In-situ Construction of Poly(tetraisopentyl acrylate) based Gel Polymer Electrolytes with Lix La2-x TiO3 for High Energy Density Lithium-Metal Batteries.

As promising alternatives to liquid electrolytes, polymer electrolytes attract much research interest recently, but their widespread use is limited by the low ionic conductivity. In this study, we use electrostatic spinning to introduce particles of an ionic conductor into polyacrylonitrile (PAN) fibers to prepare a porous membrane as the host of gel polymer electrolytes (GPEs). The relevant in-situ produced GPE performs a high ionic conductivity of 6.0×10-3  S cm-1 , and a high lithium transfer number (tLi + ) of 0.85 at 30 °C, respectively. A symmetrical Li cell with this GPE can cycle stably for 550 h at a current density of 0.5 mA cm-2 . While the capacity retention of the NCM|GPE|Li cell is 79.84 % after 500 cycles at 2 C. Even with an increased cut-off voltage of 4.5 V, the 1st coulomb efficiency reaches 91.58 % with a specific discharge capacity of 213.4 mAh g-1 . This study provides a viable route for the practical application of high energy density lithium metal batteries.

Solid Electrolyte Interphase on Lithium Metal Anodes.

Lithium metal batteries (LMBs) represent the most promising next-generation high-energy density batteries. The solid electrolyte interphase (SEI) film on the lithium metal anode plays a crucial role in regulating lithium deposition and improving the cycling performance of LMBs. In this review, we comprehensively present the formation process of the SEI film, while elucidating the key properties such as electronic conductivity, ionic conductivity, and mechanical performance. Furthermore, various approaches for constructing the SEI film are discussed from both electrolyte regulation and artificial coating design perspectives. Lastly, future research directions along with development recommendations are also provided. This review aims to provide possible strategies for the further improvement of SEI film in LMBs and highlight their inspiration for future research directions.

Polyacrylonitrile Porous Membrane-Based Gel Polymer Electrolyte by In Situ Free-Radical Polymerization for Stable Li Metal Batteries.

Because of their high ionic conductivity, utilizing gel polymer electrolytes (GPEs) is thought to be an effective way to accomplish high-energy-density batteries. Nevertheless, most GPEs have poor adaptability to Ni-rich cathodes to alleviate the problem of inevitable rapid capacity decay during cycling. Therefore, to match LiNi0.8Co0.1Mn0.1O2 (NCM811), we applied pentaerythritol tetraacrylate (PETEA) monomers to polymerize in situ in a polyacrylonitrile (PAN) membrane to obtain GPEs (PETEA-TCGG-PAN). The impedance variations and key groups during the in situ polymerization of PETEA-TCGG-PAN are investigated in detail. PETEA-TCGG-PAN with a high lithium-ion transference number (0.77) exhibits an electrochemical decomposition voltage of 5.15 V. Noticeably, the NCM811|PETEA-TCGG-PAN|Li battery can cycle at 2C for 120 cycles with a capacity retention rate of 89%. Even at 6C, the discharge specific capacity is able to reach 101.47 mAh g-1. The combination of LiF and Li2CO3 at the CEI interface is the reason for the improved rate performance. Moreover, when commercialized LFP is used as the cathode, the battery can also cycle stably for 150 cycles at 0.5C. PETEA and PAN can together foster the transportation of Li+ with the construction of a fast ion transport channel, making a contribution to stable charge-discharge of the above batteries. This study provides an innovative design philosophy for designing in situ GPEs in high-energy-density lithium metal batteries.

Synthesis, characterization, and comparison of antibacterial effects and elucidating the mechanism of ZnO, CuO and CuZnO nanoparticles supported on mesoporous silica SBA-3.

Silanized iminodiacetic acid (GLYMO-IDA) modified mesoporous silica (G-SBA) was prepared following a co-condensation method. G-SBA/Cu2+, G-SBA/Zn2+ and G-SBA/Cu2+-Zn2+ were obtained through the impregnation method with coordination by GLYMO-IDA. SBA/CuO, SBA/ZnO, and SBA/CuZnO were generated after calcination of G-SBA/Cu2+, G-SBA/Zn2+ and G-SBA/Cu2+-Zn2+. After modification, the amount of metal ion was 6 to 70 times higher than that of the blank mesoporous silica. The diameter of nano-copper oxide particles in mesoporous silica was 4.8 nm. The bacteriostatic rates of SBA/CuO at a copper oxide concentration of 250 ppm against E. coli and S. aureus were 85.87% and 100%, respectively. SBA/CuO and SBA/CuZnO with {111} lattice planes exhibited better antibacterial effects compared to the commercial-grade nano-zinc oxide and nano-copper oxide. When exposed to ultraviolet light, SBA/CuZnO displayed the highest photocatalytic activity and optimal antimicrobial effect. Therefore, SBA/CuZnO can be an alternative to antibiotics because of its non-toxic nature and good antibacterial properties.

Synthesis of mesoporous silica post-loaded by methyl eugenol as an environment-friendly slow-release bio pesticide.

Salicylaldimine, furfuralimine and benzaldehyde imine were adopted to modify mesoporous silica (MCM) respectively denoted as Sal-MCM, Fur-MCM and Ben-MCM before loading methyl eugenol (Me) for pesticide delivery. Me was adsorbed by Schiff base mesoporous silica without destructing regular hexagonal pore structure verified by the characterization results. DSC result implied that Me in amorphous state which was distributed in the pores of the mesoporous silica. The loading content of Me-Sal-MCM, Me-Fur-MCM and Me-Ben-MCM 67.89%, 73.34% and 73.84% which was higher than Me-MCM without modification (67.35%).Because the electrostatic interaction and π-π interaction between Schiff base and Me strengthened the adsorption capacity of the carrier. And the electrostatic interaction played a more important role in interaction between Me and Schiff base modified mesoporous silica. As a result, Schiff base modified sustained release system also has significantly longer sustained release time with a sequence of Me-Sal-MCM > Me-Ben-MCM > Me-Fur-MCM in release speed in negative correlation with the electric potential sequence. The behaviors of their sustained release performance can be fitted by First order kinetic model before Schiff base modification. After modification, their sustained release behaviors were consistent with Korsmeyer-Peppas equation with non-Fickian diffusion mechanism indicating that main impact on the release process after modification was no longer mainly controlled by the difference of the concentration. Finally, the highest lure rate of the modified MCM (Me-Fur-MCM) equals to the 73% of the pure Me due to its highest BET surface area and strongest interaction with Me among the three Schiff base modified samples. Therefore, the environment-friendly slow-release bio pesticide with long service life was prepared to reduce the damage on the environment caused by pesticide.

Long-lasting anti-bacterial activity and bacteriostatic mechanism of tea tree oil adsorbed on the amino-functionalized mesoporous silica-coated by PAA.

Tea tree oil (TTO) is an efficient natural antibacterial agent. However, the bacteriostatic effect of TTO does not prevail for a long period because of the volatile nature of the oil. Therefore, a novel sustained-release formulation of TTO should be developed for improving the applicability of TTO. Herein, the mesoporous silica was selected for constructing a carrier for TTO. Mesoporous silica is non-toxic, easy to modify and exhibited an adjustable pore size. First, the mesoporous silica was modified by an aminated silane coupling agent (NH2-MCM-41). Then, the polyacrylic acid (PAA) was bonded by electrostatic bonds (PAA-NH2-MCM-41), which imparted the sustained-release effect in the TTO, supported in the mesoporous silica channel (TTO/PAA-NH2-MCM-41). The prepared bacteriostatic agent can achieve long-term sustained-release properties. At room temperature (26 ℃), the release rate of TTO after 11 h release reached 50 %. However, the release rate of TTO from TTO/PAA-NH2-MCM-8 reached only 42 % after 24 h. Furthermore, the sustained release behavior of TTO/PAA-NH2-MCM-41 was consistent with the Korsmeyer-Peppas kinetic model. Compared to TTO, TTO/PAA-NH2-MCM-41 exhibited a stable and sustained bacteriostatic effect even after 50 days in a natural environment. The minimum inhibitory concentration (MIC) value of the TTO/PAA-NH2-MCM-41 against Escherichia coli (E. coli) was 0.37∼0.44 mg/mL. TTO altered the cell morphology of E. coli and broke the integrity of the cell membrane, leading to cell death.

Synthesis of ZnO nanoparticles supported on mesoporous SBA-15 with coordination effect -assist for anti-bacterial assessment.

Polyethyleneimine (PEI) was immobilized on SBA-15 for obtaining polyethyleneimine-modified silica PEI@SBA-15s (PEI@SBA-1.0, PEI@SBA-1.5, and PEI@SBA-2.0). With the coordination from PEI, zinc ions were impregnated on the PEI@SBA-15s, and then, Zn2+-PEI@SBA-15s were calcined at 550 ℃ to obtain the nano zinc oxide loaded on the mesoporous silica, ZnO-SBA-15s (ZnO-SBA-1.0, ZnO-SBA-1.5, and ZnO-SBA-2.0). The anti-bacterial activity of ZnO-loaded SBA-15 was; thereafter, assessed by the zone of inhibition and enzyme labeling methods. The results confirmed that the coordination ability of the imino groups in PEI helped adsorb more zinc ions during the process of impregnation so that more nano-ZnO could be supported on the surface of SBA-15. The modification did not change the mesostructure of the two-dimensional hexagonal phase and orderliness of SBA-15. At the mass ratio of PEI:SBA-15 = 1.0:1, 1.5:1, and 2.0:1, the concentration of zinc element (wt.%) was measured by inductively coupled plasma optical emission spectrometry as 2.5, 2.56, and 3.5% for ZnO-SBA-1.0, ZnO-SBA-1.5, and ZnO-SBA-2.0, respectively. The size of inhibition of SBA-15, ZnO-SBA-0, ZnO-SBA-1.0, ZnO-SBA-1.5, and ZnO-SBA-2.0 were 0, 1.14 ± 0.01, 2.56 ± 0.01, 2.58 ± 0.01, and 2.69 ± 0.02 cm, respectively. ZnO-SBA-15s suppressed the growth of Escherichia coli compared to blank SBA-15 in a ZnO dose-dependent manner.

Coordination bonding-based polydopamine-modified mesoporous silica for sustained avermectin release.

Mesoporous silica nanoparticle (MSN) is a novel vehicle to deliver pesticide. MSN can be modified with different chemical groups to increase its interaction with pesticides. In this study, polydopamine-modified mesoporous silica (MSN-PDA) was prepared through a one-pot method with the addition of dopamine (DA). Copper ions, zinc ions, and iron ions were impregnated on MSN-PDA. In addition, avermectin (AVM) was used as the model drug. We investigated the materials' structure, adsorption and release behaviors, anti-UV properties, as well as their adhesive capability, especially the bridge effect of metal ions, π-π stacking of PDA and electrostatic interaction. The results demonstrated that the above materials possessed spherical morphology with surface areas from 635.833 to 1048.960 m2/g. Except for the zinc ions, the complexation with copper and iron ions not only enhanced materials' UV resistance but also increased their adsorption rate and the loading amount of AVM from 133 mg/g to 248 and 243 mg/g, respectively. At pH 3, 7, and 10, the bridge effect of the metal ions demonstrated a cumulative release rate using MSN-PDA not over 30% for AVM in 180 h, while the cumulative release rate for MSN reached its 50% in 60, 90, and 50 h under different pH values, respectively. We further demonstrated that the adhesive effect of PDA could be decreased by metal ions.

Synthesis of Nano-Zinc Oxide Loaded on Mesoporous Silica by Coordination Effect and Its Photocatalytic Degradation Property of Methyl Orange.

Salicylaldimine-modified mesoporous silica (Sal-MCM-3 and Sal-MCM-9) was prepared through a co-condensation method with different amounts of added salicylaldimine. With the coordination from the salicylaldimine, zinc ions were impregnated on Sal-MCM-3 and Sal-MCM-9. Then, Zn-Sal-MCM-3 and Zn-Sal-MCM-9 were calcined to obtain nano-zinc oxide loaded on mesoporous silica (ZnO-MCM-3 and ZnO-MCM-9). The material structures were systematically studied by Fourier transform infrared spectroscopy (FTIR), N2 adsorption/desorption measurements, X-ray powder diffraction (XRD), zeta potential, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), ultraviolet diffused reflectance spectrum (UV-vis DRS), and thermogravimetry (TGA). Methyl orange (MO) was used to investigate the photocatalysis behavior of ZnO-MCM-3 and ZnO-MCM-9. The results confirmed that nano ZnO was loaded in the channels as well as the outside surface of mesoporous silica (MCM-41). The modification of salicylaldimine helped MCM-41 to load more nano ZnO on MCM-41. When the modification amount of salicylaldimine was one-ninth and one-third of the mass of the silicon source, respectively, the load of nano ZnO on ZnO-MCM-9 and ZnO-MCM-3 had atomic concentrations of 1.27 and 2.03, respectively. ZnO loaded on ZnO-MCM-9 had a wurtzite structure, while ZnO loaded on ZnO-MCM-3 was not in the same crystalline group. The blocking effect caused by nano ZnO in the channels reduced the orderliness of MCM-41. The photodegradation of MO can be divided in two processes, which are mainly controlled by the surface areas of ZnO-MCM and the loading amount of nano ZnO, respectively. The pseudo-first-order model was more suitable for the photodegradation process.