In recent years, we are having mixed feelings regarding the use of polyethylene terephthalate (PET) bottles for storing water. The aim of this study is to determine any associations between bacterial load and the physical condition of the water bottle. For this study, bottled water was purchased, and parameters like pH, electrical conductivity (EC), total dissolved solids (TDS), heterotrophic plate count (HPC), total coliform count, and Pseudomonas spp. count were determined as per the American Public Health Association, 2005. The pH value of water samples tested ranged from 5.2 to 6.8. The majority of samples (96%) were found to contain pH values that were unacceptable as per the Department of Food Technology and Quality Control (DFTQC) guideline. Value of electrical conductivity (EC) ranged from 5 to 199 μS/cm. HPC revealed that, out of 100 samples, 48 (48%) samples were found to be acceptable as per the DFTQC guideline value (<25 cfu/mL). Among 100 samples, Pseudomonas spp. was found to be present in 23% of bottled water. Acidic pH and elevated concentrations of TDS and EC may lead to the survival of extremophiles present in HPC which may lead to degradation of PET. Extremophile bacteria that survive in bottled water for a long time rely on several survival mechanisms including evolutionary development (evo-devo) and solely survive on complex polymers like PET.

The systematic chemical modification of cyclodextrins (CDs) provides an opportunity to create new substances with novel phase transfer, guest–host, solubility, and network properties. Such materials have several potential applications in polymer science, including free‐volume modifiers, stabilizers or compatibilizers, and scaffolds or templates for synthesizing new materials. In this study, we describe simple, inexpensive, and easy purification one‐pot methods to selectively functionalize CD rings with short‐ and long‐chain alkyl derivatives of varying polarity. Using bifunctional reagents in the same reaction scheme yields CD‐based polymer networks. Particular attention is devoted to solution and solid‐state NMR experiments that reveal the type and extent of functionalization, which may be used to control solubility and swelling. Alkyl chain functionalization may be expressed as the average number of CH2 units attached per CD ring, the magnitude of which can reach at least 16 and the product still be water soluble, but products become insoluble in water at a value of 32. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012

A modular approach for the synthesis of polymer networks with well-defined node and cross-linking dimensions is described. Each node or tie point in the network is a cyclodextrin molecule, which imparts discrete molecular guest–host capabilities to the network. C60 fullerenes homogeneously intercalate in the network, presumably via van der Waals guest–host interactions with the hydrophobic γ-cyclodextrin cavity, resulting in stable C60-filled polymer networks with improved mechanical properties. Networks prepared with α-cyclodextrin, whose inner cavity is smaller than γ-cyclodextrin, and smaller than the C60 diameter, do not yield materials with stable C60 intercalation. Characterization of the final composites reveals that the cross-linked γ-cyclodextrin-based composites maintain stable C60 concentrations, even after multiple extractions with toluene, which itself is a good solvent for C60. Membranes prepared from the cyclodextrin polymer network, prior to C60 intercalation, should also be useful for C60 extraction from C60–solvent mixtures. The synthetic route we describe here is not limited to C60 and should be generally applicable to a wide variety of guests.

No abstract

No abstract