Solution Concentration Ratio Research Articles

Tailoring the properties of Cu2ZnSnS4 thin films grown by ultrasonic spray pyrolysis

Cu2ZnSnS4 (CZTS) thin films are grown using an automated ultrasonic spray pyrolysis setup. Sn concentration is varied to attain properties suitable for solar cell applications. Kesterite tetragonal structured CZTS phase is dominant in all films. When Cu/(Zn+Sn)>0.83, films showed Cu2S phase in addition to CZTS phase. Film is nearly stoichiometric when Cu/(Zn+Sn) concentration ratio in the precursor solution is 1.07. When Sn concentration is reduced, Cu concentration increases proportionally and a significant change in morphology occurred for the Cu-rich films. All the samples are p-type in nature and their resistivity varies between 255 and 0.9×10−3ohmcm. Sample with Cu/(Zn+Sn) ratio of 0.83 is found to be suitable for solar cell applications.

A novel approach for methylene blue removal by calcium dodecyl sulfate enhanced precipitation and microbial flocculant GA1 flocculation

A novel approach was proposed for the removal of methylene blue (MB), a soluble cationic dye, from aqueous solution by calcium dodecyl sulfate (Ca(DS)2) enhanced precipitation which was based on the solubilization of sodium dodecyl sulfate (SDS) on MB and Ca2+ effect on SDS micelles, and microbial flocculant GA1 (MBFGA1) flocculation. The independent and interactive effects of factors, such as SDS, Ca2+ and MBFGA1 dosages, on the MB removal and interaction between SDS and Ca2+ were investigated. The response surface methodology (RSM), environmental scanning electron microscope (ESEM) and energy dispersive spectrometer (EDS) analysis were employed to discuss the interaction mechanism between SDS and Ca2+, and MB removal mechanism. The results showed that MB and SDS removal efficiency could reach 98.63% and 88.97%, respectively, with pH (10), MB (50mg/L), SDS (8mM), Ca2+ (5mM) and MBFGA1 (4mL/L). Under the optimal conditions, residual SDS and Ca2+ concentrations in the upper phase were 0.88mM and 1.27mM, respectively, which reached the Ksp of Ca(DS)2. The concentration consumption ratio between SDS and Ca2+ was 2.0. The interaction between SDS and Ca2+ was depended on the SDS-Ca2+ concentration ratio in aqueous solution rather than the CMC of SDS. When Ca2+ concentration was relatively sufficient, SDS micelles containing the solubilized MB (SDS-MB micelles) would disassemble to generate MB loaded Ca(DS)2 particles (CDS-MB particles) which would be flocculated by MBFGA1. Whereas, when SDS concentration was superfluous relatively, SDS micelles formed in the upper phase would redissolve the CDS-MB particles in flocs.

Loading Capacity versus Enzyme Activity in Anisotropic and Spherical Calcium Carbonate Microparticles.

A new method of fabrication of calcium carbonate microparticles of ellipsoidal, rhomboidal, and spherical geometries is reported by adjusting the relative concentration ratios of the initial salt solutions and/or the ethylene glycol content in the reaction medium. Morphology, porosity, crystallinity, and loading capacity of synthesized CaCO3 templates were characterized in detail. Particles harboring dextran or the enzyme guanylate kinase were obtained through encapsulation of these macromolecules using the layer-by-layer assembly technique to deposit positively and negatively charged polymers on these differently shaped CaCO3 templates and were characterized by confocal laser scanning fluorescence microscopy, fluorometric techniques, and enzyme activity measurements. The enzymatic activity, an important application of such porous particles and containers, has been analyzed in comparison with the loading capacity and geometry. Our results reveal that the particles' shape influences morphology of particles and that, as a result, affects the activity of the encapsulated enzymes, in addition to the earlier reported influence on cellular uptake. These particles are promising candidates for efficient drug delivery due to their relatively high loading capacity, biocompatibility, and easy fabrication and handling.

Chloride Transport in Undersea Concrete Tunnel

Based on water penetration in unsaturated concrete of underwater tunnel, a diffusion-advection theoretical model of chloride in undersea concrete tunnel was proposed. The basic parameters including porosity, saturated hydraulic conductivity, chloride diffusion coefficient, initial water saturation, and moisture retention function of concrete specimens with two water-binder ratios were determined through lab-scale experiments. The variation of chloride concentration with pressuring time, location, solution concentration, initial saturation, hydraulic pressure, and water-binder ratio was investigated through chloride transport tests under external water pressure. In addition, the change and distribution of chloride concentration of isothermal horizontal flow were numerically analyzed using TOUGH2 software. The results show that chloride transport in unsaturated concrete under external water pressure is a combined effect of diffusion and advection instead of diffusion. Chloride concentration increased with increasing solution concentration for diffusion and increased with an increase in water pressure and a decrease in initial saturation for advection. The dominant driving force converted with time and saturation. When predicting the service life of undersea concrete tunnel, it is suggested that advection is taken into consideration; otherwise the durability tends to be unsafe.

Effect of very low to high Sb-doping on the structural, electrical, photo-conductive and thermoelectric properties of fluorine-doped SnO2 (FTO) thin films prepared by spray pyrolysis technique

Transparent conducting fluorine and Sb-doped [SnO2: (F, Sb)] thin films have been deposited onto preheated glass substrates using the spray pyrolysis technique by the various dopant quantity of spray solution. The effect of antimony impurities on the structural, morphological, electrical, Thermo-electrical, optical and photoconductive properties of films has been investigated. The [F/Sn] atomic concentration ratio (x) in the spray solution is kept at value of 0.7 and the [Sb/Sn] atomic ratio (y) varied at values of 0, 0.0005, 0.001, 0.002, 0.01, 0.03, 0.05, 0.07 and 0.10. It is found that the films are polycrystalline in nature with a tetragonal crystal structure corresponding to SnO2 phase having orientation along the (110) and (200) planes. SEM images indicated that nanostructure of the films has a particle type growth. The average grain size increases with increasing spraying quantity of Sb-dopant. The compositional analysis of SnO2: (F, Sb) thin films were studied using EDAX. SEM and AFM study reveals the surface of SnO2: (F, Sb) to be made of nanocrystalline particles. The Hall Effect measurements have shown n-type conductivity in all deposited films. The lowest sheet resistance and highest the carrier concentration about 7.7 Ω/□ and 6.6 × 1022, respectively, were obtained for the film deposited with y = [Sb/Sn] = 0.001 and x = [F/Sn] = 0.7. The maximum of the Seebeck coefficient equal to 12.8 μV K−1 was obtained at 400 K for the film deposited with y = [Sb/Sn] = 0.10. The average transmittance of films varied over the range 10–80 % with change of Sb-concentration. The band gap values of samples were obtained in the range of 3.19–3.8 eV. From the photoconductive studies, the Sb-doped films exhibited sensitivity to incident light especially in y = 0.001. The electrical resistivity and carrier concentration vary in range 5.44 × 10−4 to 1.02 × 10−2Ω cm and 2.6 × 1022–6.6 × 1022 cm−3, respectively.

Kinetically Trapped Two-Component Self-Assembled Adlayer

A two-component self-assembly process that results in three different compositional phases is observed and explained. Solutions containing various molar ratios of cobalt octaethylporphyrin (CoOEP) and coronene in phenyloctane were brought into contact with a clean Au(111) surface. At no relative concentration was coexistence of the CoOEP and coronene phase observed. Rather, at intermediate concentrations a new 1–1 surface structure (1 coronene to 1 CoOEP) is formed with sharp compositional boundaries. This behavior is unusual in that only weak van der Waals forces, slight variations in surface charge exchange, and steric effects stabilize the 1–1 structure and that it occurs where the solution concentration ratio is an order of magnitude different than the surface concentration. The nature of this 1–1 structure and the transitions between the three phases (pure CoOEP, 1–1, and pure coronene) were studied by variable temperature STM and by density functional theory (DFT). Adsorption energies for CoOEP and ...

A comparison of mathematical models for chemical transfer from soil to surface runoff with the impact of rain

Chemical transfer is considered as one of the main contributors to water pollution. Three physical based models (complete-, incomplete-mixing models and the equivalent model of convection) were refined and applied to describe the process of solute transport into runoff on loessial slope land. The effects of rain intensity, slope gradient and initial water content on solute transport was studied with simulated rain. Most parameters in the models can be measured directly, some parameters, for example, α (the solute concentration ratio between the infiltration and the effective mixing depth), β (the solute concentration ratio between the runoff and the effective mixing depth) and S (the soil adsorptivity) in the incomplete-mixing model were determined by curve fitting method based on the experimental data. And, hm (the effective mixing depth in the complete-mixing model), hm′ (the effective mixing depth in the incomplete mixing model) and H0 (the equivalent depth of transfer) can be expressed with a regression equation related to rain intensity, slope gradient and initial water content, respectively. Simulated results indicated that the three models are suitable to predict the amount of solute loss, and the refined equivalent model of convection fits solute transport process in runoff rather than the effective-mixing models on loessial plateau area. The complete-mixing model and the refined equivalent model of convection are convenient to use for simplified parameters, and the incomplete-mixing model was more appropriate for practical situations.

Enhanced oil recovery from fractured carbonate reservoir using membrane technology

Abstract Membrane technology has been investigated experimentally for enhanced oil recovery (EOR) in fractured rocks in this paper. Two membrane-forming material fluids, copper sulfate solution and potassium hexacyanoferrate solution, are sequentially injected into a fractured rock which was pre-saturated with mineral oil and irreducible water using a high solute fluid, to form a semi-permeable membrane over the surface of fractured rock. Then a low solute concentration fluid is injected into the rock to establish a chemical potential gradient across the membrane. As a result, water can enter the matrix across the membrane to increase the pore pressure and to displace additional oil from the matrix. Factors which influence osmotic pressure have been examined for their effect on oil recovery. It was found that the rate of oil recovery increases with increasing concentrations of membrane-forming materials, increasing temperature, and increasing solute concentration ratio between matrix water and injection solution, as well as decreasing permeability of the matrix rocks. Such correlation is attributed to the spontaneously occurrence of osmosis, leading to water entering the matrix and oil being displaced. The results are indicating that the membrane technology may be an effective EOR method for a fractured carbonate reservoir.

Experimental investigation of the effect of Zn/S molar ratios on the physical and electrochemical properties of ZnS thin films

ZnS thin films were deposited onto ITO-(glass) substrate by the electrodeposition process using an acidic solution, containing Zinc (II) acetate (Zn(CH3COOH)2) and sodium thiosulfate (Na2S2O3) as precursors. The depositions were carried out at the solution temperature of 80°C under an applied potential of −1300mV vs Ag/AgCl. The value of the concentration ratio in the plating solution of sulfur and zinc was varied between 0.1 and 1. The structural and morphological studies (XRD and AFM) show that the films obtained using Zn/S= 0.2 consist essentially of ZnS cubic phase and they exhibit the best crystallinity with a (200) preferential orientation. Moreover, the optical analysis via the transmittance and reflectance reveal that the band-gap energy Eg decreases slightly as a function of Zn/S composition (Eg varies from 3.75eV to 3.56eV). On the other hand, electrochemical impedance spectroscopy was employed for analyzing the capacitive nature of ZnS/Na2SO4 interface. From Mott–Schottky plot, the films obtained from the starting molar ratio of Zn/S= 0.2 exhibit n-type character with a flat band potential and a density of majority carrier of the order −0.46V and 3.2×1016cm−3, respectively.

IMS-MS and IMS-IMS investigation of the structure and stability of dimethylamine-sulfuric acid nanoclusters.

Recent studies of new particle formation events in the atmosphere suggest that nanoclusters (i.e, the species formed during the early stages of particle growth which are composed of 10(1)-10(3) molecules) may consist of amines and sulfuric acid. The physicochemical properties of sub-10 nm amine-sulfuric acid clusters are hence of interest. In this work, we measure the density, thermostability, and extent of water uptake of <8.5 nm effective diameter dimethylamine-sulfuric (DMAS) nanoclusters in the gas phase, produced via positive electrospray ionization. Specifically, we employ three systems to investigate DMAS properties: ion mobility spectrometry (IMS, with a parallel-plate differential mobility analyzer) is coupled with mass spectrometry to measure masses and collision cross sections for <100 kDa positively charged nanoclusters, two differential mobility analyzers in series (IMS-IMS) are used to examine thermostability, and finally a differential mobility analyzer coupled to an atmospheric pressure drift tube ion mobility spectrometer (also IMS-IMS) is used for water uptake measurements. IMS-MS measurements reveal that dry DMAS nanoclusters have densities of ∼1567 kg/m(3) near 300 K, independent of the ratio of dimethylamine to sulfuric acid originally present in the electrospray solution. IMS-IMS thermostability studies reveal that partial pressures of DMAS nanoclusters are dependent upon the electrospray solution concentration ratio, R = [H2SO4]/[(CH3)2NH]. Extrapolating measurements, we estimate that dry DMAS nanoclusters have surface vapor pressures of order 10(-4) Pa near 300 K, with the surface vapor pressure increasing with increasing values of R through most of the probed concentration range. This suggests that nanocluster surface vapor pressures are substantially enhanced by capillarity effects (the Kelvin effect). Meanwhile, IMS-IMS water uptake measurements show clearly that DMAS nanoclusters uptake water at relative humidities beyond 10% near 300 K, and that larger clusters uptake water to a larger extent. In total, our results suggest that dry DMAS nanoclusters (in the 5-8.5 nm size range in diameter) would not be stable under ambient conditions; however, DMAS nanoclusters would likely be hydrated in the ambient (in some cases above 20% water by mass), which could serve to reduce surface vapor pressures and stabilize them from dissociation.

Study of structural, electrical and photoconductive properties of F and P co-doped SnO2 transparent semiconducting thin film deposited by spray pyrolysis

Transparent conducting phosphorus–fluorine co-doped tin oxide (SnO2:(P, F)) thin films have been deposited onto preheated glass substrates using the spray pyrolysis technique by the various dopant quantity of spray solution. The [F/Sn] atomic concentration ratio (x) in the spray solution is kept at value of 0.7 and the [P/Sn] atomic ratio (y) varied at values of 0, 0.001, 0.005, 0.01, 0.02, 0.04, 0.06, and 0.10. The structural, morphological, X-ray diffraction, electrical, optical and photoconductive properties of these films have been studied. It is found that the films are polycrystalline in nature with a tetragonal crystal structure corresponding to SnO2 phase having orientation along the (110) plane and polyhedrons like grains appear in the FE-SEM image. The average grain size increases with increasing P-dopant concentration. The compositional analysis of FTO:P thin films were studied using EDAX. The Hall effect measurements have shown n-type conductivity in all deposited films. The lowest sheet resistance and highest the carrier concentration about 6.4Ω/□ and 7.4×1022, respectively, were obtained for the film deposited with y=[P/Sn]=0.01. The films deposited with y=0.04 phosphorus-doped SnO2:F shows 68% optical transparency. From the photoconductive studies, the P-doped films exhibited sensitivity to incident light especially in y=0.04. The electrical resistivity and carrier concentration vary in rang 6.2×10−4 to 21.1×10−4Ωcm and 7.4×1022 to 1.3×1022cm−3, respectively.

Processing and characterization of ZnO nanowire-grown PBO fibers with simultaneously enhanced interfacial and atomic oxygen resistance properties

The surface of poly(p-phenylene benzobisoxazole) (PBO) fibers was modified by Zinc oxide nanowires (ZnO NWs) using a mild hydrothermal method to enhance the interfacial properties of PBO fiber/epoxy composites. A functionalization technique was developed to improve the bonding between the PBO fiber and ZnO NWs and was validated by X-ray photoelectron spectroscopy (XPS). Energy dispersive spectrometry (EDS), X-ray diffractometry (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), atomic force microscopy (AFM), wettability testing and single fiber tensile testing were performed to characterize the hybrid fibers. The quantitative relationships between the process parameters (solution concentration ratio and growth time), structure and interfacial shear strength (IFSS) of ZnO NW-grown PBO fibers were systematically investigated. Moreover, the possible interfacial property enhancing reasons were explored. Experimental testing showed that the ZnO NWs interphase developed here offered a significant increase in the IFSS (increased by 50.7%) without degrading the base fiber. It was also shown for the first time that dense ZnO NWs could serve as barriers to protect the PBO fiber underneath from atomic oxygen (AO) erosion, which resulted in their potential applications.

Research on ration selection of mixed absorbent solution for membrane air-conditioning system

Absorption air-conditioning system is a good alternative to vapor compression system for developing low carbon society. To improve the performance of the traditional absorption system, the membrane air-conditioning system is configured and its COP can reach as high as 6. Mixed absorbents are potential for cost reduction of the membrane system while maintaining a high COP. On the purpose of finding ideal mixed absorbent groups, this paper makes analysis on COP, cost-effectiveness and economy of the membrane system with mixed LiBr–CaCl2 absorbent solution. The models of the system have been developed for the analysis. The results show the COP is higher for the absorbent groups with lower concentration of the total solute and higher concentration ratio of LiBr. It also reveals when the total solutes concentration is about 50%, it achieves the best cost-effectiveness and the economy. The process of the analysis provides a useful method for mixed absorbents selection.

Computer Simulations of the Formation of Bile Salt Micelles and Bile Salt/DPPC Mixed Micelles in Aqueous Solutions

Brownian dynamics simulations for a coarse-grained model have been performed to study the formation of micelles from bile salts and mixed micelles with dipalmitoyl-phosphatidylcholine (DPPC) in aqueous solutions. The particular association behavior of bile salts as facial surfactants was shown to be caused by their special molecular architecture with a hydrophilic and a hydrophobic side. The experimentally observed smooth transition into the micellar region with increasing concentration is reproduced. Micelle size distributions have been evaluated at different bile salt concentrations. Typical structures of pure bile salt micelles could be identified. The composition and the structure of mixed micelles have been studied in their dependence on the bile salt/lipid concentration ratio in the aqueous solution. We have found that the bile salt fraction in the mixed micelles increases considerably with increasing bile salt/lipid concentration ratio and decreasing micelle size. The structural and thermodynamic features of micelle formation in the aqueous bile salt solutions with DPPC, which we have studied with the coarse-grained model, are in good qualitative agreement with experimental findings.

Photochemically deposited and post annealed copper indium disulphide thin films

Copper indium disulfide (CIS) thin films were deposited using novel photochemical deposition (PCD) technique by selective deposition parameters. In this work CIS film deposition was made by cationic, anionic precursor solution concentration ratio 1:1:2. Na2EDTA was used as a chelating agent. The as deposited CIS films were post annealed at different temperatures up to 400°C in vacuum. The as deposited and annealed CIS films were examined to reveal the structural, optical, morphological, compositional and electrical properties by X-ray diffraction, Raman analysis, UV–Vis spectroscopy, Scanning Electron Microscopy, TEM, EDX and Hall effect respectively. From the XRD and Raman studies the Cu–Au ordering was confirmed both in as deposited and annealed films. The crystallite size increases with increasing of annealing temperature and the surface structuring shows rod like microstructure.

Tuning Physical and Optical Properties of ZnO Nanowire Arrays Grown on Cotton Fibers

This article reports the first systematic study on the quantitative relationship between the process parameters of solution concentration ratio, structure, and physical and optical properties of ZnO nanowires grown on cotton surfaces. To develop a fundamental understanding concerning the process-structure-activity relations, we grew a series of well-defined, radially oriented, highly dense, and uniform single-crystalline ZnO nanorods and nanoneedles on cotton surfaces by a simple and inexpensive two-step optimized hydrothermal process at a relatively low temperature. This process involves seed treatment of a cotton substrate with ZnO nanocrystals that will serve as the nucleation sites for subsequent anisotropic growth of single crystalline ZnO nanowires. All of the ZnO nanowires exhibit wurtzite crystal structure oriented along the c-axis. For investigating structure-controlled properties, seed-to-growth solutions concentrations ratio ([S]/[G]) of the synthesis process was varied over six different values. Superhydrophobicity was achieved for all morphologies after 1-dodecanethiol modification, which was highly durable after prolonged UV irradiation. Durability of the ZnO materials under laundry condition was also verified. Variation of the [S]/[G] ratio resulted in a morphological transform from nanorods to needle-like structures in conjunction with a drastic change in the physical and optical properties of the ZnO modified cotton surfaces. Higher [S]/[G] ratios yielded formation of ZnO nanoneedles with high degree of crystallinity and higher aspect ratio compared to nanorods. Increasing [S]/[G] ratio resulted in the amount of ZnO grown on the cotton surface to drop significantly, which also caused a decrease in the surface hydrophobicity and UV absorption. In addition, room temperature photoluminescence measurements revealed that the band gap of ZnO widened and the structural defects were reduced as the morphology changed from nanorods to nanoneedles. A similar trend was observed in the UV-vis absorption of nanorods and nanoneedles, the onset of the latter exhibiting a blue-shift that correlates with the widening of band gap with nanoneedle formation.

Nylon Fibers as Template for the Controlled Growth of Highly Oriented Single Crystalline ZnO Nanowires

This article reports the first controlled synthesis of large scale continuous arrays of single-crystalline ZnO nanowires with tunable size and properties on nylon fibers using a two-step low-temperature hydrothermal growth strategy. This process involves seed treatment of the substrate with ZnO nanocrystals that will form nucleation sites for subsequent epitaxial growth of single crystalline ZnO nanowires. Well-defined, vertically oriented, highly dense, and uniform ZnO nanowires of the wurtzite crystal structure covering the entirety of the fibers were achieved. In order to study the size and shape-dependent optical and electrochemical properties of the nanowires, the seed-to-growth solution concentration ratio was varied, resulting in hexagonal flat-ended (nanorods) and tapered (nanoneedles) morphologies. The amount of ZnO nanorods and nanoneedles grown on nylon fibers were determined as 30.1 ± 0.5% and 11.4 ± 0.7% ZnO by weight, respectively. In comparison to nanorods, ZnO nanoneedles demonstrated enhanced crystallinity, better orientation along the c-axis, and widened band gap. A similar trend was observed in the UV–vis absorption of nanorods and nanoneedles, the absorption-edge of the latter exhibiting a blue-shift that correlates with the widening of the band gap with nanoneedle formation. Moreover, the surface charge transport properties showed strong dependence on the ZnO morphology in which ZnO nanorods exhibited lower surface charge transfer resistance.

Fabrication of Silicon Nanowires by Electroless Etching for Thermoelectric Application

The fabrication procedure of silicon nanowire thermoelectric device has been developed based on the electroless etching method. Under a fixed etching solution concentration ratio and the etching reaction temperature, silicon nanowire arrays of different lengths manufactured at different etching time were investigated. The longer etching time results in the longer nanowire length. The silicon nanowire arrays were utilized to produce a silicon nanowire thermoelectric device. The I-V characteristics of the present SiNWs thermoelectric device were recorded under different heating temperatures, and the power outputs of silicon nanowire thermoelectric devices were calculated. The longer the silicon nanowire thermoelectric device lines, the greater the power output of thermoelectric device is. The SiNWs TED power output in the present study ranges from 1.62 to 7.2 nano-Watt with the chip size 2×2 cm2 while the applied temperature at 150 °C.

Ecophysiology of nickel phytoaccumulation: a simplified biophysical approach

Solute active transport or exclusion by plants can be identified by the values of the Transpiration Stream Concentration Factor (TSCF=xylem:solution solute concentration ratio). The aim of this study was to estimate this parameter for Ni uptake by the Ni-hyperaccumulator Leptoplax emarginata or the Ni-excluder Triticum aestivum cultivar 'Fidel'. The Intact Plant TSCF for nickel (IPTSCF(Ni)) was calculated as the ratio between the nickel mass accumulation in the leaves and the nickel concentration in solution per volume of water transpired. Predominantly, Ni active transport occurred for L. emarginata, with IPTSCF(Ni) values of 4.7-7.2 and convective component proportions of the root Ni uptake flow of only 15-20% for a range of Ni concentrations in solutions of 2-16 µmol Ni l(-1), regardless of the growth period and the time of Ni uptake. Hyperaccumulator roots were permeable to both water and nickel (mean reflection coefficient for Ni, σ(Ni), of 0.06), which was mainly attributed to an absence of exodermis. Results provide a new view of the mechanisms of Ni hyperaccumulation. By contrast, the wheat excluder was characterized by an extremely low mean IPTSCF(Ni) value of 0.006, characterizing a predominantly Ni sequestration in roots. From a methodological viewpoint, the 'microscopic' TSCF(Ni), measured directly on excised plants was 2.4 times larger than its recommended 'macroscopic' IPTSCF(Ni) counterpart. Overall, IPTSCF and σ determined on intact transpiring plants appeared to be very useful biophysical parameters in the study of the mechanisms involved in metal uptake and accumulation by plants, and in their modelling.

Synthesis and Characterization of Biocompatible Poly(ethylene glycol)-b-Poly(L-lactide) and Study on Their Electrospun Scaffolds

A series of multiblock copolymer, Poly(L-lactide)-b-Poly(ethylene glycol) (PLLA-b-PEG) were synthesized and characterized by Fourier transform infrared spectra, differential scanning calorimetry and wide angle X-ray diffraction. PLLA-b-PEG fibrous scaffolds were prepared by electrospinning. The morphology of the fibers was affected by the solution concentration and different weight ratio of PLLA/PEG. In comparison with the electrospun PLLA membrane, the electrospun fibrous membranes of PLLA-b-PEG demonstrated an enhanced water absorption percentage and reductive water contact angle. The electrospun PLLA-b-PEG with weight ratio 90/10 and 75/25 fibrous membranes exhibited good flexibility and deformability to be beneficial for tissue engineering scaffolds.