Reaction Of Graphite Research Articles

Sulfonyl chloride-intensified metal chloride intercalation of graphite for efficient sodium storage

Metal chloride-intercalated graphite with excellent conductivity and a large interlayer spacing is highly desired for use in sodium ion batteries. However, halogen vapor is usually indispensable in initiating the intercalation process, which makes equipment design and experiments challenging. In this work, SO2Cl2 was used as a chlorine generator to intensify the intercalation of BiCl3 into graphite (BiCl3-GICs), which avoided the potential risks, such as Cl2 leakage, in traditional methods. The operational efficiency in the experiment was also improved. After the reaction of SO2Cl2, BiCl3, and graphite at 200 oC for 20 h, the synthesized BiCl3-GICs had a large interlayer spacing (1.26 nm) and a high amount of BiCl3 intercalation (42%), which gave SIBs a high specific capacity of 213 mAh g−1 at 1 A g−1 and an excellent rate performance (170 mAh g−1 at 5 A g−1). In-situ Raman spectra revealed that the electronic interaction between graphite and intercalated BiCl3 is weakened during the first discharge, which is favorable for sodium storage. This work broadly enables the increased intercalation of other metal chloride-intercalated graphites, offering possibilities for developing advanced energy storage devices.

One‐pot synthesis of aluminum phosphate‐supported, chitosan‐linked expandable graphite as a novel flame retardant for textile

AbstractAlthough cotton is the most common polymer in daily life, its limited use is due to its propensity to catch fire. To solve this issue, we developed an innovative flame‐retardant aluminum phosphate‐supported, chitosan‐linked expandable graphite composite (CAlPEG). The CAlPEG was synthesized by the reaction of natural graphite, aluminum phosphate, and chitosan biopolymer in a one‐pot method. When CAlPEG was coated with cotton fabric and exposed to continuous flame, the fabric did not catch fire up to 760 s, whereas only expandable graphite (EG), aluminum phosphate (AIP), and CS, coated cotton fabric burned within 20 s. Flame‐retardant proficiency of CAlPEG‐coated cloth was confirmed by flame tests such as a limiting oxygen index (LOI) and vertical flammability test. The blank cotton has 17% LOI and is completely burnt out. On the other hand, the as‐prepared composite has a 43% LOI rating, which denotes a high level of flame retardancy. The VFT test result showed the formation of a 3 cm char, which confirms the flame‐retardant material possesses self‐extinguishing qualities. The article develops a new method for utilizing bioresources such as chitosan and offers fresh perspectives on the environmentally friendly synthesis of phosphorylated EG‐linked chitosan on the AlPO4 matrix.

Surface-Constrained Metropolis Monte Carlo: Simulation of Reactions on Triply Periodic Minimal Surfaces.

Triply periodic minimal surfaces (TPMS) inspired by nature serve as a foundation for developing novel nanomaterials, such as templated silicas, graphene sponges, and schwarzites, with customizable optical, poroelastic, adsorptive, catalytic, and other properties. Computer simulations of reactions on TPMS using reactive intermolecular potentials hold great promise for constructing and screening potential TPMS with the desired properties. Here, we developed an off-lattice, surface-constrained Metropolis Monte Carlo (SC-MMC) algorithm that utilized a temperature quench process. The presented SC-MMC algorithm was used to investigate the process of graphitization reactions on the Schwarz primitive, Schwarz diamond, and Schoen gyroid TPMS, all with a cubic lattice parameter of 8 nm. We show that the optimized carbon TPMS exhibits a low energy, approximately -7.1 eV/atom, comparable to that of graphite and diamond crystals, along with a variety of topological defects. Furthermore, these structures showcase extensive and smooth surfaces characterized by a negative discrete Gaussian curvature, a distinctive feature indicative of an interconnected morphology. They possess specific surface areas of ∼2700 m2/g, comparable to graphene, and exhibit a significant porosity of around 90%. The theoretical X-ray correlation functions and nitrogen adsorption isotherms confirm that the constructed TPMS exhibit remarkably similar surface properties, although the pore space topology varies significantly.

Actinide Triamidoamine (TrenR) Chemistry: Uranium and Thorium Derivatives Supported by a Diphenyl‐tert‐Butyl‐Silyl‐Tren Ligand

AbstractWe report the synthesis and characterisation of thorium(IV), uranium(III), and uranium(IV) complexes supported by a sterically demanding triamidoamine ligand with N‐diphenyl‐tert‐butyl‐silyl substituents. Treatment of ThCl4(THF)3.5 or UCl4 with [Li3(TrenDPBS)] (TrenDPBS={N(CH2CH2NSiPh2But)3}3−) afforded [An(TrenDPBS)Cl] (An=Th, 1Th; U, 1U). Complexes 1An react with benzyl potassium to afford the cyclometallates (TrenDPBScyclomet) [An{N(CH2CH2NSiPh2But)2(CH2CH2NSiPhButC6H4)}] (An=Th, 2Th; U, 2U). Treatment of 1An with sodium azide affords [An(TrenDPBS)N3] (An=Th, 3Th; U, 3U). Reaction of 3Th with potassium graphite affords 2Th. In contrast, 3Th reacts with cesium graphite to afford the doubly‐cyclometallated (TrenDPBSd‐cyclomet) ate complex [Th{N(CH2CH2NSiPh2But)(CH2CH2NSiPhButC6H4)}2Cs(THF)3] (4). In contrast to 3Th, reaction of 3U with potassium graphite produces the uranium(III) complex [U(TrenDPBS)] (5), and 5 can also be prepared by reaction of potassium graphite with 1U. The loss of azide instead of conversion to nitrides contrasts to prior work when the silyl group is iso‐propyl silyl, underscoring how ligand substituents profoundly drive the reaction chemistry. Several complexes exhibit T‐shaped meta‐C−H⋅⋅⋅phenyl and staggered parallel π–π‐stacking interactions, demonstrating subtle weak interactions that drive ancillary ligand geometries. Compounds 1An–3An, 4, and 5 have been variously characterised by single crystal X‐ray diffraction, multi‐nuclear NMR spectroscopy, infrared spectroscopy, UV/Vis/NIR spectroscopy, and elemental analyses.

Silicon Graphite Composite Anode Degradation: Effects of Silicon Ratio, Current Density, and Temperature

Recently, a graphite–silicone (GrSi) composite anode has attracted a lot of attention due to its enhanced capacity and stability over pure Si anode. Herein, the abnormal behaviors and the degradation of the composite electrode during the repeated charging/discharging cycles are investigated. At each cycle, the capacity retention, Coulombic efficiency, irreversible, and differential capacity are analyzed to examine the contribution of each Gr and Si on the capacity. Generally, the composite electrodes are found to show a rapid initial decrease in capacity as the silicon ratio increases, indicating that silicone is the major contributor of the initial drop. Also, the capacity contribution of the graphite can also decrease rapidly for some conditions such as low temperature and high rate due to higher charge transfer resistance of the graphite. Interestingly, at certain conditions, the capacity decreases initially and recovers; differential capacity analysis revealed that this was due to the initial loss and recovery of graphite reactions. The degree of recovery decreased with increasing Si partly due to the higher resistivity of Si. Our findings could be useful for designing and operating composite electrodes with higher performance and stability.

SYNTHESIS OF FUNCTIONALIZED GRAPHENE NANOPLATELETS THROUGH OXIDATIVE CHLOROPHOSPHORYLATION: TECHNICAL NOTE

This paper is devoted to the investigation of functionalized graphene nanoplatelets (FGNPs) samples. Synthesis of FGNPs was carried out through oxidative chlorophosphorylation (OxCh) reaction, i.e. reaction of graphite with PCl3 in the presence of oxygen under different conditions. For this, the reaction of graphite with PCl3 in the presence of oxygen was carried out separately both at a temperature of 65°C and at room temperature in a CCl4 medium and at a temperature of 65°C in a CCl4 medium. The FGNPs samples obtained by this method were named FGNPs1, FGNPs2, and FGNPs3, respectively. FGNPs1, FGNPs2, and FGNPs3 were investigated using Fourier Transform Infrared (FTIR) and ultraviolet–visible (UV–Visible) spectroscopy, scanning electron microscopy (SEM), and X-ray diffraction (XRD) analysis methods. The results of FTIR spectroscopy showed that all FGNPs samples contain phosphonate groups. Based on the UV–Vis spectroscopy, the optical band gap of the samples was calculated and compared with pristine graphite. It has been established that the width of the optical bands of FGNPs1 (1.17[Formula: see text]eV), FGNPs2 (1.22[Formula: see text]eV), and FGNPs3 (1.24[Formula: see text]eV) is wider than that of the pristine graphite (1.04[Formula: see text]eV). Based on the XRD analysis, it was determined that the functionalization causes a change in the crystal lattice parameters of graphite. Based on the XRD analysis, it was determined that the functionalization causes a change in the crystal lattice parameters of graphite and FGNPs samples (number of graphene layers: [Formula: see text]; [Formula: see text]; [Formula: see text]) to consist of fewer graphene layers than graphite ([Formula: see text]).

Microstructure evolution and reaction mechanism of reactive plasma sprayed Ti–C–N coatings

This investigation focuses on the feasibility of the reaction synthesis of Ti–C–N phase using plasma spraying powder mixture of Ti and graphite under nitrogen ion flame flow. To regularize the microstructure and properties of the sprayed Ti–C–N coating, the microstructure evolution of the Ti-graphite-N2 system was analyzed based on water quenching tests. The reaction pathway of the Ti-graphite-N2 system has been investigated by thermodynamic calculations and thermal analysis, revealing the mechanisms of the reaction during plasma spraying. The results show that the as-deposited coatings exhibit a typical layered structure consisting mainly of TiCxNy and TiO2. The quenched powders exhibit a melting process from irregular particles to smooth spherical particles, forming complete droplets with increasing spray distance. Based on phase evolution of the quenched powders and the thermal analysis of Ti powders or Ti/graphite powders under N2/Ar atmosphere, it found that the Ti powder can reacted with graphite or N2 by solid-solid or solid-gas reaction to form TiCx and TiNy, and TiNy can be formed preferentially as compared with TiCx phase. As the spraying distance increases, the Ti and graphite reactions are enhanced, and a pronounced TiCx phase can be detected once a large liquid Ti phase is formed. As the spray distance increases, formed TiNy and TiCx phases aggregate into droplets and rapidly transform into TiCxNy phase by solid-solution reactions. In addition, titanium oxide coexists in lamellae of Ti–C–N coatings due to the absorption and dissociation of O₂ from the atmosphere at the droplet surface.

Selective Cleavage of the Strong or Weak C–C Bonds in Biphenylene Enabled by Rare-Earth Metals

Selective cleavage of C-C bonds within arene rings is of great interest but remains elusive, especially for the molecules possessing the active and inert C-C bonds. Here, we report that the active and inert C-C bonds of biphenylene could be controllably cleaved by the reaction of biphenylene, potassium graphite, and rare-earth complexes with different metal centers. For scandium, the bond activation occurs at the Caryl-Caryl single bond, yielding 9-scandafluorene. For Lu, the reaction goes through ring contraction of the aromatic ring in biphenylene to provide benzopentalene dianionic lutetium. The origin of the selectivity and the reaction mechanism were illustrated by the isolation of intermediates and DFT calculations.

Monitoring of anodic corrosion on carbon-based gas diffusion layer in a flow cell

Due to the recent increase in carbon-based gas diffusion layer (GDL) usage for high-rate electrochemical reactors, the study on mitigating anodic corrosion associated with the GDL is imperative. In this study, the anodic corrosion of a high-rate electrochemical flow cell was evaluated using an on-line universal gas chromatography protocol with iridium oxide supported GDL (IrO2/GDL) as a model electrode, and it could be evidently alleviated in the alkaline media (1 M KOH) with an inert gas (Ar or N2) environment within current densities of 500 mA cm−2. In addition, the quantitative CO2/CO formation rate and Faradaic efficiencies results, along with the qualitative hydrophobicity maintenance ability of the anode, revealed that the anodic oxidation reaction could be efficiently suppressed in the carbon support samples with both high graphitization and good oxygen evolution reaction (OER) activity, such as the multi-walled carbon nanotubes. Therefore, further modification of the carbon-based GDL itself may help to prevent its corrosion above 500 mA cm−2. This work is important for tracing the origin of electrocatalysis deactivation and directing the design of carbon materials for the future electrodes that involving the GDL on a high-rate electrochemical reactor.

Effect of a Weak Coordination Solvent on a Kinetically Favorable Electrode Reaction in Concentrated Lithium-Ion Battery Electrolytes

We present highly concentrated electrolytes prepared with a fluorinated acetate solvent that has much weaker coordination power, allowing for a kinetically favorable electrode reaction in lithium (Li)-ion batteries (LIBs). Among the concentrated electrolytes using conventional organic solvents, the concentrated electrolyte containing a 2,2,2-trifluoroethyl acetate (TFEAc) solvent and 3.2 mol dm–3 LiFSA salt (FSA: bis(fluorosulfonyl)amide) had the lowest ionic conductivity but a wide electrochemical window (∼5 V), allowing for a LIB electrode reaction. Compared to an analogous electrolyte containing LiTFSA salt (TFSA: bis(trifluoromethanesulfonyl)amide), the concentrated LiFSA/TFEAc electrolyte demonstrated significantly improved charge–discharge behavior with a high C-rate performance on the graphite negative electrode. The activation energy (Ea) of the graphite electrode reaction (i.e., Li+-insertion reaction) was determined experimentally to be Ea = 19.9 kJ mol–1 in the concentrated LiFSA/TFEAc electrolyte, which was significantly lower than that reported previously for dilute carbonate-based electrolytes. Furthermore, a combination of high-energy X-ray total scattering experiments and all-atom molecular dynamics simulations revealed that Li ions are co-coordinated with TFEAc molecules and FSA anions to form intricate ion-ordered complexes in the bulk solution with no free solvent and counteranion. From a structural viewpoint, we discussed the characteristic Ea in the current concentrated electrolyte system and concluded that the weak interaction between Li-ion and TFEAc remaining in the activation state plays a key role in triggering energetically easier decoordination during the charge transfer process, achieving a kinetically unique graphite electrode reaction.

Mechanochemical Preparation of Edge-Selectively justify Hydroxylated Graphene Nanosheets Using Persulfate via a Sulfate Radical-Mediated Process.

The production of water-dispersed graphene with low defects remains a challenge. The dry ball milling of graphite with additives produces edge-selectively functionalized graphene. However, the "inert" additives require a long milling time and cause inevitable in-plane defects. Here, the mechanochemical reaction of graphite with persulfate solved the above drawback and produced edge-selectively hydroxylated graphene (EHG) nanosheets through a 2 h ball-milling and a subsequent 0.5 h sonication. The mechanochemical cleavage of persulfate yielded SO4 ⋅- to spontaneously oxidize graphite to form the carbon radical cations selectively at edges, followed by hydroxylation with water of moisture. Because the O-O bond dissociation energy of persulfate is 20 % of the graphitic C-C bond, the rather low milling energy allowed the hydroxylation of graphite at edges with nearly no in-plane defects. The obtained EHG showed high water-dispersibility and excellent photothermal and electrochemical properties, thereby opening up a new door to fabricate graphene-based composites.

Designing high efficiency graphite felt electrode via HNO3 vapor activation towards stable vanadium redox flow battery

A new method of preparing nitric acid vapor treated graphite felt for vanadium redox flow battery (VRFB) is developed. This method outperforms traditional impregnation methods in convenience, efficacy and controllability of fabrication process. A sequence reaction mechanism is proposed for nitric acid vapor treated graphite felt reactions occurring at 200 °C. The modified-graphite felt (m-GF) with excellent electrocatalytic redox reversibility toward VO2+/VO2+ and V2+/V3+ redox couples is prepared in the conditions of VHNO3/mpGF=0.45 mL g−1 at 200 °C in 300 min (m-GF-0.45). The nitric acid vapor reaction with graphite felts occurs preferentially on the surface of amorphous carbon and at defect sites in the graphitic structure, yields N2 and carbon-oxygen surface complexes, resulting in a higher double layer capacity (DLC) from 146 μF mg−1 (p-GF) to 1514 μF mg−1 (m-GF-0.45). Thus, the energy efficiency and discharge capacity of m-GF-0.45 electrode increases significantly by 8.7% and 100% at 150 mA cm−2, respectively.

Internal short circuit and thermal runaway evolution mechanism of fresh and retired lithium-ion batteries with LiFePO4 cathode during overcharge

The safety evolution behavior of LiFePO4/graphite batteries with different states of health (SOHs) under overcharge is studied based on material morphology, structure, thermal stability and heat analysis. The overcharge results of the 100 % SOH battery show that with increasing state of charge (SOC), the cathode material gradually falls off due to binder oxidation. The number of pores in the separator is significantly reduced when the SOC reaches 120 %, resulting in increased internal resistance. Before the internal short circuit (ISC), the degree of lithium intercalation in the anode increases, and the heat release of the reaction between lithiated graphite and the binder increases, whereas both decrease after ISC due to severe side reactions. The heat release from SEI decomposition increases after ISC as the SOH of the retired battery decreases, while the heat release from the reaction between lithiated graphite and binder decreases. The ISC starts from the positive collector side. Thermal analysis results show that Joule heat plays a key role in the occurrence of ISC. After ISC, QSEI (SEI decomposition heat) + QLi-ele (lithium and electrolyte reaction heat) and QLi-bin (lithiated graphite and binder reaction heat) together determine the difference in thermal runaway (TR) behavior of different SOH batteries.

Electrochemical Grafting of a Pyridinium‐Conjugated Assembly on Graphite for H 2 O 2 Electrochemical Production

Carbon materials have shown great promise as cost-effective electrocatalysts for H 2 O 2 electrochemical production. In this work, we prepare a series of well-defined pyridinium-conjugated graphite sheets via nucleophilic substitution reaction of graphite with pyridine derivatives in anodic oxidation process. A combination of experimental and computational investigations confirm that the pyridine derivatives are electrochemically grafted onto the armchair-type edges of graphitic layers, where the adjacent carbon atoms show the positively charged state by the intramolecular charge transfer. The strong charge delocalization on pyridinium-conjugated graphite sheets can yield the enhanced electrocatalytic performance for oxygen reduction on both of the activity and selectivity (above 97 %) for H 2 O 2 production. Moreover, we find that the yield of H 2 O 2 production is also affected by the H 2 O 2 decomposing capabilities of functional groups on pyridinium. As one kind of pyrolysis-free strategies, the proposed electrochemical grafting can serve as a molecularly precise regulation to develop nitrogen doped carbon materials for more applications.

Composites of (C4F)n and (CF)n Synthesized by Uncatalyzed Fluorination of Graphite

A new solid-state 19F magic-angle spinning NMR signal at an isotropic 19F chemical shift of −53 ppm is measured from graphite fluoride synthesized by reaction of graphite with F2 at temperatures above 750 K with no catalyst. Two-dimensional NMR suggests the −53 ppm 19F NMR signal originates from covalent fluoromethanetriyl groups belonging to ordered (CyF)n bulk domains composited with the major (CF)n domains. Quantitative 19F and 13C NMR find y=4.32±0.64. DFT calculations of NMR chemical shifts for unsaturated fluorographene models show that a (C4F)n phase with fluorine bound covalently to a single side of the carbon layer best explains the observed NMR chemical shifts. We assign the new phase to this (C4F)n structure, which constitutes up to 15% of the carbon in our graphite fluoride composites. The (C4F)n content of the composite affects bulk electrochemical properties in a manner similar to graphite fluorides produced by conventional, catalyzed fluorination processes.

Study on the microstructure and mechanical properties of reactive plasma sprayed TiCxN1−x composite coatings with different Ti/graphite powders

In this present paper, the effects of Ti/graphite mass ratio (4:1, 6:1, 8:1 and 10:1) on the composite, grain size and mechanical properties of TiCN coatings were investigated. Based on the solid-solid reaction of Ti with graphite and solid-gas reaction of Ti with N2 in plasma jet, TiCN phase were in situ synthesized. Results show that all coatings consist of TiCxN1−x(0 ≤ x ≤ 1) main phase, small amount of Ti2O, amorphous graphite and CNx phases. The amount of TiCN phase firstly increases and then decreases along with mass ratio increases, and the content reachs the maximum when the Ti/graphite ratio is 6:1. Besides, the highest sp3C-N fraction (about 36.22%) is detected in the coating, which is benefical to improve hardness and elasticity modulus. Therefore, the value of H/E (0.095) and H3/E2 (0.23 GPa) are higher than other three coatings, which is conductive to improve mechanical and tribological properties. A joint wear mechanism of abrasive wear and adhesive wear is found for TiCN coatings.

Ba

Single crystals of Ba21[BN2]11[C2]4 were obtained by the reaction of barium metal, graphite and hexagonal boron nitride in silica-jacketed niobium capsules at 1030°C. They occur as shiny black, intergrown square platelets and adopt a new structure type crystallising in the tetragonal space group I4̄, exhibiting the cell parameters a = 1538.79(6) pm and c = 1007.36(4) pm (c/a = 0.655, Z = 2). The Raman spectrum was used to corroborate the nature of the anionic moieties: linear [BN2]3− and [C2]2− groups. They provide coordination spheres with seven to nine atoms from their respective termini for the Ba2+ cations. More structural features and the Raman data are discussed and compared with related compounds.

Synthesis and Reactivity of a Neutral Homocyclic Silylene.

Isolation of the neutral homocyclic silylene 2 is possible via amine ligand abstraction with potassium graphite (KC8) and subsequent reaction with SiMe3Cl from a bicyclic silicon(I) amide J. This reaction proceeds via an anionic homoaromatic silicon ring compound 1 as an intermediate. The twofold‐coordinated silicon atom in the homocyclic silylene 2 is stabilized by an allyl‐type π‐electron delocalization. 2 reacts in an oxidative addition with two equivalents of MeOH and in cycloadditions with ethene, phenylacetylene, diphenylacetylene and with 2,3‐dimethyl‐1,3‐butadiene to afford novel functionalized ring compounds.

Joining of SiC ceramics using the Ni-Mo filler alloy for heat exchanger applications

In order to meet the sealing demands of SiC heat exchanger, the Ni-Mo filler alloy was designed, prepared and employed to braze SiC ceramics. Wetting behavior of the Ni-Mo filler alloy on SiC ceramics and interfacial microstructure of the brazed joints were systematically characterized using optical observation furnace and XRD, SEM, EDS, TEM, respectively. Flexural strengths of the brazed joints at room temperature and high temperature were measured with four-point flexural strength method. HCl immersion test was performed to evaluate the corrosion resistance of the joints. The Ni-Mo filler alloy exhibited excellent wettability on SiC ceramics. During the process of brazing, SiC reacted with element Ni of the Ni-Mo filler alloy, resulting in the formation of Ni2Si + graphite reaction layer adjacent to the SiC substrate. Ni3Mo3C and Ni2Si compounds were precipitated at the center of brazing seam. When the brazing temperature increased from 1250 ℃ to 1400 ℃, the thickness of Ni2Si + graphite layer increased gradually. The maximum room-temperature flexural strength of 174 ± 33 MPa was obtained when brazed at 1300 ℃ for 40 min. The joints also exhibited stable high-temperature strength and acid corrosion resistance. When the test temperature was 700 ℃, 800 ℃, 900 ℃, the joints gave the strength retention rate of 92.5 %, 79.8 %, 67.2 %, respectively. It was believed that the formation of high melting point phases played an important role. Residual strength of the joints after HCl corrosion exceeded 130 MPa, revealing a good potential for applications in corrosion environment.

Bio-based multifunctional carbon aerogels from sugarcane residue for organic solvents adsorption and solar-thermal-driven oil removal

With the population increasing and industrialization developing, the high demand for clean water has become a major issue that should be meet. In particular, leak of oils and organic solvents, discharge of wastewater put greater pressure on water resource. Hence, the effective and environment-friendly treatment method for the wastewater has received much attention in international society. The carbon aerogels obtained from high-temperature carbonized treatment (C-cane) without chemical modification were regarded as effective monolithic hydrophobic/oleophilic oil-absorber in our work. Benefitting from the graphitization and aromatization reaction during carbonization process, the prepared sugarcane-based carbon aerogel obtained desirable hydrophobicity and oleophilicity. On this account, high absorption capacity for organic solvents (17.1 g/g–37.7 g/g) can be reached easily. Moreover, the C-cane can be used in emulsion separation. Due to the super resistance to fire, sugarcane-based carbon aerogel also presents good reusability. Meanwhile, the excellent photo-thermal conversion capability obtained during carbonization promote the adsorption of high viscous oil into sugarcane-based aerogel, presenting the solar-assisted oil absorption capability ranged from 31.9 g/g to 55.02 g/g. Outstanding light captive and photothermal conversion performance also enable them to be competent for rapidly separating high viscosity oil from water. The work convert agricultural residue into a highly-efficient adsorbing material, offering a commercially-available and scalable approach to solve the leakage of organic solvents and oil.