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Objective To compare foot posture, plantar sensation, plantar fascia thickness, intrinsic foot muscle performance, and abductor hallucis morphology in individuals with and without plantar heel pain (PHP). Design Cross-Sectional. Setting Laboratory. Participants Sixteen individuals with PHP and sixteen matched healthy participants. Main outcome measures Static foot posture, plantar sensation, plantar fascia thickness, intrinsic foot muscle performance and abductor hallucis morphology were evaluated. Foot posture was assessed with the Foot Posture Index-6. Abductor hallucis morphology and plantar fascia thickness were measured utilizing diagnostic ultrasound. Plantar foot sensation was assessed at the head of the first metatarsal and medial longitudinal arch using Semmes-Weinstein Monofilaments. Intrinsic foot muscle performance was assessed using the intrinsic foot muscle test (IFMT). Mann-Whitney U and independent t-tests were used to examine between group differences. Results Individuals with PHP exhibited a more pronated foot posture and greater plantar fascia thickness at the proximal insertion compared to healthy controls. Plantar sensation thresholds were higher in the PHP compared to healthy controls at the head of the first metatarsal. There were no group differences in abductor hallucis morphology or IFMT performance. Conclusions Individuals with PHP exhibited a more pronated foot posture, thicker plantar fascia, and diminished plantar tactile sensation.

A methylimidazolium ionic-liquid-functionalized graphene oxide (mimGO) sponge was prepared by facile amidation reaction followed by freeze-drying. Covalent functionalization of graphene oxide (GO) was confirmed by SEM, XRD, XPS, FT-IR, Raman and TGA. The mimGO sponge was employed to remove direct red 80 (DR80) dye from aqueous solutions. Results showed exceptional affinity for adsorption of azo dye direct red 80 (DR80) due to the charge-induced adsorption aided by protonated amine and cationic methylimidazolium ionic liquid pendant groups. Detailed adsorption characteristics of mimGO sponge including operational parameters, adsorption kinetics and adsorption isotherms were investigated. Adsorption on the mimGO sponge followed pseudo-second-order kinetic model, and the equilibrium capacity was described by the Langmuir adsorption model. An ultrahigh adsorption rate of 588.2 mg/(g·min) and equilibrium adsorption capacity of 501.3 mg/g for DR80 were observed for the mimGO sponge, which is much higher than th...

Oil pollution in water and separation of oil from water are receiving much attention in recent years due to the growing environmental concerns. Membrane technology is one of the emerging solutions for oil-water separation. However, there is a limitation in using polymeric membrane for oil water separation due to its surface properties (wetting behaviour), thermal and mechanical properties. Here, we have shown a simple method to increase the hydrophilicity of the polyethersulfone (PES) hollow fibre ultrafiltration (UF) membrane by using carboxyl, hydroxyl and amine modified graphene attached poly acrylonitrile-co-maleimide (G-PANCMI). The prepared membranes were characterized for its morphology, water and oil contact angle, liquid entry pressure of oil (LEPoil), water permeability and finally subjected to a continuous 8 h filtration test of oil emulsion in water. The experimental data indicates that the G-PANCMI play an important role in enhancing the hydrophilicity, permeability and selectivity of the PES membrane. The water contact angle (CAw) of the PES membrane is reduced from 63.7 ± 3.8° to 22.6 ± 2.5° which is 64.5% reduction while, the oil contact angle was increased from 43.6 ± 3.5° to 112.5 ± 3.2° which is 158% higher compared to that of the PES membrane. Similarly, the LEPoil increased 350% from 50 ± 10 kPa of the control PES membrane to 175 ± 25 kPa of PES-G-PANCMI membrane. More importantly, the water permeability increased by 43% with >99% selectivity. Based on our findings we believe that the development of PES-G-PANCMI membrane will open up a solution for successful oil-water separation.

Carbon nanomaterials such as graphene and its derivatives based membranes in real applications are still far from reality due to their hydrophobic nature and limitations in their fabrication process. Here, we have devised a simple and feasible fabrication method to bring the high end nanocarbon based material to real downstream applications. In order to achieve this objective, the wettability of graphene was initially increased to an ultra-wetting level by incorporating amine and carboxyl functionality onto the graphene. The amine and carboxylated graphene is then covalently attached to a polymer matrix to fabricate a water filtration membrane. The characterization of the modified supported graphene-based membrane indicates that significantly higher hydrophilicity than previously expected is achieved, with the water contact angle reduced to zero. The ultra-wetting graphene increases the water permeability of the membrane by 126% without any changes in the selectivity. Based on our findings, we conclude that the ultra-wetting graphene will be an ideal material for new generation water filtration membranes.

Hydrophobic surface modifying macromolecules (SMM) and pore forming poly(vinyl pyrrolidone) (PVP) were added to fabricate poly(vinylidene fluoride) (PVDF)-PVP-hydrophobic SMM composite membranes through the phase inversion process. The composite PVDF-SMM nano-fibers membranes were also fabricated. The SMM was characterized in details by nuclear magnetic resonance spectroscopy. The membranes were characterized using the contact angle, liquid entry pressure of water, scanning electron microscopy, and porometry measurements. Both cast and nanofiber membranes were tested by direct contact membrane distillation (DCMD) with feed 3.5 wt% NaCl solution. Finally, the membrane performance of cast and nanofiber membranes was compared. The prepared hydrophobic SMM modified PVDF electro-spun nano-fibers membranes when combined with the casted membranes are very promising in DCMD for sea water desalination after running for 48 h operational timeframe.

In this study, functional modification of PES hollow fiber membrane has been carried out by incorporating highly hydrophilic polyethylene glycol (PEG) and silver nanoparticles (Ag) through thermal grafting. Poly(acrylonitrile-comaleic acid) (PANCMA) was used as a linker to chemically attach PEG and silver to PES hollow fiber membrane. The successful functional modification of PES membrane was confirmed using different analytical techniques such as, Fourier transform infrared (FTIR) spectroscopy, Energy-Dispersive X-ray (EDX) studies, water contact angle (CA), Fourier Emission Scanning Electron Microscopy (FESEM), and the porometer. Further, the membranes were tested for the pure water flux and antifouling properties. From the contact angle data, it was identified that the new surface modification can increase the membrane hydophilicity. The water contact angle of the PES UF membrane can be reduced by around 75.5% from 62.6±3.7° to 15.3±1.2° and the pure water flux increased by about 36% from 513LMH to 702LMH for the modified membrane. Antibacterial activity of the modified membranes was confirmed by the clear zone obtained in the zone of inhibition test. Based on the experimental data, the prepared modified UF membranes seem promising for wastewater filtration.

Conventional membrane distillation (MD) membranes typically consist of two layers i.e. a support layer and a microporous hydrophobic layer that is usually casted onto the support layer. In this paper a triple layer configuration, consisting of a thin hydrophobic nanofiber layer over the conventional casted microporous layer in addition to the support layer is prepared. The layers are bound to each other by heat pressing and solvent binding. The unique membrane was characterized using the measurement of the liquid entry pressure of water (LEPw), scanning electron microscopy (SEM), pore size, mat thickness and the surface water contact angle (CA). The triple layer membranes, conventional dual layer membranes and nanofiber only membranes were tested in an Air-Gap Membrane Distillation (AGMD) process using a feed solution containing 3.5 wt.% NaCl. The water contact angle of the nanofiber selective layer, middle micro porous layer and the hydrophilic supportive layers are approximately 145°, 92° and 30° respectively. The LEPw of the triple layer composite membrane was found to be 1.6 times higher than the conventional dual layer membrane (i.e. without the nanofiber selective layer) and more than 8.7 times higher than that of the nanofiber membrane. The fabricated triple layer composite membranes were tested in an AGMD process and the flux was also found to be 1.5 times higher than that for the dual layer membrane (i.e. without nanofiber selective layer). In terms of salt penetration, the triple layer membrane had the lowest salt penetration ⩽0.02% at different feed water temperatures, while the salt penetration of the dual layer membrane was higher at ⩽0.07% and increased with increasing feed water temperature. The nanofiber only membrane’s salt penetration increased dramatically to more than 90% within the first few minutes of filtration indicating severe pore wetting. The triple layer membrane could be operated continuously for more than 40 h without any significant change to permeate quality, whereas the dual layer membrane could only be operated for 10 h before pore wetting occurred. Based on the results it is proposed that the triple layer configuration with nanofiber based selective layer above the conventional dual layer could be a promising membrane for membrane distillation.

Electrospun nanofiber membranes consisting of poly(vinylidene fluoride) (PVDF) blended with clay nanocomposites were prepared and tested in this paper for direct contact membrane distillation (DCMD) applications. Various compositions of PVDF–clay nanocomposite nanofiber membranes (NNMs) were prepared and characterized by water contact angle, Fourier transform infrared spectroscopy, differential scanning calorimetry, scanning electron microscopy and investigated for DCMD. The incorporation of clay nanocomposites increase the hydrophobicity of the membranes, which increase as the concentration of clay nanocomposite increases in the mixture. The highest water contact angle achieved was 154.20 ± 3.04°. The melting point of the PVDF–clay electrospun nanofiber membrane increases with the increasing concentration of clay indicating that the clay particles influence the crystallization process of the nanocomposite membrane. The PVDF–clay NNMs showed improved performance in DCMD applications and provide a way to prevent pore wetting in DCMD process.

Bio-fouling is a serious problem in many membrane-based separation processes for water and wastewater treatment. Current state of the art methods to overcome this are to modify the membranes with either hydrophilic additives or with an antibacterial compound. In this study, we propose and practise a novel concept to prevent bio-fouling by developing a killing and self-cleaning membrane surface incorporating antibacterial silver nanoparticles and highly hydrophilic negatively charged carboxylic and amine functional groups. The innovative surface chemistry helps to reduce the contact angle of the novel membrane by at least a 48% and increase the pure water flux by 39.4% compared to the control membrane. The flux drop for the novel membrane is also lower (16.3% of the initial flux) than the control membrane (55.3% of the initial flux) during the long term experiments with protein solution. Moreover, the novel membrane continues to exhibit inhibition to microbes even after 1320 min of protein filtration. Synthesis of self-cleaning ultrafiltration membrane with long lasting properties opens up a viable solution for bio-fouling in ultrafiltration application for wastewater purification.

The innovative design and synthesis of nanofiber based hydro-philic/phobic membranes with a thin hydro-phobic nanofiber layer on the top and a thin hydrophilic nanofiber layer on the bottom of the conventional casted micro-porous layer which opens up a solution for membrane pore wetting and improves the pure water flux in membrane distillation.