scholarly journals Environmentally Friendly and Multifunctional Shaddock Peel-Based Carbon Aerogel for Thermal-Insulation and Microwave Absorption

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Weihua Gu ◽  
Jiaqi Sheng ◽  
Qianqian Huang ◽  
Gehuan Wang ◽  
Jiabin Chen ◽  
...  
Keyword(s):  
Microwave Absorption ◽  
Thermal Insulation ◽  
Freeze Drying ◽  
Thermal Infrared ◽  
Carbon Aerogel ◽  
Carbon Aerogels ◽  
List Type ◽  
Drying Method ◽  
Cross Sectional ◽  
Compression Resistance

Highlights The eco-friendly shaddock peel-derived carbon aerogels were prepared by a freeze-drying method. Multiple functions such as thermal insulation, compression resistance and microwave absorption can be integrated into one material-carbon aerogel. Novel computer simulation technology strategy was selected to simulate significant radar cross-sectional reduction values under real far field condition. . Abstract Eco-friendly electromagnetic wave absorbing materials with excellent thermal infrared stealth property, heat-insulating ability and compression resistance are highly attractive in practical applications. Meeting the aforesaid requirements simultaneously is a formidable challenge. Herein, ultra-light carbon aerogels were fabricated via fresh shaddock peel by facile freeze-drying method and calcination process, forming porous network architecture. With the heating platform temperature of 70 °C, the upper surface temperatures of the as-prepared carbon aerogel present a slow upward trend. The color of the sample surface in thermal infrared images is similar to that of the surroundings. With the maximum compressive stress of 2.435 kPa, the carbon aerogels can provide favorable endurance. The shaddock peel-based carbon aerogels possess the minimum reflection loss value (RLmin) of − 29.50 dB in X band. Meanwhile, the effective absorption bandwidth covers 5.80 GHz at a relatively thin thickness of only 1.7 mm. With the detection theta of 0°, the maximum radar cross-sectional (RCS) reduction values of 16.28 dB m2 can be achieved. Theoretical simulations of RCS have aroused extensive interest owing to their ingenious design and time-saving feature. This work paves the way for preparing multi-functional microwave absorbers derived from biomass raw materials under the guidance of RCS simulations.

scholarly journals N-Doped Carbon Aerogels Obtained from APMP Fiber Aerogels Saturated with Rhodamine Dye and Their Application as Supercapacitor Electrodes

2019 ◽  
Vol 9 (4) ◽  
pp. 618 ◽  
Author(s):  
Lei E ◽  
Wei Li ◽  
Jiaming Sun ◽  
Zhenwei Wu ◽  
Shouxin Liu
Keyword(s):  
Freeze Drying ◽  
Sol Gel ◽  
Carbon Aerogel ◽  
Carbon Aerogels ◽  
Alkaline Peroxide ◽  
3D Network ◽  
Rhodamine Dye ◽  
Carbon Network ◽  
Pyridinic N ◽  
A Current

We developed an efficient and environmentally friendly strategy for synthesizing an N-doped carbon aerogel by the carbonization of an alkaline peroxide mechanical pulp (APMP) fiber aerogel saturated with rhodamine B (RB) dyes. The APMP aerogel was prepared via cellulose extraction, sol-gel, and freeze drying. The resulting aerogel had a high adsorption capacity (250 mg g−1) and a fast adsorption rate (within 30 s) towards RB dyes. The saturated aerogel was used as a starting material for further carbonization to prepare N-doped carbon aerogels. SEM studies showed that the 3D network structure of the APMP aerogels was well preserved after RB adsorption and carbonization. The prepared carbon aerogel exhibited a graphitized structure, and N (2.15%) was doped at pyridinic N and pyrrolic N sites in the 3D carbon network. The specific capacitance of the N-doped carbon aerogel reached 185 F g−1 at a current density of 1 A g−1, which is higher than carbon aerogels (155 F g−1).

scholarly journals Step-freeze-drying method for carbon aerogels: a study of the effects on microstructure and mechanical property

RSC Advances ◽  
2019 ◽  
Vol 9 (18) ◽  
pp. 9931-9936 ◽  
Author(s):  
Lei Hu ◽  
Rujie He ◽  
Zhang Lu ◽  
Keqiang Zhang ◽  
Xuejian Bai
Keyword(s):  
Mechanical Property ◽  
Freeze Drying ◽  
Carbon Aerogels ◽  
Drying Method ◽  
Microstructure And Mechanical Property

In this paper, a novel step-freeze-drying method was used to prepare carbon aerogels.

scholarly journals Hierarchical Nafion enhanced carbon aerogels for sensing applications

Nanoscale ◽  
2016 ◽  
Vol 8 (6) ◽  
pp. 3416-3424 ◽  
Author(s):  
Bo Weng ◽  
Ailing Ding ◽  
Yuqing Liu ◽  
Jianglin Diao ◽  
Joselito Razal ◽  
...  
Keyword(s):  
Freeze Drying ◽  
Carbon Aerogels ◽  
Drying Method ◽  
Sensing Applications

This work describes the fabrication of hierarchical Nafion enhanced carbon aerogels (NECAGs) for sensing applications via a fast freeze drying method.

scholarly journals Evaluation of Innovative Dried Purée from Jerusalem Artichoke—In Vitro Studies of Its Physicochemical and Health-Promoting Properties

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2644
Author(s):  
Jan Oszmiański ◽  
Sabina Lachowicz ◽  
Paulina Nowicka ◽  
Paweł Rubiński ◽  
Tomasz Cebulak
Keyword(s):  
Freeze Drying ◽  
Jerusalem Artichoke ◽  
Polyphenolic Compounds ◽  
Raw Material ◽  
Vacuum Drying ◽  
Drying Methods ◽  
Drying Method ◽  
Activity Inhibition ◽  
Health Promoting

The present study aimed to evaluate the effect of Jerusalem artichoke processing methods and drying methods (freeze drying, sublimation drying, vacuum drying) on the basic physicochemical parameters, profiles and contents of sugars and polyphenolic compounds, and health-promoting properties (antioxidant activity, inhibition of the activities of α-amylase, α-glucosidase, and pancreatic lipase) of the produced purée. A total of 25 polyphenolic compounds belonging to hydroxycinnamic phenolic acids (LC-PDA-MS-QTof) were detected in Jerusalem artichoke purée. Their average content in the raw material was at 820 mg/100 g dm (UPLC-PDA-FL) and was 2.7 times higher than in the cooked material. The chemical composition and the health-promoting value of the purées were affected by the drying method, with the most beneficial values of the evaluated parameters obtained upon freeze drying. Vacuum drying could offer an alternative to freeze drying, as both methods ensured relatively comparable values of the assessed parameters.

Ultramicroporous carbon aerogels encapsulating sulfur as the cathode for lithium–sulfur batteries

2021 ◽  
Author(s):  
Maryam Nojabaee ◽  
Brigitta Sievert ◽  
Marina Schwan ◽  
Jessica Schettler ◽  
Frieder Warth ◽  
...  
Keyword(s):  
Carbon Aerogel ◽  
Composite Cathode ◽  
Microporous Carbon ◽  
Carbon Aerogels ◽  
Lithium Sulfur Batteries ◽  
Lithium Sulfur

In the presented study, a sulfur infiltrated ultra-microporous carbon aerogel as a composite cathode for lithium sulfur batteries is developed and investigated.

scholarly journals Biocompatibility and osteoconductivity of scaffold porous composite collagen–hydroxyapatite based coral for bone regeneration

2020 ◽  
Vol 18 (1) ◽  
pp. 584-590 ◽  
Author(s):  
◽  
Dyah Hikmawati ◽  
Umi Kulsum ◽  
Djony Izak Rudyardjo ◽  
Retna Apsari ◽  
...  
Keyword(s):  
Bone Regeneration ◽  
Freeze Drying ◽  
Bone Growth ◽  
Viable Cell ◽  
Drying Method ◽  
Porous Composite ◽  
Viable Cells

AbstractThe synthesis of collagen–hydroxyapatite composites has been carried out, and the biocompatibility and osteoconductivity properties have been tested. This research was conducted to determine the ability of hydroxyapatite–collagen composites to support the bone growth through the graft surface. Hydroxyapatite used in this study was synthesized from coral with a purity of 96.6%, while collagen was extracted from the chicken claw. The process of forming a scaffold of collagen–hydroxyapatite composites was carried out using the freeze-drying method at −80°C for 4 h. The biocompatibility characteristics of the sample through the cytotoxicity tests showed that the percentage of viable cells in collagen–hydroxyapatite biocomposite was 108.2%, which is higher than the percentage of viable cells of hydroxyapatite or collagen material. When the viable cell is above 100%, collagen–hydroxyapatite composites have excellent osteoconductivity as a material for bone regeneration.

scholarly journals Structural Engineering of Hierarchical Aerogels Comprised of Multi-dimensional Gradient Carbon Nanoarchitectures for Highly Efficient Microwave Absorption

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Yongpeng Zhao ◽  
Xueqing Zuo ◽  
Yuan Guo ◽  
Hui Huang ◽  
Hao Zhang ◽  
...  
Keyword(s):  
Microwave Absorption ◽  
Structural Engineering ◽  
Carbon Nanomaterials ◽  
Wave Attenuation ◽  
Impedance Matching ◽  
Chemical Vapor ◽  
Electromagnetic Properties ◽  
Effective Bandwidth ◽  
Carbon Aerogels ◽  
Chemical Vapor Deposition Method

AbstractRecently, multilevel structural carbon aerogels are deemed as attractive candidates for microwave absorbing materials. Nevertheless, excessive stack and agglomeration for low-dimension carbon nanomaterials inducing impedance mismatch are significant challenges. Herein, the delicate “3D helix–2D sheet–1D fiber–0D dot” hierarchical aerogels have been successfully synthesized, for the first time, by sequential processes of hydrothermal self-assembly and in-situ chemical vapor deposition method. Particularly, the graphene sheets are uniformly intercalated by 3D helical carbon nanocoils, which give a feasible solution to the mentioned problem and endows the as-obtained aerogel with abundant porous structures and better dielectric properties. Moreover, by adjusting the content of 0D core–shell structured particles and the parameters for growth of the 1D carbon nanofibers, tunable electromagnetic properties and excellent impedance matching are achieved, which plays a vital role in the microwave absorption performance. As expected, the optimized aerogels harvest excellent performance, including broad effective bandwidth and strong reflection loss at low filling ratio and thin thickness. This work gives valuable guidance and inspiration for the design of hierarchical materials comprised of dimensional gradient structures, which holds great application potential for electromagnetic wave attenuation. "Image missing"

scholarly journals Light-induced levitation of ultralight carbon aerogels via temperature control

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Reo Yanagi ◽  
Ren Takemoto ◽  
Kenta Ono ◽  
Tomonaga Ueno
Keyword(s):  
Carbon Nanotubes ◽  
Heat Capacity ◽  
Porous Materials ◽  
Temperature Control ◽  
Light Absorption ◽  
Carbon Aerogel ◽  
Carbon Aerogels ◽  
Halogen Lamp ◽  
Absorption Properties ◽  
Air Density

AbstractWe demonstrate that ultralight carbon aerogels with skeletal densities lesser than the air density can levitate in air, based on Archimedes' principle, when heated with light. Porous materials, such as aerogels, facilitate the fabrication of materials with density less than that of air. However, their apparent density increases because of the air inside the materials, and therefore, they cannot levitate in air under normal conditions. Ultralight carbon aerogels, fabricated using carbon nanotubes, have excellent light absorption properties and can be quickly heated by a lamp owing to their small heat capacity. In this study, an ultralight carbon aerogel was heated with a halogen lamp and levitated in air by expanding the air inside as well as selectively reducing its density. We also show that the levitation of the ultralight carbon aerogel can be easily controlled by turning the lamp on and off. These findings are expected to be useful for various applications of aerogels, such as in communication and transportation through the sky.

Construction of a CsPbBr3 modified porous g-C3N4 photocatalyst for effective reduction of CO2 and mechanism exploration

2021 ◽  
Author(s):  
Yunqi Wang ◽  
Zhixiang Liu ◽  
Xu Tang ◽  
Pengwei Huo ◽  
Zhi Zhu ◽  
...  
Keyword(s):  
High Temperature ◽  
Porous Structure ◽  
Freeze Drying ◽  
Drying Method ◽  
Full Spectrum ◽  
Effective Reduction ◽  
Reduction Of Co2 ◽  
High Temperature Calcination

A P-CN/CsPbBr3 photocatalyst with a lamellar porous structure was prepared by a high temperature calcination and freeze drying method, and it exhibited superior CO2 reduction performance under the conditions of full spectrum irradiation.

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