November 30, 2022
Volume 20, Number 2
Pages: 26-45
PREFACE
Editorial
Academician Evgeni Budevski - inspirer, wise leader and a friendIt is our great pleasure to present this special edition of journal “Nanoscience& Nanotechnology: Nanostructured Materials Application and Innovation Transfer” dedicated in honor of Academician Evgeni Budevski marking the centenary of his birth and appreciation of his remarkable contribution to the development of the Electrochemical science as well as Nanoscience and Nanotechnology in Bulgaria. On May 11, 2022 a special session was held within the framework of the Sofia Electrochemical Days - SED 2022, where a group generations of graduate, colleagues, friends and followers of Acad. Budevski paid a well-deserved tribute to his notable personality as a world-famous scientist and innovator in the field of physical chemistry and electrochemistry, an outstanding inspirer, mentor and role model for several generations of electrochemists. Some photos on the next pages are illustrating the atmosphere of this event. Being an outstanding scientific and visionary leader, Acad. Evgeni Budevski established the National Nanotechnology Council (NNC) of Bulgaria in 1999 and became its first President. Scientists from many institutes across the Bulgarian Academy of Sciences, universities, small and medium-sized enterprises, as well as representatives of some Bulgarian ministries have joined the newly formed NNC. Over the years the Bulgarian nano-community has grown much larger, integrating with equivalent international scientific groups. The R&D in this new and very promising part of science and technology gradually obtained world-wide importance. The establishment of the journal “Nanoscience & Nanotechnology: Nanostructured Materials Application and Innovation Transfer” (NSNT) was also initiated by Acad. Budevski. The journal started in 2001 and ever since has been a desirable place for publishing of contributions from various areas of nanoscience and nanotechnologies authored by scientists from different countries. Nowadays NSNT obtained its new vision of modern on-line open access journal. It was a great honor and responsibility for us as editors to compile this special issue greatly appreciating the authors for their efforts and dedication in preparing the included materials. We express also our special gratitude to Corr.-mem. Prof. Dr. Evelina Slavcheva, Assoc. Prof. Willy Obretenov, Prof. DSc Ana Proikova, Dr. Lyubinka Stoilova for providing commemorative articles dedicated to Acad. Evgeni Budevski. Such team dedication and efforts make possible to fulfill our desire to celebrate the 100th birthday of Academician Evgeni Budevski on the pages of the Journal “Nanoscience & Nanotechnology” - an official edition of "National Coordinating Council for Nanotechnology (NCCNT)" at the Bulgarian Academy of Sciences. We are thankful to other authors who also contributed scientific articles to this special issue.
Antonia Stoyanova, Editor-in-Chief
Emilia Balabanova, Honorable editor
Anodic formation of nanofibers of aluminum oxide during aluminum anodizing in oxalic acid
Igor Vrublevsky, Kate Chernyakova, Boryana Tsaneva, Valentin Videkov
Keywords: nanofibers, aluminum oxide, anodic formation, aluminum anodizing, oxalic acid, high voltage
In present work, the processes of formation and anodic growth of nanofibers of aluminum oxide during aluminum anodizing were studied. Porous anodic alumina films with surface layer of nanofibers of anodic oxide were formed by anodizing of Al foil in a 0.3 M aqueous solution of oxalic acid at 100 V. Surface morphology of anodic films was analyzed by SEM. The analysis of SEM images of anodic films was performed by ImageJ software to determine the porous structure parameters. The results obtained showed that the diameter of the nanofibers is about 20 ± 2 nm. Anodic oxide possesses a two-layer structure: an upper layer, which consists of nanofibers, and a lower layer of anodic alumina with a nanoporous structure. It was found that anodic growth of nanofibers of aluminum oxide was initiated at the anodizing voltage of 100 V, at the points adjacent to three porous cells.
Features in the manufacture of nanowires for sensor elements
Tobiya Slavov Karagyozov
Keywords: anodic aluminum oxide; conductive silicone; nanowires;
Applications of nanoelements for the production of sensors and in particular the application of nanowires for the production of conductive composites are considered. Attention is paid to the technological processes in the production of nanowires by electrochemical growth in a nanostructured matrix of аnodic aluminum oxide. The issues related to the use of silver nanowires in the preparation of a conductive polymer for electrodes for use in medicine are presented.
Battery emulator for traction drive hybrid energy system
Dimitar Boychev, Blagoy Burdin, Daria Vladikova
Keywords: battery emulator, traction drive energy system, fuel cell/battery hybrid system
When building inverters for traction drive motors, a test bench for optimization in conditions close to those for real operation can accelerate the procedure and its quality and efficiency. This is of prime importance for fuel cell based electric vehicles which are under intensive development, since they are expected to fill the gap for zero emission heavy duty vehicles where batteries cannot provide the necessary range and charging time. There is a special interest in traction drive systems powered by combined fuel cell/ battery energy source, where an optimization in respect of efficiency and price can be achieved. In the classical approach the two energy sources are connected to a DC bus witch powers the traction inverter. In this work a battery emulator concept, design and realization as part of a 10kW test bench for optimization of the hybrid system fuel cell/battery is presented. Its advantage is that the tests are not limited by the battery capacitance. Moreover, the battery emulator has unlimited charge-discharge cycles and can be charged instantly in comparison to the real battery conditions. The battery performance is emulated based on the i-V curves which reflect the ability of the system to produce energy. The block diagrams of the charge and discharge capacitance calculators as well as of the whole emulator are presented. On this stage the emulator is built and the first experiments for validation of its are under preparation.
Issue Content
Anodic formation of nanofibers of aluminum oxide during aluminum anodizing in oxalic acid
Igor Vrublevsky, Kate Chernyakova, Boryana Tsaneva, Valentin VidekovFeatures in the manufacture of nanowires for sensor elements
Tobiya Slavov KaragyozovBattery emulator for traction drive hybrid energy system
Dimitar Boychev, Blagoy Burdin, Daria Vladikova