Lukman Hakim

• Doctor of Science
• Professor (Assistant) at University of Brawijaya

The occupancy of hydrogen inside the voids of ice Ic and ice II, which gives two stable hydrogen hydrate compounds at high pressure and temperature, has been examined using a hybrid grand-canonical Monte Carlo simulation in wide ranges of pressure and temperature. The simulation reproduces the maximum hydrogen-to-water molar ratio and gives a detai...

A hybrid grand-canonical Monte Carlo simulation has been performed to investigate the hydrogen hydrate compounds in which hydrogen molecules are stored in ice II and ice I{c}. A simple theoretical model, which can reproduce the simulation results, provides the phase diagrams of the two-component system in the pressure-composition plane. Stability e...

The production of vegetable-based fuels has intensified in recent years due to the decreasing availability of fossil fuels and their environmental impacts. This study explores the synthesis, characterization, and application of nickel-molybdenum (NiMo) bimetal-dispersed silica catalysts for converting used palm cooking oil into liquid biofuels. The...

Advancements in analytical quality and management have been achieved using flow chemical analysis (FCA) techniques such as FIA, SIA, computer-controlled FCA (CC-FCA) and other related techniques. Using FIA, sensitivity improvement has been achieved and lowering tedious, time-consuming and laborious tasks in analytical chemistry laboratories have be...

Research on the synthesis of mesoporous silica catalyst, as well as its activity and selectivity in the hydrocracking of used palm oil, has been carried out. The research involved the preparation of mesoporous silica catalyst by varying the volume ratio of TEOS:CTAB at 2:1, 4:1, and 8:1, then calcined at 500 °C. Synthesis success was confirmed by F...

The hydrocracking of used cooking oil into biofuel over mesoporous silica was systematically studied. This research aims to induce the silica pores using NaHCO3 and employ the heteropore silica for the hydrocracking process of used cooking oil into biofuel. The mesoporous silica material was synthesized with various ratios of NaHCO3 and TEOS, and c...

Curcumin is a natural product with potential pharmaceutical applications that can be augmented by drug delivery technology such as nano emulsion. Our study focuses on microscopic structural and dynamics response of curcumin encapsulation in micellar system with lecithin as a natural surfactant under variations of composition and temperature using m...

Ionic liquid (IL)-based electrolytes are a promising material for the development of sodium-ion batteries, and their performance can be quantified by electrical conductivity. In this highly concentrated ionic system, the correlated motions of ion pairs are influential on the ionic transport properties. Herein, all-atom analyses are conducted throug...

Nanoscale materials are currently an attractive research subject because their properties are in contrast to their macroscopic counterparts. An inert material, such as bulk platinum metal for example, is known to exhibit a catalytic properties when its size is reduced into nanoscale. A stable material can become flammable or combustible, such as al...

The underlying principle of surface wettability has obtained great attentions for the development of novel functional surfaces. Molecular dynamics simulations has been widely utilized to obtain molecular-level details of surface wettability that is commonly quantified in term of contact angle of a liquid droplet on the surface. In this work, the se...

Research on mesoporous silica synthesis using CTAB template as well as its activity and selectivity in the hydrocracking of used palm oil has been conducted. This research was initiated with the synthesis of mesoporous silica material by varying the TEOS to CTAB ratios at 2:1, 4:1, and 8:1, later calcined at varying temperatures of 300, 350, and 40...

Ionic liquid (IL) has been considered as a potential electrolyte for developing next-generation sodium-ion batteries. A highly concentrated ionic system such as IL is characterized by the significant influence of intramolecular polarization and intermolecular charge transfer that vary with the combination of cations and anions in the system. In thi...

Clathrate hydrate is a promising material that can be used to trap the carbon dioxide (CO 2 ) as a mean for the greenhouse-gas emission control. A compromise between experimental findings and density functional theory calculations was recently made to determine the occupancy of the newly reported CO 2 clathrate hydrate of ice XVII structure. In thi...

Mobile chemical analysis (MCA) systems were examined to improve on-site analysis. The MCAs developed were expected to be superior in rapidity and robustness to batch-wise methods in chemical analysis, as well as being less heavy and battery-driven, and to be able to measure multi-components in a system. Also, the system had better to be simple, and...

Various separation methods for carbon dioxide gas have been proposed to control its release to the atmosphere, including the separation using an inorganic membranes such as ceramic MgO. In this work, molecular dynamics simulations are performed to clarify the condensation behaviour of carbon dioxide, in its pure and mixture state, onto the surface...

Molecular dynamics simulations are performed to investigate the permeation and separation of methane and carbon dioxide mixture through a layered inorganic membrane at high temperature to circumvent carbon dioxide adsorption on membrane surface. The simulations show that a single layer membrane with narrow cylindrical-pore favors methane permeation...

In this work, a molecular dynamics simulation was performed to investigate a reversible hydrophobic-hydrophilic properties of a surface model as a function of external electric potential. The surface is composed of a self-assembled monolayer (SAM) of a functionalized carbon chains that are immobilized on a supporting metal surface. The simulation s...

A solid-phase material based on modified chitosan using tripolyphosphate (TPP) and ethylene glycol diglycidyl ether (EGDE) as a crosslinker has been prepared, and its ability in adsorbing Cr(VI) has been examined. In this work, a chitosan flake was shaped into beads using TPP, and its chemical stability was improved through reaction with EGDE as th...

Statistical mechanical and simulation studies have been reviewed for the filled ice Ic and ice II containing hydrogen molecules. The occupancy of hydrogen inside the voids of ice Ic and ice II is examined using a hybrid grand-canonical Monte Carlo simulation in wide ranges of pressure and temperature. A simple theoretical model provides a global ph...

The adsorption of metallic elements on the solid phase chelating resins is probably the most effective separation and preconcentration methods. In this work, portable Solid phase extraction (SPE) was constructed using a commercially available plastic syringe containing certain amount of the Analiq ME-02 chelating resin. The ability of this portable...

A hybrid type of grand-canonical Monte Carlo simulation is carried out to investigate the accommodation of guest particle, i.e. neon, inside ice I c and its influence to the ice structure. The simulation is extended from low pressure and temperature where the pure ice I c structure is stable. As the compression proceeds, ice I c structure become un...

A hybrid type of grand-canonical Monte Carlo simulation is carried out to investigate the accommodation of guest particle, i.e., neon, inside ice I c and its influence to the ice structure. The simulation is extended from low pressure and temperature where the pure ice I c structure is stable. As the compression proceeds, ice I c structure become u...

The stability of ice I cubic (ice Ic) whose voids are occupied by neon particles is investigated using a hybrid type of isobaric grand-canonical Monte Carlo simulation. We show that the resulting neon hydrate is stable under high pressure and temperature where ice Ic alone is unstable, suggesting the existence of a novel neon hydrate of ice Ic. We...

Chitosan resin possessing the 4-hydroxyphthalic acid moiety (CCTS-HPA resin) was synthesized. This resin could adsorb chromium(VI) at pH 3 to 5, whereas chromium(III) could not be retained in the acidic region. The CCTS-HPA resin was used for collecting chromium(VI), and ME-03 resin was used for collecting chromium(III) before their measurement by...

Chitosan resin possessing the 4-hydroxyphthalic acid moiety (CCTS-HPA resin) was synthesized. This resin could adsorb chromium(VI) at pH 3 to 5, whereas chromium(III) could not be retained in the acidic region. The CCTS-HPA resin was used for collecting chromium(VI), and ME-03 resin was used for collecting chromium(III) before their measurement by...

A novel chitosan-based chelating resin modified with tris(2-aminoethyl)amine moiety (CCTS-TAA) was synthesized, and its characteristics in the collection/concentration of mercury was examined. The synthesized resin showed good adsorption toward mercury in a wide pH range, and the adsorbed mercury can be easily eluted by using 2M HNO(3) without any...

A novel chitosan-based resin functionalized with threonine moiety was synthesized, and applied to the collection/concentration of Mo, V and Cu in environmental water samples, followed by their determination using inductively coupled plasma-atomic emission spectrometer (ICP-AES). The synthesized resin, cross-linked chitosan-threonine (CCTS-Thr), sho...

A new chelating resin using chitosan as a base material was synthesized. Functional moiety of 2-amino-5-hydroxy benzoic acid (AHBA) was chemically bonded to the amino group of cross-linked chitosan (CCTS) through the arm of chloromethyloxirane (CCTS-AHBA resin). Several elements, such as Ag, Be, Cd, Co, Cu, Ni, Pb, U, V, and rare earth elements (RE...

A novel chelating resin functionalized with serine diacetic acid moiety was synthesized by using chitosan as base material, and applied to the collection/concentration of trace elements in environmental water samples, followed by the determination using inductively coupled plasma-atomic emission spectrometer (ICP-AES). The synthesized resin, crossl...

A chitosan resin derivatized with 3,4-dihydroxybenzoic acid moiety (CCTS-DHBA resin) was newly synthesized for the collection/concentration of trace uranium by using cross-linked chitosan (CCTS) as base material, and the adsorption behavior of uranium as well as 60 elements on the resin was examined by passing the sample solutions through a mini-co...

A triply-synchronized automated on-line pretreatment system coupled with ICP-AES, Multi-Auto-Pret AES system, was developed for the rapid determination of trace metals in water samples. The Multi-Auto-Pret AES system consists of three sets of a single Auto-Pret system, one more selection valve and a switching valve. Each single Auto-Pret system has...