scholarly journals Nanocarbon from Rocket Fuel Waste: The Case of Furfuryl Alcohol-Fuming Nitric Acid Hypergolic Pair

Nanomaterials ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 1
Author(s):  
Nikolaos Chalmpes ◽  
Athanasios B. Bourlinos ◽  
Smita Talande ◽  
Aristides Bakandritsos ◽  
Dimitrios Moschovas ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Furfuryl Alcohol ◽  
Materials Science ◽  
Ambient Conditions ◽  
Materials Synthesis ◽  
Rocket Fuel ◽  
Carbon Nanosheets ◽  
New Synthesis ◽  
Fuming Nitric Acid ◽  
Liquid Rocket

In hypergolics two substances ignite spontaneously upon contact without external aid. Although the concept mostly applies to rocket fuels and propellants, it is only recently that hypergolics has been recognized from our group as a radically new methodology towards carbon materials synthesis. Comparatively to other preparative methods, hypergolics allows the rapid and spontaneous formation of carbon at ambient conditions in an exothermic manner (e.g., the method releases both carbon and energy at room temperature and atmospheric pressure). In an effort to further build upon the idea of hypergolic synthesis, herein we exploit a classic liquid rocket bipropellant composed of furfuryl alcohol and fuming nitric acid to prepare carbon nanosheets by simply mixing the two reagents at ambient conditions. Furfuryl alcohol served as the carbon source while fuming nitric acid as a strong oxidizer. On ignition the temperature is raised high enough to induce carbonization in a sort of in-situ pyrolytic process. Simultaneously, the released energy was directly converted into useful work, such as heating a liquid to boiling or placing Crookes radiometer into motion. Apart from its value as a new synthesis approach in materials science, carbon from rocket fuel additionally provides a practical way in processing rocket fuel waste or disposed rocket fuels.

scholarly journals Hypergolic Synthesis of Inorganic Materials by the Reaction of Metallocene Dichlorides With Fuming Nitric Acid At Ambient Conditions: The Case of Photocatalytic Titania

2021 ◽  
Author(s):  
Nikolaos Chalmpes ◽  
Georgios Asimakopoulos ◽  
Maria Baikousi ◽  
Athanasios B. Bourlinos ◽  
Michael A. Karakassides ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Materials Science ◽  
Organometallic Compounds ◽  
Inorganic Materials ◽  
Titania Nanoparticles ◽  
Titanocene Dichloride ◽  
Ambient Conditions ◽  
Materials Synthesis ◽  
Wide Range ◽  
Fuming Nitric Acid

Hypergolic materials synthesis is a new preparative technique in materials science that allows a wide range of carbon or inorganic solids with useful properties to be obtained. Previously we have demonstrated that metallocenes are versatile reagents in the hypergolic synthesis of inorganic materials, such as γ-Fe2O3, Cr2O3, Co, Ni and alloy CoNi. Here, we take one step further by using metallocene dichlorides as precursors for the hypergolic synthesis of additional inorganic phases, such as photocatalytic titania. Metallocene dichlorides are closely related to metallocenes, thus expanding the arsenal of organometallic compounds that can be used in hypergolic materials synthesis. In the present case, we show that hypergolic ignition of the titanocene dichloride-fuming nitric acid pair results in the fast and spontaneous formation of titania nanoparticles at ambient conditions in the form of anatase-rutile mixed phases. The obtained titania shows good photocatalytic activity towards Cr(VI) removal (100 % within 9 h), the latter being dramatically enhanced after calcination of the powder at 500 °C (100 % within 3 h). Worth noting, this performance was found to be comparable to that of commercially available P25 TiO2 under identical conditions. The cases of zirconocene, hafnocene and molybdocene dichlorides are complementary discussed in this work, aiming to show the wider applicability of metallocene dichlorides in the hypergolic synthesis of inorganic materials (ZrO2, HfO2, MoO2).

scholarly journals Carbon Nanostructures Derived through Hypergolic Reaction of Conductive Polymers with Fuming Nitric Acid at Ambient Conditions

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1595
Author(s):  
Nikolaos Chalmpes ◽  
Dimitrios Moschovas ◽  
Iosif Tantis ◽  
Athanasios B. Bourlinos ◽  
Aristides Bakandritsos ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Carbon Nanostructures ◽  
Carbon Nanomaterials ◽  
Conductive Polymers ◽  
Ambient Conditions ◽  
Organic Fuel ◽  
Carbon Nanosheets ◽  
New Synthesis ◽  
New Type ◽  
Fuming Nitric Acid

Hypergolic systems rely on organic fuel and a powerful oxidizer that spontaneously ignites upon contact without any external ignition source. Although their main utilization pertains to rocket fuels and propellants, it is only recently that hypergolics has been established from our group as a new general method for the synthesis of different morphologies of carbon nanostructures depending on the hypergolic pair (organic fuel-oxidizer). In search of new pairs, the hypergolic mixture described here contains polyaniline as the organic source of carbon and fuming nitric acid as strong oxidizer. Specifically, the two reagents react rapidly and spontaneously upon contact at ambient conditions to afford carbon nanosheets. Further liquid-phase exfoliation of the nanosheets in dimethylformamide results in dispersed single layers exhibiting strong Tyndall effect. The method can be extended to other conductive polymers, such as polythiophene and polypyrrole, leading to the formation of different type carbon nanostructures (e.g., photolumincent carbon dots). Apart from being a new synthesis pathway towards carbon nanomaterials and a new type of reaction for conductive polymers, the present hypergolic pairs also provide a novel set of rocket bipropellants based on conductive polymers.

scholarly journals Hypergolic Synthesis of Inorganic Materials by the Reaction of Metallocene Dichlorides with Fuming Nitric Acid at Ambient Conditions: The Case of Photocatalytic Titania

Sci ◽  
2021 ◽  
Vol 3 (4) ◽  
pp. 46
Author(s):  
Nikolaos Chalmpes ◽  
Georgios Asimakopoulos ◽  
Maria Baikousi ◽  
Athanasios B. Bourlinos ◽  
Michael A. Karakassides ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Materials Science ◽  
Organometallic Compounds ◽  
Inorganic Materials ◽  
Titania Nanoparticles ◽  
Titanocene Dichloride ◽  
Ambient Conditions ◽  
Materials Synthesis ◽  
Wide Range ◽  
Fuming Nitric Acid

Hypergolic materials synthesis is a new preparative technique in materials science that allows a wide range of carbon or inorganic solids with useful properties to be obtained. Previously we have demonstrated that metallocenes are versatile reagents in the hypergolic synthesis of inorganic materials, such as γ-Fe2O3, Cr2O3, Co, Ni and alloy CoNi. Here, we go one step further by using metallocene dichlorides as precursors for the hypergolic synthesis of additional inorganic phases, such as photocatalytic titania. Metallocene dichlorides are closely related to metallocenes, thus expanding the arsenal of organometallic compounds that can be used in hypergolic materials synthesis. In the present case, we show that hypergolic ignition of the titanocene dichloride–fuming nitric acid pair results in the fast and spontaneous formation of titania nanoparticles at ambient conditions in the form of anatase–rutile mixed phases. The obtained titania shows good photocatalytic activity towards Cr(VI) removal (100% within 9 h), with the latter being dramatically enhanced after calcination of the powder at 500 °C (100% within 3 h). Notably, this performance was found to be comparable to that of commercially available P25 TiO2 under identical conditions. The cases of zirconocene, hafnocene and molybdocene dichlorides are discussed in this work, which aims to show the wider applicability of metallocene dichlorides in the hypergolic synthesis of inorganic materials (ZrO2, HfO2, MoO2).

scholarly journals Hypergolic Materials Synthesis through Reaction of Fuming Nitric Acid with Certain Cyclopentadienyl Compounds

2020 ◽  
Vol 6 (4) ◽  
pp. 61 ◽  
Author(s):  
Nikolaos Chalmpes ◽  
Athanasios B. Bourlinos ◽  
Veronika Šedajová ◽  
Vojtěch Kupka ◽  
Dimitrios Moschovas ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Organometallic Chemistry ◽  
Carbon Materials ◽  
Materials Science ◽  
Inorganic Materials ◽  
Materials Synthesis ◽  
Fuming Nitric Acid

Recently we have shown the importance of hypergolic reactions in carbon materials synthesis. However, hypergolic reactions could be certainly expanded beyond carbon synthesis, offering a general preparative pathway towards a larger variety of materials. Cyclopentadienyls are one of the most common ligands in organometallic chemistry that react hypergolicly on contact with strong oxidizers. By also considering the plethora of cyclopentadienyl compounds existing today, herein we demonstrate the potential of such compounds in hypergolic materials synthesis in general (carbon or inorganic). In a first example, we show that cyclopentadienyllithium reacts hypergolicly with fuming nitric acid to produce carbon. In a second one, we show that ferrocene and cobaltocene also react hypergolicly with the concentrated acid to afford magnetic inorganic materials, such as γ-Fe2O3 and metallic Co, respectively. The present results further emphasize the importance and universal character of hypergolic reactions in materials science synthesis, as an interesting new alternative to other existing and well-established preparative methods.

scholarly journals Hypergolic Ignition of 1,3-Cyclodienes by Fuming Nitric Acid toward the Fast and Spontaneous Formation of Carbon Nanosheets at Ambient Conditions

Micro ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 15-27
Author(s):  
Nikolaos Chalmpes ◽  
Dimitrios Moschovas ◽  
Athanasios B. Bourlinos ◽  
Konstantinos Spyrou ◽  
Konstantinos C. Vasilopoulos ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Carbon Nanostructures ◽  
Carbon Matrix ◽  
Preparative Method ◽  
Expandable Graphite ◽  
Ambient Conditions ◽  
Organic Fuel ◽  
Carbon Nanosheets ◽  
Organic Fuels ◽  
Fuming Nitric Acid

A hypergolic system is a combination of organic fuel and oxidizer that ignites spontaneously upon contact without any external ignition source. Although their main usage pertains to rocket bipropellants, it is only recently that hypergolics have been established from our group as a revolutionary preparative method for the synthesis of different types of carbon nanostructures depending on the organic fuel-oxidizer pair. In an effort to further enrich this concept, the present work describes new hypergolic pairs based on 1,3-cyclohexadiene and 1,3-cyclooctadiene as the organic fuels and fuming nitric acid as the strong oxidizer. Both carbon-rich compounds (ca. 90% C) share a similar chemical structure with unsaturated cyclopentadiene that is also known to react hypergolically with fuming nitric acid. The particular pairs ignite spontaneously upon contact of the reagents at ambient conditions to produce carbon nanosheets in suitable yields and useful energy in the process. The nanosheets appear amorphous with an average thickness of ca. 2 nm and containing O and N heteroatoms in the carbon matrix. Worth noting, the carbon yield reaches the value of 25% for 1,3-cyclooctadiene, i.e., the highest reported so far from our group in this context. As far as the production of useful energy is concerned, the hot flame produced from ignition can be used for the direct thermal decomposition of ammonium dichromate into Cr2O3 (pigment and catalyst) or the expansion of expandable graphite into foam (absorbent and insulator), thus demonstrating a mini flame-pyrolysis burner at the spot.

scholarly journals Hypergolics in Carbon Nanomaterials Synthesis: New Paradigms and Perspectives

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2207 ◽  
Author(s):  
Nikolaos Chalmpes ◽  
Konstantinos Spyrou ◽  
Konstantinos C. Vasilopoulos ◽  
Athanasios B. Bourlinos ◽  
Dimitrios Moschovas ◽  
...  
Keyword(s):  
Carbon Nanomaterials ◽  
Product Formation ◽  
Spontaneous Ignition ◽  
Sodium Peroxide ◽  
Ambient Conditions ◽  
Materials Synthesis ◽  
Carbon Nanosheets ◽  
Released Energy ◽  
Nanomaterials Synthesis

Recently we have highlighted the importance of hypergolic reactions in carbon materials synthesis. In an effort to expand this topic with additional new paradigms, herein we present novel preparations of carbon nanomaterials, such-like carbon nanosheets and fullerols (hydroxylated fullerenes), through spontaneous ignition of coffee-sodium peroxide (Na2O2) and C60-Na2O2 hypergolic mixtures, respectively. In these cases, coffee and fullerenes played the role of the combustible fuel, whereas sodium peroxide the role of the strong oxidizer (e.g., source of highly concentrated H2O2). The involved reactions are both thermodynamically and kinetically favoured, thus allowing rapid product formation at ambient conditions. In addition, we provide tips on how to exploit the released energy of such highly exothermic reactions in the generation of useful work.

scholarly journals Functional Carbon Materials Derived through Hypergolic Reactions at Ambient Conditions

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 566 ◽  
Author(s):  
Nikolaos Chalmpes ◽  
Georgios Asimakopoulos ◽  
Konstantinos Spyrou ◽  
Konstantinos C. Vasilopoulos ◽  
Athanasios B. Bourlinos ◽  
...  
Keyword(s):  
Heat Source ◽  
Carbon Materials ◽  
Thermal Conversion ◽  
Nitrile Rubber ◽  
Ambient Conditions ◽  
Carbon Nanosheets ◽  
Whole Process ◽  
Hydrazide Derivative ◽  
Energy Consuming ◽  
Fuming Nitric Acid

Carbon formation from organic precursors is an energy-consuming process that often requires the heating of a precursor in an oven at elevated temperature. In this paper, we present a conceptually different synthesis pathway for functional carbon materials based on hypergolic mixtures, i.e., mixtures that spontaneously ignite at ambient conditions once its ingredients contact each other. The reactions involved in such mixtures are highly exothermic, giving-off sizeable amounts of energy; hence, no any external heat source is required for carbonization, thus making the whole process more energy-liberating than energy-consuming. The hypergolic mixtures described here contain a combustible organic solid, such as nitrile rubber or a hydrazide derivative, and fuming nitric acid (100% HNO3) as a strong oxidizer. In the case of the nitrile rubber, carbon nanosheets are obtained, whereas in the case of the hydrazide derivative, photoluminescent carbon dots are formed. We also demonstrate that the energy released from these hypergolic reactions can serve as a heat source for the thermal conversion of certain triazine-based precursors into graphitic carbon nitride. Finally, certain aspects of the derived functional carbons in waste removal are also discussed.

Bio-Inspired Processing of Ceramic Materials

2006 ◽  
Vol 45 ◽  
pp. 643-651 ◽  
Author(s):  
Joachim Bill
Keyword(s):  
Organic Molecules ◽  
Materials Science ◽  
Ceramic Materials ◽  
Research Field ◽  
Self Assembled Monolayers ◽  
Ambient Conditions ◽  
Ceramic Synthesis ◽  
New Synthesis ◽  
Assembled Monolayers ◽  
Living Nature

Ceramic processing without firing, sintering and expensive equipment represents a growing research field within materials science. With respect to the search of new synthesis pathways living nature provides paradigms for procedures that occur at ambient conditions and by apparently simple means. In this connection, biomineralization yields highly complex organic/inorganic structures, e. g. within nacre or bones. In general, the formation of these biominerals involves organic molecules that act as templates during the mineralization of inorganic phases. Bio-inspired ceramic synthesis aims to imitate such principles by technical means. Accordingly, these routes consider the template-induced formation and the structural design of ceramics from solutions of suitable metal salts. This paper describes such routes by means of the preparation of ceramics like titania, vanadia, and zinc oxide. The influence of (bio)organic molecules (e. g. polyelectrolytes, self-assembled monolayers, amino acids, peptides and proteins) on the micro- and nanostructure formation and on the evolution of the morphology of these solids will be discussed. Furthermore, mechanical as well as functional properties of the obtained architectures are treated.

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