In order to investigate the effects of pre-oxidation conditions on adsorption performance of activated carbon fibers ( ACFs) ,electrospun polyacrylonitrile ( PAN) fiber webs were adopted as precursors for preparing AC...In order to investigate the effects of pre-oxidation conditions on adsorption performance of activated carbon fibers ( ACFs) ,electrospun polyacrylonitrile ( PAN) fiber webs were adopted as precursors for preparing ACFs. Firstly,the webs were stabilized under different pre-oxidation conditions; secondly,the pre-oxidative fibers were chemically activated by high temperature treatment in nitrogen. Pre-oxidation temperature,heating rate,and treatment time are the main factors on affecting the adsorption performance of the ACFs. Scanning electron microscope ( SEM) , differential scanning calorimeter ( DSC ) ,and Fourier transform infrared spectroscopy ( FTIR ) were used to characterize the structure and property of the pre-oxidative fibers,and the dynamic benzene adsorption capacity of benzene of ACFs was measured. The results indicate that the moderate pre-oxidation condition is necessary to prepare the ACFs with better adsorption capacity,and the optimal oxidation conditions are to increase from room temperature to 230 ℃ with a heating rate of 0. 75 ℃·min - 1 ,held at the peak temperature for 30 min.展开更多
利用自主改进的静电纺丝装置制备亲水性聚丙烯腈(polyacrylonitrile,PAN)与疏水性聚氯乙烯(polyvinylchloride,PVC)微纳米纤维/棉纤维包芯纱,并将其作为纬纱织造织物小样。结合扫描电子显微镜(scanning electron microscope,SEM)进行包...利用自主改进的静电纺丝装置制备亲水性聚丙烯腈(polyacrylonitrile,PAN)与疏水性聚氯乙烯(polyvinylchloride,PVC)微纳米纤维/棉纤维包芯纱,并将其作为纬纱织造织物小样。结合扫描电子显微镜(scanning electron microscope,SEM)进行包芯纱表面形貌表征与纤维直径测量,测试纱线强力,并对织物进行形貌观察以及水接触角测试与液态水分管理性能测试,以研究不同亲疏水性的微纳米纤维/棉纤维包芯纱对其织物导湿性能的影响。试验结果表明:亲水的PAN微纳米纤维/棉纤维包芯纱能够增强织物的导湿性,疏水的PVC微纳米纤维/棉纤维包芯纱对织物导湿性能的提升无积极作用;相比纯棉纱织物,PAN包芯纱/棉纱织物液态水单向传递指数提高了4级,并赋予其单向导湿性能。展开更多
In this article, we compared four types of knitted fabrics with high two-ply shape retention. Experimental samples of a two-layer knitted fabric have been developed and graphic symbols have been applied on a flat-need...In this article, we compared four types of knitted fabrics with high two-ply shape retention. Experimental samples of a two-layer knitted fabric have been developed and graphic symbols have been applied on a flat-needle weaving machine of the 12th class LONG-XING SM 252 (China).展开更多
Structure of PAN fibers during pre-oxidation and carbonization was studied using two dimensional small angle X-ray scattering/wide angle X-ray diffraction （2D SAXS/WAXD）. The SAXS results show that during pre-oxidat...Structure of PAN fibers during pre-oxidation and carbonization was studied using two dimensional small angle X-ray scattering/wide angle X-ray diffraction （2D SAXS/WAXD）. The SAXS results show that during pre-oxidation between 180 ℃ and 275 ℃, the volume content of microvoids increases with the temperature increasing, which may be one of reasons for the decrease of tensile strength ofpre-oxidized fibers. 253 ℃ was the critical transition temperature, the length, diameter, aspect ratio and orientation distribution of microvoids increased with temperature before this temperature and decreased after this temperature. After the high temperature carbonization, lots of spindly microvoids formed. WAXD patterns demonstrate that the crystallite size of PAN fibers first increased before 230 ℃ and then decreased with the increase of temperature during the pre-oxidation. The diffraction peak of PAN fibers at 2θ ≈ 17°almost disappeared at the end of pre- oxidation while the diffraction peak of aromatic structure at 2θ ≈ 25° appeared at 253 ℃. During carbonization, the peak intensity at 2θ ≈ 25° increased apparently due to the formation of graphite structure. The results obtained give a deep understanding of the microstrncture development in the PAN fibers during pre-oxidation and carbonization, which is important for the preparation of high performance carbon fibers.展开更多
文摘In order to investigate the effects of pre-oxidation conditions on adsorption performance of activated carbon fibers ( ACFs) ,electrospun polyacrylonitrile ( PAN) fiber webs were adopted as precursors for preparing ACFs. Firstly,the webs were stabilized under different pre-oxidation conditions; secondly,the pre-oxidative fibers were chemically activated by high temperature treatment in nitrogen. Pre-oxidation temperature,heating rate,and treatment time are the main factors on affecting the adsorption performance of the ACFs. Scanning electron microscope ( SEM) , differential scanning calorimeter ( DSC ) ,and Fourier transform infrared spectroscopy ( FTIR ) were used to characterize the structure and property of the pre-oxidative fibers,and the dynamic benzene adsorption capacity of benzene of ACFs was measured. The results indicate that the moderate pre-oxidation condition is necessary to prepare the ACFs with better adsorption capacity,and the optimal oxidation conditions are to increase from room temperature to 230 ℃ with a heating rate of 0. 75 ℃·min - 1 ,held at the peak temperature for 30 min.
文摘利用自主改进的静电纺丝装置制备亲水性聚丙烯腈(polyacrylonitrile,PAN)与疏水性聚氯乙烯(polyvinylchloride,PVC)微纳米纤维/棉纤维包芯纱,并将其作为纬纱织造织物小样。结合扫描电子显微镜(scanning electron microscope,SEM)进行包芯纱表面形貌表征与纤维直径测量,测试纱线强力,并对织物进行形貌观察以及水接触角测试与液态水分管理性能测试,以研究不同亲疏水性的微纳米纤维/棉纤维包芯纱对其织物导湿性能的影响。试验结果表明:亲水的PAN微纳米纤维/棉纤维包芯纱能够增强织物的导湿性,疏水的PVC微纳米纤维/棉纤维包芯纱对织物导湿性能的提升无积极作用;相比纯棉纱织物,PAN包芯纱/棉纱织物液态水单向传递指数提高了4级,并赋予其单向导湿性能。
文摘In this article, we compared four types of knitted fabrics with high two-ply shape retention. Experimental samples of a two-layer knitted fabric have been developed and graphic symbols have been applied on a flat-needle weaving machine of the 12th class LONG-XING SM 252 (China).
基金financially supported by Innovation Method Fund of China(2011IM030400)NSFC(No.10835008)+4 种基金the Knowledge Innovation Project of CAS(No.KJCX2-YW-N39)973 Program(No.2011CB605604)the Opening Foundation of Shenzhen Key Laboratory of Functional Polymers(FP20120012)Natural Science Foundation of Shenzhen University(Grant no.201204)the Shenzhen basic research project(JCYJ20120614085820810)
文摘Structure of PAN fibers during pre-oxidation and carbonization was studied using two dimensional small angle X-ray scattering/wide angle X-ray diffraction （2D SAXS/WAXD）. The SAXS results show that during pre-oxidation between 180 ℃ and 275 ℃, the volume content of microvoids increases with the temperature increasing, which may be one of reasons for the decrease of tensile strength ofpre-oxidized fibers. 253 ℃ was the critical transition temperature, the length, diameter, aspect ratio and orientation distribution of microvoids increased with temperature before this temperature and decreased after this temperature. After the high temperature carbonization, lots of spindly microvoids formed. WAXD patterns demonstrate that the crystallite size of PAN fibers first increased before 230 ℃ and then decreased with the increase of temperature during the pre-oxidation. The diffraction peak of PAN fibers at 2θ ≈ 17°almost disappeared at the end of pre- oxidation while the diffraction peak of aromatic structure at 2θ ≈ 25° appeared at 253 ℃. During carbonization, the peak intensity at 2θ ≈ 25° increased apparently due to the formation of graphite structure. The results obtained give a deep understanding of the microstrncture development in the PAN fibers during pre-oxidation and carbonization, which is important for the preparation of high performance carbon fibers.
