PHD
  1. Inorganic chemistry  1.1. Coordination chemistry  1.1.1. Ligand field theory  1.1.2. Crystal field theory  1.1.3. Molecular Orbital Theory for Coordination Compounds  1.1.4. Stability of Coordination Compounds  1.1.5. Electronic spectra of coordination compounds  1.1.6. Isomerism in Coordination Compounds  1.1.7. Kinetics and mechanism of coordination reactions  1.2. Organometallic Chemistry  1.2.1. Metal Carbonyls  1.2.2. Metal alkyl and aryl  1.2.3. Fischer and Schrock carbonaceans  1.2.4. Oxidative Addition and Reductive Elimination  1.2.5. Metal Hydrides  1.2.6. Catalysis by organometallic compounds  1.2.7. Metallocenes and Sandwich Complexes  1.2.8. CH activation  1.3. Solid state chemistry  1.3.1. Crystal structures and lattices  1.3.2. Band theory and electrical properties  1.3.3. Defects in the crystal  1.3.4. Synthesis of solid state materials  1.3.5. Magnetic and optical properties of solids  1.3.6. Superconductivity  1.3.7. Solid state ionics  1.4. Bio-inorganic chemistry  1.4.1. Metalloproteins and enzymes  1.4.2. Metal ion transport and storage  1.4.3. The role of metals in medicine  1.4.4. Bioinspired catalysis  1.4.5. Metal–DNA interactions  1.4.6. Metal Complexes in Medical Science  1.5. Lanthanides and Actinides  1.5.1. Electronic configuration and oxidation states in lanthanides and actinides  1.5.2. Spectral and Magnetic Properties in Lanthanides and Actinides  1.5.3. Separation and Extraction of Lanthanides and Actinides  1.5.4. Coordination chemistry of f-block elements  1.6. Main Group Chemistry  1.6.1. Chemistry of boron compounds  1.6.2. Chemistry of Silicon and Germanium Compounds  1.6.3. Chemistry of Phosphorus and Sulfur Compounds  1.6.4. Organosilicon chemistry  1.6.5. Noble Gas Chemistry
  2. Organic chemistry  2.1. Reaction mechanism  2.1.1. Nucleophilic substitution reactions  2.1.2. Electrophilic addition and substitution reactions  2.1.3. Elimination reactions  2.1.4. Rearrangement reactions  2.1.5. Radical reactions  2.1.6. Pericyclic Reactions  2.1.7. Photochemical reactions  2.2. Stereoscopic  2.2.1. Chirality and optical activity  2.2.2. Structural analysis  2.2.3. Stereoelectronic effects  2.2.4. Asymmetric synthesis  2.2.5. Dynamic Stereochemistry  2.3. Organometallic Chemistry in Organic Synthesis  2.3.1. Organolithium and organomagnesium reagents  2.3.2. Transition metal catalyzed coupling reactions  2.3.3. Palladium-catalyzed reactions  2.3.4. Olefin Metathesis  2.3.5. Gold and silver catalysis  2.4. Natural products chemistry  2.4.1. Alkaloids and terpenoids  2.4.2. Steroids and Flavonoids  2.4.3. Total synthesis of natural products  2.4.4. Biosynthesis of natural products  2.5. Supramolecular Chemistry  2.5.1. Host-Guest Chemistry  2.5.2. Self-assembly and molecular recognition  2.5.3. Supramolecular Catalysis  2.5.4. Molecular Machines
  3. Physical Chemistry  3.1. Thermodynamics  3.1.1. Laws of Thermodynamics  3.1.2. Chemical Potential and Equilibrium  3.1.3. Statistical thermodynamics  3.1.4. Non-equilibrium thermodynamics  3.2. Quantum Chemistry  3.2.1. Schrödinger equation and its applications  3.2.2. Molecular orbital theory  3.2.3. Density functional theory  3.2.4. Post-Hartree–Fock methods  3.3. Chemical kinetics  3.3.1. Reaction rate theory  3.3.2. Mechanism and rate laws  3.3.3. Catalysis and enzyme kinetics  3.3.4. Reaction dynamics  3.4. Spectroscopy and molecular structure  3.4.1. Infrared Spectroscopy  3.4.2. UV-visible spectroscopy  3.4.3. Nuclear Magnetic Resonance Spectroscopy  3.4.4. Mass Spectrometry  3.4.5. Raman Spectroscopy  3.5. Surface and Colloid Chemistry  3.5.1. Absorption and Catalysis  3.5.2. Surfactants and micelles  3.5.3. Colloidal Stability  3.5.4. Nanomaterials and Interfaces
  4. Analytical chemistry  4.1. Chromatography  4.1.1. Gas Chromatography  4.1.2. High Performance Liquid Chromatography  4.1.3. Thin Layer Chromatography  4.1.4. Ion Chromatography  4.2. Electroanalytical techniques  4.2.1. Voltammetry and Polarography  4.2.2. Conductometry and potentiometry  4.2.3. Colometry  4.3. Spectroscopic Methods  4.3.1. Atomic absorption spectroscopy  4.3.2. Fluorescence Spectroscopy  4.3.3. X-ray diffraction  4.3.4. Electron paramagnetic resonance spectroscopy  4.4. Chemometrics  4.4.1. Data processing and statistical methods  4.4.2. Multidisciplinary analysis  4.4.3. Machine Learning in Analytical Chemistry
  5. Theoretical and Computational Chemistry  5.1. Molecular dynamics simulation  5.2. Quantum chemistry methods  5.3. Computational drug design  5.4. Machine Learning in Chemistry  5.5. Ab initio molecular dynamics
  6. Biophysics and Medicinal Chemistry  6.1. Drug discovery and design  6.2. Enzyme kinetics and inhibition  6.3. Chemical biology approach  6.4. Protein-ligand interactions  6.5. Bioorthogonal chemistry
  7. Materials chemistry  7.1. Polymer chemistry  7.1.1. Polymerization mechanism  7.1.2. Functional Polymers  7.1.3. Biodegradable Polymer  7.1.4. Conducting and semiconducting polymers  7.2. Nano Chemistry  7.2.1. Nanoparticles and nanostructures  7.2.2. Carbon-based nanomaterials  7.2.3. Quantum dots  7.3. Energy and Environmental Chemistry  7.3.1. Battery and Fuel Cell Chemistry  7.3.2. Green chemistry and sustainable materials  7.3.3. Photocatalysis

PHD → Physical Chemistry → Surface and Colloid Chemistry ↓


Nanomaterials and Interfaces


Within the field of chemistry, particularly within the discipline of physical chemistry, the study of surfaces and colloids plays an important role. Surface and colloid chemistry deals with the properties and behavior of surfaces and interfaces. Nanomaterials have emerged as an important area of interest due to their unique properties that arise at the nanoscale. The aim of this text is to explore the complex world of nanomaterials and interfaces in the context of surface and colloid chemistry, keeping the explanations as simple as possible.

What are nanomaterials?

Nanomaterials are materials whose structural components are smaller than 100 nanometers. At this scale, materials often display unusual physical and chemical properties compared with their bulk counterparts. Because of the high surface area-to-volume ratio and the dominance of surface atoms, nanomaterials can exhibit unique optical, electronic, and mechanical properties. They are widely used in applications ranging from medicine to catalysis, electronics, and energy storage.

Understanding the interface

An interface is a boundary where two phases meet. In the context of nanomaterials, these interfaces can exist between solids and liquids, solids and gases, or even between two different solid phases. The study of interfaces involves exploring how molecules behave at these boundaries. The interactions that occur at interfaces often dominate the overall behavior of materials, affecting properties such as stability, reactivity, and adhesion and wetting.

Surface chemistry of nanomaterials

The chemistry and physics that occur at the interface of nanomaterials contribute significantly to their overall properties and potential applications. Several key concepts are important in understanding surface chemistry:

Surface energy and surface tension

Surface energy is the energy required to increase the surface area of a material. For nanomaterials, high surface energy is typical because the proportion of surface atoms is higher compared to bulk atoms. Surface tension observed in liquids is a manifestation of surface energy. It describes the energy required to increase the surface area of a liquid. Surface tension plays an important role in processes such as wetting and adhesion.

γ = F / L

Where γ is the surface tension, F is the force, and L is the length over which the force acts.

Wetting and contact angle

Wetting is the ability of a liquid to maintain contact with a solid surface. It is often measured by the contact angle, which is the angle formed at the meeting point of the liquid, solid, and air. The smaller the contact angle, the better the wetting.

Consider a drop of water on a flat surface:

θ < 90° (good wetting)
θ = 90° (neutral wetting)
θ > 90° (poor wetting)

Chemical reactivity and catalysis

The reactivity of a substance can be quite high at the interface. Nanoparticles often serve as catalysts because their high surface area exposes more active sites for reactions. This makes them highly efficient in processes such as hydrogenation, oxidation, and other chemical reactions where catalysis is needed.

Colloid chemistry of nanomaterials

Colloid chemistry deals with systems in which finely divided particles are dispersed in a continuous medium. Nanomaterials can function as colloids because their size enables them to remain suspended indefinitely in liquids or gases.

Stability of colloids

The stability of colloidal systems depends on the balance of forces between the particles. There are two primary forces involved:

  • Van der Waals forces: These are attractive forces that can lead to aggregation.
  • Electrostatic forces: Charges on the surface of nanoparticles can repel each other, preventing aggregation.

Aggregate stability is often described by DLVO theory, which combines these forces to predict whether a colloidal system will remain stable or aggregated.

Applications in medicine

Colloidal nanoparticles are used in medicine for drug delivery, imaging, and diagnostic purposes. They can be engineered to target specific cells or tissues, increasing the effectiveness of treatments and reducing side effects.

Examples and applications of nanomaterial interfaces

Nanomaterials have many applications due to their unique properties at their interfaces. Here are some examples:

Nanostructured catalysts

Nanostructured catalysts take advantage of large surface areas and increased surface reactivity. For example, platinum nanocatalysts are widely used to improve the efficiency of reactions in fuel cells.

2H 2 + O 2 → 2H 2 O

This reaction, driven by a nanocatalyst, produces water and releases energy.

Electronics and sensors

Nanoscale interfaces are vital in the development of electronics and sensors. Graphene, a single layer of carbon atoms arranged in a hexagonal lattice, has remarkable electrical properties and is used in applications such as flexible electronics and extremely sensitive sensors.

Environmental applications

Nanomaterials are used to remove pollutants from water and air. For example, nano-adsorbents can capture heavy metals from water, providing a promising solution for clean and safe water.

Visual example: interaction of light with nanoscale structures

Nanolayer Light interactions

This diagram shows how light interacts with nanolayers, changing their colour and optical properties due to phenomena such as quantum confinement and plasmonic effects.

Conclusion

Nanomaterials and their interfaces form an exciting frontier in chemistry, opening up avenues for innovation in a variety of fields. Their unique surface properties, catalytic capabilities, and abilities to interact with their environment enable numerous technological advancements. Ongoing research in this field promises to revolutionize industries ranging from healthcare to electronics and environmental sustainability.


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