Professor Patrick Fairclough
Department of Mechanical Engineering
Professor of Polymer and Composite Engineering
p.fairclough@sheffield.ac.uk
+44 114 222 7798
+44 114 222 7798
Sir Frederick Mappin Building
Full contact details
Professor Patrick Fairclough
Department of Mechanical Engineering
Sir Frederick Mappin Building
Mappin Street
Sheffield
S1 3JD
Department of Mechanical Engineering
Sir Frederick Mappin Building
Mappin Street
Sheffield
S1 3JD
- Profile
-
Professor Fairclough completed a BSc in Physics at the University of Birmingham in 1990 and then a PhD in Neutron Scattering graduating in 1995.
A postdoc in polymer science took him to UMIST in Manchester in 1994 (after briefly working as a service engineer) and the postdoc lasted until 1997 when he was recruited to the Department of Chemistry at the University of Sheffield.
In 2013 he took up the chair position in the Department of Mechanical Engineering.
- Research interests
-
Patrick's research covers a wide variety of polymers, soft materials and composite systems and his research spans the fundamentals of the network structure of epoxy resins, as used in protective coatings, to novel mould-free manufacturing of carbon fibre composites.
The current research group has projects including mould-free manufacturing, fibre splicing and tailored fibre placement. The mould-free work uses carbon black to create a conductive carbon composite that can be electrically cured and in the future can be developed to allow for the direct creation of composite parts from software without the use of conventional “tooling”.
The group also work on projects looking at thermoplastic composite materials and, in particular, systems that can be hydrolysed back to monomer species. The hydrolysis process takes place at high pressures and temperatures but with water as a solvent for the material. The group are working to develop this as a way of reusing recycled polymers, PET fibres from old bottles for example, to create recyclable structures.
They have had a long-standing interest in structural colour from using block copolymer mixtures as an easy way to create structural colour, to creating environmentally friendly replacements for TiO2. This work led them to study white beetle scales and to create a full 3D tomographic map of the scale by the use of synchrotron radiation at the ESRF in Grenoble France.
- Publications
-
Journal articles
- Investigating the feasibility of processing activated carbon/UHMWPE polymer composite using laser powder bed fusion. Polymers, 14(16).
- Study of Salting Effect of Inorganic Salts on Nano- and Giant Polymersomes. Macromolecular Research, 30(9), 609-614.
- Additive manufacturing of high density carbon fibre reinforced polymer composites. Additive Manufacturing, 103044-103044.
- Effects of tool coating and tool wear on the surface quality and flexural strength of slotted CFRP. Wear, 498-499.
- The effect of particle reinforcements on chip formation and machining induced damage of modified epoxy carbon fibre reinforced polymers (CFRPs). Composites Part A: Applied Science and Manufacturing, 154. View this article in WRRO
- Chip formation mechanism during orthogonal cutting of rubber microparticles and silica nanoparticles modified epoxy polymers. Procedia CIRP, 103, 176-181. View this article in WRRO
- Residual stress in fiber reinforced thermosetting composites : a review of measurement techniques. Polymer Composites.
- X-ray nano-tomography of complete scales from the ultra-white beetles Lepidiota stigma and Cyphochilus. Scientific Data, 7(1). View this article in WRRO
- Epifluorescent microscopy of edge-trimmed carbon fibre-reinforced polymers : an alternative to computed tomography scanning. Advanced Composites Letters, 29. View this article in WRRO
- Varying CFRP workpiece temperature during slotting: Effects on surface metrics, cutting forces and chip geometry. Procedia CIRP, 85, 37-42. View this article in WRRO
- A comparative study of the effects of milling and abrasive water jet cutting on flexural performance of CFRP. Procedia CIRP, 85, 277-283. View this article in WRRO
- Liquid–liquid phase separation morphologies in ultra-white beetle scales and a synthetic equivalent. Communications Chemistry, 2(1). View this article in WRRO
- Characterisation of UHMWPE polymer powder for laser sintering. Materials, 12(21). View this article in WRRO
- Well-defined networks from DGEBF - the importance of regioisomerism in epoxy resin networks. Macromolecules. View this article in WRRO
- Effects of machine stiffness and cutting tool design on the surface quality and flexural strength of edge trimmed carbon fibre reinforced polymers. Composites Part A: Applied Science and Manufacturing. View this article in WRRO
- Towards mould free composites manufacturing of thermoset prepregs. Incremental curing with localised pressure-heat (ICULPH). Procedia CIRP, 85, 237-242.
- Highly-ordered onion micelles made from amphiphilic highly-branched copolymers. Polymer Chemistry, 9(47), 5617-5629. View this article in WRRO
- The Effect of High-Intensity Ultraviolet Light to Elicit Microalgal Cell Lysis and Enhance Lipid Extraction.. Metabolites, 8(4). View this article in WRRO
- Does 1,8-diiodooctane affect the aggregation state of PC71BM in solution?. Royal Society Open Science. View this article in WRRO
- Wing scale ultrastructure underlying convergent and divergent iridescent colours in mimetic Heliconius butterflies. Journal of the Royal Society Interface, 15(141). View this article in WRRO
- Control of the Porous Structure of Polystyrene Particles Obtained by Nonsolvent Induced Phase Separation. Langmuir, 33(46), 13303-13314. View this article in WRRO
- Porosity of silica Stöber particles determined by spin-echo small angle neutron scattering. Soft Matter, 12(21), 4709-4714. View this article in WRRO
- Spatially modulated structural colour in bird feathers. Scientific Reports, 5(1). View this article in WRRO
- Self-Assembly Driven Electrospinning: The Transition from Fibers to Intact Beaded Morphologies. Macromolecular Rapid Communications, 36(15), 1452-1452. View this article in WRRO
- Spin echo small angle neutron scattering using a continuously pumped 3He neutron polarisation analyser. Review of Scientific Instruments, 86(2), 023902-023902. View this article in WRRO
- Coupling pH-responsive polymer brushes to electricity: switching thickness and creating waves of swelling or collapse.. Langmuir, 29(11), 3628-3635.
- pH-dependent control of particle motion through surface interactions with patterned polymer brush surfaces.. Langmuir, 28(36), 12955-12961.
- Interplay between gelation and phase separation in aqueous solutions of methylcellulose and hydroxypropylmethylcellulose.. Langmuir, 28(28), 10551-10557. View this article in WRRO
- Importance of particle tracking and calculating the mean-squared displacement in distinguishing nanopropulsion from other processes.. Langmuir, 28(30), 10997-11006.
- Direct imaging of the orientational dynamics of block copolymer lamellar phase subjected to shear flow. Macromolecules, 45(12), 5260-5272.
- Controlling the motion and placement of micrometer-sized metal particles using patterned polymer brush surfaces.. Langmuir, 27(19), 11801-11805.
- Characterization of polymer-silica nanocomposite particles with core-shell morphologies using Monte Carlo simulations and small angle X-ray scattering.. Langmuir, 27(13), 8075-8089.
- Using Multimodal Blends to Elucidate the Mechanism of Flow-Induced Crystallization in Polymers. J POLYM SCI POL PHYS, 49(9), 621-628.
- Shear ordered diblock copolymers with tuneable optical properties.. Phys Chem Chem Phys, 13(8), 3179-3186.
- Continuously tuneable optical filters from self-assembled block copolymer blends. SOFT MATTER, 7(8), 3721-3725.
- Monodisperse macromolecules - A stepping stone to understanding industrial polymers. European Polymer Journal, 47(4), 447-464.
- Time-resolved small-angle X-ray scattering studies of polymer-silica nanocomposite particles: initial formation and subsequent silica redistribution.. J Am Chem Soc, 133(4), 826-837.
- Control of Structural Morphology in Shear-Induced Crystallization of Polymers. MACROMOLECULES, 43(5), 2389-2405.
- Unexpected facile redistribution of adsorbed silica nanoparticles between latexes.. J Am Chem Soc, 132(7), 2166-2168.
- Phase Transformations of Glutamic Acid and Its Decomposition Products. CRYST GROWTH DES, 10(2), 988-994.
- Monodisperse macromolecules - A stepping stone to understanding industrial polymers. European Polymer Journal.
- Influence of ultra-high pressure sterilization on the structure of polymer films. Packaging Technology and Science, 22(5), 303-310.
- Toughening by nanostructure. POLYMER, 49(21), 4475-4488.
- The specific work of flow as a criterion for orientation in polymer crystallization. MACROMOLECULES, 41(6), 1901-1904.
- Segmented polyimides with poly(ethylene oxide) blocks exhibiting liquid crystallinity. MACROMOLECULES, 41(3), 1034-1040.
- First user results from the HOTWAXS detector system. IEEE Transactions on Nuclear Science, 55(2), 729-733.
- First user results from the HOTWAXS detector system. IEEE Nuclear Science Symposium Conference Record, 4, 2416-2420.
- The HOTWAXS detector. Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 580(3), 1526-1535.
- Noncovalent cross-linking of casein by epigallocatechin gallate characterized by single molecule force microscopy.. J Agric Food Chem, 54(12), 4077-4081.
- Highly branched poly(N-isopropylacrylamide) for use in protein purification.. Biomacromolecules, 7(4), 1124-1130.
- Small angle neutron scattering study of the structure and hydration of polyoxyethylene-block-polyoxybutylene in aqueous solution. Polymer International, 55(7), 793-797.
- A toolbox approach to adhesive design. REACT FUNCT POLYM, 66(1), 41-49.
- Creaming in black tea.. J Agric Food Chem, 53(20), 7997-8002.
- Structure development in reactive polycarbonate-Poly(ethylene terephthalate) melt blends. Journal of Macromolecular Science - Physics, 44 B(6), 1087-1102.
- Molecular model for astringency produced by polyphenol/protein interactions.. Biomacromolecules, 5(3), 942-949.
- Synthesis and characterisation of symmetric 4-armed star copolymers of PS capped with butadiene and PI: Importance of the location of the interface. Polymer, 45(12), 4121-4131.
- Crystallization behavior of oxyethylene/oxybutylene diblock and triblock copolymers. POLYMER, 44(22), 6843-6850.
- Early stages of crystallization in isotactic polypropylene. MACROMOLECULES, 36(10), 3656-3665.
- Mesophase behavior of aqueous micellar solutions of triblock copolymers of ethylene oxide and 1,2-butylene oxide (type EmBnEm). LANGMUIR, 19(4), 1075-1081.
- Structure and rheology of aqueous gels. Annual Reports on the Progress of Chemistry - Section C, 99, 243-276.
- Are metastable, precrystallisation, density-fluctuations a universal phenomena?. Faraday Discuss, 122, 343-361.
- Bulk morphology and micellization of poly (diene)-poly (ethylene oxide) diblock copolymers in water. POLYMER, 43(25), 7155-7160.
- Isothermal crystallization kinetics and melting behavior of poly(oxyethylene)-b-poly(oxybutylene)/poly(oxybutylene) blends. MACROMOLECULES, 35(18), 6937-6945.
- Effect of architecture on the crystal morphology of block copolymers. Small-angle X-ray scattering and differential scanning calorimetry. MACROMOLECULES, 35(12), 4838-4840.
- Morphological confinement on crystallization in blends of poly(oxyethylene-block-oxybutylene) and poly(oxybutylene). MACROMOLECULES, 35(9), 3614-3621.
- Chain folding in block copolymers crystallized from solution. American Chemical Society, Polymer Preprints, Division of Polymer Chemistry, 43(1), 223-224.
- Crystallization in block copolymer melts: Small soft structures that template larger hard structures. J CHEM PHYS, 114(12), 5425-5431.
- Micro- vs. macro-phase separation in binary blends of poly(styrene)-poly(isoprene) and poly(isoprene)-poly(ethylene oxide) diblock copolymers. Europhysics Letters, 53(5), 680-686. View this article in WRRO
- Aqueous mesophases of block copolymers of ethylene oxide and 1,2-butylene oxide. PHYS CHEM CHEM PHYS, 3(15), 2972-2980.
- Ordered melts of block copolymers of ethylene oxide and 1,2-butylene oxide. PHYS CHEM CHEM PHYS, 3(15), 2961-2971.
- Microphase separation in oxyethylene/oxybutylene copolymers with diblock and triblock architectures. MACROMOL RAPID COMM, 21(14), 964-967.
- Microphase-separation behavior of triblock copolymer melts, comparison with diblock copolymer melts. MACROMOLECULES, 33(14), 5124-5130.
- Correlation of lattice deformation with macroscopic strain for the hexagonal-packed cylinder phase of a triblock copolymer. POLYMER, 41(7), 2577-2582.
- First observation of an ordered microphase in melts of poly(oxyethylene)-poly(oxypropylene) block copolymers. Physical Chemistry Chemical Physics, 2(7), 1503-1507.
- A shear induced transition of lamellar alignment in a concentrated diblock copolymer solution. POLYMER, 40(20), 5709-5714.
- Scattering study of nucleation phenomena in homopolymer melts.. ABSTR PAP AM CHEM S, 218, U677-U677.
- Processing and properties of thin block copolymer films.. ABSTR PAP AM CHEM S, 218, U567-U567.
- Equilibrium chain folding in semicrystalline block copolymers in the bulk and in thin films.. ABSTR PAP AM CHEM S, 218, U579-U580.
- Microphase separation behavior in di- and triblock copolymers: Confirmation of the universality of chi.. ABSTR PAP AM CHEM S, 218, U519-U519.
- Lamellar-to-gyroid transition in a poly(oxyethylene)-poly(oxybutylene) diblock copolymer melt. PHYS CHEM CHEM PHYS, 1(9), 2097-2101.
- Chain folding in poly(epsilon-caprolactone) studied by small-angle X-ray scattering and Raman spectroscopy. A strategy for blending in the crystalline state. J MATER CHEM, 9(5), 1059-1063.
- Chain length dependence of the mean field temperature in poly(oxyethylene)-poly(oxybutylene) diblock copolymers. PHYS CHEM CHEM PHYS, 1(9), 2093-2095.
- Diblock copoly(oxyethylene/oxybutylene) E41B8 in water: Liquid-crystal mesophases studied by small-angle X-ray scattering. MACROMOLECULES, 32(6), 2058-2060.
- Processing and properties of thin block copolymer films. American Chemical Society, Polymer Preprints, Division of Polymer Chemistry, 40(2).
- X-ray scattering in polymers and micelles. Radiation Physics and Chemistry, 56(1-2), 159-173.
- Equilibrium chain folding in semi-crystalline block copolymers in the bulk and in thin films. American Chemical Society, Polymer Preprints, Division of Polymer Chemistry, 40(2), 1022-1023.
- A scattering study of nucleation phenomena in polymer crystallisation. FARADAY DISCUSS, 112(112), 13-29.
- Microphase separation in poly(oxyethylene)-poly(oxybutylene) diblock copolymers. MACROMOLECULES, 31(23), 8110-8116.
- A study of lyotropic mesophases of concentrated solutions of a triblock copolymer of ethylene oxide and 1,2-butylene oxide, E16B10E16, using rheometry, polarized light microscopy, and small-angle X-ray scattering. LANGMUIR, 14(20), 5782-5789.
- Shear-induced orientational order in the hexagonal phase of oxyethylene/oxybutylene diblock copolymer gels. POLYMER, 39(20), 4891-4896.
- Transformations to and from the gyroid phase in a diblock copolymer. Macromolecules, 31(17), 5702-5716.
- A scattering study of nucleation phenomena in homopolymer melts. ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY, 216, U895-U895.
- Crystal thicknesses in semicrystalline oxyethylene/oxybutylene block copolymers by atomic force microscopy and SAXS. POLYMER, 39(15), 3321-3326.
- Shear-induced orientational transitions in the body-centered cubic phase of a diblock copolymer gel. MACROMOLECULES, 31(12), 3906-3911.
- Orientational ordering of a poly( oxyethylene)-poly(oxybutylene) diblock copolymer gel under steady shear flow. MACROMOLECULES, 31(9), 2952-2956.
- Raman spectroscopy combined with small angle x-ray scattering and wide angle x-ray scattering as a tool for the study of phase transitions in polymers. Review of Scientific Instruments, 69(5), 2114-2117.
- Density fluctuations: The nucleation event in isotactic polypropylene crystallization. Polymer, 39(11), 2381-2385.
- Effect of shear on cubic phases in gels of a diblock copolymer. J CHEM PHYS, 108(16), 6929-6936.
- Crystallization thermodynamics and kinetics in semicrystalline diblock copolymers. Polymer, 39(6-7), 1429-1437.
- Micellar ordering in concentrated solutions of Di- and triblock copolymers in a slightly selective solvent. Macromolecules, 31(4), 1188-1196.
- Structure Control in Sol-Gel Silica Synthesis Using Ionene Polymers—Evidence from X-ray Scattering. Journal of Sol-Gel Science and Technology, 13(1-3), 27-30.
- Chain folding in semicrystalline oxyethylene/oxybutylene diblock copolymers. MACROMOLECULES, 30(26), 8392-8400.
- High-resolution calorimetry study of the order-disorder transition in a diblock copolymer melt. Macromolecules, 30(21), 6674-6676.
- Ordered phases in aqueous solutions of diblock oxyethylene/oxybutylene copolymers investigated by simultaneous small-angle X-ray scattering and rheology. Macromolecules, 30(19), 5721-5728.
- Chain folding in crystallizable block copolymers. Macromolecules, 30(6), 1723-1727.
- A small angle neutron scattering study of the conformation of a side chain liquid crystal poly(Methacrylate) in the smectic c phase. Liquid Crystals, 22(6), 679-684.
- Crystallization in Oriented Semicrystalline Diblock Copolymers. Macromolecules, 29(27), 8835-8843.
- Order-disorder transition in poly(oxyethylene)-poly(oxybutylene) diblock copolymers. Macromolecules, 29(19), 6212-6221.
- Crystallization of nanoscale-confined diblock copolymer chains. Polymer, 37(19), 4425-4429.
- Structure and dynamics of concentrated solutions of asymmetric block copolymers in slightly selective solvents. Macromolecules, 29(18), 5955-5964.
- Morphologies of microphase-separated A
2 B simple graft copolymers. Macromolecules, 29(15), 5091-5098.
- Complex phase behavior in solvent-free nonionic surfactants. Science, 271(5251), 976-978.
- Small-angle neutron-scattering studies of the fractal-like network formed during desorption and adsorption of water in porous materials.. Phys Rev B Condens Matter, 49(9), 5911-5917.
- Diffuse Neutron Scattering from Yttrium Hydride*. Zeitschrift für Physikalische Chemie, 1(1), 297-303.
- Powder metallurgical processing of Tb
0.27 Dy0.73 Fe2-x (0<x≤0.5) by hydrogen decrepitation. Journal of Applied Physics, 69(8), 5774-5776.
- In-situ measurements of deuterium uptake into a palladium electrode using time-of-flight neutron diffractometry. Journal of Electroanalytical Chemistry, 281(1-2), 323-330.
- Direct Integration of Perovskite Solar Cells with Carbon Fibre Substrates. Advanced Materials.
- Development of a Novel Friction Model for Machining Simulations in Unidirectional Composite Materials. Polymers, 14(5), 847-847.
- Structural Variation and Chemical Performance—A Study of the Effects of Chemical Structure upon Epoxy Network Chemical Performance. ACS Applied Polymer Materials.
- Preparation of Giant Polymersomes via Inkjet Printing and Confined Geometry Hydration Applied to Micropipette Aspiration Experiments. Macromolecular Materials and Engineering, 2000094-2000094.
Chapters
- Self-Assembling Polymer Photonics, Organic and Hybrid Photonic Crystals (pp. 127-143). Springer International Publishing
- Structures of amphiphilic block copolymers in their liquid and solid states, Amphiphilic Block Copolymers (pp. 151-167). Elsevier
Conference proceedings papers
- Online non-intrusive curing identification of CFRP assisted by pattern recognition with a novel in-situ curing apparatus. 2019 IEEE International Conference on Systems, Man and Cybernetics (SMC), 6 October 2019 - 9 October 2019.
- Towards mold-free composites. A novel control method to cure carbon fiber through punctual force. 2019 24th IEEE International Conference on Emerging Technologies and Factory Automation (ETFA), 10 September 2019 - 13 September 2019.
- Synthesis and analysis of photodegradable polyurethanes with poly (propylene glycol) and nitro-benzene derivatives. ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY, Vol. 258
- Influence of laser power on morphology and properties of laser-sintered UHMWPE. Solid Freeform Fabrication 2016: Proceedings of the 27th Annual International Solid Freeform Fabrication Symposium - An Additive Manufacturing Conference, SFF 2016 (pp 814-833)
- The specific work of flow as a universal parameter to control the formation of shish-kebab morphology in polymers. XVTH INTERNATIONAL CONGRESS ON RHEOLOGY - THE SOCIETY OF RHEOLOGY 80TH ANNUAL MEETING, PTS 1 AND 2, Vol. 1027 (pp 496-498)
- Opalescent coatings from block copolymers: Enhanced refractive index and curing. ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY, Vol. 230 (pp U3610-U3610)
- Poly(oxyalkylene) block copolymers in aqueous solution - Phase behavior and transition kinetics. JOURNAL OF MACROMOLECULAR SCIENCE-PHYSICS, Vol. B43(1) (pp 71-93)
- The effect of architecture on the morphology and crystallization of oxyethylene/oxybutylene block copolymers from micelles in n-hexane. JOURNAL OF MATERIALS CHEMISTRY, Vol. 13(11) (pp 2740-2748)
- A double area detector system for simultaneous small and wide-angle X-ray scattering. NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, Vol. 477(1-3) (pp 329-334)
- Lamellar phases and microemulsions in model ternary blends containing amphiphilic block copolymers. JOURNAL OF MATERIALS CHEMISTRY, Vol. 11(11) (pp 2864-2874)
- A scattering study of nucleation phenomena in homopolymer melts. SCATTERING FROM POLYMERS, Vol. 739 (pp 201-217)
- Diffuse Neutron Scattering from Yttrium Hydride*. Zeitschrift für Physikalische Chemie, Vol. 179(Part_1_2) (pp 281-287)
- Natural Material Short Fibre Composites via Additive Manufacturing. Proceedings of the 4th World Congress on Mechanical, Chemical, and Material Engineering, 16 August 2018 - 18 August 2018.
Patents
- Copolymer Blends, Light Reflective Films Comprising the Same and Methods for their preparation and use. GB1013274.4 Appl. 01 Jan 1970.
- SELF-ASSEMBLING BLOCK COPOLYMER FILM. GB 0506362.3 Appl. 01 Jan 1970.
- Film composites. 2000-GB1156; 2000058760 Appl. 01 Jan 1970.
- Kit of block copolymers exhibiting temperature-dependent adhesion and release properties. GB3870, 2002020688 Appl. 01 Jan 1970.
- Investigating the feasibility of processing activated carbon/UHMWPE polymer composite using laser powder bed fusion. Polymers, 14(16).
- Grants
-
- Soft Nanotechnology November 2007 to October 2012; £796,000 with Prof. Richard A. L. Jones (Pl), Prof. Anthony J. Ryan, Prof. Mark Geoghegan, Prof. David Lidzey
- EPSRC KTA KickStart Funding Biologics October 2011 to June 2012, £1116,000 with Prof. Richard Ross, Prof. Nigel Clark, and Prof. Peter Artumuik
- The Effects of Poilydispersity on Self Assembly in Block Copolymers: February 2007 to October 2010 £254,000 with Prof. Sebastien Perrier (Sydney), Prof Mark Matsen (Reading)
- The Microscale Polymer Procesing Consortium for Macromolecular Engineering (MuPP ii): Toolbox Development and Application March 2005 - March 2009 £815,000 Prof. Anthony J. Ryan, Dr Ellen Heeley collaboration as part of the larger MuPP ii grant with Prof. Tom C. B. McLeish (Pl), Dr R. Alan Duckett, Dr Oliver G. Harlen, Prof. Peter Hine, Prof. Pete Jimack, Prof. Alexei Likhtman, Dr Helen J Wilson, Prof. Phil D. Coates, Prof. Malcolm Mackley, Dr Lian R. Hutchings, Dr Nigel Clarke, Prof. C Paul Buckley
- Accelerated Discovery for New Organic Semiconductors November 2004 to October 2007, £234,000 Prof. Mick Turner and Dr Martin Grell
- Teaching interests
-
- MEC132: Matter Flow and Energy (Thermofluids)
- MEC406:: Engineering Composite Materials (Solids)