Review on biochar as a sustainable green resource for the rehabilitation of petroleum hydrocarbon-contaminated soil

Petroleum pollution is one of the primary threats to the environment and public health. Therefore, it is essential to create new strategies and enhance current ones. The process of biological reclamation, which utilizes a biological agent to eliminate harmful substances from polluted soil, has drawn much interest. Biochars are inexpensive, environmentally beneficial carbon compounds extensively employed to remove petroleum hydrocarbons from the environment. Biochar has demonstrated an excellent capability to remediate soil pollutants because of its abundant supply of the required raw materials, sustainability, affordability, high efficacy, substantial specific surface area, and desired physical-chemical surface characteristics. This paper reviews biochar's methods, effectiveness, and possible toxic effects on the natural environment, amended biochar, and their integration with other remediating materials towards sustainable remediation of petroleum-polluted soil environments. Efforts are being undertaken to enhance the effectiveness of biochar in the hydrocarbon-based rehabilitation approach by altering its characteristics. Additionally, the adsorption, biodegradability, chemical breakdown, and regenerative facets of biochar amendment and combined usage culminated in augmenting the remedial effectiveness. Lastly, several shortcomings of the prevailing methods and prospective directions were provided to overcome the constraints in tailored biochar studies for long-term performance stability and ecological sustainability towards restoring petroleum hydrocarbon adultered soil environments.

A minireview on the utilization of petroleum coke as a precursor for carbon-based nanomaterials (CNMs): perspectives and potential applications

The remarkable properties of carbon-based nanomaterials (CNMs) have stimulated a significant increase in studies on different 0D, 1D and 2D nanostructures, which have promising applications in various fields of science and technology. However, the use of graphite as a raw material, which is essential for their production, limits the scalability of these nanostructures. In this context, petroleum coke (PC), a by-product of the coking process in petrochemical industry with a high carbon content (>80 wt%), is emerging as an attractive and low-cost option for the synthesis of carbonaceous nanostructures. This brief review presents recent research related to the use of PC as a precursor for CNMs, such as graphene and its oxidized (GO) and reduced (RGO) variants, among other carbon-based nanostructures. The work highlights the performance of these materials in specific areas of application. In addition, this review describes and analyzes strategies for transforming low-cost, environmentally friendly waste into advanced technological innovations with greater added value, in line with the UN's 2030 Agenda.

Advancing PFAS Sorbent Design: Mechanisms, Challenges, and Perspectives

Per- and polyfluoroalkyl substances (PFAS) are a group of synthetic chemicals characterized with persistence and multisurface resistance. Their accumulation in the environment and toxicity to human beings have contributed to the rapid development of regulations worldwide since 2002. The sorption strategy, taking advantage of intermolecular interactions for PFAS capture, provides a promising and efficient solution to the treatment of PFAS contaminated sources. Hydrophobic and electrostatic interactions are the two commonly found in commercially available PFAS sorbents, with the fluorous interaction being the novel mechanism applied for sorbent selectivity. The main object of this Perspective is to provide a critical review on the current design criteria of PFAS sorbents, with particular focus on their sorption and interaction mechanisms as well as limitations. An outlook on future innovative design for efficient PFAS sorbents is also provided.

Liquid-Liquid Interfacial Nanoarchitectonics

Science in the small world has become a crucial key that has the potential to revolutionize materials technology. This trend is embodied in the postnanotechnology concept of nanoarchitectonics. The goal of nanoarchitectonics is to create bio-like functional structures, in which self-organized and hierarchical structures are working efficiently. Liquid-liquid interface like environments such as cell membrane surface are indispensable for the expression of biological functions through the accumulation and organization of functional materials. From this viewpoint, it is necessary to reconsider the liquid-liquid interface as a medium where nanoarchitectonics can play an active role. In this review, liquid-liquid interfacial nanoarchitectonics is classified by component materials such as organic, inorganic, carbon, and bio, and recent research examples are discussed. Examples discussed in this paper include molecular aggregates, supramolecular polymers, conductive polymers film, crystal-like capsules, block copolymer assemblies, covalent organic framework (COF) films, complex crystals, inorganic nanosheets, colloidosomes, fullerene assemblies, all-carbon π-conjugated graphite nanosheets, carbon nanoskins and fullerphene thin films at liquid-liquid interfaces. Furthermore, at the liquid-liquid interface using perfluorocarbons and aqueous phases, cell differentiation controls are discussed with the self-assembled structure of biomaterials. The significance of liquid-liquid interfacial nanoarchitectonics in the future development of materials will then be discussed.

Triazine-Based Porous Organic Polymers: Synthesis and Application in Dye Adsorption and Catalysis

The scientific community has been developing promising materials to increase the sustainability and efficiency of production processes and pollutant environmental remediation strategies. Porous organic polymers (POPs) are of special interest, as they are insoluble custom-built materials at the molecular level, endowed with low densities and high stability, surface areas, and porosity. This paper describes the synthesis, characterization, and performance of three triazine-based POPs (T-POPs) in dye adsorption and Henry reaction catalysis. T-POPs were prepared by a polycondensation reaction between melamine and a dialdehyde (terephthalaldehyde (T-POP1) or isophthalaldehyde derivatives with a hydroxyl group (T-POP2) or both a hydroxyl and a carboxyl group (T-POP3)). The crosslinked and mesoporous polyaminal structures, with surface areas between 139.2 and 287.4 m² g^-1, positive charge, and high thermal stability, proved to be excellent methyl orange adsorbents, removing the anionic dye with an efficiency >99% in just 15-20 min. The POPs were also effective for methylene blue cationic dye removal from water, reaching efficiencies up to ca. 99.4%, possibly due to favorable interactions via deprotonation of T-POP3 carboxyl groups. The modification of the most basic polymers, T-POP1 and T-POP2, with copper(II) allowed the best efficiencies in Henry reactions catalysis, leading to excellent conversions (97%) and selectivities (99.9%).

Biomass Nanoarchitectonics for Supercapacitor Applications

Nanoarchitectonics integrates nanotechnology with numerous scientific disciplines to create innovative and novel functional materials from nano-units (atoms, molecules, and nanomaterials). The objective of nanoarchitectonics concept is to develop functional materials and systems with rationally architected functional units. This paper explores the progress and potential of this field using biomass nanoarchitectonics for supercapacitor applications as examples of energetic materials and devices. Strategic design of nanoporous carbons that exhibit ultra-high surface area and hierarchically pore architectures comprising micro- and mesopore structure and controlled pore size distributions are of great significance in energy-related applications, including in high-performance supercapacitors, lithium-ion batteries, and fuel cells. Agricultural wastes or natural biomass are lignocellulosic materials and are excellent carbon sources for the preparation of hierarchically porous carbons with an ultra-high surface area that are attractive materials in high-performance supercapacitor applications due to high electrical and ion conduction, extreme porosity, and exceptional chemical and thermal stability. In this review, we will focus on the latest advancements in the fabrication of hierarchical porous carbon materials from different biomass by chemical activation method. Particularly, the importance of biomass-derived ultra-high surface area porous carbons, hierarchical architectures with interconnected pores in high-energy storage, and high-performance supercapacitors applications will be discussed. Finally, the current challenges and outlook for the further improvement of carbon materials derived from biomass or agricultural wastes in the advancements of supercapacitor devices will be discussed.

Molecular Machines and Microrobots: Nanoarchitectonics Developments and On-Water Performances

This review will focus on micromachines and microrobots, which are objects at the micro-level with similar machine functions, as well as nano-level objects such as molecular machines and nanomachines. The paper will initially review recent examples of molecular machines and microrobots that are not limited to interfaces, noting the diversity of their functions. Next, examples of molecular machines and micromachines/micro-robots functioning at the air-water interface will be discussed. The behaviors of molecular machines are influenced significantly by the specific characteristics of the air-water interface. By placing molecular machines at the air-water interface, the scientific horizon and depth of molecular machine research will increase dramatically. On the other hand, for microrobotics, more practical and advanced systems have been reported, such as the development of microrobots and microswimmers for environmental remediations and biomedical applications. The research currently being conducted on the surface of water may provide significant basic knowledge for future practical uses of molecular machines and microrobots.

Pore creation nanoarchitectonics from non-porous metal-organic framework to porous carbon for adsorptive elimination of sulfanilamide and chloroxylenol from aqueous solution

Three isomeric metal-organic frameworks (MOFs) such as MAF-5, - 6, and - 32 (with the same composition of [Zn(2-ethylimidazole)₂]) were carbonized and, for the first time, activated further with KOH to prepare highly porous MOF-derived carbons (MDCs). Importantly, MDC-32 derived from non-porous MAF-32 had the highest porosity among the three MDCs although it has the lowest porosity when no KOH activation was done. Adsorption of sulfanilamide and chloroxylenol from water was investigated with the MDCs. Among the MDCs, MDC-32 showed the best adsorptive performance for sulfanilamide and chloroxylenol. Moreover, MDC-32, had the highest adsorption capacity (256 mg/g) for removing sulfanilamide from water, compared with any adsorbent reported so far. Based on the observed adsorption and properties of the adsorbate and adsorbent, π-π and hydrogen bonding interactions, with a slight contribution of repulsive electrostatic interaction, could be suggested as the mechanism for the sulfanilamide adsorption over the MDC-32. Moreover, the MDC-32 could be recycled easily for up to four cycles. It could be suggested that non-porous MOFs can be a good precursor for highly porous MDCs, if activated well using KOH, for example. Finally, MAF-32-derived carbon, MDC-32, might be suggested as a plausible adsorbent to eliminate organics such as sulfanilamide from water.

Functionalized metal-organic framework-derived carbon: Effective adsorbent to eliminate methylene blue, a small cationic dye from water

Elimination of organic dyes from wastewater is very important for our safe environment and sound health. In this work, adsorptive removal of cationic dyes, especially small ones, was investigated with carbonaceous materials to develop a competitive adsorption technology. To improve the performance of metal-organic framework (MOF)-derived carbons (MDCs) in dye adsorption, an MDC, derived from a MOF (MAF-6), was oxidatively functionalized with ammonium persulfate solutions (APSs). Although the porosity of pristine MDC decreased with functionalization via oxidation, functionalized MDCs (FMDCs), especially FMDC(1.0) that was obtained via treating MDC with APS (1.0 M), showed remarkable performances in the adsorption of small cationic dyes like methylene blue (MB) and azure B. For example, FMDC(1.0) had the maximum adsorption capacity (Q_o) of 625.0 mg/g (for MB) which is larger than any reported value with carbonaceous materials. Moreover, the obtained Q_o was around 4 and 2 times that of activated carbon with Q_o of 160 mg/g and MDC with Q_o of 298 mg/g, respectively. On the contrary, oxidative treatment of MDC was negative in adsorption of an anionic dye such as methyl orange. Moreover, the functionalized MDC was not very effective in the adsorption of cationic dyes with large sizes (like brilliant green, crystal violet, Janus green B, and rhodamine B) because of the limited pore size of the studied adsorbent FMDC(1.0). The remarkable adsorption of MB over FMDC(1.0) could be explained by electrostatic and π-π interactions. Finally, the facile recyclability of the FMDC(1.0) in MB adsorption was confirmed via successive adsorptions, FT-IR, and nitrogen adsorption; therefore, FMDC(1.0) can be suggested as a potential adsorbent to remove cationic dyes, especially with small molecular sizes.

Molecule-to-Material-to-Bio Nanoarchitectonics with Biomedical Fullerene Nanoparticles

Nanoarchitectonics integrates nanotechnology with various other fields, with the goal of creating functional material systems from nanoscale units such as atoms, molecules, and nanomaterials. The concept bears strong similarities to the processes and functions seen in biological systems. Therefore, it is natural for materials designed through nanoarchitectonics to truly shine in bio-related applications. In this review, we present an overview of recent work exemplifying how nanoarchitectonics relates to biology and how it is being applied in biomedical research. First, we present nanoscale interactions being studied in basic biology and how they parallel nanoarchitectonics concepts. Then, we overview the state-of-the-art in biomedical applications pursuant to the nanoarchitectonics framework. On this basis, we take a deep dive into a particular building-block material frequently seen in nanoarchitectonics approaches: fullerene. We take a closer look at recent research on fullerene nanoparticles, paying special attention to biomedical applications in biosensing, gene delivery, and radical scavenging. With these subjects, we aim to illustrate the power of nanomaterials and biomimetic nanoarchitectonics when applied to bio-related applications, and we offer some considerations for future perspectives.

Materials nanoarchitectonics in a two-dimensional world within a nanoscale distance from the liquid phase

Promoted understanding of nanotechnology has enabled the construction of functional materials with nanoscale-regulated structures. Accordingly, materials science requires one-step further innovation by coupling nanotechnology with the other materials sciences. As a post-nanotechnology concept, nanoarchitectonics has recently been proposed. It is a methodology to architect functional material systems using atomic, molecular, and nanomaterial unit-components. One of the attractive methodologies would be to develop nanoarchitectonics in a defined dimensional environment with certain dynamism, such as liquid interfaces. However, nanoarchitectonics at liquid interfaces has not been fully explored because of difficulties in direct observations and evaluations with high-resolutions. This unsatisfied situation in the nanoscale understanding of liquid interfaces may keep liquid interfaces as unexplored and attractive frontiers in nanotechnology and nanoarchitectonics. Research efforts related to materials nanoarchitectonics on liquid interfaces have been continuously made. As exemplified in this review paper, a wide range of materials can be organized and functionalized on liquid interfaces, including organic molecules, inorganic nanomaterials, hybrids, organic semiconductor thin films, proteins, and stem cells. Two-dimensional nanocarbon sheets have been fabricated by molecular reactions at dynamically moving interfaces, and metal-organic frameworks and covalent organic frameworks have been fabricated by specific interactions and reactions at liquid interfaces. Therefore, functions such as sensors, devices, energy-related applications, and cell control are being explored. In fact, the potential for the nanoarchitectonics of functional materials in two-dimensional nanospaces at liquid surfaces is sufficiently high. On the basis of these backgrounds, this short review article describes recent approaches to materials nanoarchitectonics in a liquid-based two-dimensional world, i.e., interfacial regions within a nanoscale distance from the liquid phase.

Recent Advancements in Cyclodextrin-Based Adsorbents for the Removal of Hazardous Pollutants from Waters

Water is an essential substance for the survival on Earth of all living organisms. However, population growth has disturbed the natural phenomenon of living, due to industrial growth to meet ever expanding demands, and, hence, an exponential increase in environmental pollution has been reported in the last few decades. Moreover, water pollution has drawn major attention for its adverse effects on human health and the ecosystem. Various techniques have been used to treat wastewater, including biofiltration, activated sludge, membrane filtration, active oxidation process and adsorption. Among the mentioned, the last method is becoming very popular. Moreover, among the sorbents, those based on cyclodextrin have gained worldwide attention due to their excellent properties. This review article overviewed recent contributions related to the synthesis of Cyclodextrin (CD)-based adsorbents to treat wastewater, and their applications, especially for the removal of heavy metals, dyes, and organic pollutants (pharmaceuticals and endocrine disruptor chemicals). Furthermore, new adsorption trends and trials related to CD-based materials are also discussed regarding their regenerative potential. Finally, this review could be an inspiration for new research and could also anticipate future directions and challenges associated with CD-based adsorbents.

Mechano-Nanoarchitectonics: Design and Function

Mechanical stimuli have rather ambiguous and less-specific features among various physical stimuli, but most materials exhibit a certain level of responses upon mechanical inputs. Unexplored sciences remain in mechanical responding systems as one of the frontiers of materials science. Nanoarchitectonics approaches for mechanically responding materials are discussed as mechano-nanoarchitectonics in this review article. Recent approaches on molecular and materials systems with mechanical response capabilities are first exemplified with two viewpoints: i) mechanical control of supramolecular assemblies and materials and ii) mechanical control and evaluation of atom/molecular level structures. In the following sections, special attentions on interfacial environments for mechano-nanoarchitectonics are emphasized. The section entitled iii) Mechanical Control of Molecular System at Dynamic Interface describes coupling of macroscopic mechanical forces and molecular-level phenomena. Delicate mechanical forces can be applied to functional molecules embedded at the air-water interface where operation of molecular machines and tuning of molecular receptors upon macroscopic mechanical actions are discussed. Finally, the important role of the interfacial media are further extended to the control of living cells as described in the section entitled iv) Mechanical Control of Biosystems. Pioneering approaches on cell fate regulations at liquid-liquid interfaces are discussed in addition to well-known mechanobiology.

Ordered Mesoporous Boron Carbon Nitrides with Tunable Mesopore Nanoarchitectonics for Energy Storage and CO2 Adsorption Properties

Porous boron carbon nitride (BCN) is one of the exciting systems with unique electrochemical and adsorption properties. However, the synthesis of low-cost and porous BCN with tunable porosity is challenging, limiting its full potential in a variety of applications. Herein, the preparation of well-defined mesoporous boron carbon nitride (MBCN) with high specific surface area, tunable pores, and nitrogen contents is demonstrated through a simple integration of chemical polymerization of readily available sucrose and borane ammonia complex (BAC) through the nano-hard-templating approach. The bimodal pores are introduced in MBCN by controlling the self-organization of BAC and sucrose molecules within the nanochannels of the template. It is found that the optimized sample shows a high specific capacitance (296 F g^-1 at 0.5 A g^-1 ), large specific capacity for sodium-ion battery (349 mAg h^-1 at 50 mAh g^-1 ), and excellent CO₂ adsorption capacity (27.14 mmol g^-1 at 30 bar). Density functional theory calculations demonstrate that different adsorption sites (BC, BN, CN, and CC) and the large specific surface area strongly support the high adsorption capacity. This finding offers an innovative breakthrough in the design and development of MBCN nanostructures for energy storage and carbon capture applications.

Engineered biochar: A multifunctional material for energy and environment

Biochar is a stable carbon-rich product loaded with upgraded properties obtained by thermal cracking of biomasses in an oxygen-free atmosphere. The pristine biochar is further modified to produce engineered biochar via various physical, mechanical, and chemical methods. The hasty advancement in engineered biochar synthesis via different technologies and their application in the field of energy and environment is a topical issue that required an up-to-date review. Therefore, this review deals with comprehensive and recent mechanistic approaches of engineered biochar synthesis and its further application in the field of energy and the environment. Synthesis and activation of engineered biochar via various methods has been deliberated in brief. Furthermore, this review systematically covered the impacts of engineered biochar amendment in the composting process, anaerobic digestion (AD), soil microbial community encouragement, and their enzymatic activities. Finally, this review provided a glimpse of the knowledge gaps and challenges associated with application of engineered biochar in various fields, which needs urgent attention in future research.

Biomimetic and Biological Nanoarchitectonics

A post-nanotechnology concept has been assigned to an emerging concept, nanoarchitectonics. Nanoarchitectonics aims to establish a discipline in which functional materials are fabricated from nano-scale components such as atoms, molecules, and nanomaterials using various techniques. Nanoarchitectonics opens ways to form a more unified paradigm by integrating nanotechnology with organic chemistry, supramolecular chemistry, material chemistry, microfabrication technology, and biotechnology. On the other hand, biological systems consist of rational organization of constituent molecules. Their structures have highly asymmetric and hierarchical features that allow for chained functional coordination, signal amplification, and vector-like energy and signal flow. The process of nanoarchitectonics is based on the premise of combining several different processes, which makes it easier to obtain a hierarchical structure. Therefore, nanoarchitectonics is a more suitable methodology for creating highly functional systems based on structural asymmetry and hierarchy like biosystems. The creation of functional materials by nanoarchitectonics is somewhat similar to the creation of functional systems in biological systems. It can be said that the goal of nanoarchitectonics is to create highly functional systems similar to those found in biological systems. This review article summarizes the synthesis of biomimetic and biological molecules and their functional structure formation from various viewpoints, from the molecular level to the cellular level. Several recent examples are arranged and categorized to illustrate such a trend with sections of (i) synthetic nanoarchitectonics for bio-related units, (ii) self-assembly nanoarchitectonics with bio-related units, (iii) nanoarchitectonics with nucleic acids, (iv) nanoarchitectonics with peptides, (v) nanoarchitectonics with proteins, and (vi) bio-related nanoarchitectonics in conjugation with materials.

Adsorptive removal of herbicides with similar structures from water over nitrogen-enriched carbon, derived from melamine@metal-azolate framework-6

Based on the recent concern on the pollution of water bodies with herbicides, adsorptive removal of typical herbicides with similar chemical structures, e. g. clofibric acid (CLFA), methylchlorophenoxypropionic acid or mecoprop (MCPP) and 2,4-dichlorophenoxyacetic acid (2,4-D) from water was studied using a porous nitrogen-enriched carbon. To prepare the nitrogen-enriched carbon, pyrolysis of a melamine (MLM) incorporated metal-azolate framework-6 (MLM(x)@MAF6; x = 0-50 M % of the ligand 2-ethylimidazole for MAF6), that was prepared for the first time via an in situ method, was carried out. The MLM(x)@MAF6-derived carbons (MDC6M(x)s) were characterized and used in the removal of CLFA, MCPP and 2,4-D from water. We found that the MDC6M(25), obtained from MLM(25)@MAF6 with 25% MLM (as the optimum precursor composition), showed the highest maximum adsorption capacity (Q₀) of 1031 mg/g for CLFA, compared with any reported adsorbents, so far. The physicochemical properties of CLFA, as well as adsorbents and adsorptions under wide pH conditions, were employed to propose a plausible adsorption mechanism including hydrogen bonding. Remarkably, the porous carbon with enriched nitrogen, derived from MAF6 loaded MLM via in situ method, was very competitive in herbicides adsorption because of the contribution of well-dispersed nitrogen sties on the adsorbent. Finally, MDC6M(25) was suggested as a potential adsorbent for the removal of herbcides, including CLFA, MCPP and 2,4-D, from water, which is highly attractive to mitigate the environmental issue, especially, water pollution by various herbicides.

Material Evolution with Nanotechnology, Nanoarchitectonics, and Materials Informatics: What will be the Next Paradigm Shift in Nanoporous Materials?

Materials science and chemistry have played a central and significant role in advancing society. With the shift toward sustainable living, it is anticipated that the development of functional materials will continue to be vital for sustaining life on our planet. In the recent decades, rapid progress has been made in materials science and chemistry owing to the advances in experimental, analytical, and computational methods, thereby producing several novel and useful materials. However, most problems in material development are highly complex. Here, the best strategy for the development of functional materials via the implementation of three key concepts is discussed: nanotechnology as a game changer, nanoarchitectonics as an integrator, and materials informatics as a super-accelerator. Discussions from conceptual viewpoints and example recent developments, chiefly focused on nanoporous materials, are presented. It is anticipated that coupling these three strategies together will open advanced routes for the swift design and exploratory search of functional materials truly useful for solving real-world problems. These novel strategies will result in the evolution of nanoporous functional materials.

Porous carbon nanoarchitectonics for the environment: detection and adsorption

As a post-nanotechnology concept, nanoarchitectonics has emerged from the 20th century to the 21st century. This review summarizes the recent progress in the field of metal-free porous carbon nanoarchitectonics.

Bio-interactive nanoarchitectonics with two-dimensional materials and environments

Like the proposal of nanotechnology by Richard Feynman, the nanoarchitectonics concept was initially proposed by Masakazu Aono. The nanoarchitectonics strategy conceptually fuses nanotechnology with other research fields including organic chemistry, supramolecular chemistry, micro/nanofabrication, materials science, and bio-related sciences, and aims to produce functional materials from nanoscale components. In this review article, bio-interactive nanoarchitectonics and two-dimensional materials and environments are discussed as a selected topic. The account gives general examples of nanoarchitectonics of two-dimensional materials for energy storage, catalysis, and biomedical applications, followed by explanations of bio-related applications with two-dimensional materials such as two-dimensional biomimetic nanosheets, fullerene nanosheets, and two-dimensional assemblies of one-dimensional fullerene nanowhiskers (FNWs). The discussion on bio-interactive nanoarchitectonics in two-dimensional environments further extends to liquid-liquid interfaces such as fluorocarbon-medium interfaces and viscous liquid interfaces as new frontiers of two-dimensional environments for bio-related applications. Controlling differentiation of stem cells at fluidic liquid interfaces is also discussed. Finally, a conclusive section briefly summarizes features of bio-interactive nanoarchitectonics with two-dimensional materials and environments and discusses possible future perspectives.

Regulation of stem cell fate and function by using bioactive materials with nanoarchitectonics for regenerative medicine

Nanoarchitectonics has emerged as a post-nanotechnology concept. As one of the applications of nanoarchitectonics, this review paper discusses the control of stem cell fate and function as an important issue. For hybrid nanoarchitectonics involving living cells, it is crucial to understand how biomaterials and their nanoarchitected structures regulate behaviours and fates of stem cells. In this review, biomaterials for the regulation of stem cell fate are firstly discussed. Besides multipotent differentiation, immunomodulation is an important biological function of mesenchymal stem cells (MSCs). MSCs can modulate immune cells to treat multiple immune- and inflammation-mediated diseases. The following sections summarize the recent advances of the regulation of the immunomodulatory functions of MSCs by biophysical signals. In the third part, we discussed how biomaterials direct the self-organization of pluripotent stem cells for organoid. Bioactive materials are constructed which mimic the biophysical cues of in vivo microenvironment such as elasticity, viscoelasticity, biodegradation, fluidity, topography, cell geometry, and etc. Stem cells interpret these biophysical cues by different cytoskeletal forces. The different cytoskeletal forces lead to substantial transcription and protein expression, which affect stem cell fate and function. Regulations of stem cells could not be utilized only for tissue repair and regenerative medicine but also potentially for production of advanced materials systems. Materials nanoarchitectonics with integration of stem cells and related biological substances would have high impacts in science and technology of advanced materials.

Nanoarchitectonics for Hierarchical Fullerene Nanomaterials

Nanoarchitectonics is a universal concept to fabricate functional materials from nanoscale building units. Based on this concept, fabrications of functional materials with hierarchical structural motifs from simple nano units of fullerenes (C60 and C70 molecules) are described in this review article. Because fullerenes can be regarded as simple and fundamental building blocks with mono-elemental and zero-dimensional natures, these demonstrations for hierarchical functional structures impress the high capability of the nanoarchitectonics approaches. In fact, various hierarchical structures such as cubes with nanorods, hole-in-cube assemblies, face-selectively etched assemblies, and microstructures with mesoporous frameworks are fabricated by easy fabrication protocols. The fabricated fullerene assemblies have been used for various applications including volatile organic compound sensing, microparticle catching, supercapacitors, and photoluminescence systems.

Microporous Carbon Nitride (C3 N5.4 ) with Tetrazine based Molecular Structure for Efficient Adsorption of CO2 and Water

Mesoporous carbon nitrides with C₃ N₅ and C₃ N₆ stoichiometries created a new momentum in the field of organic metal-free semiconductors owing to their unique band structures and high basicity. Here, we report on the preparation of a novel graphitic microporous carbon nitride with a tetrazine based chemical structure and the composition of C₃ N_5.4 using ultra-stable Y zeolite as the template and aminoguanidine hydrochloride, a high nitrogen-containing molecule, as the CN precursor. Spectroscopic characterization and density functional theory calculations reveal that the prepared material exhibits a new molecular structure, which comprises two tetrazines and one triazine rings in the unit cell and is thermodynamically stable. The resultant carbon nitride shows an outstanding surface area of 130.4 m²  g^-1 and demonstrates excellent CO₂ adsorption per unit surface area of 47.54 μmol m^-2 , which is due to the existence of abundant free NH₂ groups, basic sites and microporosity. The material also exhibits highly selective sensing over water molecules (151.1 mmol g^-1 ) and aliphatic hydrocarbons due to its unique microporous structure with a high amount of hydrophilic nitrogen moieties and recognizing ability towards small molecules.

Removal of Particulate Matters by Using Zeolitic Imidazolate Framework-8s (ZIF-8s) Coated onto Cotton: Effect of the Pore Size of ZIF-8s on Removal

Removal of particulate matter (PM) like PM2.5 and PM10 from air was carried out with cotton coated with metal-organic frameworks (MOFs) having various pore sizes to understand the effect of the pore size of MOFs (here, ZIF-8s) on the performances in PM elimination. Both removal efficiency and quality factor, based on the unit surface area of ZIF-8s, in the filtration of PMs with ZIF-8/cotton did not rely considerably on the pore size of ZIF-8s. More importantly, small pores (even less than 0.5 nm) of conventional MOFs like ZIF-8 are more than enough in the elimination of large PMs like PM10 with a size of microns probably because small active sites (such as polar functional groups) on PMs can interact with porous materials having polarity. Additionally, electrostatic interactions between PMs and porous materials could be confirmed as a plausible mechanism for PM removal with ZIF-8/cotton.

How neutral nitrogen-containing compounds are oxidized in oxidative-denitrogenation of liquid fuel with TiO2@carbon

Oxidative-denitrogenation (ODN) of indole (IND) and methyl-substituted INDs (methyl-INDs), representative neutral nitrogen-containing compounds (NCCs), was carried out with TiO₂@C and H₂O₂ as heterogeneous catalyst and oxidant, respectively, under ultrasound irradiation. The oxidation of INDs progressed through radical formation, as evidenced by electron spin resonance and radical scavenger experiments. The oxidized position of INDs in the ODN process was checked via characterization of the obtained products. It was observed that the oxidation finally occurred on the carbon rather than on the nitrogen atom of INDs, unlike the oxidation of basic NCCs (e.g., oxidation on the nitrogen atom, as respective N-oxides were formed) and sulfur-containing compounds. To understand the relative reactivity and oxidation position, electron density (ED) on the nitrogen atom of the studied INDs and relative stability of representative intermediates/products were calculated. It could be confirmed that ED on the nitrogen atom of the INDs is very important in the oxidation of INDs since the ODN reactivity of INDs was enhanced with increasing ED on the nitrogen atom of the investigated INDs. Moreover, theoretical analyses of the relative stability of substrate and intermediates/products (especially for IND) can explain the route for the observed final products in ODN. In other words, oxygen on the nitrogen atom, obtained via the first step of oxidation (electrophilic addition of an active oxygen atom on nitrogen), moves to the nearby carbon atom, because of the relative stability of the intermediates and products.