Yang Li

Bio: Yang Li is an academic researcher from Central South University. The author has contributed to research in topics: Coating & Mullite. The author has an hindex of 21, co-authored 87 publications receiving 1103 citations. Previous affiliations of Yang Li include University of Bayreuth & National University of Defense Technology.

Ultra-thin and highly flexible cellulose nanofiber/silver nanowire conductive paper for effective electromagnetic interference shielding

Abstract: Exploring an electromagnetic interference (EMI) shielding material with lightweight, flexible and easy fabricating process to deal with the increasingly serious electromagnetic environment pollution has become a current developing trend. Here, we reported a novel cellulose nanofiber (CNF)/silver nanowire (AgNW) conductive paper with a distinctive hierarchical structure by a facile “blending-filtration-peeling” process. Results showed that the obtained paper with a thickness of ~40 μm exhibited excellent tensile strength of ~49.1 MPa, a low percolation threshold of 1.4 vol% AgNWs, no significant changes in electrical conductivity after 2000 bending. The outstanding synergy between green CNFs and AgNWs endowed the paper with high EMI shielding effectiveness of up to 39.3 dB in X band and effective shielding effects on electromagnetic signals for realistic mobile phone communication. The special CNF/AgNW papers are expected to broaden new application fields as electronic devices e.g. flexible electronic components or effective ultra-thin EMI shielding materials for daily demands.

Electrospun fibrous materials and their applications for electromagnetic interference shielding: A review

Abstract: Owing to the development of electronic information technology, the pollution of electromagnetic wave (EMW) radiation is getting worse. Thus, it is urgent to investigate shielding materials with excellent electromagnetic interference (EMI) shielding properties. Recently, electrospinning has been developed in various fields, and one-dimensional nanofibers prepared by electrospinning can realize the shielding of EMW, due to their outstanding advantages. In this review, at the beginning, the basic mechanism of electrospinning technology and related EMI shielding are introduced. Then, different fibrous materials directly from electrospinning for the EMI shielding are summarized. Next, electrospun EMI shielding composites by different post treatments are discussed. Finally, various influencing factors on the EMI shielding properties are summarized. At the end, conclusions and future perspectives are provided. Hopefully, this review would provide basic understanding on the development of electrospun fibrous materials for EMI shielding, and give the future roadmap for the high performance electrospun fiber-based EMI shields.

A novel Co/TiO2 nanocomposite derived from a metal–organic framework: synthesis and efficient microwave absorption

Abstract: To overcome the shortcomings (poor impedance mismatching and weak electromagnetic wave attenuation) of the Co nanoparticles embedded into nanoporous carbon (Co@NPC) derived from the thermal decomposition of zeolitic imidazolate framework-67 (ZIF-67), two coated titanium oxide (TiO2) routes are designed to prepare core–shell Co@NPC@TiO2 and multi-interfaced yolk–shell C–ZIF-67@TiO2 (obtained from the thermal decomposition of ZIF-67@TiO2) structures. The permittivity and permeability of C–ZIF-67@TiO2 significantly depend on the thickness of the TiO2 shell in ZIF-67@TiO2, and the thickness of the TiO2 shell in the as-obtained samples can be easily controlled via changing the addition content of tetrabutyl titanate in the hydrolyzation process. The as-prepared samples have remarkable absorbing characteristics in wide frequency bands from 2–18 GHz with thicknesses of 1.0–5.0 mm. 50 wt% of the C–ZIF-67@TiO2-2 (the addition amount of tetrabutyl titanate is 2 mL) nanocomposite filled within paraffin shows a maximum reflection loss (RL) of −51.7 dB at an absorbing thickness of 1.65 mm, meanwhile, for the Co@NPC@TiO2-1.2 (the addition amount of tetrabutyl titanate is 1.2 mL) nanocomposite, a maximum RL can be achieved of −31.7 dB at 1.5 mm. This study provides a good reference for the future preparation of other carbon-based lightweight microwave absorbing materials derived from metal organic frameworks.

Biomedical applications of biodegradable polymers

Abstract: Utilization of polymers as biomaterials has greatly impacted the advancement of modern medicine. Specifically, polymeric biomaterials that are biodegradable provide the significant advantage of being able to be broken down and removed after they have served their function. Applications are wide ranging with degradable polymers being used clinically as surgical sutures and implants. To fit functional demand, materials with desired physical, chemical, biological, biomechanical, and degradation properties must be selected. Fortunately, a wide range of natural and synthetic degradable polymers has been investigated for biomedical applications with novel materials constantly being developed to meet new challenges. This review summarizes the most recent advances in the field over the past 4 years, specifically highlighting new and interesting discoveries in tissue engineering and drug delivery applications.

Dielectric Loss Mechanism in Electromagnetic Wave Absorbing Materials

Abstract: Electromagnetic (EM) wave absorbing materials play an increasingly important role in modern society for their multi‐functional in military stealth and incoming 5G smart era. Dielectric loss EM wave absorbers and underlying loss mechanism investigation are of great significance to unveil EM wave attenuation behaviors of materials and guide novel dielectric loss materials design. However, current researches focus more on materials synthesis rather than in‐depth mechanism study. Herein, comprehensive views toward dielectric loss mechanisms including interfacial polarization, dipolar polarization, conductive loss, and defect‐induced polarization are provided. Particularly, some misunderstandings and ambiguous concepts for each mechanism are highlighted. Besides, in‐depth dielectric loss study and novel dielectric loss mechanisms are emphasized. Moreover, new dielectric loss mechanism regulation strategies instead of regular components compositing are summarized to provide inspiring thoughts toward simple and effective EM wave attenuation behavior modulation.