Conjugated polymer (CP) aggregates with linear/cross-linked structures are widely reported as photocatalysts for hydrogen evolution reaction. For full disclosure of the relationship between the photocatalytic performance and structural features of the CP photocatalysts, homogeneous dispersion of these CPs in aqueous medium is necessary, which however is difficult to be achieved. Herein, we report several coassembled polymeric dots (Pdots) consisting of PEG 45 -b-PMMA 103 and CPs with various structural features. We found that the Pdots of hyperbranched soluble CP nanoparticles (SCPNs) exhibit a high H 2 evolution rate up to 840 μmol h −1 g −1 with no platinum or rhodium as a cocatalyst, superior to their analogues with the linear or cross-linked structure. A possible charge-transfer mechanism suggests that the photoelectrons directly mobilize to the surface of these single-particulate Pdots over three-dimensional skeleton and successfully avoid the ineffective intermolecular charge transfer, leading to the shortened diffusion path of photoelectrons and enhanced photolysis efficacy. We believe that the high dispersion stability (2 months), solution processability, and structural tunability of these Pdots with hyperbranched SCPNs would inspire further research on designing multicomponent photocatalysts for highly efficient visible light-driven hydrogen evolution reaction.

Combinatorial polymerization method has been exploited to prepare a library of soluble conjugated polymeric nanoparticles (SCPNs), by varying symmetrical monomers, Ax and By (x > 2, y ≥ 2), plus modification with variant terminal groups.

A fluorescence sensing array (or fluorescent electronic nose) is designed on a disposable paper card using 36 sets of soluble conjugated polymeric nanoparticles (SCPNs) as sensors to easily identify wide ranges of volatile analytes, including explosives and toxic industrial chemicals (amines and pungent acids). A 108-dimensional vector obtained from the fluorescent color change in the sensing array is defined and directly treated as an index in a standard chemical library (30 kinds of volatile analytes and a control group). Hierarchical clustering analysis (HCA) and principal component analysis (PCA) indicated the diversity in electronic structures; saturated vapor pressure and miscibility of analytes are keys in differentiating the analytes, with electron-rich arenes and alkylamines enhancing fluorescence and electron-deficient analytes attenuating fluorescence. A support vector machine (SVM) works well to predict an unknown sample, reaching 99.5% accuracy. The excellent fluorescence stability (no fluorescence quenching after being exposed in air for one month) and high sensitivity (emission color changes within minutes when exposed to analytes) suggest that the fluorescent polymer-based electronic nose will play an important role in field detection and identification of a wide spreading of hazardous substances.

Conjugated polymers are attractive components of modern plastic electronics and photovoltaic devices. They are synthesized mainly through a step-growth polymerization (SGP) mechanism. However, due to the uncontrollable characteristic of classical SGP, this effort leads to batch-to-batch variations in solubility, uncontrolled molecular weight, and broad polydispersity of the polymers obtained, thus, severely limiting their processing properties and performance.Here we demonstrate a general theoretical model of controlled SGP process by examining the possibility of the polymer chains further involvement in the SGP and how this correlated with their respective molecular weights. Subsequently, we proposed a practical method by which the SGP system was confined in nano-sized reactors. This method enabled the synthesis of a variety of polymers, having precisely controlled molecular weights with narrow polydispersity. We anticipate that this venture would exemplify a starting point for a more sophisticated molecular and structural design of functional polymers in widespread applications.

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