Nanomanufacturing

Block copolymers with diverse compositions and topologies can self-assemble into multi-hierarchical structures, yielding materials with a wide range of functional properties. By adjusting external stimuli such as temperature, solvent polarity, mechanical force, and light exposure, these polymers form various nanostructures—including nanocrystals, micelles, and vesicles in solution; spherical, cylindrical, and lamellar microphases in bulk; and even “fractal” morphologies at interfaces. These hierarchical materials exhibit tailored functionality based on molecular design, enabling broad applications in nanomedicine, electronic devices, optical elements, and catalytic systems. In this review, we first summarize synthetic strategies for block copolymers with varying compositions and architectures. We then discuss their self-assembly behaviors and resulting nanoscale morphologies in bulk, solution, and interfacial environments. Several representative examples of assembled block copolymer systems and their practical applications are highlighted. Finally, we offer perspectives on future developments in the fabrication and application of block copolymer-based nanomaterials. This review provides an overview of strategies and examples for constructing precision nanostructures via block copolymer self-assembly, aiming to inspire further advances in nanomanufacturing technologies.

Titanium dioxide nanoparticles were synthesized via hydrothermal treatment of tetrabutyl titanate in sulfuric acid, with controlled reaction times (10 h and 24 h) and zinc sulfate as a modifier. XRD confirmed exclusive formation of the anatase phase, with longer reaction times promoting crystallite growth. SEM and BET analyses showed that introducing Zn during synthesis suppressed agglomeration, decreased the particle size, and modified porosity while maintaining the mesoporous nature of all samples. UV–Vis diffuse reflectance spectroscopy showed a band gap near 3.2 eV, which was unaffected by Zn content or morphology. Photoconductivity studies showed a several-orders-of-magnitude increase in conductivity under vacuum conditions, especially in samples heat-treated for 24 h, due to the generation of oxygen vacancies and ${\mathrm{Ti}}^{3+}$ states that prolong the carrier lifetime. In particular, the TS24Z8 sample exhibited a photoconductivity enhancement of five orders of magnitude relative to its dark conductivity and nearly 30 times higher than that of the commercial P25 benchmark. In contrast, in air, photoconductivity remained low because of strong surface recombination with adsorbed oxygen. These results emphasize the critical influence of hydrothermal duration and zinc incorporation on the defect structure and electronic response of ${\mathrm{TiO}}_2$, offering insights for improved photocatalytic and optoelectronic applications.

Given the environmental hazards of 2,4,6-trinitrophenol (TNP) and the limitations of existing detection methods, sodium-doped fluorescent carbon dots (Na-CDs) were successfully synthesized via a one-step hydrothermal method using citric acid and ascorbic acid as carbon sources. Compared with undoped carbon quantum dots, Na-CDs exhibited nearly identical surface functional groups but significantly enhanced fluorescence stability and markedly improved selective responsiveness toward TNP. Accordingly, a Na-CD-based fluorescent probe was developed for the highly selective detection of TNP. Results demonstrated a good linear relationship between the relative fluorescence intensity change (F₀ − F)/F₀ and TNP concentration ranging from 7 × 10⁻⁷ to 2 × 10⁻⁵ mol/L, with a detection limit of 3.5 × 10⁻⁸ mol/L. When applied to detect TNP in local river water samples, the method achieved recoveries of 95.40–104.0%, confirming its reliability for real-world environmental sample analysis. This study develops a novel, sensitive, and highly selective approach for monitoring TNP in environmental systems.