Nanotechnology, Organic Chemistry, and Analytical Techniques Practice Flashcards

Comprehensive vocabulary flashcards covering nanochemistry definitions, analytical characterisation techniques, organic nomenclature, isomerism, and reaction mechanisms based on the lecture transcript.

Nanochemistry

The study of the synthesis, characterisation, and chemical properties of materials at the nanoscale, typically ranging from $1$ to $100\,\text{nanometres}$.

Surface-area-to-volume ratio

A property that increases significantly as material size decreases, altering optical, electronic, and chemical reactivity in nanomaterials.

Single-walled carbon nanotubes (SWCNTs)

Nanostructures consisting of a single graphene cylinder fabricated primarily from carbon atoms.

Multi-walled carbon nanotubes (MWCNTs)

Nanostructures containing multiple concentric graphene cylinders with diameters usually measured between $2$ and $100\,\text{nm}$.

Quantum dots

Nanostructures known for unique optical and semiconducting properties that arise from quantum confinement effects; commonly used in QLED displays.

Bottom-up synthesis

A nanofabrication approach that involves building structures atom by atom or molecule by molecule, such as chemical vapour deposition (CVD) or molecular self-assembly.

Top-down synthesis

A nanofabrication technique that involves breaking bulk material down to the nanoscale, such as mechanical milling or lithography.

Fullerenes

Molecules composed entirely of carbon atoms arranged in a hollow sphere, ellipsoid, or tube, such as buckminsterfullerene ($C_{60}$).

Scherrer equation

$D = \frac{K\lambda}{\beta \cos(\theta)}$; used to estimate crystallite size ($D$) from X-ray Diffraction (XRD) data, where $K$ is the shape factor and $\lambda$ is the X-ray wavelength.

Dynamic Light Scattering (DLS)

A technique used to measure the hydrodynamic diameter or size distribution of particles in a suspension.

Zeta potential

An indicator of the colloidal stability of a nanoparticle suspension; an absolute value $|\zeta| > 30\,\text{mV}$ generally indicates good stability.

Brunauer–Emmett–Teller (BET) analysis

A gas adsorption method commonly used to perform surface area analysis of nanomaterials.

Energy Dispersive X-ray Spectroscopy (EDS/EDX)

An analytical technique used in conjunction with SEM to determine the elemental composition of a sample.

Surface Plasmon Resonance (SPR)

Absorption bands used in UV-Visible spectroscopy to characterise metallic nanoparticles, such as gold nanoparticles which absorb at approximately $520\,\text{nm}$.

Fractional distillation

A separation technique using a fractionating column to provide multiple vaporisation–condensation cycles, allowing the separation of liquids with close boiling points.

Retention factor ($R_f$)

In thin-layer chromatography (TLC), it is the ratio calculated as: $\text{Distance travelled by compound} \div \text{Distance travelled by solvent front}$. It can never be greater than $1$.

Catenation

The self-linking ability of carbon atoms to form long chains or rings.

Isomerism

The phenomenon where two or more compounds have the same molecular formula but different structural formulae or spatial arrangements.

Esterification

A condensation reaction between an alcohol ($R'OH$) and a carboxylic acid ($RCOOH$) to produce an ester ($RCOOR'$) and water ($H_2O$).

Empirical formula

The chemical formula that shows the simplest ratio of the different atoms present in a compound.

$sp^2$ Hybridisation

A type of hybridisation resulting in a trigonal planar shape with a bond angle of $120^{\circ}$, commonly found in alkenes like ethene.

Functional isomers

Compounds like aldehydes ($RCH_{2}CH_{2}CHO$) and ketones ($RCH_{2}COCH_{3}$) that share the same molecular formula but have different functional groups.

Olefins

Another name for alkenes, which are unsaturated hydrocarbons containing at least one carbon–carbon double bond.

Saponification

The process of producing soap through the alkaline hydrolysis of fats or oils.

Homolytic cleavage

Bond breaking in which each atom receives one electron from the shared pair, generating uncharged reactive intermediates called radicals.

Heterolytic cleavage

Bond breaking in which one atom receives both electrons from the shared pair, resulting in the formation of charged intermediates (cations and anions).

Enthalpy of reaction ($\Delta H$)

The energy absorbed or released during a chemical reaction; a negative value indicates an exothermic process.

Activation energy barrier

The energy threshold that must be overcome for reactants to proceed to products in a chemical reaction.

Nucleophilic

Literally 'nucleus-loving'; describes a reagent that donates an electron pair to an electrophile to form a chemical bond.

Electrophilic

Literally 'electron-loving'; describes a reagent that accepts an electron pair from a nucleophile.

Allotropy

The existence of a chemical element in two or more different physical forms, such as carbon existing as diamond, graphite, or graphene.

Chiral carbon atom

An asymmetric carbon atom that is attached to four different groups, potentially making the molecule optically active.

Enantiomers

Chiral molecules that are non-superimposable mirror images of each other.

Resolution

The laboratory method used to separate a racemic mixture into its pure enantiomers.

Geometric isomers

Isomers that have the same structural formula but differ in the spatial arrangement of atoms around a double bond, such as cis-but-2-ene and trans-but-2-ene.

Conformational isomers

Different spatial arrangements of the same molecule that result from rotation around single bonds, such as the gauche and anti forms of butane.

Meso compound

A stereoisomer that contains chiral centres but is achiral (optically inactive) due to having an internal plane of symmetry.

Cracking

The chemical process of breaking down large, heavy petroleum hydrocarbon molecules into smaller, lower-boiling gaseous or liquid hydrocarbons.

Vitalism

An early chemical theory, disproven by Friedrich Wöhler in $1828$ upon synthesising urea, which suggested that organic substances could only be produced by living organisms.

Scherrer equation variable $D$

Represents the crystallite size of a material being analyzed via X-ray Diffraction.