In Situ High-performance Gel Polymer Electrolyte with Dual-reactive Cross-linking for Lithium Metal Batteries

Lithium metal batteries have been considered as one of the most promising next-generation power-support devices due to their high specific energy and output voltage.However,the uncontrollable side-reaction and lithium dendrite growth lead to the limited serving life and hinder the practical application of lithium metal batteries.Here,a tri-monomer copolymerized gel polymer electrolyte(TGPE)with a cross-linked reticulation structure was prepared by introducing a cross-linker(polyurethane group)into the acrylate-based in situ polymerization system.The soft segment of polyurethane in TGPE enables the far migration of lithium ions,and the-NH forms hydrogen bonds in the hard segment to build a stable cross-linked framework.This system hinders anion migration and leads to a high Li^(+)migration number(t_(Li^(+))=0.65),which achieves uniform lithium deposition and effectively inhibits lithium dendrite growth.As a result,the assembled symmetric cell shows robust reversibility over 5500 h at a current density of 1 mA cm^(-2).The LFP∷TGPE∷Li cell has a capacity retention of 89.8%after cycling 800 times at a rate of 1C.In summary,in situ polymerization of TGPE electrolytes is expected to be a candidate material for high-energy-density lithium metal batteries.

Molecule‑Level Multiscale Design of Nonflammable Gel Polymer Electrolyte to Build Stable SEI/CEI for Lithium Metal Battery

The risk of flammability is an unavoidable issue for gel polymer electrolytes(GPEs).Usually,flameretardant solvents are necessary to be used,but most of them would react with anode/cathode easily and cause serious interfacial instability,which is a big challenge for design and application of nonflammable GPEs.Here,a nonflammable GPE(SGPE)is developed by in situ polymerizing trifluoroethyl methacrylate(TFMA)monomers with flame-retardant triethyl phosphate(TEP)solvents and LiTFSI–LiDFOB dual lithium salts.TEP is strongly anchored to PTFMA matrix via polarity interaction between-P=O and-CH_(2)CF_(3).It reduces free TEP molecules,which obviously mitigates interfacial reactions,and enhances flame-retardant performance of TEP surprisingly.Anchored TEP molecules are also inhibited in solvation of Li^(+),leading to anion-dominated solvation sheath,which creates inorganic-rich solid electrolyte interface/cathode electrolyte interface layers.Such coordination structure changes Li^(+)transport from sluggish vehicular to fast structural transport,raising ionic conductivity to 1.03 mS cm^(-1) and transfer number to 0.41 at 30℃.The Li|SGPE|Li cell presents highly reversible Li stripping/plating performance for over 1000 h at 0.1 mA cm^(−2),and 4.2 V LiCoO_(2)|SGPE|Li battery delivers high average specific capacity>120 mAh g^(−1) over 200 cycles.This study paves a new way to make nonflammable GPE that is compatible with Li metal anode.

Preparation and evaluation of ophthalmic thermosensitive in situ gels of penciclovir

Aim To develop pluronic F127 （PF127） based formulations of penciclovir （PCV） aimed at enhancing its ocular bioavailability. Methods Thermosensitive in situ gels of penciclovir were prepared through combination of HPMC K4M or carbopol 934P and pluronic F127. Optimized formulations were examined through measuring gelation temperature, rheology speciality, drug release behavior, pharmacokinetics and ocular irritation. Results The gelation temperature was reduced by adding HPMC K4M or carbopol 934P, and the viscosity was enhanced slightly. Either HPMC K4M or carbopol 934P delayed the release of PCV from in situ gel. PCV was released by non-Fickian diffusion. The study of ocular irritation for different PCV formulations did not show any irritation or damage for the cornea. PCV bioavailability from combination of carbopol 934P and pluronic F127 gels was higher than that obtained from any other gels. Conclusion Pluronic F127 formulations of PCV can be used as liquid for administration by instilling into the eye. Facilitated by the appropriate eye temperature, the formulations were transformed to gel phase. On the basis of in vitro and in vivo results, PCV formulations containing HPMC K4M or carbopol 934P and low concentration of pluronic F127 （12%） showed potential for use as a drug delivery system with improved ocular bioavailability.

The preparation of Thermosensitive in Situ Gel of Iodine

objective:To Investigate the preparation,dissolution and release in vitro of thermosensitive in situ gel of iodine.Methods:Using orthogonal test method for screening the best prescription;Using the formula of gel accumulative dissolution percentage=(W1-Wt)/(W1-W0)to calculate the dissolution rate of Q by membrane-free;Calculating the accumulative release rate by the standard curve.As time increases,the dissolution rate and the release rate of the gel increased significantly.Conclusion:Thermosensitive in situ gel of iodine has good sustained release effect.

In situ forming hydrogels based on chitosan for drug delivery and tissue regeneration

In situ forming hydrogels with simple sol–gel transition are more practicable as injectable hydrogels for drug delivery and tissue regeneration. State-of-the-art in situ gelling systems can easily and efficiently be formed by different mechanisms in situ. Chitosan is a kind of natural polysaccharide that is widely exploited for biomedical applications due to its good biocompatibility, low immunogenicity and specific biological activities. Chitosan-based in situ gelling systems have already gained much attention as smart biomaterials in the development of several biomedical applications, such as for drug delivery systems and regeneration medicine. Herein, we review the typical in situ gelling systems based on chitosan and mechanisms involved in hydrogel forming, and report advances of chitosan-based in situ gels for the applications in drug delivery and tissue regeneration. Finally, development prospects of in situ forming hydrogels based on chitosan are also discussed in brief.

Role of clove oil in solvent exchange-induced doxycycline hyclate-loaded Eudragit RS in situ forming gel

Solvent exchange induced in situ forming gel(ISG) is the promising drug delivery system for periodontitis treatment owing to the prospect of maintaining an effective high drug level in the gingival crevicular fluid. In the present study, the influence of clove oil(CO) on the characteristics of doxycycline hyclate(DH)-loaded ISG comprising Eudragit RS(ERS) was investigated including viscosity/rheology, syringeability, in vitro gel formation/drug release, matrix formation/solvent diffusion and antimicrobial activities. CO could dissolve ERS and increase the viscosity of ISG and its hydrophobicity could also retard the diffusion of solvent and hinder the drug diffusion; thus, the minimization of burst effect and sustained drug release were achieved effectively. All the prepared ISGs comprising CO could expel through the 27-gauge needle for administration by injection and transform into matrix depot after exposure to the simulated gingival crevicular fluid. The antimicrobial activities against Staphylococcus aureus, Escherichia coli, Streptococcus mutans and Porphyromonas gingivalis were increased when the ratio of CO and N-methyl pyrrolidone(NMP) was decreased from 1:1 to 1:10 owing to higher diffusion of DH except that for C. albicans was increased as CO amount was higher.Therefore, CO could minimize the burst while prolonging the drug release of DH-loaded ERS ISG for use as a local drug delivery system for periodontitis treatment.

A stepwise optimization strategy to formulate in situ gelling formulations comprising fluconazole-hydroxypropyl-beta-cyclodextrin complex loaded niosomal vesicles and Eudragit nanoparticles for enhanced antifungal activity and prolonged ocular delivery

Fungal keratitis and endopthalmitis are serious eye diseases.Fluconazole(FL)is indicated for their treatment,but suffers from poor topical ocular availability.This study was intended to improve and prolong its ocular availability.FL niosomal vesicles were prepared using span 60.Also,polymeric nanoparticles were prepared using cationic Eudragit RS100 and Eudragit RL100.The investigated particles had adequate entrapment efficiency(EE%),nanoscale particle size and high zeta potential.Subsequently,formulations were optimized using full factorial design.FL-HP-β-CD complex was encapsulated in selected Eudragit nanoprticles(FL-CD-ERS1)and niosmal vesicles.The niosomes were further coated with cationic and bioadhesive chitosan(FL-CD-Nios-ch).EE%for FL-CD-ERS1 and FL-CD-Niosch formulations were 76.4%and 61.7%;particle sizes were 151.1 and 392 nm;also,they exhibited satisfactory zeta potential+40.1 and+28.5 m V.In situ gels were prepared by poloxamer P407,HPMC and chitosan and evaluated for gelling capacity,rheological behavior and gelling temperature.To increase the precorneal residence time,free drug and selected nano-formulations were incorporated in the selected in situ gel.Release study revealed sustained release within 24 h.Permeation through excised rabbits corneas demonstrated enhanced drug flux and large AUC0-6 h in comparison to plain drug.Corneal permeation of selected formulations labeled with Rhodamine B was visualized by Confocal laser microscopy.Histopathological study and in vivo tolerance test evidenced safety.In vivo susceptibility test using Candida albicans depicted enhanced growth inhibition and sustained effect.In this study the adopted stepwise optimization strategy combined cylodextrin complexation,drug nano-encapsulation and loading within thermosenstive in situ gel.Finally,the developed innovated formulations displayed boosted corneal permeation,enhanced antifungal activity and prolonged action.

Research progress of in-situ gelling ophthalmic drug delivery system

Blindness and vision impairment are the most devastating global health problems resulting in a substantial economic and social burden.Delivery of drug to particular parts of the anterior or posterior segment has been a major challenge due to various protective barriers and elimination mechanisms associated with the unique anatomical and physiological nature of the ocular system.Drug administration to the eye by conventional delivery systems results in poor ocular bioavailability(<5%).The designing of a novel approach for a safe,simple,and effective ocular drug delivery is a major concern and requires innovative strategies to combat the problem.Over the past decades,several novel approaches involving different strategies have been developed to improve the ocular delivery system.Among these,the ophthalmic in-situ gel has attained a great attention over the past few years.This review discussed and summarized the recent and the promising research progress of in-situ gelling in ocular drug delivery system.

Disulfiram thermosensitive in-situ gel based on solid dispersion for cataract

To improve the corneal permeability and water-solubility of disulfiram(DSF), which is an ocular drug for cataract, P188 was selected as a matrix to prepare solid dispersion of DSF(DSF SD) by hot melt method. The DSF SD was characterized by DSC, XRD, and IR, and the results suggested that DSF was amorphous in DSF SD. The DSF SD was added to borate buffer solution(BBS) contained 20% poloxamer P407 and 1.2% poloxamer P188 to form in-situ gel. In vitro and in vivo experiments revealed that DSF SD combined with in-situ gel(DSF SD/in-situ gel) increased the residence time and the amount of DSF penetrated through the corneal. The pharmacodynamics studies exhibited DSF SD/in-situ gel delayed the development of selenium-induced cataract at some content. These results investigated that DSF SD/in-situ gel as a drug delivery system can improve DSF ocular permeability.

In-Situ Synthesis of Terbium Complex with Salicylic Acid in Silica Matrix by a Two-Step Sol-Gel Process

A process for in situ synthesis of terbium complex with salicylic acid by a two-step solgel method in silica matrix has been proposed. The luminescence properties of the silica gelscodoped with terbium and salicylic acid have also been discussed with respect to that of the geldoped with terbium and that of pure terbium complex with salicylic acid.

Study on Rheology and Release Kinetics of Chuanqi Ophthalmic Microemulsion in situ Gel

[Objectives] To study the rheology and release kinetics of Chuanqi ophthalmic microemulsion in situ gel,so as to provide references for its future study and development. [Methods]The fluid properties and linear viscoelastic regions of this preparation were investigated by MCR 102 rheometer. The release kinetics of Chuanqi ophthalmic microemulsion in situ gel was evaluated by modified Franz diffusion cell method,the ligustrazine and ligustilide were selected as the indictors,and semi-permeable membrane was used as a barrier,sampling time point was 0. 5,1,2,4,6,and 8 h respectively. [Results]Chuanqi ophthalmic microemulsion in situ gel was a pseudoplastic fluid and it had a linear viscoelastic region. Taking the shear stress as the indicator,the linear viscoelastic region was 0-302. 74 Pa; taking the strain as the indicator,the linear viscoelastic region was 0-7. 45%. At the critical point,the storage modulus( G') = the loss modulus( G″) =2 976. 60 Pa,critical shear stress was 302. 74 Pa and critical strain was 7. 45%. The average cumulative release of ligustrazine of 6 samples within 8 h was 33. 71 μg,the average cumulative release rate reached 90. 08%,and the release kinetics followed Higuchi equation. The average cumulative release of ligustilide of 6 samples within 8 h was 68. 46 μg,the average cumulative release rate reached 84. 32%,and the release kinetics followed the zero-order kinetics equation. [Conclusions] Chuanqi ophthalmic microemulsion in situ gel has excellent viscoelasticity and its strain is reversible in a certain range. The release kinetics of ligustrazine is the result from synergistic effect of its physicochemical properties and matrix skeleton,while the release kinetics of ligustilide is mainly affected by its physicochemical properties.

Micro Structural Development of in Situ Heated and Deformed Pure and Silica Gel-Doped Polycrystalline Halite Using High Energy Synchrotron Radiation

This paper presents an experimental investigation of the microstructural development upon in situ compression and heating of pure and SiO2 gel-doped （5 wt%） polycrystalline halite, with grain sizes ranging from 45 μm to 〉70 μm （cold pressed at 200 MPa and heated at 150 ℃ for one week）, using high energy synchrotron x-ray radiation. Texture development of the samples was studied at room temperature, 100, 200 and 300 ℃. At each temperature, the samples were axially compressed keeping the load constant at every -500 N step up to the maximum 2,400 N （- 48 MPa）. At the different loads and temperatures, 2D images and load/elongation curves were recorded in situ to get information about the texture development and the rheological behaviour of the potycrystalline halite samples. At high stresses, the doped halite samples show an increase in the elastic moduli and in the microstrain The results were confirmed by the single grain orientation analyses using the FABLE program, where a sharpening of the texture was observed.

Preparation and Evaluations of Ibuprofen Thermosensitive in situ Gel

[Objectives] To prepare Ibuprofen-β-CD for thermosensitive in situ gel administration to achieve a slow drug release. [Methods]By saturation solution process,the best inclusion technology was screened out with orthogonal design. [Results]The prescription of in situ gel contained ibuprofen-β-CD complex,poloxamer P407,P188,and HPMCK4M( w/v 10%,18%,3%,and 0. 5%). The gelation temperature of ibuprofen gel was 34. 6 ± 0. 3℃. The viscosity of ibuprofen gel increased significantly above 35℃ and showed semi-solid attribute. [Conclusions] The release of ibuprofen from in situ gel was slow and stable in 96 h,demonstrated a proximate zero order release between 24 h and 96 h.

Sol-Gel与在位聚合联用制备分散良好的纳米杂化材料

采用 Sol- Gel法与在位聚合相结合的方法 ,使正硅酸乙酯在聚合物单体中进行水解、缩聚 ,然后再加入引发剂使单体聚合 ,制得了稳定分散的纳米粒子杂化的聚合物材料 ,该材料性能优良 ,具有很好的透明度。在保持树脂光学性能的前提下 ,材料的抗冲击性能有所改善。

纳米复合凝胶AgNPs@Gel的制备及催化性能研究

以2-丙烯酰胺基-2-甲基丙磺酸(AMPS)、N,N-二甲基丙烯酰胺(DMAA)为单体,通过水溶液聚合法制备P(AMPS-co-DMAA)凝胶.再以该凝胶为模板,通过原位还原法成功制备了纳米复合凝胶AgNPs@Gel,并对AgNPs@Gel进行结构表征和催化性能测试.SEM和XRD分析表明,纳米银粒子在AgNPs@Gel中分散较均匀,粒径尺寸在100~200 nm之间.AgNO_(3)浓度、凝胶用量、电场、反应温度均能影响AgNPs@Gel的催化性能,当AgNO_(3)浓度为0.03 mol/L,凝胶用量为50 mg,电压为0 V,反应温度为20℃时,AgNPs@Gel对4-NP的催化反应平衡时间为120 min,催化转化率为96.30%,催化速率常数值为2.75×10^(-2) min^(-1).AgNPs@Gel具有较好的重复使用性能,在第5次催化转化率仍达到86.62%.

基于压缩应力表征透明质酸钠交联反应进程方法

背景:目前,凝胶交联反应进程可通过核磁检测等方法测定交联度来表征,也可以采用流变仪监测交联固化过程中黏弹性行为的变化来表征,但这些方法操作复杂且会破坏样品,急需建立一种操作简单、测定时不用特殊制样、不会破坏样品的交联反应进程监控方法。目的:建立一种表征透明质酸钠交联反应进程的方法。方法:采用1,4-丁二醇二缩水甘油醚作为交联剂,选择不同交联度(1%,2%,3%和4%)、不同透明质酸钠分子质量(400,700,1500和3000 kD)、不同氢氧化钠溶液浓度(1%,2%和3%)和不同反应温度(4,25,37和50℃)这4个因素来制备透明质酸钠凝胶。利用电子万能拉力试验机测定交联凝胶被下压形变1 mm时的压缩应力,根据压缩应力变化情况来监控交联进程,进而判断交联反应充分性及交联工艺对交联进程的影响。结果与结论:①交联时间延长,凝胶硬度增强,压缩应力增加,达到一定值后,透明质酸钠交联结构在强碱作用下发生降解,凝胶硬度减小,压缩应力下降,因此可以根据压缩应力的大小表征凝胶的软硬程度,通过压缩应力与交联时间绘制曲线来表征交联反应进程。根据压缩应力变化情况可知,交联反应温度对交联反应时间及凝胶的硬度有着明显影响,其他反应因素(交联度、交联时碱浓度、透明质酸钠分子质量)对反应时间无明显影响,但是对凝胶硬度有着较大的影响。②根据CORREL函数处理结果表明,随着交联时间的变化,压缩应力与弹性模量和动力黏度的变化趋势一致,均可以用来表征透明质酸钠凝胶的交联进程。③基于交联凝胶压缩应力不仅能表征交联反应进程,还能初步判定凝胶软硬程度,该方法能够进行实时、原位检测,具有操作简单、不会破坏样品等优点,为透明质酸钠及其他物质交联反应进程监控提供了一种解决办法和新的思路。

Formulation and evaluation of herbal gel of Pothos scandens Linn

Objective:To formulate Pothos scandens Linn(P.scandens) leaf extract in to a gel and investigate their burn wound healing activity.Methods:Ethanolic extract of dried leaves of P. scandens were subjected to priliminery phytochemical evaluation and wound healing activities studies.Different gel formulations of ethanolic extract of P.scandens(4%w/v) were prepared using polymers carbopol 934 and carbopol 940 bv varying their concentration.These formulations were evaluated for physical parameters,drug content.pH,viscosity,extrudability.spreadability. primary skin irritation,pharmacological activity and stability.Results:Wound healing studies of ethanolic extract revealed that P.scandens treated animals were found to epithelise in 22 days while the solvent control and the untreated rats epithelise within 35 and 40 days respectively. The formulation with 1.5%w/w carbopol 934 was found to be more promising as it shows better physicochemical characteristics,higher pharmacological activity and stability compared to other formulations.Conclusions:P.scandens alcoholic extract shows significant improvement in burn wound contraction and hence this is a promising candidate in burn wound healing.

Synthesis and Luminescence Properties of Ternary Europium Complexes inTitania Matrix in the Presence of Dimethylformamide by a Sol-Gel Process

In-situ synthesis of ternary europium complex with thenoyltrifluoacetone (TTA) and 1,10-phenanthroline (phen) in titania matrix in the presence of dimethylformamide (DMF) by a sol-gel process was described, which was confirmed by the luminescence excitation spectra and infrared spectra. The titania gel that contains europium complex exhibits Eu3+ characteristic emission bands and presents a longer fluorescence lifetime than the pure complexes dissolved in ethanol solution. The concentration effect on the luminescence intensity was also investigated.

Effect of B_2O_3 on the Structure and Photoluminescence Properties of Sol-gel Glass Doped with Terbium Organic Complex

Both silica and boron-silica glass materials doped with terbium organic complex were prepared by in situ sol-gel method respectively. XRD and SEM measurements were performed to verify the non-crystalline structure of the glass. The influence of the glass contents on the structure of the glass and the erwrgy level of the doped Tb （Ⅲ） ions was analyzed by the emission spectra and IR spectra. The effect of B2O3 on the photolumirwscence properties of rare earth organic complex in silica- based glass was investigated. The IR spectra indicate that the in situ sylthesized rare earth complex molecule was confined to the micropores of the bost and the vibration of the ligands was frozen. When B2O3 was added into the silica host gel, B2O3 had little influence on the noncrystallirw structure of the glass, and BO3 triangle, which had a layer structure different from the silica framework, could form. So the silica network became more inhomogenous, and the luminescence of terbium complexes was quenched with the increase of the B2O23 amount.

<i>In-Situ</i>Impregnation of Copper Nanoparticles on Palm Empty Fruit Bunch Powder

Copper nanoparticles were impregnated onto oil palm empty fruit bunch (EFB) powders via in-situ sol-gel method. The impregnation and interfacial interaction of copper nanoparticles with EFB were analysed by fourier transformed infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) and atomic force microscopy (AFM). The interaction of copper nanoparticles with the surface functional groups of EFB powders was identified by FTIR analysis. The peak shift of O-H and C-O functional groups indicated the interaction between EFB and copper nanoparticles. Besides that, XRD and EDX analysis confirmed the formation of copper nanoparticles on EFB powder. Due to the copper impregnation, the crystallinity of the EFB was increased as shown by XRD. The particles size of nanoparticles was analysed via TEM and AFM where the sizes were in the range of 60 - 100 nm. These findings strongly suggest that, copper nanoparticles impregnated EFB powders can be synthesized via in- situ sol gel method.