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Natural rubber (NR) latex gloves are widely used as a very important barrier for healthcare workers. However, they can still be perforated easily by sharp devices and instruments. The aim of this study was to investigate the effect of the addition of graphene oxide (GO) to low-ammonia NR latex on its puncture resistance, mechanical properties and thermal stability. GO was synthesized using modified Hummers’ reaction. The produced GO was mixed into the NR latex solution at various doses (0.01-1.0 wt. %), followed by a coagulant dipping process using ceramic plates to produce film samples. Puncture resistance was enhanced by 12% with 1.0 wt. % GO/NR. Also, the incorporation of GO improved the stress at 300% and 500%, the modulus at 300% and 500% and the tear strength of low-ammonia NR latex films.

In this work, a scalable method was developed to produce graphene oxide (GO) via high-shearing of pre-oxidized graphite. Various oxidation states of pre-oxidized graphite were obtained following different oxidation periods through a modified Hummers’ method. The oxidized graphite flakes were investigated by X-ray diffractometry, Fourier transform infrared spectroscopy, and Raman spectroscopy. Instead of a prolonged oxidation period of more than 24 hours, the graphite sample that underwent 6 hours of oxidation was selected for the high-shearing process to obtain exfoliated GO. The transmission electron microscopy and atomic force microscopy results confirmed that large-area and single-layer GO can be produced by the high-shear exfoliation method with pre-oxidized graphite flakes. This modified procedure enables the remarkably simple, fast, and effective production of high-quality GO.

The present study describes the preparation of CaCO3-loaded cellulose aerogel and evaluation of its adsorptive removal of Congo Red (CR) from aqueous solution. The CaCO3-cellulose aerogel was produced via in situ precipitation of CaCO3 into as-prepared cellulose aerogel, which was prepared by freeze-drying a crosslinked cellulose solution that was dissolved using a NaOH/urea solution. The particles that formed in the aerogel were confirmed to be calcite CaCO3. Adsorption studies illustrated that the CR uptake by the aerogel was dependent on the dye concentration and temperature. Incorporation of CaCO3 into the cellulose aerogel significantly enhanced the adsorption capacity of the aerogel toward CR. The maximum adsorption capacity of the CaCO3-cellulose aerogel was approximately 75.81 mg/g.

The present study describes the evaluation of vaterite calcium carbonate (CaCO3) for the adsorption of Congo red (CR) from aqueous solution. Vaterite CaCO3 is produced via a precipitation method assisted by ethylene glycol (EG), which acts as stabilizer to prevent transformation of vaterite to others polymorphs of CaCO3. The crystal structure of vaterite CaCO3 formed was proven by SEM, XRD and FTIR. The highest zeta potential of the vaterite CaCO3 was 15.2 mV, which was obtained at pH 5. Batch adsorption studies illustrated that the adsorption of CR to the vaterite CaCO3 was dependent on different parameters, such as pH, initial dye concentration and temperature. The adsorption isotherm data were highly consistent with Langmuir isotherm model, while the adsorption kinetics data fitted better to the pseudo-second-order model. The maximum adsorption capacity of the CaCO3, 32.60 mg/g, was obtained from the adsorption kinetic experiment under adsorption conditions, pH 5, adsorbent dose 0.2 g, adsorbate concentration 100 mg/L and temperature 25 °C. The adsorption of CR on the CaCO3 was proven to be endothermic and non-spontaneous in nature.