Issue 1


Priority of Materials Research for Reaching Climate Neutrality Goals

Ashutosh Tiwari

Advanced Materials Letters, 2022, Volume 13, Issue 1, Pages 2201-1683
DOI: 10.5185/amlett.2022.011683

The scientific foot is directed towards a range of net-zero paths, which can predict the sustainable future of society. Climate neutral practices require ultimate plan of action for people, planet, and prosperity. It is critical to set synergy among education, industry, and government policies for creating a clear vision to evolve various sectors addressing net-zero utilization and climate neutrality objectives on regional basis. The materials research drives in the direction of climate neutrality goal by advancing the field. The net-zero emissions must be globally achieved by 2050 and important objectives should be decided. The global trends of materials research are shifting towards important directions highlighting innovation and trends for promising materials industry. Thus, advancement of materials could concur with health, energy, and environmental technologies, which are not harming to biodiversity and ecosystem. The recent advances increase the role of intelligent materials more in current scope. Therefore, making smart building blocks and devices are getting very high attention. The emerging global trends for net-zero technology require transforming research and innovations such as green energy, waste conversation and digitalization.

Review Article

Comparison of Material Properties for Dental Implants: Titanium, Polyetheretherketone, Zirconium and Silicon Nitride

Manuel Aparicio-Razo; José Luis Jr. Mongalo-Vázquez; J. A. Yáñez Ramos; Adolfo Navarro-Zárate; Víctor Hugo Santos-Enríquez; Israel Vivanco-Pérez; J. Flores Méndez; Genaro Alberto Paredes-Juárez

Advanced Materials Letters, 2022, Volume 13, Issue 1, Pages 2201-1684
DOI: 10.5185/amlett.2022.011684

This review article presents the biological and technological properties of biomaterials: titanium, polyetheretherketone, zirconium and Si3N4, focused on the application of dental implants. The methodology focused on examining different works related to the topics of biocompatibility, biofilm formation and adhesion properties, fibroblast proliferation, bone resorption, peri-implant infection, osseointegration, histology, cytotoxicity, toxicity, carcinogenicity, genotoxicity, hemocompatibility, vascularization, mechanical resistance and approval for use by the FDA. The results of the review show that all four biomaterials have favorable properties that can revolutionize implants, however, more studies are needed to confirm the results in the short and medium term.

Research Article

Reactor Design for Manufacturing Carbon Hybrid Materials

Sung Yong Kim; Megha Chitranshi; Anuptha Pujari; Vianessa Ng; Ashley Kubley; Ronald Hudepohl; Vesselin Shanov; Devanathan Anantharaman; Daniel Chen; Devika Chauhan; Mark Schulz

Advanced Materials Letters, 2022, Volume 13, Issue 1, Pages 2201-1685
DOI: 10.5185/amlett.2022.011685

This paper addresses the design of a reactor system for manufacturing carbon nanotube (CNT) fabric and carbon hybrid materials (CHM). A web or sock of CNT is formed in a reactor tube in the gas phase pyrolysis method. The sock exits the reactor tube and is wound layer by layer onto a drum to directly form a nonwoven fabric. Metal nanoparticles and continuous microfibers can be integrated into the synthesis process to form CHM. Continuous direct manufacturing of fabric is an advantage of the method. However, the reliability of this manufacturing process in our particular reactor system is affected by several problems. These include occasional breaking of the sock, the need for daily cleaning of the ceramic reactor tube due to carbon deposits on the inside, sagging/bending of the reactor tube, and safety in handling the hydrogen gas produced from the reaction. Possible solutions to the problems are proposed. The importance of this research is that no other bulk material has the combination of properties of CNT hybrid fabric. If the properties can be further improved and customized, and if manufacturing of the material can be scaled-up at reasonable cost, many new commercial applications for nanotube custom materials could open up. 

Removal of crystal violet dye using grafted guar gum along with nanoclay and MWCNT

Fiza Simran; Prathiksha Karumbaiah; Pratik Roy; R.R.N. Sailaja

Advanced Materials Letters, 2022, Volume 13, Issue 1, Pages 2201-1686
DOI: 10.5185/amlett.2022.011686

The present study is aimed to remove toxic crystal violet dye from aqueous solutions. In this study guar gum (GG) has been grafted with acrylic acid (AA) by following microwave assisted grafting method. Two different nanomaterials i.e., nanoclay (NC) and multiwalled carbon nanotubes (MWCNT) has been incorporated either alone or in combination during the grafting reaction. The synthesized nanocomposites have been used for removal of crystal violet dye from aqueous solutions. Study showed higher dye adsorption capacity of the synthesized composites after addition of nanomaterials. The adsorption isotherm followed both Langmuir and Freundlich model. It was found that GG grafted AA composite with MWCNT showed highest crystal violet dye adsorption compared to others. Swelling behaviour of the synthesized composites in acidic, neutral and alkaline medium has been studied. The swelling kinetics in acidic, neutral and alkaline medium was found to follow pseudo second order kinetic model with <R2> value more than 0.98. Fourier transform infrared spectroscopy (FTIR) showed efficient grafting of AA on GG. X-ray diffraction (XRD) and morphological characteristics depicted enhanced dispersion of nanomaterials in GG matrix.  

A probability based methodology for multi object optimization in material selection

Maosheng Zheng; Yi Wang; Haipeng Teng

Advanced Materials Letters, 2022, Volume 13, Issue 1, Pages 2201-1687
DOI: 10.5185/amlett.2022.011687

Multi object optimization in material selection involves the satisfaction of optimizing the multi attributes simultaneously, which analogically corresponds to the simultaneous appearance of the event of the multi attributes in the viewpoint of probability theory, thus the optimization of multi – object becomes the assessment of the “joint probability” of these multi – attribute problem. Furthermore, the preferential degree of the candidate material in the material selection is reflected by the concept of preferential probability, and a quantitative approach for evaluating the partial preferential probability of each material attribute indicator and the total (joint) preferential probability of candidate material in the material selection is proposed on basis of probability theory correspondingly. In the approach, all material attribute indicators are divided into beneficial or unbeneficial types; each material attribute indicator of the candidate contributes one partial preferential probability linearly to its authorized material upon its nature of whether beneficial or unbeneficial type merely; the product of all partial preferential probabilities of a candidate makes its total preferential probability, which is the final unique index in the material selection decisively; the candidate materials can be ranked according to their total preferential probabilities, which determines the result of the selection. Furthermore, the condition of discrete input variables and the objects is extended to the case of continuous input variables and the objects. Some examples are given in detail, satisfied results are obtained.

Improved graphene-base heterojunction transistor with different collector semiconductors for high-frequency applications

Carsten Strobel; Carlos Chavarin; Sebastian Leszczynski; Karola Richter; Martin Knaut; Johanna Reif; Sandra Voelkel; Matthias Albert; Christian Wenger; Johann Wolfgang Bartha; Thomas Mikolajick

Advanced Materials Letters, 2022, Volume 13, Issue 1, Pages 2201-1688
DOI: 10.5185/amlett.2022.011688

A new kind of transistor device with a graphene monolayer embedded between two n-type silicon layers is fabricated and characterized. The device is called graphene-base heterojunction transistor (GBHT). The base-voltage controls the current of the device flowing from the emitter via graphene to the collector. The transit time for electrons passing by the ultrathin graphene layer is extremely short which makes the device very promising for high frequency RF-electronics. The output current of the device is saturated and clearly modulated by the base voltage. Further, the silicon collector of the GBHT is replaced by germanium to improve the device performance. This enabled the collector current to be increased by almost three orders of magnitude. Also, the common-emitter current gain (Ic/Ib) increased from 10-3 to approximately 0.3 for the newly designed device. However, the ON-OFF ratio of the improved germanium based GBHT has so far been rather low. Further optimizations are necessary in order to fully exploit the potential of the graphene-base heterojunction transistor.  

Gas Sensing Investigation of Porous Hot-wire Molybdenum Disulphide Thin Films

Giorgos Papadimitropoulos; Angelika Balliou; Dimitris Kouvatsos; Dimitris Davazoglou

Advanced Materials Letters, 2022, Volume 13, Issue 1, Pages 2201-1689
DOI: 10.5185/amlett.2022.011689

The gas sensing properties of porous hot-wire MoS2 (hwMoS2) thin films have been studied. The films were deposited on oxidized silicon substrates by heating a molybdenum filament in a vacuum chamber in H2S environment. The samples remain at room temperature during the deposition and the grown films are amorphous and porous.  Reversible changes of the current values in the hwMoS2 films were observed due to the presence or upon removal of chemical gases such as hydrogen (H2) and carbon monoxide (CO). The sensitivity, was dependent on the concentrations of the gases and the temperature of measurement. The response time was found to be comparable to the recovery time and of the order of a few seconds. It is important to note that the surface of the hwMoS2 films was not activated with any catalyst, which is a common practice in most thin films used for gas sensing, rendering our process simpler and cheaper.