Self-healable and flexible all-in-one self-powering smartsensing devices have recently attracted great attention.Herein,a flexible all-in-one solid-state electronic system of polyvinyl alcohol(PVA)hydrogel-based super...Self-healable and flexible all-in-one self-powering smartsensing devices have recently attracted great attention.Herein,a flexible all-in-one solid-state electronic system of polyvinyl alcohol(PVA)hydrogel-based supercapacitors for self-powering ammonia smartsensors has been fabricated.Self-healing supercapacitors are prepared by integrating polypyrrole(PPy)and boron crosslinked PVA/KCl hydrogel as a sandwich configuration,exhibiting large specific capacitance of 244.81 mF cm^(-2)at 0.47 mA cm^(-2),and good charging/discharging stability of 2000 cycles,while ammonia sensors are realized by a SnO_(2)/PPy-modified conductive PVA hydrogel film,demonstrating an excellent sensing behavior toward NH_(3) vapor under 50 ppb–500 ppm.As a result,selfhealing supercapacitors could well store energy and then self-power sensing unit for remotely real-time detection via a smartphone,acquiring high flexibility of energy-sensing system.With attractive biocompatibility and selfhealing performance toward various environment,this all-in-one flexible energy-smartsensor system would pave the way to novel fabrication process in realization of wearable self-healing smart devices.展开更多
As an excellent room temperature sensing material,polyaniline(PANI)needs to be further investigated in the field of high sensitivity and sustainable gas sensors due to its long recovery time and difficulty to complete...As an excellent room temperature sensing material,polyaniline(PANI)needs to be further investigated in the field of high sensitivity and sustainable gas sensors due to its long recovery time and difficulty to complete recovery.The ZnO/PANI film with p-n heterogeneous energy levels have successfully prepared by spraying Zno nanorod synthesized by hydrothermal method on the PANI film rapidly synthesized at the gas-liquid interface.The presence of p-n heterogeneous energy levels enables the ZnO/PANI film to detect 0.1-100 ppm(1 ppm=10^(-6))NH_(3)at room temperature with the response value to 100 ppm NH_(3)doubled(12.96)and the recovery time shortened to 1/5(31.2s).The ability of high response and fast recovery makes the ZnO/PANI filmto be able to detect NH_(3)at room temperature continuously.It provides a new idea for PANI to prepare sustainable room temperature sensor and promotes the development of room temperature sensor in public safety.展开更多
Ammonia sensors have broad spectrum of applications for industrial process control as well as for environ-mental monitoring. An optical fiber ammonia sensor probe has been developed by using a bent optical fiber havin...Ammonia sensors have broad spectrum of applications for industrial process control as well as for environ-mental monitoring. An optical fiber ammonia sensor probe has been developed by using a bent optical fiber having dual poly(methyl methacrylate) (PMMA)/chlorophenol red (CPR) coatings as a transducer. This sen-sor probe was tested for monitoring trace ammonia in gas samples using air as sample matrix. The reaction of ammonia with CPR causes a color change of the reagent, which was detected by using fiber optic evanes-cent wave absorption spectrometry as a sensing signal. By adopting a dual layer coating structure, the sensor probe has faster response compared to a sensor using a broadly accepted sensing reagent-immobilized poly-mer coating structure. The sensor developed in this work is sensitive, has a detection limit of 2.7 ppb NH3 in air, which is the most sensitive among the reported optical fiber ammonia sensors to the best knowledge of the authors. The sensor is also reversible and has a response time of 25 minutes. The features of high sensi-tivity, reversibility and reasonable response time make this sensor technique very attractive for air quality monitoring.展开更多
Polypyrrole (Ppy) was synthesized using Ferric Chloride (FeCl3) as oxidant. The ratio of monomer to oxidant was 1:2.4. The polymerization was carried out at 5。C. Attempts were made to increase the electrical conduc-t...Polypyrrole (Ppy) was synthesized using Ferric Chloride (FeCl3) as oxidant. The ratio of monomer to oxidant was 1:2.4. The polymerization was carried out at 5。C. Attempts were made to increase the electrical conduc-tivity by using various dopants viz. Lithium per Chlorate (LiClO4), para-Toluene Sulfonate (p-TS) and Nap-thalene Sulfonic acid (NSA). The materials were characterized using FTIR, X-Ray diffraction and SEM. The electrical conductivity was measured by two probe method and was found to be in the range of 10-3 to 10-2 S/cm. Thin films of these preparations were casted on the interdigited electrodes to study the detection of gases such as ammonia and LPG. It was found that for the pure Ppy and one doped with LiClO4, when ammonia gas was allowed to flow in, there was a sudden increase in the current, which decreased rapidly when gas was stopped. This behavior is in contradiction to that observed in earlier investigations where Ppy was prepared by electrochemical method. However when Ppy doped with p-TS and NSA were used, the trend was reversed. Similarly it was noted that for pure Ppy and one doped with LiClO4, p-TS and NSA there was an increase in the current when LPG gas was brought in. However the response to LPG was somewhat low as compared ammonia gas.展开更多
Polypyrrole (Ppy) was synthesized using Ammonium Peroxy Disulfate (APS) as oxidant in a standard ratio of monomer to oxidants at 5℃. Attempts were made to increase the electrical conductivity by using various dopants...Polypyrrole (Ppy) was synthesized using Ammonium Peroxy Disulfate (APS) as oxidant in a standard ratio of monomer to oxidants at 5℃. Attempts were made to increase the electrical conductivity by using various dopants viz. Lithium per Chlorate (LiClO4), para-Toluene Sulfonate (p-TS) and Napthalene Sulfonic acid (NSA). The materials were characterized using FTIR, X Ray diffraction and SEM. The electrical conductivity was measured by two probe method and was found to be in the range of 10-3 S/cm. Thin films of these preparations were casted on the interdigited electrodes to study the detection of gas such as ammonia. It was found that for the pure Ppy when ammonia gas was allowed to flow in, there was a sudden increase in the current, which decreased rapidly when gas was stopped. However when Ppy doped with p-TS, NSA and LiClO4, the trend was reversed.展开更多
Selective Catalytic Reduction (SCR) catalysts respond slowly to transient inputs, which is troublesome when designing ammonia feed controllers. An experimental SCR test apparatus installed on a slipstream of a Coo-per...Selective Catalytic Reduction (SCR) catalysts respond slowly to transient inputs, which is troublesome when designing ammonia feed controllers. An experimental SCR test apparatus installed on a slipstream of a Coo-per-Bessemer GMV-4, 2-stroke cycle natural gas engine is utilized. Ammonia (NH3) feed rate control algo-rithm development is carried out. Two control algorithms are evaluated: a feed forward control algorithm, using a pre ammonia injection ceramic NOx sensor and a feed forward plus feedback control algorithm, us-ing a pre ammonia injection ceramic NOx sensor and post catalyst ceramic NOx sensor to generate feedback signals. The feed forward algorithm controls to constant user input NH3/NOx molar ratio. The data show the lack of pressure compensation on the ceramic NOx sensors cause errors in feed forward NOx readings, re-sulting in sub optimal ammonia feed. The feedback system minimizes the post catalyst ceramic NOx sensor signal by adjusting the NH3/NOx molar ratio. The NOx sensors respond to ammonia + NOx;therefore, the feed forward plus feedback algorithm minimizes the sum of NOx emissions and ammonia slip. Successful application of the feedback control minimization technique is demonstrated with feedback periods of 15 and 5 minutes with molar ratio step sizes of 5 and 2.5%, respectively.展开更多
The main goal of this work is to explore the possibility of using Au-modified hydroxyapatite(HA) as a potential sensor material. Tube-like HA structure was fabricated with the aid of a Nafion N-117 cation exchange mem...The main goal of this work is to explore the possibility of using Au-modified hydroxyapatite(HA) as a potential sensor material. Tube-like HA structure was fabricated with the aid of a Nafion N-117 cation exchange membrane and gold(Au) nanoparticles were added by a hydrothermal method. The morphology, structure and composition were characterized by scanning electron microscopy(SEM), transmission electron microscopy(TEM), X-ray diffraction(XRD), and X-ray photoelectron spectroscopy(XPS). The gas sensing properties were also investigated. Results show that Au nanoparticles are dispersed into the HA powder, which is tube-like, with rough inner and outer surfaces. Compared with pure HA, Au-modified HA exhibits improved sensing properties for NH_3. 5%(mass fraction) Au-modified HA shows the highest response with relatively short response/recovery time. The response is up to 79.2% when the corresponding sensor is exposed to 200×10^(-6) NH_3 at room temperature, and the response time and recovery time are 20 s and 25 s, respectively. For lower concentration, like 50×10^(-6), the response is still up to 70.8%. Good selectivity and repeatability are also observed. The sensing mechanism of high response and selectivity for NH_3 gas was also discussed. These results suggest that Au-HA composite is a promising material for NH_3 sensors operating at room temperature.展开更多
基金financial support from National Natural Science Foundation of China(Grant No.22074010)Dalian Science and Technology Bureau,China(Grant No.2019J12SN54)+1 种基金Basic and Applied Basic Research Program of Guangzhou City,China(Grant No.202002030434)Zhang Dayu School of Chemistry,Dalian University of Technology,China。
文摘Self-healable and flexible all-in-one self-powering smartsensing devices have recently attracted great attention.Herein,a flexible all-in-one solid-state electronic system of polyvinyl alcohol(PVA)hydrogel-based supercapacitors for self-powering ammonia smartsensors has been fabricated.Self-healing supercapacitors are prepared by integrating polypyrrole(PPy)and boron crosslinked PVA/KCl hydrogel as a sandwich configuration,exhibiting large specific capacitance of 244.81 mF cm^(-2)at 0.47 mA cm^(-2),and good charging/discharging stability of 2000 cycles,while ammonia sensors are realized by a SnO_(2)/PPy-modified conductive PVA hydrogel film,demonstrating an excellent sensing behavior toward NH_(3) vapor under 50 ppb–500 ppm.As a result,selfhealing supercapacitors could well store energy and then self-power sensing unit for remotely real-time detection via a smartphone,acquiring high flexibility of energy-sensing system.With attractive biocompatibility and selfhealing performance toward various environment,this all-in-one flexible energy-smartsensor system would pave the way to novel fabrication process in realization of wearable self-healing smart devices.
基金supported by the National Natural Science Foundation of China(Grant Nos.21771060 and 61271126)the International Science&Technology Cooperation Program of China(Grant No.2016YFE0115100)+2 种基金the Program for Science and Technology Project of Heilongjiang Province(Grant No.JQ2021B002)the Heilongjiang Provincial Natural Science Foundation of China(Grant No.2019LH0320)the Reform and Development Fund Project of Local University supported by the Central Government,Heilongjiang Touyan Innovation Team Program.
文摘As an excellent room temperature sensing material,polyaniline(PANI)needs to be further investigated in the field of high sensitivity and sustainable gas sensors due to its long recovery time and difficulty to complete recovery.The ZnO/PANI film with p-n heterogeneous energy levels have successfully prepared by spraying Zno nanorod synthesized by hydrothermal method on the PANI film rapidly synthesized at the gas-liquid interface.The presence of p-n heterogeneous energy levels enables the ZnO/PANI film to detect 0.1-100 ppm(1 ppm=10^(-6))NH_(3)at room temperature with the response value to 100 ppm NH_(3)doubled(12.96)and the recovery time shortened to 1/5(31.2s).The ability of high response and fast recovery makes the ZnO/PANI filmto be able to detect NH_(3)at room temperature continuously.It provides a new idea for PANI to prepare sustainable room temperature sensor and promotes the development of room temperature sensor in public safety.
文摘Ammonia sensors have broad spectrum of applications for industrial process control as well as for environ-mental monitoring. An optical fiber ammonia sensor probe has been developed by using a bent optical fiber having dual poly(methyl methacrylate) (PMMA)/chlorophenol red (CPR) coatings as a transducer. This sen-sor probe was tested for monitoring trace ammonia in gas samples using air as sample matrix. The reaction of ammonia with CPR causes a color change of the reagent, which was detected by using fiber optic evanes-cent wave absorption spectrometry as a sensing signal. By adopting a dual layer coating structure, the sensor probe has faster response compared to a sensor using a broadly accepted sensing reagent-immobilized poly-mer coating structure. The sensor developed in this work is sensitive, has a detection limit of 2.7 ppb NH3 in air, which is the most sensitive among the reported optical fiber ammonia sensors to the best knowledge of the authors. The sensor is also reversible and has a response time of 25 minutes. The features of high sensi-tivity, reversibility and reasonable response time make this sensor technique very attractive for air quality monitoring.
文摘Polypyrrole (Ppy) was synthesized using Ferric Chloride (FeCl3) as oxidant. The ratio of monomer to oxidant was 1:2.4. The polymerization was carried out at 5。C. Attempts were made to increase the electrical conduc-tivity by using various dopants viz. Lithium per Chlorate (LiClO4), para-Toluene Sulfonate (p-TS) and Nap-thalene Sulfonic acid (NSA). The materials were characterized using FTIR, X-Ray diffraction and SEM. The electrical conductivity was measured by two probe method and was found to be in the range of 10-3 to 10-2 S/cm. Thin films of these preparations were casted on the interdigited electrodes to study the detection of gases such as ammonia and LPG. It was found that for the pure Ppy and one doped with LiClO4, when ammonia gas was allowed to flow in, there was a sudden increase in the current, which decreased rapidly when gas was stopped. This behavior is in contradiction to that observed in earlier investigations where Ppy was prepared by electrochemical method. However when Ppy doped with p-TS and NSA were used, the trend was reversed. Similarly it was noted that for pure Ppy and one doped with LiClO4, p-TS and NSA there was an increase in the current when LPG gas was brought in. However the response to LPG was somewhat low as compared ammonia gas.
文摘Polypyrrole (Ppy) was synthesized using Ammonium Peroxy Disulfate (APS) as oxidant in a standard ratio of monomer to oxidants at 5℃. Attempts were made to increase the electrical conductivity by using various dopants viz. Lithium per Chlorate (LiClO4), para-Toluene Sulfonate (p-TS) and Napthalene Sulfonic acid (NSA). The materials were characterized using FTIR, X Ray diffraction and SEM. The electrical conductivity was measured by two probe method and was found to be in the range of 10-3 S/cm. Thin films of these preparations were casted on the interdigited electrodes to study the detection of gas such as ammonia. It was found that for the pure Ppy when ammonia gas was allowed to flow in, there was a sudden increase in the current, which decreased rapidly when gas was stopped. However when Ppy doped with p-TS, NSA and LiClO4, the trend was reversed.
文摘Selective Catalytic Reduction (SCR) catalysts respond slowly to transient inputs, which is troublesome when designing ammonia feed controllers. An experimental SCR test apparatus installed on a slipstream of a Coo-per-Bessemer GMV-4, 2-stroke cycle natural gas engine is utilized. Ammonia (NH3) feed rate control algo-rithm development is carried out. Two control algorithms are evaluated: a feed forward control algorithm, using a pre ammonia injection ceramic NOx sensor and a feed forward plus feedback control algorithm, us-ing a pre ammonia injection ceramic NOx sensor and post catalyst ceramic NOx sensor to generate feedback signals. The feed forward algorithm controls to constant user input NH3/NOx molar ratio. The data show the lack of pressure compensation on the ceramic NOx sensors cause errors in feed forward NOx readings, re-sulting in sub optimal ammonia feed. The feedback system minimizes the post catalyst ceramic NOx sensor signal by adjusting the NH3/NOx molar ratio. The NOx sensors respond to ammonia + NOx;therefore, the feed forward plus feedback algorithm minimizes the sum of NOx emissions and ammonia slip. Successful application of the feedback control minimization technique is demonstrated with feedback periods of 15 and 5 minutes with molar ratio step sizes of 5 and 2.5%, respectively.
基金Project(51272289) supported by the National Natural Science Foundation of China
文摘The main goal of this work is to explore the possibility of using Au-modified hydroxyapatite(HA) as a potential sensor material. Tube-like HA structure was fabricated with the aid of a Nafion N-117 cation exchange membrane and gold(Au) nanoparticles were added by a hydrothermal method. The morphology, structure and composition were characterized by scanning electron microscopy(SEM), transmission electron microscopy(TEM), X-ray diffraction(XRD), and X-ray photoelectron spectroscopy(XPS). The gas sensing properties were also investigated. Results show that Au nanoparticles are dispersed into the HA powder, which is tube-like, with rough inner and outer surfaces. Compared with pure HA, Au-modified HA exhibits improved sensing properties for NH_3. 5%(mass fraction) Au-modified HA shows the highest response with relatively short response/recovery time. The response is up to 79.2% when the corresponding sensor is exposed to 200×10^(-6) NH_3 at room temperature, and the response time and recovery time are 20 s and 25 s, respectively. For lower concentration, like 50×10^(-6), the response is still up to 70.8%. Good selectivity and repeatability are also observed. The sensing mechanism of high response and selectivity for NH_3 gas was also discussed. These results suggest that Au-HA composite is a promising material for NH_3 sensors operating at room temperature.
