Nanoparticels

are particles with at least one dimension in the size range of 1 to 100 nanometers (nm), where

Nanoparticles (NPs)

All three dimensions are nanoscale (e.g., quantum dots, fullerenes, metal NPs)

0D Nanoparticles:

is macro-scale (e.g., nanowires, nanotubes, nanorods)

1D Nanomaterials:

are macro-scale (e.g., graphene sheets, thin films, nanoplatelets)

2 D Nanomaterials

Bulk materials composed of nanosized units (e.g., nanocomposites

3 D Nanostructured Materials

Physical Properties of Nanoparticles

Size and Size Distribution
Surface Area-to-Volume Ratio
Optical Properties

The surfaces of nanoparticles are highly reactive due to the high density of unsatisfied bonds (dangling bonds) and defects

Surface Chemistry

Nanoparticles in suspension develop a surface charge through ionization, adsorption of ions, or dissociation of surface groups

Surface Charge and Zeta Potential

Surface energy determines whether particles are hydrophilic or hydrophobic, dictating behavior in aqueous or organic media.

Wettability

When a charged nanoparticle is suspended in an electrolyte solution, it attracts oppositely charged counter-ions from the solution, forming a structured ionic environment around it.

Interactions The Electrical Double Layer (EDL)

is named after Boris Derjaguin and Lev Landau, Evert Verwey, and Jan Theodoor Gerard Overbeek, who independently and concurrently developed the theory during World War II.

(The Cornerstone of Colloidal Stability)

DLVO Theory

Environmental Remediation Applications

Water treatment
Air purification
Soil remediation
Oil spill cleanup

Enable smaller and faster electronic devices.

Nanoelectronics

Quantum dots act as qubits for data processing

Quantum computing

Improve heat transfer in cooling systems. Sensors: Allow highly sensitive detection of gases and biomolecules

Nanofluids

Synthesis Methods

Top-down approach
Bottom-up approach

Bulk materials are broken down into nanoscale particles through physical processes. Examples: Ball milling, laser ablation

Top-down approach

Nanoparticles are built atom by-atom or molecule-by molecule through chemical processes. Examples: Chemical reduction, sol-gel process

Bottom-up approach

Uses a beam of electrons transmitted through a thin sample to produce high-resolution images. It allows direct observation of nanoparticle size, shape, and even atomic structure

TEM (Transmission Electron Microscopy)

cans the surface using electrons to create detailed images of morphology and texture. It is useful for studying surface features and particle arrangement.

SEM (Scanning Electron Microscopy):

Measures the movement of nanoparticles in a liquid by analyzing scattered light. It is commonly used to determine particle size distribution and stability in suspensions

DLS (Dynamic Light Scattering):

Uses X-rays to identify the crystal structure and phase of materials. It also helps estimate crystallite size based on diffraction patterns

XRD (X-ray Diffraction)

Measures the specific surface area of nanoparticles by gas adsorption. This is important for applications like catalysis where surface area affects performance

BET (Brunauer–Emmett–Teller Analysis)

Analyzes the surface chemistry by detecting the elements and their chemical states on the nanoparticle surface

XPS (X-ray Photoelectron Spectroscopy)