Open ceramics 

Abstract: Scientific exploration of extraterrestrial planets has gripped human imagination since the advent of space travel. Human missions to Mars could produce insight into the essential questions of how, when and where life began on Earth. Such missions would only be feasible using local space resources materials, a concept called in situ resource utilization (ISRU). In the absence of organic materials from plants, the globally available oxidic surface minerals (regolith) are the only viable resource for large-scale construction efforts such as habitats, greenhouses, landing pads and equipment building. This review provides the first comprehensive literature review of ISRU materials research employing Martian simulants. It gives a detailed overview of all Mars simulants, their history, properties, and challenges, introducing a generational concept for simulants development. The available Mars simulant processing literature (including selected work on lunar simulants) is categorized into seven regolith bonding concepts. The state-of-the-art on additive manufacturing (AM) in ISRU research is discussed. Detailed feasibility assessments for all processing approaches are given, including overview graphs comparing the mechanical performance of each fusion concept with feedstock availability on the surface of Mars. Finally, major open questions and future challenges of materials processing for early Mars missions is examined.

Abstract: MXene, a two-dimensional (2D) carbide, carbonitride, and nitride, was discovered in 2011. A certain number of elements in the periodic table have contributed to the synthesis of MXene from the beginning to the present. Most researchers, however, are focused on a particular type of MXene, Ti3C2Tx, although the scientific community seldom considers the synthesis cost of this outstanding and potentially helpful substance. Herein, we explore the cost of MXene by going through each stage of the production process. Instead, the actual cost may vary by a small margin due to differences in the materials and procedures. However, this study provides a clear understanding of the cost, which is governed by the steps directly involved in the synthesis and characterization of MXene. The cost associated with various essential characterization tools like scanning electron microscope (SEM), transmission electron microscope (TEM), ultraviolet–visible spectroscopy (UV–Vis), and x-ray diffraction (XRD) is necessary to ensure the successful synthesis of MXene. All local expenses are converted into USD, except for the instrumental life cycle analysis and infrastructure cost values. The cost of each gram of MXene is predicted to be $20.33. The predicted cost is close to the market price of MXene, proving the accuracy of the cost calculation presented in this research. This work will assist the scientific community in planning and optimizing MXene's synthesis procedures so that the production cost can be potentially reduced if this material is produced on a larger scale.

Abstract: Although calcium aluminate cement (CAC) has been widely used, one of the critical unclear issues in the field of cement chemistry focuses on certain mechanisms that manipulate the rate of cement hydration. A better understanding of hydration provides critical information such that issues, such as setting time, strength gain, and durability, can be better addressed. This study aimed to initially provide theoretical predictions using experimental information on the dissolution, nucleation, and precipitation mechanisms of ions, induction time (tind), interfacial free energy (γ), and the crystal growth mechanism of CAC containing accelerating and retarding agents in microstructural systems. We also aimed to investigate the early-age performance of CAC, including the setting time of pastes and strength development of mortars. Results found that adding accelerating and retarding agents affected the dissolution, nucleation, and precipitation mechanisms of the CAC hydration. This finally affected the phase formation of the final products.

Abstract: The combination of ceramic and metallic properties of the MAX phases makes them attractive for numerous technological applications. The very recent experimental synthesis of the Zn-based MAX phase Ti3ZnC2 is an important addition to the MAX phase family as it further expands the diversity of physical characteristics of this family. Here we have employed density functional theory (DFT) calculations to investigate the structural, electronic, mechanical, lattice dynamic and thermal properties of Ti3ZnC2 for comparison with existing Ti3AC2 phases. Additional transition metal Zn at A-site in newly synthesized Ti3ZnC2 reduces most of the elastic constants and moduli as well as the Debye temperature and thermal conductivity. All the Ti3AC2 phases have the potential to be etched into 2D MXenes with great possibility for Ti3ZnC2. Ti3ZnC2 is highly anisotropic in the Ti3AC2 MAX phase family.