span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">and NO<sub>3</sub><sup style="margin-left:-9px;">-</sup></span><span style="font-family:Verdana;"> adsorption. The kinetic model for adsorption was linear using Pseudo-second order. The application of modified SCG after enrich</span><span style="font-family:Verdana;">ment with PO<sub>4</sub><sup style="margin-left:-9px;">3-</sup></span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">and NO<sub>3</sub><sup style="margin-left:-9px;">-</sup></span><span style="font-family:Verdana;"> for plant growth (</span><i><span style="font-family:Verdana;">Raphanus sativus</span></i><span style="font-family:Verdana;">) showed</span><span style="font-family:Verdana;"> optimum growth at a dose of 0.3% with value of germination index was 203%.</span>展开更多
This paper reported the facile preparation of pyrolytic carbon derived from spent coffee grounds and the evaluation of its electrochemical performance when used as anode in sodium-ion battery.X-ray diffraction analys...This paper reported the facile preparation of pyrolytic carbon derived from spent coffee grounds and the evaluation of its electrochemical performance when used as anode in sodium-ion battery.X-ray diffraction analysis,scanning electron microscope,Brunauer–Emmett–Teller were employed to characterize the structure of pyrolytic carbon.Electrochemical performances were tested by constant current charge–discharge,cyclic voltammetry and electrochemical impedance spectroscopy.Results showed that the pyrolytic carbon possess a porous structure(1–2 lm)and a specific surface area of 94.35 m2 g1.When used as anodes in sodium-ion batteries,a reversible capacity of 154.2 mA h g1 at a current density of 200 mA g1 after 50 cycles was obtained.Several electrolytes were evaluated and their electrochemical performances were compared.The result indicated that this material has excellent storage capacity and good cycling stability.Our method provided a preparation of pyrolytic carbon from environmentally friendly resources.展开更多
The conductive polymer composites(CPCs) with highly efficient electromagnetic interference(EMI)shielding effectiveness(SE) are always accompanied with excessive reflectivity, which would cause serious secondary EMI po...The conductive polymer composites(CPCs) with highly efficient electromagnetic interference(EMI)shielding effectiveness(SE) are always accompanied with excessive reflectivity, which would cause serious secondary EMI pollution. In this regard, the significant reduction of EMI reflection of CPCs to alleviate secondary pollution is deemed to be very important. Herein, a promising cyanate ester(CE) based composite was successfully fabricated by compounding carbonized spent coffee grounds(C-SCG) and graphene nanosheets(GNSs) via a facile solution blending followed by a hot-pressing method. Benefiting from the porous structure of C-SCG and the layered structure of GNSs, a three-dimensional(3 D)multi-interface conductive network in the CE was easily constructed. The EMI SE of the resultant 9 wt%C-SCG/CE composite(C9) is 15.38 d B and dramatically enhanced to 31.09 d B with the presence of 3 wt% GNSs. The remarkable enhancement is mainly attributed to the formation of the efficient conductive pathways as well as the well-dispersion of the incorporated fillers. Meanwhile, the absorption-dominated shielding mechanism in the prepared composites gets benefit from the synergistic effect of porous C-SCG and lamellar GNSs, which effectively captures and attenuates electromagnetic waves. These encouraging findings extend the practical applications of porous biocarbon materials in EMI shielding field.展开更多
文摘As the world's population exponentially grows,so does the need for the production of food,with cereal production growing annually from an estimated 1.0 billion to 2.5 billion tons within the last few decades.This rapid growth in food production results in an ever increasing amount of agricultural wastes,of which already occupies nearly 50%of the total landfill area.For example,is the billions of dry tons of cellulose-containing spent coffee grounds disposed in landfills annually.This paper seeks to provide a method for isolating cellulose nanocrystals(CNCs)from spent coffee grounds,in order to recycle and utilize the cellulosic waste material which would otherwise have no applications.CNCs have already been shown to have vast applications in the polymer engineering field,mainly utilized for their high strength to weight ratio for reinforcement of polymer-based nanocomposites.A successful method of purifying and hydrolyzing the spent coffee grounds in order to isolate usable CNCs was established.The CNCs were then characterized using current techniques to determine important chemical and physical properties.A few crucial properties determined were aspect ratio of 12±3,crystallinity of 74.2%,surface charge density of(48.4±6.2)mM/kg cellulose,and the ability to successfully reinforce a polymer based nanocomposite.These characteristics compare well to other literature data and common commercial sources of CNCs.
文摘Spent Coffee Ground (SCG) is characterized by high organic content, in the form of insoluble polysaccharides bound and phenol compounds. Phenol compounds are toxic to nature and <span style="font-family:Verdana;">are</span><span style="font-family:Verdana;"> a cause of environmental pollution. Composting method of this study is aerobic static batch composting with temperature control with adding activators of some fungi such as </span><i><span style="font-family:Verdana;">Aspergillus sp</span></i><span style="font-family:Verdana;">, and </span><i><span style="font-family:Verdana;">Penicillium sp. </span></i><span style="font-family:Verdana;">The purpose of the research is to fill the research gap from previous studies of spent coffee grounds compost, which requires a long time in composting, so that if it is used directly on the soil and plants, the positive effect also requires a long time. The result of composting for 28 days with this method is that mature compost has black crumb and normal pH, with characteristics of C/N ratio below 10: C1 (7.06), C2 (6.99). This value is far from the control with a C/N ratio of 8.33. Decompose rate of macromolecule are above 40% for lignin and 70% for cellulose. Implementation of compost in radish plants, resulting Germination Index above 80% which indicates that the compost is ripe: control (92.39%), C1 (183.88%), C2 (191.86%). The results of the analysis with FTIR also showed that the compost was mature and stable, and rich in minerals. So, it can be concluded </span><span style="font-family:Verdana;">that</span><span style="font-family:Verdana;"> this composting method can speed up composting time and optimize the results of compost produced.</span>
文摘Phosphate (PO<sub>4</sub><sup style="margin-left:-9px;">3-</sup><span style="font-family:Verdana;">) and Nitrate (NO<sub>3</sub><sup style="margin-left:-9px;">-</sup></span><span style="font-family:Verdana;">) are two main nutrients that cause wa</span><span style="font-family:Verdana;">ter eutrophication. In the other hand, the presence of PO<sub>4</sub><sup style="margin-left:-9px;">3-</sup></span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">and NO<sub>3</sub><sup style="margin-left:-9px;">-</sup></span><span style="font-family:Verdana;"> is </span><span style="font-family:Verdana;">needed for plant growth. The aims of this study </span><span style="font-family:Verdana;">are </span><span style="font-family:Verdana;">to recycl</span><span style="font-family:Verdana;">e</span><span style="font-family:Verdana;"> Spent Coffee Ground (SCG) modified with calcium hydroxide for adsorption PO<sub>4</sub><sup style="margin-left:-9px;">3-</sup></span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">and NO<sub>3</sub><sup style="margin-left:-9px;">-</sup></span><span style="font-family:Verdana;">. The optimum adsorption capacity for PO<sub>4</sub><sup style="margin-left:-9px;">3-</sup></span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">and NO<sub>3</sub><sup style="margin-left:-9px;">-</sup></span><span style="font-family:Verdana;"> is 36.74 mg/L and 20.21 mg/L, respectively. The Freundlich isotherm model was suitable for PO<sub>4</sub><sup style="margin-left:-9px;">3-</sup></span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">and NO<sub>3</sub><sup style="margin-left:-9px;">-</sup></span><span style="font-family:Verdana;"> adsorption. The kinetic model for adsorption was linear using Pseudo-second order. The application of modified SCG after enrich</span><span style="font-family:Verdana;">ment with PO<sub>4</sub><sup style="margin-left:-9px;">3-</sup></span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">and NO<sub>3</sub><sup style="margin-left:-9px;">-</sup></span><span style="font-family:Verdana;"> for plant growth (</span><i><span style="font-family:Verdana;">Raphanus sativus</span></i><span style="font-family:Verdana;">) showed</span><span style="font-family:Verdana;"> optimum growth at a dose of 0.3% with value of germination index was 203%.</span>
基金the National Key Research and Development Program(Grant No.2016YFB0100106)the Youth Innovation Promotion Association,Chinese Academy of Sciences(2015239)for financial supports.
文摘This paper reported the facile preparation of pyrolytic carbon derived from spent coffee grounds and the evaluation of its electrochemical performance when used as anode in sodium-ion battery.X-ray diffraction analysis,scanning electron microscope,Brunauer–Emmett–Teller were employed to characterize the structure of pyrolytic carbon.Electrochemical performances were tested by constant current charge–discharge,cyclic voltammetry and electrochemical impedance spectroscopy.Results showed that the pyrolytic carbon possess a porous structure(1–2 lm)and a specific surface area of 94.35 m2 g1.When used as anodes in sodium-ion batteries,a reversible capacity of 154.2 mA h g1 at a current density of 200 mA g1 after 50 cycles was obtained.Several electrolytes were evaluated and their electrochemical performances were compared.The result indicated that this material has excellent storage capacity and good cycling stability.Our method provided a preparation of pyrolytic carbon from environmentally friendly resources.
基金financial support from the National Natural Science Foundation of China (No. 51773167)the Natural Science Foundation of Shaanxi Province (No. 2019CGXNG-033)+2 种基金the Science and Technology Plan Project of Xi’an (Nos. 2019217814GXRC014CG015-GXYD14.7, and 2019217814GXRC014CG015-GXYD14.8)the China Postdoctoral Science Foundation (No. 2019M650268)the Opening Project of State Key Laboratory of Polymer Materials Engineering (Sichuan University) (No. sklpme2020-4-16)。
文摘The conductive polymer composites(CPCs) with highly efficient electromagnetic interference(EMI)shielding effectiveness(SE) are always accompanied with excessive reflectivity, which would cause serious secondary EMI pollution. In this regard, the significant reduction of EMI reflection of CPCs to alleviate secondary pollution is deemed to be very important. Herein, a promising cyanate ester(CE) based composite was successfully fabricated by compounding carbonized spent coffee grounds(C-SCG) and graphene nanosheets(GNSs) via a facile solution blending followed by a hot-pressing method. Benefiting from the porous structure of C-SCG and the layered structure of GNSs, a three-dimensional(3 D)multi-interface conductive network in the CE was easily constructed. The EMI SE of the resultant 9 wt%C-SCG/CE composite(C9) is 15.38 d B and dramatically enhanced to 31.09 d B with the presence of 3 wt% GNSs. The remarkable enhancement is mainly attributed to the formation of the efficient conductive pathways as well as the well-dispersion of the incorporated fillers. Meanwhile, the absorption-dominated shielding mechanism in the prepared composites gets benefit from the synergistic effect of porous C-SCG and lamellar GNSs, which effectively captures and attenuates electromagnetic waves. These encouraging findings extend the practical applications of porous biocarbon materials in EMI shielding field.