Advances in lead-free pyroelectric materials: a comprehensive review

2020 ◽  
Vol 8 (5) ◽  
pp. 1494-1516 ◽  
Author(s):  
Hongying He ◽  
Xin Lu ◽  
Emil Hanc ◽  
Chao Chen ◽  
Hao Zhang ◽  
...  
Keyword(s):  
Potential Energy ◽  
Temperature Change ◽  
Electrical Response ◽  
Functional Materials ◽  
Lead Free ◽  
Comprehensive Review ◽  
Different Types

Pyroelectric materials are important functional materials that can generate an electrical response upon a temperature change. In recent years, significant advances have been achieved in different types of lead-free pyroelectrics and are rising to potential energy-related applications.

scholarly journals Method for Introducing Zeolites and MCM-41 into Polypropylene Melt-Blown Nonwovens

2019 ◽  
Vol 19 (4) ◽  
pp. 312-323
Author(s):  
Agnieszka Brochocka ◽  
Aleksandra Zagawa ◽  
Rafał Panek ◽  
Jarosław Madej ◽  
Wojciech Franus
Keyword(s):  
Functional Materials ◽  
Polymer Fibers ◽  
Protective Equipment ◽  
Silica Material ◽  
Paraffin Oil ◽  
Different Types ◽  
Oil Mist ◽  
European Standards ◽  
Polypropylene Melt ◽  
Mcm 41

Abstract In this work, a method for introducing zeolites and mesoporous siliceous materials into the melt-blown process for the production of polypropylene nonwovens was developed and the functional materials obtained were tested. Both types of additives were introduced in the melt-blown technology using a device placed in the duct of the die assembly. Nine types of polypropylene melt-blown nonwovens were made with different types of zeolites (clinoptilolite, Na-X, Na-A, Na-P1, sodalite, Na-P1 with hexadecyl trimethylammonium bromide (HDTMA), ZeoEco 20, and BioZeo R.01) or mesoporous silica material (Mobil Composition of Matter No. 41, abbreviated as MCM-41). The nonwovens were studied in terms of protective and functional parameters: sodium chloride and paraffin oil mist aerosol penetration, airflow resistance, and sorption capacity for toluene, ammonia, acetone, and cyclohexane, in accordance with the requirements of the European standards concerning respiratory protective equipment. The tests showed that zeolites and MCM-41 can be successfully incorporated within the structure of elementary polymer fibers using an environmentally friendly “dry” melt-blown technology with nonwovens modified so as to impart multiple functionalities in one integrated technological process. The developed method of introducing the studied materials to polypropylene melt-blown nonwovens led to the production of new multipurpose materials with good protective and functional properties. The best polypropylene nonwovens were produced with the addition of 250 g/m2 of MCM-41 or Na-P1 zeolite modified with HDTMA.

scholarly journals The hetero-Friedel-Crafts-Bradsher Cyclizations with Formation of Ring Carbon-Heteroatom (P, S) Bonds, Leading to Organic Functional Materials

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4751
Author(s):  
Joanna Skalik ◽  
Marek Koprowski ◽  
Ewa Różycka-Sokołowska ◽  
Piotr Bałczewski
Keyword(s):  
Flame Retardants ◽  
Bond Formation ◽  
Functional Materials ◽  
Semiconducting Materials ◽  
Conjugated Molecules ◽  
Comprehensive Review ◽  
Ring Carbon ◽  
New Methods ◽  
Cyclic Molecules ◽  
Methods Of Synthesis

The interest in functional materials possessing improved properties led to development of new methods of their synthesis, which allowed to obtain new molecular arrangements with carbon and heteroatom motifs. Two of the classical reactions of versatile use are the Friedel-Crafts and the Bradsher reactions, which in the new heteroatomic versions allow to replace ring carbon atoms by heteroatoms. In the present work, we review methods of synthesis of C–S and C–P bonds utilizing thia- and phospha-Friedel-Crafts-Bradsher cyclizations. Single examples of C–As and lack of C–Se bond formation, involving two of the closest neighbors of P and S in the periodic table, have also been noted. Applications of the obtained π-conjugated molecules, mainly as semiconducting materials, flame retardants, and resins hardeners, designed on the basis of five- and six-membered cyclic molecules containing ring phosphorus and sulfur atoms, are also included. This comprehensive review covers literature up to August 2020.

Benzoyl Halide as Alternative Precursor for Synthesis of Lead Free Double Perovskite Cs3Bi2Br9 Nanocrystals

2020 ◽  
Vol 20 (6) ◽  
pp. 3802-3808
Author(s):  
Ashish Kumar ◽  
S. S. Rawat ◽  
Sanjay Kumar Swami ◽  
Vidya Nand Singh ◽  
Ritu Srivastava
Keyword(s):  
Visible Region ◽  
Functional Materials ◽  
Double Perovskite ◽  
Luminescent Properties ◽  
Lead Free ◽  
Time Resolved ◽  
Injection Process ◽  
Vis Spectroscopy ◽  
Different Temperatures ◽  
Reduced Toxicity

Ternary bismuth halides are interesting functional materials closely related to Pb halide perovskite photovoltaic material, and are widely sought after due to reduced toxicity of Bi compared to Pb. There are several reports on synthesis of Cs3Bi2Br9 nanocrystals (NCs) due to its being relatively stable compared to lead perovskite. Cs3Bi2Br9 nanocrystals have been synthesised using benzoyl bromide as an precursor using hot injection process at two different temperatures of 120 °C and 160 °C. Samples have been characterized for its structural, optical, microstructural and luminescent properties using X-ray diffraction, (XRD) UV-Vis spectroscopy, high resolution transmission electron microscopy and photoluminescent spectroscopy. XRD showed formation of Cs3Bi2Br9 phase with mono-crystalline structure. UV-Vis showed two types of band gap in the visible region which shows that the material can be used for photovoltaic applications. HRTEM confined the particles to be composed of nanocrystals with ˜5 nm particles in the samples grown at 120 °C and it the particles joined together yield various structures composed of nanoparticles. The time resolved photoluminescence shows average life times of 3.067 ns and 4.761 ns for samples grown at two different temperatures. To the best of our knowledge, this is the first report where benzoyl halide has been used as alternative precursor for the synthesis of lead free double perovskite Cs3Bi2Br9 nanocrystals which have many applications.

scholarly journals Recent Progress in Hydrogen-Bonded π-Conjugated Systems Displaying J-Type Aggregates

2020 ◽  
Vol 02 (01) ◽  
pp. 047-063 ◽  
Author(s):  
Nelson Ricardo Ávila-Rovelo ◽  
Amparo Ruiz-Carretero
Keyword(s):  
Hydrogen Bonding ◽  
Self Assembly ◽  
Noncovalent Interactions ◽  
Functional Materials ◽  
Organic Electronic Devices ◽  
Conjugated Systems ◽  
Hydrogen Bonding Interactions ◽  
Different Types ◽  
J Aggregates ◽  
Additional Hydrogen

Supramolecular approaches are of great interest in the design of functional materials. The types of aggregates arising from different noncovalent interactions endow materials with intriguing properties. In this sense, J-type aggregates are very attractive due to their unique optical properties and capacity to transport excitons. These features make them great candidates in the design of materials for organic electronic devices. Furthermore, the incorporation of additional hydrogen-bonding functionalities provides J-aggregates with superior directionality and connection among the different π-conjugated cores. The control over the formation of H-bonds to achieve functional aggregates is therefore a promising strategy towards controlled structures with specific functions.This review outlines the most relevant and recent works of π-conjugated systems exhibiting J-type aggregates resulting from hydrogen-bonding interactions. Different types of hydrogen-bonding functionalities will be discussed together with their roles in the aggregate properties, their impact in the optoelectronic properties, the self-assembly mechanisms, and their applications in organic electronics.

scholarly journals Thermal Time Constant of PV Roof Tiles Working under Different Conditions

2019 ◽  
Vol 9 (8) ◽  
pp. 1626 ◽  
Author(s):  
Kurz ◽  
Nawrowski
Keyword(s):  
Energy Balance ◽  
Thermal Resistance ◽  
Temperature Change ◽  
Environmental Parameters ◽  
Thermal Capacity ◽  
Electrical Characteristics ◽  
Legal Regulations ◽  
Temperature Changes ◽  
Different Types ◽  
The Relationship

This paper presents different types of photovoltaic (PV) roof tiles integrating PV cells with roof covering. Selected elastic photovoltaic roof tiles were characterised for their material and electrical characteristics. Practical aspects of using PV roof tiles are discussed, alongside the benefits and drawbacks of their installation on the roof. Thermal resistance, heat transfer coefficient and thermal capacity were identified for elastic PV roof tiles and roof construction built of boards and PV roof tiles, according to valid standards and legal regulations. The resistance–capacity (RC) models of PV roof tiles and roofs are proposed according to the time constants identified for the analysed systems. The energy balance of the studied systems (PV roof tiles alone and the roof as a whole) is presented, based on which temperature changes in the PV cells of the roof tiles working under different environmental conditions were identified. The timing of PV cells’ temperature change obtained by material data and energy balance analyses were compared. The relationship between the temperature change times of PV cells and the thermal resistance and heat capacity of the whole system are demonstrated, alongside environmental parameters.

scholarly journals p63 Is a Promising Marker in the Diagnosis of Unusual Skin Cancer

2019 ◽  
Vol 20 (22) ◽  
pp. 5781 ◽  
Author(s):  
Artem Smirnov ◽  
Lucia Anemona ◽  
Flavia Novelli ◽  
Cristina M. Piro ◽  
Margherita Annicchiarico-Petruzzelli ◽  
...  
Keyword(s):  
Skin Cancer ◽  
Ozone Depletion ◽  
Essential Role ◽  
Climate Changes ◽  
Prognostic Markers ◽  
Common Type ◽  
P53 Family ◽  
Comprehensive Review ◽  
Diagnosis And Prognosis ◽  
Different Types

Skin cancer is the most common type of cancer worldwide. Ozone depletion and climate changes might cause a further increase in the incidence rate in the future. Although the early detection of skin cancer enables it to be treated successfully, some tumours can evolve and become more aggressive, especially in the case of melanoma. Therefore, good diagnostic and prognostic markers are needed to ensure correct detection and treatment. Transcription factor p63, a member of the p53 family of proteins, plays an essential role in the development of stratified epithelia such as skin. In this paper, we conduct a comprehensive review of p63 expression in different types of skin cancer and discuss its possible use in the diagnosis and prognosis of cutaneous tumours.

scholarly journals A comprehensive review of impression techniques in implant dentistry

2021 ◽  
Vol 6 (1) ◽  
pp. 16-23
Author(s):  
Shweta V Annaldasula ◽  
◽  
Chein Shee Antoinette Yen ◽  
Keyword(s):  
Oral Cavity ◽  
Crucial Role ◽  
Three Dimensional ◽  
Review Article ◽  
Comprehensive Review ◽  
Different Types ◽  
Natural Teeth ◽  
Fixed Appliances ◽  
Implant Dentistry ◽  
Edentulous Patients

Regardless of the demonstrable success of fixed appliances like implants for the replacements of missing natural teeth in partially and fully edentulous patients, countable hindrances still persist. A crucial role is played by impressions used in the fabrication of dental implants for the success, durability and outcome of the restoration. An impression is a three dimensional negative likeness of the future position of the implant in the oral cavity. In view of the absence of periodontal ligaments that serve as natural compensators of the slight but significant details of the impression surface, therefore, impressions in implants are very crucial for implant success. Taking this factor into consideration, the present review article emphasizes on the different types of impression techniques used in implant dentistry.

scholarly journals Temperature deformation of frozensoils at sharp change of temperature

2017 ◽  
pp. 66-71
Author(s):  
S. S. Volokhov ◽  
I. N. Nikitin ◽  
D. S. Lavrov
Keyword(s):  
Temperature Change ◽  
Soil Type ◽  
Sudden Change ◽  
Frozen Soil ◽  
Temperature Deformation ◽  
Sharp Change ◽  
Frozen Soils ◽  
One Stage ◽  
Different Types ◽  
Number Of Cycles

The results are described of the study of temperature deformation of different types of frozen soil in the cycles of cooling-heating at sudden change in temperature. The differences in the nature of the temperature deformation at step and one stage temperature change are shown. The dependences are investigated of the temperature deformation of frozen soils on soil type, moisture and total number of cycles of cooling-heating.

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