Imperial College London

ProfessorDarylWilliams

Faculty of EngineeringDepartment of Chemical Engineering

Professor of Particle Science
 
 
 
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Contact

 

+44 (0)20 7594 5611d.r.williams Website

 
 
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Location

 

439ACE ExtensionSouth Kensington Campus

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Summary

 

Publications

Publication Type
Year
to

149 results found

Cherukupally P, Sun W, Williams DR, Ozin GA, Bilton AMet al., 2022, Reclamation of Oily Wastewater at High Temperatures Using Thermosetting Polyurethane-Nanosilicon Sponges, ACS APPLIED POLYMER MATERIALS, Vol: 4, Pages: 1544-1550, ISSN: 2637-6105

Journal article

Mohamed NAN, Han Y, Hector AL, Houghton AR, Hunter-Sellars E, Reid G, Williams DR, Zhang Wet al., 2022, Increasing the Diameter of Vertically Aligned, Hexagonally Ordered Pores in Mesoporous Silica Thin Films, LANGMUIR, Vol: 38, Pages: 2257-2266, ISSN: 0743-7463

Journal article

Velasquez-Hernandez MDJ, Lopez-Cervantes VB, Martinez-Ahumada E, Tu M, Hernandez-Balderas U, Martinez-Otero D, Williams DR, Martis V, Sanchez-Gonzalez E, Chang J-S, Lee JS, Balmaseda J, Ameloot R, Ibarra IA, Jancik Vet al., 2022, CCIQS-1: A Dynamic Metal-Organic Framework with Selective Guest-Triggered Porosity Switching, CHEMISTRY OF MATERIALS, Vol: 34, Pages: 669-677, ISSN: 0897-4756

Journal article

Molisso S, Williams DR, Ces O, Rowlands LJ, Marsh JM, Law RVet al., 2021, Molecular interaction and partitioning in α-Keratin using 1H NMR Spin-Lattice (T1) relaxation times, Journal of the Royal Society Interface, Vol: 18, Pages: 1-8, ISSN: 1742-5662

The interactions between small molecules and keratins are poorly understood. In this paper an NMR method is presented to measure changes in the 1H T1 relaxation times of small molecules in human hair keratin to quantify their interaction with the fiber. Two populations of small molecule compounds were identified with distinct relaxation times, demonstrating the partitioning of the compounds into different keratin environments. The changes in relaxation time for solvent in hair compared to bulk solvent were shown to be related to the molecular weight, MW, and the partition coefficient, LogP, of the solvent investigated. Compounds with low molecular weights and high hydrophilicities had greater reductions in their T1 relaxation times and therefore experienced increased interactions with the hair fiber. The relative population sizes were also calculated. This is a significant step toward modelling the behavior of small molecules in keratinous materials and other large insoluble fibrous proteins.

Journal article

Azmi LHM, Cherukupally P, Hunter-Sellars E, Ladewig PB, Williams RDet al., 2021, Fabrication of MIL-101-polydimethylsiloxane composites for environmental toluene abatement from humid air, CHEMICAL ENGINEERING JOURNAL, Vol: 429, ISSN: 1385-8947

Journal article

Kondor A, Santmarti A, Mautner A, Williams D, Bismarck A, Lee K-Yet al., 2021, On the BET surface area of nanocellulose determined using volumetric, gravimetric and chromatographic adsorption methods, Frontiers in Chemical Engineering, Vol: 3, Pages: 1-12, ISSN: 2673-2718

Volumetric N2 adsorption at –196 °C is generally accepted as “gold standard” for estimating the Brunauer-Emmet-Teller (BET) surface area of nanocellulose. It is unclear however, whether the BET surface area of nanocellulose obtained at such low temperatures and pressures is meaningful at an absolute sense, as nanocellulose is used at ambient temperature and pressure. In this work, a systematic evaluation of the BET surface area of nanocellulose using a highly crystalline bacterial cellulose (BC) as model nanocellulose was undertaken to achieve a comprehensive understanding of the limitations of BET method for nanocellulose. BET surface area obtained using volumetric N2 adsorption at –196 °C was compared with the BET surface area acquired from gravimetric experiments using n-octane adsorption measured using dynamic vapour sorption (DVS) and n-octane adsorption determined by inverse gas chromatography (iGC), both at 25 °C. It was found that the BET surface area calculated from volumetric N2 adsorption data was 25% lower than that of n-octane adsorption at 25 °C obtained using DVS and iGC adsorption methods. These results supported the hypothesis that the BET surface area of nanocellulose is both a molecular scale (N2 vs n-octane, molecular cross section of 0.162 nm2 vs 0.646 nm2) and temperature (–196 °C vs 25 °C) dependent property. This study also demonstrates the importance of selecting appropriate BET pressure range based on established criteria and would suggest that the room temperature gravimetric measurement is more relevant for many nanocellulose applications.

Journal article

Cheung PCW, Williams DR, Barrett J, Barker J, Kirk DWet al., 2021, On the Origins of Some Spectroscopic Properties of "Purple Iron" (the Tetraoxoferrate(VI) Ion) and Its Pourbaix Safe-Space, MOLECULES, Vol: 26

Journal article

Lopez-Olvera A, Antonio Zarate J, Martinez-Ahumada E, Fan D, Diaz-Ramirez ML, Saenz-Cavazos PA, Martis V, Williams DR, Sanchez-Gonzalez E, Maurin G, Ibarra IAet al., 2021, SO2 Capture by Two Aluminum-Based MOFs: Rigid-like MIL-53(Al)-TDC versus Breathing MIL-53(Al)-BDC, ACS APPLIED MATERIALS & INTERFACES, Vol: 13, Pages: 39363-39370, ISSN: 1944-8244

Journal article

Lyu P, Wright AM, Lopez-Olvera A, Mileo PGM, Antonio Zarate J, Martinez-Ahumada E, Martis V, Williams DR, Dinca M, Ibarra IA, Maurin Get al., 2021, Ammonia Capture via an Unconventional Reversible Guest-Induced Metal-Linker Bond Dynamics in a Highly Stable Metal-Organic Framework, CHEMISTRY OF MATERIALS, Vol: 33, Pages: 6186-6192, ISSN: 0897-4756

Journal article

del Gaudio I, Hunter-Sellars E, Parkin IP, Williams D, Da Ros S, Curran Ket al., 2021, Water sorption and diffusion in cellulose acetate: The effect of plasticisers, CARBOHYDRATE POLYMERS, Vol: 267, ISSN: 0144-8617

Journal article

Cavazos PAS, Diaz-Ramirez ML, Hunter-Sellars E, McIntyre SR, Lima E, Ibarra IA, Williams DRet al., 2021, Fluorinated MIL-101 for carbon capture utilisation and storage: uptake and diffusion studies under relevant industrial conditions, RSC ADVANCES, Vol: 11, Pages: 13304-13310

Journal article

Holmes AS, Kiziroglou ME, Yang SKE, Yuan C, Boyle DE, Lincoln DM, McCabe JDJ, Szasz P, Keeping SC, Williams DR, Yeatman EMet al., 2021, Minimally invasive online water monitor, IEEE Internet of Things Journal, ISSN: 2327-4662

Sensor installation on water infrastructure is challenging due to requirements for service interruption, specialised personnel, regulations and reliability as well as the resultant high costs. Here, a minimally invasive installation method is introduced based on hot-tapping and immersion of a sensor probe. A modular architecture is developed that enables the use of interchangeable multi-sensor probes, non-specialist installation and servicing, low-power operation and configurable sensing and connectivity. A prototype implementation with a temperature, pressure, conductivity and flow multi-sensor probe is presented and tested on an evaluation rig. This paper demonstrates simple installation, reliable and accurate sensing capability as well as remote data acquisition. The demonstrated minimally invasive multi-sensor probes provide an opportunity for the deployment of water quality sensors that typically require immersion such as pH and spectroscopic composition analysis. This design allows dynamic deployment on existing water infrastructure with expandable sensing capability and minimal interruption, which can be key to addressing important sensing parameters such as optimal sensor network density and topology.

Journal article

Cherukupally P, Sun W, Williams DR, Ozin GA, Bilton AMet al., 2021, Wax-wetting sponges for oil droplets recovery from frigid waters, Science Advances, Vol: 7, ISSN: 2375-2548

Energy-efficient recovery of oil droplets from ice-cold water, such as oil sands tailings, marine, and arctic oil spills, is challenging. In particular, due to paraffin wax crystallization at low temperatures, the crude oil exhibits high viscosity, making it difficult to collect using simple solutions like sponges. Here, we report a wax-wetting sponge designed by conforming to the thermoresponsive microstructure of crude oil droplets. To address paraffin wax crystallization, we designed the sponge by coating a polyester polyurethane substrate with nanosilicon functionalized with paraffin-like octadecyl ligands. The wax-wetting sponge can adsorb oil droplets from wastewater between 5° and 40°C with 90 to 99% removal efficacy for 10 cycles. Also, upon rinsing with heptol, the adsorbed oil is released within seconds. The proposed approach of sponges designed to conform with the temperature-dependent microstructure of the crude oils could enable cold water technologies and improve circular economy metrics in the oil industry.

Journal article

Rivera-Almazo M, Diaz-Ramirez ML, Hernandez-Esparza R, Vargas R, Martinez A, Martis V, Saenz-Cavazos PA, Williams D, Lima E, Ibarra IA, Garza Jet al., 2021, Identification of the preferential CO and SO2 adsorption sites within NOTT-401, PHYSICAL CHEMISTRY CHEMICAL PHYSICS, Vol: 23, Pages: 1454-1463, ISSN: 1463-9076

Journal article

Mohd Azmi LH, Williams D, Ladewig B, 2021, Polymer-assisted modification of metal-organic framework MIL-96 (Al): influence of HPAM concentration on particle size, crystal morphology and removal of harmful environmental pollutant PFOA, Chemosphere, Vol: 262, Pages: 1-9, ISSN: 0045-6535

A new synthesis method was developed to prepare an aluminum-based metal organic framework (MIL-96) with a larger particle size and different crystal habits. A low cost and water-soluble polymer, hydrolyzed polyacrylamide (HPAM), was added in varying quantities into the synthesis reaction to achieve >200% particle size enlargement with controlled crystal morphology. The modified adsorbent, MIL-96-RHPAM2, was systematically characterized by SEM, XRD, FTIR, BET and TGA-MS. Using activated carbon (AC) as a reference adsorbent, the effectiveness of MIL-96-RHPAM2 for perfluorooctanoic acid (PFOA) removal from water was examined. The study confirms stable morphology of hydrated MIL-96-RHPAM2 particles as well as a superior PFOA adsorption capacity (340 mg/g) despite its lower surface area, relative to standard MIL-96. MIL-96-RHPAM2 suffers from slow adsorption kinetics as the modification significantly blocks pore access. The strong adsorption of PFOA by MIL-96-RHPAM2 was associated with the formation of electrostatic bonds between the anionic carboxylate of PFOA and the amine functionality present in the HPAM backbone. Thus, the strongly held PFOA molecules in the pores of MIL-96-RHPAM2 were not easily desorbed even after eluted with a high ionic strength solvent (500 mM NaCl). Nevertheless, this simple HPAM addition strategy can still chart promising pathways to impart judicious control over adsorbent particle size and crystal shapes while the introduction of amine functionality onto the surface chemistry is simultaneously useful for enhanced PFOA removal from contaminated aqueous systems.

Journal article

Hunter-Sellars E, Saenz-Cavazos PA, Houghton AR, McIntyre SR, Parkin IP, Williams DRet al., 2020, Sol-Gel Synthesis of High-Density Zeolitic Imidazolate Framework Monoliths via Ligand Assisted Methods: Exceptional Porosity, Hydrophobicity, and Applications in Vapor Adsorption, ADVANCED FUNCTIONAL MATERIALS, Vol: 31, ISSN: 1616-301X

Journal article

Grape ES, Gabriel Flores J, Hidalgo T, Martinez-Ahumada E, Gutierrez-Alejandre A, Hautier A, Williams DR, O'Keeffe M, Ohrstrom L, Willhammar T, Horcajada P, Ibarra IA, Inge AKet al., 2020, A Robust and Biocompatible Bismuth Ellagate MOF Synthesized Under Green Ambient Conditions, JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, Vol: 142, Pages: 16795-16804, ISSN: 0002-7863

Journal article

Gorla S, Diaz-Ramirez ML, Abeynayake NS, Kaphan DM, Williams DR, Martis V, Lara-Garcia HA, Donnadieu B, Lopez N, Ibarra IA, Montiel-Palma Vet al., 2020, Functionalized NU-1000 with an Iridium Organometallic Fragment: SO2 Capture Enhancement, ACS APPLIED MATERIALS & INTERFACES, Vol: 12, Pages: 41758-41764, ISSN: 1944-8244

Journal article

Zárate JA, Domínguez-Ojeda E, Sánchez-González E, Martínez-Ahumada E, López-Cervantes VB, Williams DR, Martis V, Ibarra IA, Alejandre Jet al., 2020, Reversible and efficient SO2 capture by a chemically stable MOF CAU-10: experiments and simulations., Dalton Trans, Vol: 49, Pages: 9203-9207

The adsorption of sulphur dioxide (SO2) in CAU-10 is obtained with the use of advanced experimental and computational tools to gain insight into the molecular mechanisms responsible for the adsorption of SO2. It is shown that the adsorption by CAU-10 is highly energy efficient and that van der Waals interactions are the driving force that controls adsorption in this system.

Journal article

Martinez-Ahumada E, Diaz-Ramirez ML, Lara-Garcia HA, Williams DR, Martis V, Jancik V, Lima E, Ibarra IAet al., 2020, High and reversible SO2 capture by a chemically stable Cr(III)-based MOF, JOURNAL OF MATERIALS CHEMISTRY A, Vol: 8, Pages: 11515-11520, ISSN: 2050-7488

Journal article

Mohd Azmi LH, Williams D, Ladewig B, 2020, Can metal organic frameworks outperform adsorptive removal of harmful phenolic compound 2-chlorophenol by activated carbon?, Chemical Engineering Research and Design, Vol: 158, Pages: 102-113, ISSN: 0263-8762

Removal of persistent organic compounds from aqueous solutions is generally achieved using adsorbent like activated carbon (AC) but it suffers from limited adsorption capacity due to low surface area. This paper describes a pioneering work on the adsorption of an organic pollutant, 2-chlorophenol (2-CP) by two MOFs with high surface area and water stability; MIL-101 and its amino-derivative, MIL-101-NH2. Although MOFs have higher surface area than AC, the latter was proven better having the highest equilibrium 2-CP uptake (345 mg g−1), followed by MIL-101 (121 mg g−1) and MIL-101-NH2 (84 mg g−1). Used MIL-101 could be easily regenerated multiple times by washing with ethanol and even showed improved adsorption capacity after each washing cycle. These results can open the doors to meticulous adsorbent selection for treating 2-CP-contaminated water.

Journal article

Hakim Mohd Azmi L, Williams DR, Ladewig BP, 2020, Polymer-Assisted Modification of Metal-Organic Framework MIL-96 (Al): Influence on Particle Size, Crystal Morphology and Perfluorooctanoic Acid (PFOA) Removal

<jats:p><jats:bold>Abstract</jats:bold>A new synthesis method was developed to prepare an aluminum-based metal organic framework (MIL-96) with a larger particle size and different crystal habits. A low cost and water-soluble polymer, hydrolyzed polyacrylamide (HPAM), was added in varying quantities into the synthesis reaction to achieve &gt;200% particle size enlargement with controlled crystal morphology. The modified adsorbent, MIL-96-RHPAM2, was systematically characterized by SEM, XRD, FTIR, BET and TGA-MS. Using activated carbon (AC) as a reference adsorbent, the effectiveness of MIL-96-RHPAM2 for perfluorooctanoic acid (PFOA) removal from water was examined. The study confirms stable morphology of hydrated MIL-96-RHPAM2 particles as well as a superior PFOA adsorption capacity (340 mg/g) despite its lower surface area, relative to standard MIL-96. MIL-96-RHPAM2 suffers from slow adsorption kinetics as the modification significantly blocks pore access. The strong adsorption of PFOA by MIL-96-RHPAM2 was associated with the formation of electrostatic bonds between the anionic carboxylate of PFOA and the amine functionality present in the HPAM backbone. Thus, the strongly held PFOA molecules in the pores of MIL-96-RHPAM2 were not easily desorbed even after eluted with a high ionic strength solvent (500 mM NaCl). Nevertheless, this simple HPAM addition strategy can still chart promising pathways to impart judicious control over adsorbent particle size and crystal shapes while the introduction of amine functionality onto the surface chemistry is simultaneously useful for enhanced PFOA removal from contaminated aqueous systems.</jats:p><jats:p />

Journal article

Hunter-Sellars E, Tee JJ, Parkin IP, Williams DRet al., 2020, Adsorption of volatile organic compounds by industrial porous materials: Impact of relative humidity, MICROPOROUS AND MESOPOROUS MATERIALS, Vol: 298, ISSN: 1387-1811

Journal article

Ngeow YW, Williams DR, Chapman A, Heng JYYet al., 2020, Surface energy mapping of modified silica using IGC technique at inite dilution, ACS Omega, Vol: 5, Pages: 10266-10275, ISSN: 2470-1343

The reinforcing silica filler, which can be more than 40% of an elastomer composite, plays a key role to achieve the desired mechanical properties in elastomer vulcanizates. However, the highly hydrophilic nature of silica surface causes silica particle aggregation. It remained a challenge for many tire manufacturers when using silica-filled elastomer compounds. Here, the silica surface energy changes when the surface is modified with coupling or noncoupling silanes; coupling silanes can covalently bond the silica to the elastomers. The surface energy of silica was determined using inverse gas chromatography (IGC) at finite dilution (FD-IGC) and found to be reduced by up to 50% when the silica surface was silanized. The spatial distribution of silica aggregates within the tire matrix is determined by transmission electron microscopy (TEM) and a direct correlation between aggregate size (silica microdispersion) and work of cohesion from IGC is reported, highlighting surface energy and work of cohesion being excellent indicators of the degree of dispersion of silica aggregates.

Journal article

Hakim Mohd Azmi L, Williams DR, Ladewig BP, 2020, Polymer-Assisted Modification of Metal-Organic Framework MIL-96 (Al): Influence on Particle Size, Crystal Morphology and Perfluorooctanoic Acid (PFOA) Removal

<jats:p><jats:bold>Abstract</jats:bold>A new synthesis method was developed to prepare an aluminum-based metal organic framework (MIL-96) with a larger particle size and different crystal habits. A low cost and water-soluble polymer, hydrolyzed polyacrylamide (HPAM), was added in varying quantities into the synthesis reaction to achieve &gt;200% particle size enlargement with controlled crystal morphology. The modified adsorbent, MIL-96-RHPAM2, was systematically characterized by SEM, XRD, FTIR, BET and TGA-MS. Using activated carbon (AC) as a reference adsorbent, the effectiveness of MIL-96-RHPAM2 for perfluorooctanoic acid (PFOA) removal from water was examined. The study confirms stable morphology of hydrated MIL-96-RHPAM2 particles as well as a superior PFOA adsorption capacity (340 mg/g) despite its lower surface area, relative to standard MIL-96. MIL-96-RHPAM2 suffers from slow adsorption kinetics as the modification significantly blocks pore access. The strong adsorption of PFOA by MIL-96-RHPAM2 was associated with the formation of electrostatic bonds between the anionic carboxylate of PFOA and the amine functionality present in the HPAM backbone. Thus, the strongly held PFOA molecules in the pores of MIL-96-RHPAM2 were not easily desorbed even after eluted with a high ionic strength solvent (500 mM NaCl). Nevertheless, this simple HPAM addition strategy can still chart promising pathways to impart judicious control over adsorbent particle size and crystal shapes while the introduction of amine functionality onto the surface chemistry is simultaneously useful for enhanced PFOA removal from contaminated aqueous systems.</jats:p><jats:p />

Journal article

Martinez-Ahumada E, Lopez-Olvera A, Jancik V, Sanchez-Bautista JE, Gonzalez-Zamora E, Martis V, Williams DR, Ibarra IAet al., 2020, MOF Materials for the Capture of Highly Toxic H2S and SO2, ORGANOMETALLICS, Vol: 39, Pages: 883-915, ISSN: 0276-7333

Journal article

Duralliu A, Matejtschuk P, Stickings P, Hassall L, Tierney R, Williams DRet al., 2020, The Influence of Moisture Content and Temperature on the Long-Term Storage Stability of Freeze-Dried High Concentration Immunoglobulin G (IgG), PHARMACEUTICS, Vol: 12

Journal article

Cherukupally P, Sun W, Wong APY, Williams DR, Ozin GA, Bilton AM, Park CBet al., 2020, Surface-engineered sponges for recovery of crude oil microdroplets from wastewater (vol 321, pg 784, 2019 ), NATURE SUSTAINABILITY, Vol: 3, Pages: 161-161, ISSN: 2398-9629

Journal article

Hunter-Sellars E, Sáenz Cavazos PA, Parkin IP, Williams DRet al., 2020, Energy-efficient air filtration media for removal of volatile chemicals

Conference paper

Mohd Azmi LH, Hunter-Sellars E, Ladewig B, Williams Det al., 2020, Facile hydrophobic modification strategy on hydrophilic metal organic frameworks for improved toluene capture

Conference paper

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