Jiayun Xu’s research while affiliated with Åbo Akademi University and other places

The agrochemical run‐off associated with crop control is an unintended consequence of droplet rebound from plant foliage, which negatively affects crop performance and the environment. This is most critical in water‐based formulations delivered on plant surfaces that are typically waxy and nonwetting. This study introduces an alternative to synthetic surfactants and high molecular weight polymers that are used as spreading agents for agrochemicals. Specifically, biopolymeric adjuvants (hemicelluloses and oligomeric lignin) extracted from wood by pressurized hot water are shown for their synergistic pinning capacity and surface activity that can effectively suppress droplet rebound from hydrophobic surfaces. Hemicellulose and lignin mixtures, alongside several model compounds, are investigated for understanding the dynamics of droplet impact and its correlation with biomacromolecule formations. The benefit of utilizing lean solutions (0.1 wt.% concentration) is highlighted for reducing droplet rebounding from leaves, outperforming synthetic systems in current use. For instance, a tenfold deposition improvement is demonstrated on citrus leaves, because of a significantly suppressed droplet roll‐off. These results establish the excellent prospects of wood extracts to improve crop performance.

Amine-functionalized solid adsorbents (NFSAs) from green and renewable biomass have been proven to be a significant breakthrough in utilizing renewable resources in the carbon capture and storage field. Lignin, a...

This study reports for the first time an innovative pH/magnetic dual-responsive hemicellulose-based nanocomposite hydrogel with a nearly 100% bio-based and biodegradable compositions. We synthesized pure Fe 3 O 4 magnetic nanoparticles (Fe 3 O 4 MNPs) using co-precipitation, then engineering xylan hemicellulose (XH), acrylic acid (AA), polyethylene glycol diacrylate (PEGDA), and Fe 3 O 4 MNPs to synthesize the pH/magnetic dual-responsive hydrogel (Fe 3 O 4 @XH-Gel), through free radical graft polymerization on natural XH with in-situ doping Fe 3 O 4 MNPs initiated by the ammonium persulfate/tetramethylethylenediamine (APS/TMEDA) redox system. Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance ( ¹ H-NMR), X-ray diffractometry (XRD), scanning electron microscopy and energy dispersive spectrometer (SEM-EDS), Brunauer-Emmett-Teller (BET), dynamic light scattering (DLS), swelling gravimetric analysis, vibrating sample magnetometer (VSM) were employed to analyze the hydrogel’s chemical structures, surface morphologies, pH-responsive behaviors, and magnetic responsiveness characteristics. The results indicate that the Fe 3 O 4 @XH-Gel nanocomposite hydrogel exhibited excellent dual responsiveness to pH and magnetism. Furthermore, an emphasis was placed on the in-depth analysis of the pH response mechanism and drug release control. Finally, we utilized this cutting-edge hydrogel to investigate the controlled-release behavior of two model drugs, Acetylsalicylic acid and Theophylline , within the simulated gastrointestinal tract. The Fe 3 O 4 @XH-Gel nanocomposite hydrogel demonstrated exceptional controlled release attributes, positioning it as a potential carrier for targeted drug delivery, particularly to the gastrointestinal conditions.

Perovskite solar cells (PSCs) have become a promising solar energy utilization technology due to their high energy conversion efficiency and low preparation cost. However, the inherent instability under UV illumination limits their practical applications. In this work, we developed a new approach to fabricate functional cellulose paper (FTH paper) with high transparency, high haze, and UV-blocking, which can be used to extend the lifespan of PSCs. When the impregnation amounts of carboxymethyl cellulose and tannic acid were 16 wt% and 0.7 wt%, the light transmittance and UV-blocking performance reached 86.8% (at 600 nm) and 83.1% (at 320 nm), respectively, while maintaining a haze of 71.5%. After protonation and desalination treatment, the FTH paper exhibited good water resistance and mechanical properties (71.49 MPa, 2156 folding cycles). More importantly, FTH paper coating can significantly improve optical path length and the UV-stability (improved by 26% after 100 h) of PSCs. This study not only provides a simple and effective strategy to improve the properties of PSCs but also opens the way for high-value utilization of paper materials.

In recent years, lignin-based nanomaterials have become increasingly relevant for researchers and producers of functional material applications due to their green and sustainable nature. However, there is still a challenge in controlling the fabrication of lignin nanoparticles (LNPs). In the current study, we explored an environmentally friendly sequential hot water extraction with an accelerated solvent extractor (ASE) to obtain a lignin-based fraction for the controllable production of LNPs. The lignin-based fractions are obtained from both Norway spruce heartwood (HW) and sapwood (SW) after sequential hot water extraction followed by separation with XAD 8 resin column and desorption with methanol (methanol fraction, MF). LNPs were successfully prepared from HWMF and SWMF with different physicochemical properties using acetonitrile/water binary solvent in an ultrasonic bath only within 1 min. The size of LNPs increased with the severity of wood ASE extraction, which is related to the reduction of β-O-4 bond, the increase of phenolic hydroxyl groups, and the decrease of aliphatic hydroxyl groups in MF. However, no direct relationship between the size of LNPs and molar mass as well as carbohydrate content was found. The controllable preparation of LNPs was directly dependent on the ASE extraction conditions without complex chemical modification. This study presents a green method for controllable preparation of LNPs and provides a promising new value-added valorization pathway for lignin-based fractions (including lignin and lignin carbohydrate complex) from wood hot water extraction.

Perovskite solar cells (PSCs) have become a promising solar energy utilization technology due to their high energy conversion efficiency and low preparation cost. However, the inherent instability under UV illumination limits their practical applications. In this work, we developed a new approach to fabricate functional cellulose paper (FTH paper) with high transparency, high haze, and UV-blocking, which can be used to extend the lifespan of PSCs. When the impregnation amounts of carboxymethyl cellulose and tannic acid were 16 wt% and 0.7 wt%, the light transmittance and UV-blocking performance reached 86.8% (at 600 nm) and 83.1% (at 320 nm), respectively, while maintaining a haze of 71.5%. After protonation and desalination treatment, the FTH paper exhibited good water resistance and mechanical properties (71.49 MPa, 2156 folding cycles). More importantly, FTH paper coating can significantly improve optical path length and the UV-stability (improved by 26% after 100 h) of PSCs. This study not only provides a simple and effective strategy to improve the properties of PSCs but also opens the way for high-value utilization of paper materials.