Công nghệ vật liệu trong y sinh học biom aterials

Biomaterials c om Lecture Lecturer: TA THI PHUONG HOA co ng Teaching Assistant: DINH THI NHUNG Advanced Program Biomedical Engineering – HUST, Vietnam cu u du o ng th an About Materials “Understanding the history of materials means understanding the history of mankind and civilization” civilization” “Who can master the materials, can master the future” future” CuuDuongThanCong.com Advanced Program Biomedical Engineering – HUST, Vietnam https://fb.com/tailieudientucntt Part 1: Material Science & Engineering Chap Properties of materials - The structure of solids - Mechanical properties of materials - Surface properties of materials - Role of water in biomaterials Chap Classes of materials used in medicine c om - Polymer - Silicone - Medical fibers & biotextiles - Hydrogels ng - Applications of “Smart Polymers” as biomaterials co - Bioresorbable and bioerodible materials Advanced Program Biomedical Engineering – HUST, Vietnam ng th an du o Part 1: Material Science & Engineering cu u Chap 2.(cont.) - Natural materials - Metals - Ceramics, glasses, and glass-ceramics - Composite - Nonfouling (Anti-fouling) surfaces - Surface modification of materials used in medicine - Textured and porous materials - Surface-immobilized Biomolecules CuuDuongThanCong.com Advanced Program Biomedical Engineering – HUST, Vietnam https://fb.com/tailieudientucntt The structure of solids ng c om Chap.1 Properties of materials- co The periodic table Advanced Program Biomedical Engineering – HUST, Vietnam ng th an du o Chap.1 Properties of materials- The structure of solids 1.1 Structure of solids Which states of materials you know? The differences of them? cu u What determine the properties of material? What are solids? - Their constituent atoms are held together by strong interatomic forces - Structure, physical properties: depend on the nature and strength of the interatomic bonds - Strong bonds: ionic, covalent and metallic Structure of solids: on many levels of scale - Atomic or molecular: 0.1- nm - Nanoscale or ultrastructural: nm- µm - Microstructural: µm- mm - Macrostructural: > 1mm CuuDuongThanCong.com Advanced Program Biomedical Engineering – HUST, Vietnam https://fb.com/tailieudientucntt Chap.1 Properties of materials- The structure of solids Atomic bonding: primary interatomic bonds and secondary bonds Primary interatomic bonds (strong bonds) Ionic bonding: * Formed by exchanging electrons between metallic and nonmetallic atoms - Electron donor atoms (metallic) transfer one or more electron to an electron acceptor (nonmetallic) to form cation and anion c om - Cations and anions strongly attract each other by Coulomb effect - The attraction of cations and anions constitutes IB (Hummel, 1997) • Ionic solid structures are limited in their atomic arrangement • Bonding energy: relative large, between 600- 1500 kJ/mol (3-8 eV/atom), leads to relative high melting temperature ng • Poor electrical conductor, relative low chemical reactivity co • Examples: NaCl, MgO Advanced Program Biomedical Engineering – HUST, Vietnam ng th an The structure of solids cu u du o Chap.1 Properties of materials- Loosely bound electrons are tightly held in the locality of the ionic bonding Fig Schematic representation of ionic bonding in sodium chloride (NaCl) CuuDuongThanCong.com Advanced Program Biomedical Engineering – HUST, Vietnam https://fb.com/tailieudientucntt Chap.1 Properties of materials- The structure of solids Covalent bonding: - Elements between metals and nonmetals (equal tendency to donate and accept electrons), many nonmetals, molecule containing dissimilar atoms - Bonding by sharing valence electron to form stable electron structure (all valence electrons in pair localized at valence bonding) - Bonding is highly directional and strong, may be very strong (diamond), • Materials as poor electric conductors co ng c om • Examples: H2, Cl2; Si, C; CH4, H2O Advanced Program Biomedical Engineering – HUST, Vietnam ng th an The structure of solids cu u du o Chap.1 Properties of materials- Fig 2: Schematic representation of covalent bonding in a molecule of methane (CH4) 10 CuuDuongThanCong.com Advanced Program Biomedical Engineering – HUST, Vietnam https://fb.com/tailieudientucntt Chap.1 Properties of materials- The structure of solids Metallic bonding: - Three-dimensional pattern with valence electrons migrating within atoms (Fig.3) - Bonding may be week or strong, energies range from 68kJ/mol (0.7 eV/atom) for mercury to 850 kJ/mol (8.8 eV/atom) for tungsten - Material may be very strong (cobalt) and have very high melting point co ng c om - Good electrical and thermal conductor Advanced Program Biomedical Engineering – HUST, Vietnam ng th an 11 The structure of solids cu u du o Chap.1 Properties of materials- Valence electrons can move freely within atoms (sea of valence electrons) Fig Schematic illutration of metallic bonding 12 CuuDuongThanCong.com Advanced Program Biomedical Engineering – HUST, Vietnam https://fb.com/tailieudientucntt Chap.1 Properties of materials- The structure of solids Secondary bonds (week bonds) Van der Waals (physical bonds) c om Fig.4 Van der Waals bonding between two dipoles - Forces arise when electrons are not distributed equally among ions that can form dipoles ng - Much weaker than hydrogen bonds, effect is over a short distance Advanced Program Biomedical Engineering – HUST, Vietnam ng th an co 13 du o Chap.1 Properties of materials- The structure of solids Hydrogen bonds cu u - Hydrogen bonds can arise when the hydrogen atom is covalently bonded to an electronegative atom so that it becomes a positive ion - The electrostatic force between them can be substancial - Bonding mechanisms are now discussed briefly Fig.5 Hydrogen bonding in hydrogen fluoride (HF) 14 CuuDuongThanCong.com Advanced Program Biomedical Engineering – HUST, Vietnam https://fb.com/tailieudientucntt Chap.1 Properties of materials- The structure of solids Atomic structure • Crystal - A solid whose atoms and ions are arranged in an orderly repeating pattern in three dimensions - Atoms can be very closely packed - Number of primary bond is maximized c om - Energy of aggregate is minimized • Crystal structure co ng - Unit cell have all the geometric properties of whole crystal Advanced Program Biomedical Engineering – HUST, Vietnam ng th an 15 du o Chap.1 Properties of materials- The structure of solids Materials, their chemical bonds and atom structure cu u Table 1: Strength of different chemical bonds as reflected in their heat of vaporization 16 CuuDuongThanCong.com Advanced Program Biomedical Engineering – HUST, Vietnam https://fb.com/tailieudientucntt The structure of solids ng c om Chap.1 Properties of materials- co Fig Some materials exhibit nearly ideal covalent, metallic or ionic bonding, but most materials exhibit a hybrid bond types Advanced Program Biomedical Engineering – HUST, Vietnam ng th an 17 The structure of solids * Metals cu u du o Chap.1 Properties of materials- A: Face-centered cubic (FCC) B: Full size atom C: Hexagonal close-packed (HCP) D: Body-centered cubic (BCC) Fig.7 Typical metal crystal structure (unit cells) 18 CuuDuongThanCong.com Advanced Program Biomedical Engineering – HUST, Vietnam https://fb.com/tailieudientucntt Chap.1 Properties of materials- The structure of solids * Crystal structure of carbon co ng c om Tab 2: Related physical properties of diamond and graphite Advanced Program Biomedical Engineering – HUST, Vietnam ng th an 19 The structure of solids cu u du o Chap.1 Properties of materials- cubic hexagonal Fig.8: Crystal structure of carbon; A: diamond, B: graphite 20 CuuDuongThanCong.com Advanced Program Biomedical Engineering – HUST, Vietnam https://fb.com/tailieudientucntt Chap.1 Properties of materials- The structure of solids • Ceramics - Various combinations of ionic and covalent bonding - Tightly packed structure - Carbon: often included with ceramics • Polymer - Thermoplastics co ng c om - Thermoset: three dimensions Advanced Program Biomedical Engineering – HUST, Vietnam ng th an 21 du o Chap.1 Properties of materials- Mechanical properties Mechanical properties of materials u Properties of solids? cu Important properties for biomaterials: mechanical and chemical StressStress- Strain behavior For materials that undergo a mechanical deformation: - Normalized load: Stress = Force/cross-section area (N/m2) - Normalized deformation: Strain = Change in length/Original length - Tension & compression (load is perpendicular to loading direction) - Shear (load is parallel to the area supporting it & dimension change is perpendicular to the reference dimension 22 CuuDuongThanCong.com Advanced Program Biomedical Engineering – HUST, Vietnam https://fb.com/tailieudientucntt .c om Chap.1 Properties of materials- Mechanical properties Shear stress and shear strain co ng Tensile stress & tensile strain Advanced Program Biomedical Engineering – HUST, Vietnam ng th an 23 du o Chap.1 Properties of materials- Mechanical properties Elastic behavior cu u - In tensile test - Extension: proportional to the load (Hook law-1687) 24 CuuDuongThanCong.com Advanced Program Biomedical Engineering – HUST, Vietnam https://fb.com/tailieudientucntt Chap.1 Properties of materials- Mechanical properties Elastic constants  = E ε , tension and compression =G, -E & G: proportionality constants shear - Tensile constant E: tensile modulus (Young’s modulus) - E and G represent inherent properties of materials - Strong bonds: high moduli, small strain co ng - Week bonds: low moduli c om - G: shear modulus Advanced Program Biomedical Engineering – HUST, Vietnam ng th an 25 cu u du o Chap.1 Properties of materials- Mechanical properties Stress versus strain for elastic solids 26 CuuDuongThanCong.com Advanced Program Biomedical Engineering – HUST, Vietnam https://fb.com/tailieudientucntt Chap.1 Properties of materials- Mechanical properties co ng c om Tab.3 Mechanical properties of some important implant materials and tissues Advanced Program Biomedical Engineering – HUST, Vietnam ng th an 27 du o Chap.1 Properties of materials- Mechanical properties Isotropy u Isotropy: properties are same in all direction cu E & G: needed to fully characterize the stiffness of an isotropic material Single crystal: anisotropic Polycrystalline materials: on average isotropic 28 CuuDuongThanCong.com Advanced Program Biomedical Engineering – HUST, Vietnam https://fb.com/tailieudientucntt Chap.1 Properties of materials- Mechanical properties co ng c om Mechanical testing Advanced Program Biomedical Engineering – HUST, Vietnam ng th an 29 du o Chap.1 Properties of materials- The structure of solids cu u Mechanical properties derivable from a tensile test 30 CuuDuongThanCong.com Advanced Program Biomedical Engineering – HUST, Vietnam https://fb.com/tailieudientucntt Chap.1 Properties of materials- Mechanical properties Plastic deformation -Only metals exhibit true plastic deformation -Ceramic and many polymer not undergo co Stress versus strain for a ductile material ng c om -Important for shaping metals and alloys Advanced Program Biomedical Engineering – HUST, Vietnam ng th an 31 du o Chap.1 Properties of materials- Mechanical properties cu u Creep and viscous flow A: Elongation vs time at constant load (creep) B: Load vs time at constant elongation A: Dash pot or cyclinder and piston model of viscous flow 32 CuuDuongThanCong.com B: Dash pot and spring model Advanced Program Biomedical Engineering – HUST, Vietnam https://fb.com/tailieudientucntt Chap.1 Properties of materials- Mechanical properties Toughness -The ability of a material to plastically deform under the influence of the complex stress field at the tip of a crack - Brittle fracture (glass, ceramics, graphite, very hard alloys, some polymer like PMMA-bone cement - Elastic fracture - Fracture toughness test: c om Single Edge Notched Bend (SENB) Test, ISO 13586: 2000 (E), GIC & KIC: Fracture toughness KIC: Critical Stress Intensity Factor; I (mode I): loading is applied perdendicular to the crack path KIC= (EGIC)1/2 co ng Sample: L = 78 mm, w = 16mm; B = 4mm, a = 8mm Advanced Program Biomedical Engineering – HUST, Vietnam ng th an 33 du o Chap.1 Properties of materials- Mechanical properties Fatigue cu u - Is process by which structure fail as a result of cyclic stresses (usually less than ultimate tensile stress) - Important for dynamic loaded structure - Fatigue strength is sensitive to environment, temperature, corrosion, deterioration and cyclic rate 34 CuuDuongThanCong.com Advanced Program Biomedical Engineering – HUST, Vietnam https://fb.com/tailieudientucntt Chap.1 Properties of materials- Mechanical properties c om A: Stress versus time in a fatigue test co ng B: Fatigue stress versus cycles to failure Advanced Program Biomedical Engineering – HUST, Vietnam ng th an 35 du o Chap.1 Properties of materials- Surface properties Surface properties of materials u •Surface properties are very important for biomaterials cu •Surface: boundary between different phases 36 CuuDuongThanCong.com Advanced Program Biomedical Engineering – HUST, Vietnam https://fb.com/tailieudientucntt Chap.1 Properties of materials- Surface properties Surface tension * Surface energy dG = dw - dA w: work done on the surface area change dA : surface energy of the material • Contact angle • Surface structure (surface area and surface chemistry decide surface energy) Surface tension of some materials Substances Temperature, oC 0.465 0.452 0.758 1.103 1.128 ng 20 327 419 1131 1120 Surface tension, N/m co Mercury Lead Zinc Copper Gold c om • Surface energy: very important for wettability and adhesion (adsortion & chemisorbtion) Advanced Program Biomedical Engineering – HUST, Vietnam ng th an 37 du o Chap.1 Properties of materials- Surface properties Several methods to determine the contact angle of solid and liquid Wilhelmy plate method with Tensiometer cu u Sessile drop method with goniometer Micro balance F (µN) Wilhelmy equation γsv Drop on flat substrate θ contact vapour angle γsl cos  F p lv γlv liquid Drop on fibre 38 CuuDuongThanCong.com Advanced Program Biomedical Engineering – HUST, Vietnam https://fb.com/tailieudientucntt Chap.1 Properties of materials- Surface properties - Roughness is a very important factor for surface energy (due to surface area) ng c om A: Rough, step, smooth; B: composed of different chemistries;C: inhomogeneous in plane co D: inhomogeneous in with depth; E: highly crystalline or disordered; F:Crystalline surface with many organisations Advanced Program Biomedical Engineering – HUST, Vietnam ng th an 39 du o Chap.1 Properties of materials- Surface properties - Surface chemistry is also very important for surface tension (due to chemical composition, especially functional groups at the surface) u - Hydrophilic groups cu - Hydrophobic groups Evaluation of a surface: -Measurement of contact angle (general surface energy) -Study morphology of the surface: SEM… -Study surface roughness: AFM, SEM -Study the surface chemistry: IR (FTIR), XPS, Raman Spectroscopy, SIMS 40 CuuDuongThanCong.com Advanced Program Biomedical Engineering – HUST, Vietnam https://fb.com/tailieudientucntt Chap.1 Properties of materials- Surface properties co ng c om Common methods for evaluation the surface properties of biomaterials Advanced Program Biomedical Engineering – HUST, Vietnam cu u du o ng th an 36 CuuDuongThanCong.com https://fb.com/tailieudientucntt ... energy) -Study morphology of the surface: SEM… -Study surface roughness: AFM, SEM -Study the surface chemistry: IR (FTIR), XPS, Raman Spectroscopy, SIMS 40 CuuDuongThanCong.com Advanced Program Biomedical... Bonding is highly directional and strong, may be very strong (diamond), • Materials as poor electric conductors co ng c om • Examples: H2, Cl2; Si, C; CH4, H2O Advanced Program Biomedical Engineering... Chap.1 Properties of materials- co Fig Some materials exhibit nearly ideal covalent, metallic or ionic bonding, but most materials exhibit a hybrid bond types Advanced Program Biomedical Engineering