No abstract

Broad‐spectrum antiviral agents targeting viral RNA‐dependent RNA polymerase (RdRp) are expected to be a key therapeutic strategy in the ongoing coronavirus disease 2019 (COVID‐19) pandemic and its future variants of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), the virus that causes COVID‐19. Molnupiravir is a nucleoside analog that in vivo experiments have been reported to inhibit the replication of SARS‐CoV‐2, the virus that causes COVID‐19. Clinical trials of molnupiravir as a therapy for patients with mild‐to‐moderate COVID‐19 also suggest its significant therapeutic efficacy in comparison to placebo. Molnupiravir is lethally mutagenic against viral RNA, but its effect on host cell DNA is being questioned. Herein, the safety concerns of molnupiravir are discussed with recent findings from published reports and clinical trials. The unchanged efficacy of molnupiravir against mutated SARS‐CoV‐2 variants is also highlighted. With its administration via the oral route, molnupiravir is expected to turn the tide of the COVID‐19 pandemic.

This research offers a novel approach of free chemical preparation to obtain algae-based biopolyol through a ball milling method. The algae-based polyurethane (AlgPU) film was obtained from a casting solution made of ball-milled algal polyol particle and methylene diphenyl diisocyanate (MDI). The characteristics of the material had been investigated using Fourier Transform Infrared, Scanning Electron Microscopy – Electron Dispersive Spectroscopy, Differential Scanning Calorimetry, and Tensile Strength Analysis. The surface area was determined by Brunauer–Emmett–Teller (BET) isotherm, meanwhile the total pore volume was by Barrett-Joyner-Halenda (BJH) isotherm, based on the adsorption-desorption of N 2 . The addition of activated carbon contributed in the increase of functional group and surface area, which were important for the NH 3 –N removal. As a result, the adsorption capacity increased greatly after the addition of activated carbon (from 187.84 to 393.43 μg/g). The results also suggested AlgPU as a good matrix for immobilizing activated carbon filler. The adsorption shows a better fit with Langmuir isotherm model, with R 2 = 0.97487 and root-mean-square error (RMSE) = 33.91952, compared to Freundlich isotherm model (R 2 = 0.96477 and RMSE = 44.05388). This means the NH 3 –N adsorption followed the assumption of homogenous and monolayer adsorption, in which the maximum adsorption was found to be 797.95 μg/g. This research suggests the potential of newly developed material for NH 3 –N removal.

Global pollution from toxic metal waste has resulted in increased research on toxic metal adsorption. A cellulose acetate–polyurethane (CA–PU) film adsorbent was successfully prepared in this research. The cellulose acetate–polyurethane film adsorbent was prepared with a polycondensation reaction between cellulose acetate and methylene diphenyl diisocyanate. The CA–PU bond formation was confirmed by functional group analysis obtained from Fourier transform infrared (FTIR) spectroscopy. The obtained film was characterized for improved tensile and thermal properties with the addition of methylene diphenyl diisocyanate (MDI). The adsorption ability of the obtained film was evaluated with laser-induced breakdown spectroscopy (LIBS). The best film adsorbent from the LIBS was selected and studied for adsorption isotherm. The FTIR analysis confirmed the formation of the CA–PU bond from the polycondensation between cellulose acetate and the methylene diphenyl diisocyanate. The result showed that the addition of methylene diphenyl diisocyanate (MDI) resulted in the urethane network’s growth. The characterization result showed an improvement in the morphology, thermal stability, and tensile strength of the film. The LIBS studies showed improvement in the adsorption of Pb2+ with CA–PU compared with the neat CA. The isotherm studies revealed that Pb2+ adsorption by cellulose acetate–polyurethane film adsorbent was heterogeneously dependent on the Freundlich isotherm model (R2 = 0.97044). Overall, the polycondensation method proposed by this study enhanced the Pb2+ removal, and was comparable to those reported in previous studies.

The use of polymeric material in heavy metal removal from wastewater is trending. Heavy metal removal from wastewater of the industrial process is of utmost importance in green/sustainable manufacturing. Production of absorbent materials from a natural source for industrial wastewater has been on the increase. In this research, polyurethane foam (PUF), an adsorbent used by industries to adsorb heavy metal from wastewater, was prepared from a renewable source. Castor oil-based polyurethane foam (COPUF) was produced and modified for improved adsorption performance using fillers, analyzed with laser-induced breakdown spectroscopy (LIBS). The fillers (zeolite, bentonite, and activated carbon) were added to the COPUF matrix allowing the modification on its surface morphology and charge. The materials were characterized using Fourier-transform infrared (FTIR), scanning electron microscopy (SEM), and thermal gravimetry analysis (TGA), while their adsorption performance was studied by comparing the LIBS spectra. The bentonite-modified COPUF (B/COPUF) gave the highest value of the normalized Pb I (405.7 nm) line intensity (2.3), followed by zeolite-modified COPUF (Z/COPUF) (1.9), and activated carbon-modified COPUF (AC/COPUF) (0.2), which indicates the adsorption performance of Pb2+ on the respective materials. The heavy metal ions’ adsorption on the B/COPUF dominantly resulted from the electrostatic attraction. This study demonstrated the potential use of B/COPUF in adsorption and LIBS quantitative analysis of aqueous heavy metal ions.