Javier Lara-Romero

• Universidad Michoacana de San Nicolás de Hidalgo

The present study describes the synthesis of SnO2 thin films achieved by the atomic layer deposition technique based on the reaction of tetrakis(dimethylamino)tin (Sn(NMe2)4 and H2O. The experiments were realized at 2.7 × 10-4 atm and 150 °C on silicon, or boron-doped silicon substrates. To characterize the physicochemical properties of the films,...

The Bacillus subtilis bacteria have been reported to be capable of degrading compounds derived from petroleum. Nitrogen-doped graphene oxide compounds were used for Bacillus subtilis proliferation studies. To achieve GO doping, hydrazine, thiourea, and urea were used as nitrogen precursors. The SEM micrographs show the bacteria on top of the surfac...

This work reports the tribological assessment of ceria (CeO2) nanoparticles supported on multiwalled carbon nanotubes as water-based lubricant additives. Crystalline multiwalled carbon nanotubes (MWCNTs) were obtained by a spray pyrolysis method using alpha-pinene, a renewable feedstock, as carbon source and ferrocene as catalyst. CeO2 nanoparticle...

The friction and wear reducing properties of ammonium thiomolybdate as a water‐soluble lubricant additive were evaluated using a pin‐on‐disck tribometer on a steel‐steel contact. The tribological performance of aqueous solutions of thiomolybdate prepared at concentrations between 0.1 and 0.3 wt% Mo were evaluated at the same load (10 N), entrainmen...

The present work is aimed at developing ZnO compounds, doping them using a novel nitrogen plasma methodology, and supporting them on graphene oxide sheets, to efficiently carry out, the photodegradation of lignin. The synthesis of ZnO was carried out using a hydrothermal methodology using microwave heating. To provide explanation and support to thi...

We report the synthesis of ceria nanoparticles supported on multiwalled carbon nanotubes via a microwave-assisted method. The resulting composites were characterized by HRTEM, XRD, TGA and Raman spectroscopy. This method enabled the growth of ceria nanoparticles of ~1.4 nm homogeneously distributed on the surface of the carbon nanotubes. The adsorp...

The synthesis of silver nanoparticles (AgNPs) supported on multiwalled carbon nanotubes (MWCNTs) by means of a microwave-assisted method is reported. The produced AgNPs/MWCNTs nano composites were characterized by high resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and R...

Molybdenum oxide synthesized by a hydrothermal microwave-assisted method was studied for environmental pollutants removal and tribology tests with excellent results. This method proved to be highly efficient to synthetize hexagonal crystalline structures in a short reaction time. The as synthesized material was stabilized by a heat treatment at 450...

Characterization of Oxide/Sulfide Molybdenum Hexagonal Rods - Carlos Ornelas, F. Paraguay-Delgado, O. Solis-Canto, W. Antunez-Flores, K. Campos, J. Lara-Romero

Study of the Molybdenum Oxide Rods Sulfidation Process - Volume 26 Supplement - C. Ornelas, K.G. Guerrero−Hernández, J. Lara-Romero, C. Leyva-Porras, F. Paraguay-Delgado

Lubricant reactions in internal combustion engines follow complex reaction pathways, in which oil (hydrocarbons) and additives form protecting films (known as tribofilms) on the surfaces of the cylinder-piston couple. Up-to-date there is not a fundamental model useful to describe the chemistry involved in formation of these tribofilms, and degradat...

Morphology Change Study of Molybdenum Oxide from 3D to 2D Particles - Volume 25 Supplement - C. Ornelas, J. Lara-Romero, C. Campos-Valadez, C. Leyva-Porras, F. Paraguay-Delgado

In this study, a set of multilayer hard nanocrystalline coatings of Al/AlN with 35, 55 and 75 bilayer were prepared by DC magnetron sputtering on AISI 52100 steel specimens at nitrogen fractions of 35 and 65% in the Ar + N2 discharge. X-ray diffraction analysis indicates a polycrystalline structure of AlN + Al and AlN phases for 35% N2 and 65% N2 f...

Porous and Lamellar Molybdenum Oxide MonoCrystalline with Hexagonal Structure - Volume 24 Supplement - F. Paraguay-Delgado, O. Solis-Canto, C. Ornelas, J. Lara-Romero

Molybdenum Oxide Structures Synthetized by Microwave Technique and Its Phase Transformation by Thermal Treatment - Volume 23 Issue S1 - C. Ornelas, F. Paraguay-Delgado, J. Lara-Romero

Multiwalled carbon-nanotubes (MWCNT) and micro-structured carbon, such as biochar or activated carbon (AC), have been seen to significantly increase the growth indices of certain plant species such as maize (Zea mays L.). Seed imbibition is the stage where environmental factors that affect water transport across the seed coat barrier, make a large...

We present a parametric study on the growth of carbon nanotubes (CNTs) by spray pyrolysis of a biorenewable feedstock obtained from living pine trees, namely α-pinene. The analyzed variables were the type of catalyst, catalyst concentration, flow of reactants and reaction time, all at a fixed temperature of 800°C. The evaluation and optimization of...

Carbon nanostructures were directly grown onto standard AISI 316 stainless steel by spray pyrolysis of α-pinene, a biorenewable material. Two different nanostructures were formed: (1) multi-walled carbon nanotubes when using ferrocene as an external catalyst mixed with α-pinene and (2) ribbon carbon nanofibers when using only α-pinene. In both case...

Se estudiaron las propiedades reológicas de un aceite lubricante base polialfaolefina (PAO) al que se agregaron nanotubos de carbono (NTC) monocapa y multicapa como aditivos. Los ensayos reológicos realizados apuntaron a estudiar la variación de la viscosidad en función de la temperatura, la carga y la tasa de cizallamiento para mezclas con conteni...

INTRODUCTION Recent work has demonstrated the efficacy of carbon nanotubes (CNT) for plant growth especially during the early stages (< 7 days) of development. Pristine CNTs (p-CNTs) apparently show the greatest relative effect (Villagarcia et al, 2012; Khodakovskaya et al, 2009; Tiwari et al, 2014). Improved water transport to the seed has been su...

Resumen Todo lo que el hombre fabrica sufre un desgaste progresivo y si éste no se controla se genera gran consumo de energía, sustitución de componentes y en consecuencia, paros en la producción que elevan los costos y traen consigo pérdidas económicas. Los lubricantes hacen parte de este panorama en la medida en que ayudan a controlar el desgaste...

This paper presents an optimisation approach for determining the best synthesis method and their corresponding operating conditions for synthesising carbon nanotubes for a desired application accounting for technical and economic issues as objective functions. Proper correlations for the interaction between the considered variables are proposed, an...

Iron sulfide films were synthesized by the solid-gas reaction of diethyl disulfide on iron foils in the temperature range of 658-768 K using a microbalance, where the film growth kinetics followed Deal-Grove behavior. Analysis of the films by X-ray photoelectron and Raman spectroscopies as well as X-ray diffraction and scanning electron microscopy...

The unique properties of carbon nanotubes (CNTs) make them suitable for an incredible range of applications in materials science, electronics, energy management, and many other fields. CNTs can be manipulated chemically and physically in very useful ways, and their final properties and dimensions strongly depend on the parameters and the nature of...

Biogenesis and recycling of iron-sulfur (Fe-S) clusters play important roles in the iron homeostasis mechanisms involved in mitochondrial function. In Saccharomyces cerevisiae, the Fe-S clusters are assembled into apoproteins by the iron-sulfur cluster machinery (ISC). The aim of the present study was to determine the effects of ISC gene deletion a...

In recent years, there has been considerable interest in employing dispersed solid particles in the nanoscale range to enhance the friction and wear characteristics of liquid lubricants. Previous studies have suggested that tiny colloidal particles, under tribochemical conditions, deposit on rubbing surfaces influencing tribological characteristics...

This paper presents a general mathematical programming formulation to determine the optimal operating conditions to synthesize nanofibers through an electrospinning process at minimum cost. Several relationships based on experimental data for different polymers to determine the nanofiber diameter and costs are proposed. Also, a general optimization...

A new Co-complex as catalytic agent {[(Pentyl)(4)N](3)CoBr3}Cl-2 to prepare Multiwalled Carbon Nanotubes (MWCNTs) has been synthesized through the reaction of tetrapentylammonium bromide (Pentyl)(4)NBr and cobalt chloride (CoCl2) in aqueous solutions. MWCNT were obtained by spray pyrolysis of toluene as carbon source using this new Co-complex as ca...

SBA-15 is an interesting mesoporous silica material having highly ordered nanopores and a large surface area, which is widely employed as catalyst supports, absorbents, drug delivery materials, etc. Since it has a lack of functionality, heteroatoms and organic functional groups have been incorporated by direct or post-synthesis methods in order to...

The wear reducing properties of aqueous solutions of ammonium thiomolybdate and ammonium thiotungstate were evaluated using a frontal cylinder-on-cylinder test tribometer on an AISI 304 steel–steel contact. The antiwear characteristics of the lubricating solutions of thiomolybdate and thiotungstate were evaluated at 24.5, 30, and 40 N keeping fixed...

MoS2 sheathed carbon nanotubes have been successfully synthesized using a hydrothermal route under controlled conditions. The resultant material was studied by XRD, EDS, HRTEM, and Raman spectroscopy. Advantages of the preparation presented here compared to other methods are: a) lower reaction temperature, b) high yield of sheathed nanotubes includ...

The molecular dynamics of poly(vinyl alcohol) (PVA) were studied by dielectric spectroscopy and dynamic mechanical analysis in the 20–300°C range. The well‐established plasticizing effect of water on the glass‐transition temperature (T g ) of PVA was revisited. Improper water elimination analysis has led to a misinterpretation of thermal relaxation...

Nowadays, chemical sensors are attracting great interest because of their widespread applications in the industrial and environmental fields. Indeed, sensors with high sensitivity and selectivity are required for real-time detection of hazardous gas leaks. In order to detect a chemical agent, the sensing platform should be capable of detecting mult...

The molecular dynamics of poly (vinyl alcohol) were studied by dielectric

The chemistry of the different components of turpentine and the effect of temperature on the synthesis of multi-walled carbon nanotubes (MWCNTs) by spray pyrolysis using ferrocene as catalyst in a temperature range of 700–1000°C at 100°C intervals was investigated. Turpentine with high α-pinene concentration (83.4%) and low β-pinene concentration (...

a b s t r a c t A molybdenum carbide catalyst prepared with a novel methodology and its toluene hydrogenation activ-ity tested at temperatures within 423–598 K and 2.76 MPa is here reported. Almost 100% hydrogenation was achieved at 473 K with this catalyst. The activation energy was 58.1 kJ/mol with a zero-order reaction for toluene concentration,...

This work reports the molecular dynamics analysis of polyvinyl alcohol (PVA) thin films with two different molecular weights investigated by dielectric spectroscopy and dynamic mechanical analysis in the 20°C-300°C temperature range. Our results show that an adequate monitoring and moisture elimination before discussing the nature of each relaxatio...

By impedance spectroscopy, Gonzalez-Campos et al. J Polym Sci Part B: Polym Phys 2009, 47, 932–943, reported the first evidence of a glass transition in a polysaccharide. To gain a better understanding on the molecular relaxations in polysaccharides, we study composites of chitosan (CS)/silver nanoparticles (AgnP) films by dynamic mechanical analys...

Multi-wall carbon nanotubes (MWCNTs) were prepared by spray-pyrolysis of a botanical hydrocarbon, alpha-pinene and ferrocene as the catalyst at 700–1000°C. The MWCNTs were analysed by scanning electron microscopy, transmission electron microscopy, Raman spectroscopy and X-ray diffraction. The microscopy studies show the formation of carbon nanotube...

Nickel nanoparticles have been deposited on carbon nanotubes by spray pyrolysis of toluene as carbon source and nickelocene as catalyst at different temperatures. The optimum temperature to produce well-grown Ni/carbon nanotubes was found to be 850°C. The carbon nanotubes were characterized by SEM, TEM, XRD, Raman spectroscopy and TGA-DTA. The micr...

Nanostructures of tungsten trioxide (WO3) have been successfully synthesized by using an aged route at low temperature (60 °C) followed by a hydrothermal method at 200 °C for 48 h under well controlled conditions. The material was studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Energy Dispersive Spectroscopy (EDS), transm...

Multi-wall carbon nanotubes (MWCNT) were prepared by spray-pyrolysis of alpha-pinene, a botanical hydrocarbon, and ferrocene as catalyst at 900 degrees C. The MWCNT were analyzed by scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), and Raman spectroscopy. The microscopy studies show the formation of carbo...

Aqueous solutions of three tetraalkylammonium thiomolybdates (R4N)(2)MoS4 (R = methyl, propyl, or hydrogen) were prepared and their tribological performance was tested using a pin-on-disc tribometer on a steel-aluminum contact. Tests were performed at the same conditions of load, entrainment speed, sliding distance, temperature, and concentration o...

Synthesis and tribological evaluation of three tetraalkylammonium thiomolybdate (R4N)2MoS4 (R=methyl, propyl, or ammonia) aqueous-based lubricant additives on a ball-on-disk tribometer was carried out for a steel–aluminum contact. Tests were performed at the same conditions of load, entrainment speed, sliding distance, temperature, and concentratio...

Bodymaker lubricants are oil-in-water emulsions used as coolants in the ironing process during production of aluminium cans. Lubricants are formulated to diminish friction during ironing and to cool down the mechanical contact interface. In the present work, a methodology based on algebraic modelling of the process is proposed to select among bodym...

Lubricant bases for metalworking applications make extensive use of water-soluble additives to reduce friction and wear. In order to do such task, these additives must form a lubricating film that separates the contact surfaces thus imparting good surface finishes to the worked parts. This paper presents a study on the tribological performance of a...

Lubricants for metalworking applications make extensive use of water-soluble additives to reduce friction and wear. In order to do such task, these additives must form a lubricating film that separates the contact surfaces thus imparting good surface finish to the worked parts. This paper presents a study on the tribological performance of aqueous...

Can bodymaker coolants are oil-in-water emulsions used as lubricants in the ironing process for making aluminum containers. The lubricant is designed to cool down the can-making interface while providing the proper lubricity for ironing. In the present work a new methodology for the selection of different bodymaker coolants as function of their tri...

Lubricants bases for metalworking applications make extensive use of water-soluble additives to reduce friction and wear. In order to do such task, these additives must form a lubricating film that separates the contact surfaces, thus imparting good surface finishes to the worked parts. This paper presents a study on the tribological performance of...

Lubricants are widely used in industrial machinery in order to separate solid tribological surfaces and support high loads under severe conditions. In tribological contacts, viscosity plays an important role in the film-forming abilities of the lubricant, but this property is strongly dependent on temperature. Consequently, small variations in temp...

The thermal decomposition of model extreme-pressure lubricant additives on clean iron was studied in ultrahigh vacuum conditions using molecular beam strategies. Methylene chloride and chloroform react to deposit a solid film consisting of FeCl2 and carbon, and evolve only hydrogen into the gas phase. No gas-phase products and less carbon on the su...

The C8 aromatics fraction in a refinery consists mainly of four isomers i.e. ortho-, meta-, para-xylene and ethylbenzene, being para-xylene the one with major industrial importance. Since the equilibrium amount of para-xylene at the outlet of the catalytic reformer is only ∼24 %, a separation of this isomer is performed, and the ortho- and meta- ri...

Aqueous solutions of three tetraalkylammonium thiomolybdates (R4N)2MoS4 (R = methyl, propyl or hydrogen) were prepared and their tribological performance was tested using a pin-on-disc tribometer on a steel-aluminum contact. Tests were performed at the same conditions of load, entrainment speed, sliding distance, temperature, and concentration of t...

The lubricating performance ofa common antiwear additive, zinc dialkyldithiophosphate, on different pairs of metallic non-ferrous fribological surfaces was studied. The specimens tested were made of AISI 52100 steel, chromium coated and titanium nitride coated steel specimens. Film thickness and friction coefficient was measured using a ball-on-fla...

Bodymaker coolants are oil-in-water emulsions used as lubricants in the ironing process for making aluminum containers. The lubricant is designed to cool down the can-making interface while providing the proper lubricity for ironing. An extreme-pressure model has been successfully applied to evaluate the tribological performance of bodymaker coolan...

The boundary lubricating behaviour of a friction modifier and viscosity modifier additives was studied using steel, chromium and titanium nitride as tribological surfaces. Film forming and friction coefficient were evaluated for a ball-on-flat contact under rolling-sliding motion. Olefin co-polymer dispersant, known to form a viscous boundary film...

The choosing and pairing of control and manipulate variables in lumped parameter chemical reactors, usually Continuous Stirred Tank Reactors (CSTR), is not an easy task because of the lack of methodologies for systematic evaluation of control schemes in nonlinear systems. Furthermore, intrinsic nonlinearities of this kind of systems provoke respons...

The thermal decomposition of model chlorine- and sulfur-containing extreme-pressure lubricant additives on clean iron was studied in ultrahigh vacuum conditions using molecular beam strategies. Methylene chloride and chloroform react to deposit a solid film consisting of FeCl2 and carbon, and evolve only hydrogen into the gas phase. No gas-phase pr...

Extreme-pressure lubricants are currently widely used in various areas of applications. However, despite of their common use, the fundamental aspects of the mechanism in which these lubricants reduce the friction coefficient are not clear yet. Earlier macrotribological experiments using chlorinated hydrocarbons have shown remarkable effectiveness....

Chlorinated and sulfurized hydrocarbons are commonly added to a base fluid to formulate lubricants used under extreme-pressure (EP) conditions. It has been demonstrated that the interfacial temperature in the EP regime varies linearly with the applied load and temperatures in excess of 1000 K can be attained promoting the reaction between the addit...

Recently, the possibility of using lubricants containing nanoparticles to control friction and wear has caught the attention of researchers. These tiny little particles are present in many important practical applications such as soot-contaminated engine oils or partially-soluble additives. Prediction of the behaviour of solid particles in differen...

The C8 aromatics fraction in a refinery consists mainly of four isomers i.e. ortho-, meta-, para-xylene and ethylbenzene, being para-xylene the one with major industrial importance. Since the equilibrium amount of para- xylene at the outlet of the catalytic reformer is only ∼24 %, a separation of this isomer is performed, and the ortho- and meta- r...