Here, we present the surface functionalization of anisotropic in form ferri-magnetic Fe3O4-nanorods (NRs) with a diblock copolymer, having a PMMA-or PDEGMEMA-block, for solubilization, and a dopamine anchor block. These polymers were synthesized through RAFT polymerization via a macro-initiator approach. The successful surface functionalization, performed via a grafting-to method, was monitored using TGA, IR and TEM measurements. The NRs were very soluble in organic solvents after functionalization. Afterwards, the liquid crystalline (LC) behavior was investigated. During solvent evaporation, birefringent domains were formed. The self-assembly into lyotropic LC structures could be observed with PEG 400 as a nonevaporating solvent. Thereby the anisotropic in form NRs aligned themselves along a director without the loss of mobility, as observed in POM, TEM and SEM images. Magnetic fields have a strong influence on the LC phases formed. They not only lead to macroscopic orientation, but also to phase separation into highly concentrated LC phases and an isotropic phase, mostly free of NRs. This can be reversed by demagnetizing the nanoparticles. We also investigated PDEGMEMA-functionalized NRs with excess PDEGMEMA polymer as solvent, and liquid crystalline phases were also observed.

The effect of surface functionalization on the structural and magnetic properties of catechol-functionalized iron oxide magnetic (γ-Fe2O3) nanocrystals was investigated.

Multilayered nanocomposites containing iron oxide nanoparticles, strongly cemented together through a dopamine modified polymer, exhibit high resistance against elastic and plastic deformation with a Young's modulus of 17 GPa and a hardness of 1.3 GPa.

Surface functionalized ZrO2 nanoparticles show strong photoluminescence and are a versatile tool for cellular targeting due to their chemical functionality. They are highly photostable, biocompatible and amenable to coupling with bioligands (e.g. secondary goat anti-rabbit antibody (GAR) and tri-phenyl phosphine (TPP)) via carbodiimide chemistry. Antibody (GAR) functionalized ZrO2 nanoparticles were used to image the nuclear protein Sirt6, whereas triphenyl phosphonium ion (TPP) functionalized ZrO2 nanoparticles specifically targeted the mitochondria. The versatility and easiness of the ZrO2 surface modification opens up new possibilities for designing non-toxic water dispersible and photostable photoluminescent NPs.