Zinc oxide–soluble starch nanocomposites (nano-ZnO) synthesized using water as a solvent and soluble starch as a stabilizer is impregnated onto cotton fabrics to impart antibacterial and UV-protection functions. Nano-ZnO synthesized by reacting zinc nitrate with sodium hydroxide in the presence of soluble starch absorbed strongly at 361 nm due to the quantum confinement effect. The average size of ZnO nanoparticles is estimated to be 38 ± 3 nm using a transmission electron microscope (TEM); this was confirmed by x-ray diffraction analysis and the effective mass approximation method. The starch content in synthesized nano-ZnO was estimated to be 37.57% using thermo-gravimetric analysis. The nano-ZnO impregnated cotton fabrics showed excellent antibacterial activity against two representative bacteria, Staphylococcus aureus (Gram positive) and Klebsiella pneumoniae (Gram negative). Also, nano-ZnO impregnation enhanced the protection of cotton fabrics against UV radiation in comparison with the untreated cotton fabrics.

We show that the hybrids of single-layer graphene oxide with manganese ferrite magnetic nanoparticles have the best adsorption properties for efficient removal of Pb(II), As(III), and As(V) from contaminated water. The nanohybrids prepared by coprecipitation technique were characterized using atomic force and scanning electron microscopies, Fourier transformed infrared spectroscopy, Raman spectroscopy, X-ray diffraction, and surface area measurements. Magnetic character of the nanohybrids was ascertained by a vibrating sample magnetometer. Batch experiments were carried out to quantify the adsorption kinetics and adsorption capacities of the nanohybrids and compared with the bare nanoparticles of MnFe2O4. The adsorption data from our experiments fit the Langmuir isotherm, yielding the maximum adsorption capacity higher than the reported values so far. Temperature-dependent adsorption studies have been done to estimate the free energy and enthalpy of adsorption. Reusability, ease of magnetic separation, high removal efficiency, high surface area, and fast kinetics make these nanohybrids very attractive candidates for low-cost adsorbents for the effective coremoval of heavy metals from contaminated water.

A study to analyse beam damage, image quality and edge contrast in the helium ion microscope (HIM) has been undertaken. The sample investigated was graphene. Raman spectroscopy was used to quantify the disorder that can be introduced into the graphene as a function of helium ion dose. The effects of the dose on both freestanding and supported graphene were compared. These doses were then correlated directly to image quality by imaging graphene flakes at high magnification. It was found that a high magnification image with a good signal to noise ratio will introduce very significant sample damage. A safe imaging dose of the order of 10 13 He + cm −2 was established, with both graphene samples becoming highly defective at doses over 5 × 10 14 He + cm −2 . The edge contrast of a freestanding graphene flake imaged in the HIM was then compared with the contrast of the same flake observed in a scanning electron microscope and a transmission electron microscope. Very strong edge sensitivity was observed in the HIM. This enhanced edge sensitivity over the other techniques investigated makes the HIM a powerful nanoscale dimensional metrology tool, with the capability of both fabricating and imaging features with sub-nanometre resolution.

Gold nanoparticles (GNPs) have gained keen interest among researchers in recent years due to their excellent physiochemical properties. In general, GNPs are biocompatible, amenable to desired functionalization, non-corroding, and exhibit...

The influence of growth regulators and nitrogenous compounds on in vitro bulblet formation and growth was studied in two hybrids of <i>Lilium</i>. Bulbscales isolated from pre-cooled bulbs of hybrids Rosato and Marco Polo were used. The basal portion with plate (5 &times; 6 mm) of inner bulbscales was cultured on Murashige and Skoog (MS) medium containing 0.5 or 1 mg/dm³ naphthaleneacetic acid (NAA) and/or benzyladenine (BA). The presence of NAA (0.5 mg per dm³) showed higher explant regeneration, producing about three bulblets per explant as compared to control. About four bulblets per explant were produced at both concentrations of BA. The bulblets with significantly higher fresh weight were obtained on medium containing NAA. Approximately a three-fold increase of bulblet fresh weight was observed with all the concentrations of TDZ in both cultivars. The bulblets cultured with nitrogenous compounds after attaining the size of 14&minus;16 cm flowered during the second year of the growing period without any phenotypic variations.

Gerbera has gained popularity in the past few years in many countries of the world and it is in great demand in the floral industry as cut flower as well as potted plant due to its beauty, colour, long vase life, and ability to rehydrate after long transportation. The most commercial cultivars are propagated through vegetative means by multiplication through divisions of clumps; however, the multiplication by this method is too slow to be commercially viable. To commercialize this crop and to meet the growing demand for planting material, tissue and organ culture techniques are being used as alternative methods for propagation in many countries. Most of the work has been carried on plant regeneration by adventitious organogenesis from capitulum, shoot tip, leaf, petiole and other parts of the plant. Attention should be paid to improve the technology to achieve 100% success in all species/cultivars to meet growing demands of the growers globally. From the literature, it is evident that gerberas are highly amenable to in vitro studies, as various explants were found to favourably respond to different culture media with different types and concentrations of growth regulators.

Epoxy resins have been extensively utilized for mechanical strength applications in the field of aerospace, automobiles, marine, defence, etc. Improving the strength as well as fracture behaviour of the light weight materials is challenging. Present work is an attempt to enhance elastic modulus, hardness and fracture resistance simultaneously by reinforcing the epoxy (bisphenol-A) matrix with a new-age two-dimensional atomically thin graphene oxide filler. Wet chemical oxidation method was used to prepare graphene oxide sheets. Morphological study of the synthesized graphene oxide was carried out using scanning electron microscopy. Fourier-transformed infrared, ultraviolet–visible and Raman spectroscopic techniques were also employed to ascertain the synthesis of graphene oxide. The results confirmed the synthesis of well oxidized graphene oxide sheets. The prepared graphene oxide sheets were then sonicated in acetone solution to ensure better dispersion in the bisphenol-A graphene oxide nano-composite using 0.25, 0.5, 1.0 and 1.5 wt.% graphene oxide reinforcement. Solution mixing method was used to synthesize the polymer nano-composite. Scanning electron microscopy results revealed the smooth dispersion of graphene oxide in the bisphenol-A matrix. Nano-indentation of the bisphenol-A graphene oxide nano-composite showed a considerable jump in elastic modulus at 1 wt.% and hardness at 0.50 wt.% of graphene oxide reinforcement. Fracture resistance of bisphenol-A graphene oxide composite as represented by ratio of elastic modulus to hardness was enhanced by 24% as compared to the pristine bisphenol-A. Our results demonstrate a promising way to improve the mechanical characteristics of epoxy resins through graphene oxide reinforcement at low weight percentages.

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