Pervaporation separation of chlorinated hydrocarbon/acetone mixtures has been investigated using nanoclay modified poly(ethylene-co-vinyl acetate) films. The results have been compared with the unfilled poly(ethylene-co-vinyl acetate) films. The nanoclay modified membranes were characterized by X-ray diffraction technique. The dispersion of layered silicates in the polymer matrix was analyzed using transmission electron microscopy. The nanoclay showed excellent dispersion in the polymer matrix. The effect of free volume on the pervaporation performance was investigated by positron annihilation lifetime spectroscopy. Poly(ethylene-co-vinyl acetate) nanocomposite membrane showed high selectivity because of the plateletlike morphology and high aspect ratio of layered silicates. The nano clay content and the swelling effects on pervaporation performance of nano composite membranes have been investigated in detail.

Purpose: Ocular morbidities like high refractive error, strabismus, and amblyopia are common among laser-treated retinopathy of prematurity children (ROP). Long-term optical status and refractive outcomes including the sensory outcomes were less investigated in these children from this region. The purpose of our study is to evaluate the long-term outcome (refractive, biometric profile, sensory) of treatment for ROP using laser. Methods: This study is a retrospective, cross-sectional, observational, and intervention research among 6–15-year-old children who underwent laser for ROP with a minimum of 6-year follow-up. Results: Eighty lasered eyes of 41 children were assessed. Mean age was 9.71 years (±3.39). Seventy-three eyes (91.2%) achieved visual acuity better than 20/40. The mean visual acuity in LogMAR was 0.18 (20/30). The mean spherical equivalence was −5.29 D ± 4.9. Mean astigmatism measured was −1.53 DC (range: +0.50 DC to −4.5DC). Fifty-three eyes (66.25%) had significant astigmatism. The mean axial length was 23.5 ± 1.35 (21–26) mm. Mean lens thickness was 3.76 ± 0.30 (3.03–4.34) mm. Correlation analysis among the low and high spherical equivalent group signified that axial length ( P value = 0.001), visual acuity ( P value = 0.0002), and myopic shift ( P value = 0.0006) were found to be statistically significant. Stereopsis better than 480 s of arc for near was observed in 41% children. Structural posterior pole sequelae developed in 3 eyes (3.75%). Conclusion: A significant number of children with high myopia, astigmatism, and strabismus had satisfactory visual outcome observed at long-term follow-up after treatment for ROP using laser. Our study revealed that myopia was influenced by an increase in axial length than the lens thickness.

Phenol-formaldehyde resin is an inevitable polymer material because of their excellent properties like heat resistance, chemical resistance, creep resistance, and low water sorption. But the drawback associated with PF matrix is buckling and brittleness. The incorporation of nanofillers can effectively reduce these problems. Carbon nanotubes is one among the nanofiller which is widely used to enhance the mechanical, thermal, electrical properties of the host matrix.The present study deals with the synthesis and comparison of two Phenol-formaldehyde nanocomposites incorporated with pristine multiwalled carbon nanotubes and carboxylated multiwalled carbon nanotubes via in-situ polymerisation technique. The effect of filler loading (MWCNT, MWCNT-COOH) with different weight percentages (0.05 wt%, 0.08 wt%, 0.12 wt%, 0.15 wt%) has been investigated in this study. Pristine MWCNT was functionalised with carboxyl groups and confirmed by XRD, FT-IR, CHN analysis, X-ray photoelectron spectroscopy, AFM and Raman spectra. All these analysis showed successful funtionalisation of pure MWCNT. The prepared nanocomposites were compared by mechanical, thermal and morphological analysis. The effect of both fillers on tensile strength, stress-strain, young’s modulus and elongation at break were also analysed. The addition of MWCNT and MWCNT-COOH have enhanced the mechanical and thermal properties of the prepared nanocomposite. The mechanical properties of PF-MWCNT nanocomposite showed a maxima for 0.12 wt% and for PF-MWCNTCOOH nanocomposite it was 0.08 wt%. Higher thermal stability was exhibited for 0.15 wt% MWCNT loading. The thermal stability enhanced by the addition of MWCNT COOH upto 0.12 wt% and then declined. Moreover the prepared nanocomposites were morphologically characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM) and from the fracture analysis it is clear that the reinforcements brought plastic deformation of phenol-formaldehyde nanocomposite from brittle to more ductile material. From the TEM image it was clear that the presence of carboxyl groups attached on MWCNT reduced agglomeration in PF matrix. Halpin-Tsai modelling was done for comparing experimental and theoretical values of tensile modulus and it illustrates good correlation.

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