Electrolytic Cell: Converts electrical energy to chemical energy (non-spontaneous reaction).

Primary Batteries (Non-rechargeable):
- Dry Cell (Leclanché): Anode: Zn, Cathode: Carbon rod in $MnO_2/C$ paste. Electrolyte: $NH_4Cl/ZnCl_2$.
- Alkaline Battery: Anode: Zn, Cathode: $MnO_2$. Electrolyte: KOH. Longer shelf life.
Secondary Batteries (Rechargeable):
- Lead-Acid Battery: Anode: Pb, Cathode: $PbO_2$. Electrolyte: $H_2SO_4$. Discharge: $Pb + PbO_2 + 2H_2SO_4 \rightarrow 2PbSO_4 + 2H_2O$.
- Ni-Cd Battery: Anode: Cd, Cathode: NiO(OH). Electrolyte: KOH. Longer cycle life, toxic.
- Lithium-ion Battery: Anode: Graphite, Cathode: $LiCoO_2$ or $LiFePO_4$. Electrolyte: Lithium salt in organic solvent. High energy density.
Fuel Cells: Convert chemical energy of fuel directly into electrical energy.
- H$_2$-O$_2$ Fuel Cell: Anode: $H_2$, Cathode: $O_2$. Electrolyte: KOH or $H_3PO_4$. Products: $H_2O$.

Thermoplastics: Can be repeatedly softened by heating and hardened by cooling (e.g., PE, PVC, PS).
Thermosets: Undergo irreversible chemical change upon heating, form rigid cross-linked structure (e.g., Bakelite, Epoxy resins).
Elastomers: Amorphous polymers with good elasticity (e.g., Natural rubber, SBR).
Polymerization Types:
- Addition Polymerization: Monomers add to each other in chain reaction (e.g., PE from ethene).
- Condensation Polymerization: Monomers combine with elimination of small molecules (e.g., Nylon-6,6, PET).

Definition: Material made from two or more constituent materials with significantly different physical or chemical properties, which remain separate and distinct at the macroscopic level within the finished structure.
Types:
- Fiber-reinforced (e.g., Fiberglass, Carbon fiber).
- Particle-reinforced (e.g., Concrete, Metal matrix composites).

1. Prevention: Prevent waste rather than treat it.
2. Atom Economy: Maximize incorporation of all materials used into the final product. $$\% \text{ Atom Economy} = \frac{\text{Molecular weight of desired product}}{\text{Molecular weight of all reactants}} \times 100$$
3. Less Hazardous Chemical Syntheses: Design syntheses to use and generate substances with little or no toxicity.
4. Designing Safer Chemicals: Design chemical products that are fully effective yet have minimum toxicity.
5. Safer Solvents and Auxiliaries: Avoid using auxiliary substances (solvents, separating agents) or make them innocuous.
6. Design for Energy Efficiency: Minimize energy requirements.
7. Use of Renewable Feedstocks: Use renewable raw materials whenever practicable.
8. Reduce Derivatives: Avoid unnecessary derivatization (blocking groups, protection/deprotection).
9. Catalysis: Catalytic reagents are superior to stoichiometric reagents.
10. Design for Degradation: Design chemical products to degrade into innocuous products after use.
11. Real-time Analysis for Pollution Prevention: Develop analytical methodologies to allow for real-time mon