Journal of Applied Polymer Science最新文献

Facial masks available in the market are primarily made of non-woven fabric. To extend their shelf life, preservatives, and essences are added to their ingredients. However, this practice has a significant impact on the environment and human health. As a result, consumers nowadays prefer to choose “Clean Beauty” products for their skincare routines. Herein, electrospinning technology was used to prepare a novel Janus nanofiber membrane comprising Polylactic acid/Polyvinylpyrrolidone (PLA/PVP) and Chitosan/Gelatin (CS/GEL), loaded with Gastrodia elata polysaccharide (GEP) and melatonin (MT). The Janus nanofiber facial mask is a solid mask that provides excellent moisturizing, antioxidant, and biocompatibility benefits. It can dissolve quickly and be absorbed by the skin, while the hydrophobic fiber helps slow down the rapid evaporation of water in the mask. This, combined with the Janus structure, helps delay the loss of water and allows for quick penetration, resulting in a long-lasting moisturizing effect. Therefore, the Janus nanofiber facial mask is an ideal choice for solid facial masks and provides technical support for its application in this field.

Fiber separation technology has been widely used in the removal of metal ions, dyes, proteins, and particles. In this work, the reversible characteristic of temperature sensitive hydrogel which possesses the expansion and contraction at different temperature is used to control the change of internal pores of filter materials for achieving the selective separation and concentration of solution. We prepared polylactic acid (PLA) hollow fiber as outer support layer by the template method and PLA electrospun membrane as internal support diaphragm by electrospinning. Then, the method of adding poly(N-isopropylacrylamide) (PNIPAM) hydrogel in the hollow fiber layer by layer was adopted to form the hydrogel/PLA fiber. When the mass ratio of PNIPAM/PLA was 3/1, the sample presented the relatively tight interior morphology and was selected for protein separation. By adjusting the temperature, the rejection capacities of PNIPAM/PLA composite fiber for bovine serum albumin (BSA), and ovalbumin (OVA) were in the range of 25–36 mg/g and 22–31 mg/g, respectively. Furthermore, the fiber reusability was investigated by swelling and deswelling elution processes. It was found that the sample could be reused 5 times. This work explores a novel control method for the graded filtration and concentration of targets.

Polyethylene (PE) foams are widely used for the advantages of light weight and reducing energy consumption. So, the preparation of environmental friendly and efficient blowing agent is essential. The use of supercritical carbon dioxide (CO₂) as physical blowing agent requires harsh experimental conditions such as high-pressure and temperature. In this study, CO₂ was captured by 1, 2-cyclohexanediamine (TRK) under atmospheric pressure, and reversibly released under heating as a blowing agent with nanosponges (NS) used as the carrier (NS:TRK-CO₂). Furthermore, three ethoxy silane coupling agents were selected to improve the compatibility between heterogeneous nucleating agent (cyclodextrin nanosponges, NS) and PE, so as to improve the nucleation effect of NS and the comprehensive properties of PE composites. Analyses showed that triethoxyvinyl silane (VTES) was a suitable candidate for improving the compatibility of NS and PE. The addition of NS:TRK-CO₂@VTES not only improved the crystallization performance, but also improved the complex viscosity and storage modulus, and enhanced the thermal properties of PE composites. The optimal cell morphology was obtained by introduction of NS:TRK-CO₂@VTES with 5 wt%, the minimum cell diameter was 50 μm, and the maximum cell density was 9.4 × 10⁴ cells/cm³. Compared with the other PE composites, PE/NS:TRK-CO₂@VTES composites showed excellent mechanical, thermal, and sound insulation properties. The maximum impact strength was 7.62 KJ/m², which was two times higher than pure PE. The thermal conductivity was 0.054 W/m k, the sound absorption coefficient was 0.836 at 1500 Hz.

Two non-fullerene acceptors (NFAs), DTBDT-ICN and DTBDT-SEH, based on dithienobenzodithiophene (DTBDT) and a 2-(3-oxo-2,3-dihydroinden-1-ylidene) malononitrile (IC) with different side chains of alkylthienyl and alkylthio-thienyl, respectively, were designed and used as electron acceptors in organic solar cells (OSCs). Both NFAs provide suitable energy level configurations that ensure efficient charge transfer with the donor polymer PBDB-T, as confirmed by significant photoluminescence reduction in the blend films. However, due to the high planarity together with strong π-π stacking interactions, the DTBDT-ICN presented significant aggregation and phase separation in the blend films, leading to suboptimal charge generation. In addition, grazing incidence wide-angle x-ray scattering measurements revealed a predominance of edge-on molecular orientations, which are unfavorable for vertical charge transport. On the other hand, DTBDT-SEH exhibited less pronounced molecular aggregation and edge-on orientation properties compared to DTBDT-ICN, resulting in improved carrier mobility (μ_e of 3.86 × 10⁻⁶ compared to 7.59 × 10⁻⁷) and mitigated recombination losses (1.19 kT/q compared to 1.21 kT/q) in OSC devices. The improved morphological features of PBDB-T:DTBDT-SEH led to a high power conversion efficiency of 3.31%, which is three times higher than that of PBDB-T:DTBDT-ICN-based devices (1.55%). Furthermore, paired with the high performance polymer PM6, PM6:DTBDT-SEH demonstrated an enhanced efficiency, reaching 7.03%.

Cu:CsPbCl_xBr_3-x quantum dots (QDs) with different Cu-to-Pb molar ratios were synthesized via a solvent-based thermal synthesis method, and highly stable blue-light PCL@Cu:CsPbCl_xBr_3-x composite fibers (CFs) were prepared by electrohydrodynamic (EHD) technology. The photoluminescence (PL) properties of these Cu²⁺-doped Cu:CsPbCl_xBr_3-x QDs and the stability of polymer encapsulation were investigated in this study. The results showed that with increasing Cu²⁺ concentration, the CsPbCl_1.5Br_1.5 QDs maintained their initial cubic crystal structure. The doping of Cu²⁺ ions effectively eliminated the surface defects of CsPbCl_1.5Br_1.5 QDs, facilitating excitonic recombination through radiative pathways. The PL quantum yield (PLQY) of Cu:CsPbCl_1.5Br_1.5 QDs increased to 85%. In addition, The fiber encapsulation method effectively improved the stability of the Cu:CsPbCl_1.5Br_1.5 QDs, After 3 days in water, the fluorescence intensity still remains at the initial 90%. Based on these results, it is believed that Cu:CsPbCl_1.5Br_1.5 QDs have promising applications in optoelectronic devices in the future.

A novel surface modification technique for graphite films (GF) to improve the interface thermal resistance with epoxy resin was presented. By utilizing the self-polymerization of dopamine (PDA), dopamine micro and nanoparticles were formed on the surface of the GF. Subsequently, the surface of the epoxy resin was functionalized with polydopamine (PDA) through grafting of the silane coupling agent 3-glycidyl ether oxy-propyl trimethoxy silane (GOPTS), enabling the introduction of epoxy resin groups onto the surface of the GF. Employing a simple folding technique, a three-dimensional GF network (3DGF) was constructed, in which modified GF was successfully incorporated into the polymer matrix. The results showed that the 3DGF network further promoted the effective transfer of heat and electrons within the composite, leading to a significant improvement in thermal and electrothermal conversion performance. The prepared 3DGPGF/epoxy resin composite exhibits high thermal conductivity (7.14 W/mK) at a relatively low GF loading (31.9 wt%). Under a voltage of 12 V, the surface temperature of the sample rapidly rises from room temperature to 130°C within 200 s, and can completely melt ice cubes within 60 s. These results indicate that epoxy-silane-dopamine-modified graphite film can be a promising candidate material, and this work provides a promising strategy for designing and manufacturing high-performance composites with improved thermal properties. The developed method has the potential to be extended to other polymer matrices and fillers, and the prepared composites have enormous potential in various applications.

The presence of well-conductive polydimethylsiloxane (PDMS)-based ionogel has changed the stereotype of PDMS of being an insulator, owing to continuous ionic liquid (IL) phase with superior ionic conductivity. However, the sacrifice on the transparency of ionogel often occurs if increasing IL content, and to overcome the immiscibility between nonpolar PDMS and polar IL is still regarded as a considerable challenge today. Herein a new strategy to prepare a transparent, highly conductive PDMS-based ionogel with high IL content is proposed, using a “composite” surfactant of KF-6017 and LiTFSI. Benefited from unique microphase separation during gel formation, the optimal ionogel of IG_{70%–1%–1%} can possess excellent transparency (>95%, ~200 μm) with IL content of 70%, while owning ionic conductivity of 3.28 mS/cm and tensile property of 100 kPa. A new mechanism on the conductivity of ionogel is proposed by the molecular simulation. The ionogel can be suitable for applying as electrolyte (B) and a polymer binder for active carbon powders (as electrode A). As a result, the assembled electrochemical double-layer capacitor (A/B/A) can be flexible accompanied with excellent electrochemical performance, which exhibits a promising future for flexible electronics and wearable devices.

The development of effective dispersants for nanoparticle suspensions is crucial for enhancing the performance and stability of various functional materials. In this study, we investigated a series of comb-like block copolymers with well-defined structures, including both categories of block copolymers and uniformly composed random copolymers, as dispersants for cerium oxide (CeO₂) suspensions. Acrylic acid (AA) units were used for anchoring and electrostatic repulsion, while methoxy polyethylene glycol acrylate (MPEGA) units provided additional steric hindrance and solubility. We explored stabilization mechanisms involving polymer topologies, chain lengths, compositions, and molecular interactions from kinetic and thermodynamic perspectives. The results demonstrate significant improvements in dispersion stability with both categories of well-controlled copolymers, especially with uniformly composed random copolymers due to their uniformly distributed multi-point anchoring and balanced electrostatic and steric stabilization. This research not only enhances the fundamental understanding of polymer-nanoparticle interactions and polymer dispersants, but also provides valuable guidance for the tailored design of dispersants for specific industrial and scientific needs.

A copolymer based on styrene and 1-hexene was synthesized using free-radical emulsion polymerization. Reaction pressure has a significant influence on copolymer formation. There was a phase separation when styrene was copolymerized with 1-hexene at lower pressure (1 bar) and a stable emulsion was observed under a pressurized reaction (4.5 bar). Additionally, a phase separation was also observed at a lower reaction pH (7.2) and was evidenced by the reduced pH value at the end of the copolymerization. H¹ nuclear magnetic resonance (NMR) spectroscopy analysis showed the disappearance of methylene proton peak intensities in both styrene and 1-hexene after the copolymerization reaction indicating the increased conversion of monomers in emulsion. Synthesized copolymer was also studied using the C¹³ NMR analysis. It was further analyzed by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The emulsion was destabilized by the synergistic action of acid and temperature to recover solid polymer. The applicability of the copolymer as a polymer modifier was studied by blending with commercial PS. Copolymer thermal properties were analyzed by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Other properties such as emulsion particle size, droplet morphology, and the effect of pH were also investigated in this study.

Six varieties of alkoxy polyhedral oligomeric silsesquioxanes (POSSs) featuring methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, and n-hexoxy as terminal groups were synthesized using the direct dehydrogenation condensation method. These POSSs were then incorporated as cross-linking agents into hydroxy-terminated polydimethylsiloxane (HPDMS) to create various formulations of room temperature vulcanized silicone rubbers (RTV SRs), denoted as SRM, SRE, SRP, SRI, SRB, and SRH. The morphology, thermal stability, and mechanical properties of the resulting SRs are analyzed using scanning electron microscopy (SEM), thermal gravimetric analysis (TGA) and universal tensile testing machine. The findings indicate that the incorporation of POSS into SRs results in significant enhancements in thermal stability and mechanical properties when compared to the control group (TEOS/SR). SRB and SRH exhibit the highest cross-linking density and tensile strength. Specifically, SRB-4 demonstrates the highest tensile strength at 2.66 MPa, representing an 8.6-fold increase compared to TEOS/SR. The maximum decomposition rate temperature of SRP-4 reaches 527°C and is 194°C higher than TEOS/SR. Because the alkoxy groups with different chain lengths on POSS have different chemical reactivity, they have a great effect on the dispersion of POSS in SRs, which affect the cross-linking density, tensile strength, and thermal stability.