The significance of this study lies in addressing critical issues prevalent in the worldwide construction sector, particularly concerning the durability and sustainability of cement-based materials. Plain cement composites commonly suffer from deficiencies in tensile strength and strain capacity, resulting in the formation of nano-cracks under relatively low tensile loads. These nano- cracks pose a significant challenge to the longevity and resilience of cement matrices, contributing to structural degradation and reduced service life of infrastructure. To mitigate these challenges, the integration of cellulose nanofibers (CNF) as reinforcements in cement composites presents a promising solution. CNF, renowned for their exceptional material properties including high stiffness, tensile strength, and corrosion resistance, offer the potential to significantly enhance the mechanical performance and durability of cement-based materials. Through systematic experimentation, this study investigates the effects of CNF reinforcement on the mechanical properties of cement composites. By leveraging ultrasonically dispersion techniques, CNF extracted from bamboo, broad leaf, and kenaf are uniformly dispersed within the cement matrix at varying concentrations. Compressive and flexural tests are subsequently conducted to evaluate the impact of CNF on the strength characteristics of the cement composites. By elucidating the efficacy of CNF reinforcement through rigorous experimentation, this study aims to provide valuable insights into the development of construction materials with improved durability and sustainability. Ultimately, this research contributes to addressing critical challenges in the construction industry, offering potential solutions to enhance the performance and longevity of cement-based infrastructure.

Porous carbon nanofiber (CNF) electrodes for supercapacitors were prepared by using polyacrylonitrile (PAN) and cucurbituril (CB), which is a macrocyclic compound comprising glycoluril units containing hollow cores. Mixture of PAN and CB in dimethyl sulfoxide was electrospun, and thermally treated to produce CNF electrodes. Their thermal stability, surface morphology, carbon microstructures, and surface porosity were investigated. Electrochemical properties were measured using three-electrode with synthesized CNFs without further treatment as a working electrode and 1 M Na2SO4 as an electrolyte. CNFs derived from PAN and CB exhibited a high specific capacitance of 183.5 F g− 1 and an energy density of 25.4 Wh kg− 1 at 0.5 A g− 1 with stable cyclic stability during 1000 cycles, which is significantly higher than those for CNFs derived from PAN only. This demonstrated that the introduction of CB successfully improved the energy storage performance of CNF electrodes.

The discharge of industrial oily wastewater and oil spill accidents has resulted in significant environmental pollution, creating an urgent need for the treatment of oily wastewater. Nanofiber membranes, known for their high stability, flux, and efficiency, are widely employed in oil–water separation. This study systematically compared the performance of polyacrylonitrile/ graphene oxide (PAN/GO) composite nanofiber membranes prepared through immersion and electrospinning methods for oily wastewater treatment. Experimental findings demonstrated that immersion-prepared membranes achieved high flux (772.9 ± 2.9 L·m−2·h−1, n-hexane/water mixture) and efficiency (98.8%) at a GO concentration of 1.0 g/mL. On the other hand, electrospinning-prepared membranes exhibited superior flux (1500.3 ± 4.4 L·m−2·h−1, n-hexane/water mixture) and efficiency (99.6%) at a higher GO concentration (1.5 g/mL). This membrane displayed excellent stability, maintaining their exceptional performance even after ten cycles of separation. This study compared the advantages and disadvantages of the two methods for preparation of PAN/GO composite nanofiber membrane, offering valuable guidance for practical applications.

Carbon nanofibers (CNFs) are promising materials for the construction of energy devices, particularly organic solar cells. In the electrospinning process, polyacrylonitrile (PAN) has been utilized to generate nanofibers, which is the simplest and most popular method of creating carbon nanofibers (CNFs) followed by carbonization. The CNFs are coated on stainless steel (SS) plates and involve an electropolymerization process. The prepared Cu, CNF, CNF–Cu, PANI, PANI–Cu, CNF–PANI, and CNF–PANI–Cu electrode materials’ electrical conductivity was evaluated using cyclic voltammetry (CV) technique in 1 M H2SO4 electrolyte solution. Compared to others, the CNF–PANI–Cu electrode has higher conductivity that range is 3.0 mA. Moreover, the PANI, CNF–PANI, and CNF–PANI–Cu are coated on FTO plates and characterized for their optical properties (absorbance, transmittance, and emission) and electrical properties (CV and Impedance) for organic solar cell application. The functional groups, and morphology-average roughness of the electrode materials found by FT–IR, XRD, XPS, SEM, and TGA exhibit a strong correlation with each other. Finally, the electrode materials that have been characterized serve to support and act as the nature of the hole transport for organic solar cells.

In this study, a milled carbon nanofiber-reinforced composite paint was prepared to enhance the anti-corrosive properties of concrete structures. Shorter-length (40 μm) milled carbon fibers (MCFs) showed an increased viscosity relative to longer MCFs (120 μm) owing to their 2 weeks (the decrease was especially strong in the acid solution). A carbon nanotube (CNT)- reinforced composite paint showed similar results in uniform distribution in the epoxy resin. The latter showed a decrease in viscosity owing to agglomerative movement in the epoxy resin. The surface hardness and tensile strength of the composite paint linearly increased as the carbon nanofiber loading was increased by up to 7.2 wt% in the epoxy resin, and slowly decreased after soaking in a sulfuric acid or sodium hydroxide solution for to those of the MCFs, whereas CNTs dispersed in isopropyl alcohol (IPA) in advance and mixed with resin showed lower hardness values than those without dispersion in IPA at the same loading. The mechanical properties such as the Shore D hardness and tensile strength of the MCF-reinforced composite paint increased significantly, resulting in a slower surface degradation of the composite paint concrete in a sulfuric acid and sodium hydroxide solution.

In this study, we have fabricated the phenolic resin (PR)/polyacrylonitrile (PAN) blend-derived core-sheath nanostructured carbon nanofibers (CNFs) via one-pot solution electrospinning. The obtained core-sheath nanostructured carbon nanofibers were further treated by mixed salt activation process to develop the activated porous CNFs (CNF-A). Compared to pure PAN-based CNFs, the activated PR/PAN blend with PR 20% (CNF28-A)-derived core-sheath nanostructured CNFs showed enhanced specific capacitance of ~ 223 F g− 1 under a three-electrode configuration. Besides, the assembled symmetric CNF28-A//CNF28-A device possessed a specific capacitance of 76.7 F g− 1 at a current density of 1 A g− 1 and exhibited good stability of 111% after 5,000 galvanostatic charge/discharge (GCD) cycles, which verifies the outstanding long-term cycle stability of the device. Moreover, the fabricated supercapacitor device delivered an energy density of 8.63 Wh kg− 1 at a power density of 450 W kg− 1.

Energy storage systems should address issues such as power fluctuations and rapid charge-discharge; to meet this requirement, CoFe2O4 (CFO) spinel nanoparticles with a suitable electrical conductivity and various redox states are synthesized and used as electrode materials for supercapacitors. In particular, CFO electrodes combined with carbon nanofibers (CNFs) can provide long-term cycling stability by fabricating binder-free three-dimensional electrodes. In this study, CFO-decorated CNFs are prepared by electrospinning and a low-cost hydrothermal method. The effects of heat treatment, such as the activation of CNFs (ACNFs) and calcination of CFO-decorated CNFs (C-CFO/ACNFs), are investigated. The C-CFO/ACNF electrode exhibits a high specific capacitance of 142.9 F/g at a scan rate of 5 mV/s and superior rate capability of 77.6% capacitance retention at a high scan rate of 500 mV/s. This electrode also achieves the lowest charge transfer resistance of 0.0063 Ω and excellent cycling stability (93.5% retention after 5,000 cycles) because of the improved ion conductivity by pathway formation and structural stability. The results of our work are expected to open a new route for manufacturing hybrid capacitor electrodes containing the C-CFO/ACNF electrode that can be easily prepared with a low-cost and simple process with enhanced electrochemical performance.

본 연구에서는 polyketone (PK)을 이용하여 전기방사 조건에 따른 섬유 형상의 특성 변화와 유수분리 가능성을 확인해 보았다. 고습과 저습 조건에서는 마이크론 직경의 섬유가 형성되었으며, 특히 고습에서는 섬유의 표면이 거칠게 변한 것이 확인되었다. 섬유 직경을 micro에서 nano로 변경하기 위하여 방사용액에 염을 추가하였으며, 그 결과 섬유 직경이 약 90% 감소하는 것을 확인할 수 있었다. 제조된 rPK-LNC와 PK-H로 유수분리 특성을 확인하기 위해 oil/water 에멀션으로 중 력 조건에서 유수분리를 진행하였으며 total organic carbon (TOC)와 탁도를 측정하여 특성을 분석하였다. 제거율 확인결과 탁도가 TOC와 동일한 경향성을 나타내는 것이 확인되었다. 따라서 본 연구에서는 고분자의 방사조건과 염의 유무에 따른 분리막의 섬유 형상과 물리적 특성변화와 이를 이용한 유수분리 특성에 대해 연구하였다.

급격한 산업화와 인구수 증가로 인한 환경 수질 오염이 발생하고 있다. 더불어 날씨 패턴의 변화로 인해 빗물이 부족해지자, 폐수를 깨끗한 물로 재활용하기 위한 요구가 나날이 늘어나고 있다. 색변화를 이용한 수중 속 중금속 검출은 아주 간단하고 효과적인 기술이다. 본 논문에는 멤브레인을 이용한 수은 이온 색검출에 대해 자세하게 논의되어 있다. 셀룰로 스, 폴리카프로락톤, 키토산, 폴리설폰 등의 멤브레인이 금속 이온 검출을 지지체로서 사용되었다. 지지체로서 사용된 멤브레 인들은 나노 섬유를 기반으로 하며 표면적이 크며, 중금속 검출의 활성 부위로 사용하기에 탁월하다. 나노 섬유를 기반으로 한 재료는 에너지, 환경, 그리고 바이오메디컬 연구에서 다양하게 응용될 수 있다. 나노 섬유로 이루어진 멤브레인들은 폴리머에 있는 적용기를 많이 받아들일 수 있으며, 표면적이 넓고 다공성이라는 장점이 있다. 이로 인해 멤브레인의 표면 구조를 변화시키거나 리간드를 섬유 표면에 부착해 나노 입자 결합을 더 쉽게 해준다.