Search results for " polymers"
showing 10 items of 465 documents
Synthesis, Structural Analysis, Fiber Formation and Preliminary Anticancer Characterization of the Organotin Polyether from Dibutyltin Dichloride and…
2012
The organotin polyether derived from reaction of dibutyltin dichloride and 2,5-dimethyl-3-hexyne-2,5-diol was rapidly synthesized employing classical interfacial polymerization in 65% yield and a chain length of 360 units. IR results are consistent with the polyether structure. Bands characteristic of the formation of the Sn-O are present and bands characteristic of the Sn-Cl are absent. F MALDI MS results in the low mass range gives ion fragment clusters to five units. Isotopic abundance matches for tin are consistent with its presence in these ion fragment clusters. In the high mass range ion fragment clusters to greater than 300 units are found. The products offer outstanding inhibition …
Durability of Biodegradable Polymer Nanocomposites
2021
Biodegradable polymers (BP) are often regarded as the materials of the future, which address the rising environmental concerns. The advancement of biorefineries and sustainable technologies has yielded various BP with excellent properties comparable to commodity plastics. Water resistance, high dimensional stability, processability and excellent physicochemical properties limit the reviewed materials to biodegradable polyesters and modified compositions of starch and cellulose, both known for their abundance and relatively low price. The addition of different nanofillers and preparation of polymer nanocomposites can effectively improve BP with controlled functional properties and change the…
Tuning the selectivity of molecularly imprinted polymer extraction of arylcyclohexylamines: From class-selective to specific
2020
Abstract A molecularly imprinted polymer (MIP) has been prepared in presence of 3-hydroxy phencyclidine (3-OH PCP) as template by bulk polymerization using N,N-dimethylformamide, as porogenic solvent, for the selective solid-phase extraction (SPE) of arylcyclohexylamines from oral fluids. Experimental variables of the extraction procedure have been studied in order to increase both, extraction recovery of 3-OH PCP, used as model analyte, and imprinting factor. By modifying the composition of the washing solvent, the selectivity of the MIP extraction procedure can be tuned, moving from an arylcyclohexylamine selective method to a 3-OH PCP specific method. The applicability of the synthesized…
Affinity Sensors for the Diagnosis of COVID-19
2021
The coronavirus disease 2019 (COVID-19) outbreak caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was proclaimed a global pandemic in March 2020. Reducing the dissemination rate, in particular by tracking the infected people and their contacts, is the main instrument against infection spreading. Therefore, the creation and implementation of fast, reliable and responsive methods suitable for the diagnosis of COVID-19 are required. These needs can be fulfilled using affinity sensors, which differ in applied detection methods and markers that are generating analytical signals. Recently, nucleic acid hybridization, antigen-antibody interaction, and change of reactive oxyge…
Application of a Novel Refinement Method for Accurate Determination of Chemical Diffusion Coefficients in Electroactive Materials by Potential Step T…
2005
We describe application of a novel refinement method for an accurate determination of the chemical diffusion coefficient, D, and the generalized kinetic parameter, A, from experimental potentiostatic intermittent titration technique (PITT) data suited for a variety of electrochemically doped electroactive polymers and inorganic intercalation host materials. The proposed, simple, two-step refinement procedure, based on earlier derived analytical expressions for the PITT response, is exemplified by the analysis of chronoamperometric responses to small-amplitude potential perturbation for p- and n-doped poly(fluorenone-bithiophene) (PFDOBT-HH) thin film electrode. The initial p-doping and the …
Towards the Generation of Self-Healing Materials by Means of a Reversible Photo-induced Approach
2011
Photo-induced reversibility as a tool for self-healing: a reversible photo-induced dendritic macromonomer was synthesized and proven to form networks with different features depending on the crosslinking conditions. While networks formed from aqueous systems exhibited a reversible change in their crosslinking degree, networks generated in bulk underwent fully reversibility. The latter was then exploited for generating self-healing materials by means of a photo-induced treatment.
Micelles of Polysoaps: The Role of Bridging Interactions
1996
Polysoaps, hydrophilic polymers incorporating amphiphilic monomers, form intrachain micelles in aqueous media. The micelles are similar to those formed by monomeric amphiphiles but are also endowed with a swollen, starlike corona formed by the spacer chains joining the amphiphiles. Long polysoaps form strings comprising many intrachain micelles. Exchange of amphiphiles between such micelles may give rise to bridging attraction, resulting in the adoption of a collapsed configuration in which the swollen micelles are close packed into a spherical globule. Upon addition of free amphiphiles, this structure unravels in a highly nonlinear fashion. Titration by surfactants, and the resulting swell…
Molecularly Imprinted Polymers as Useful Sorbents for Bioanalysis
2022
The determination of various active compounds in different types of biological samples attracts recently considerable attention. Unfortunately, the complexity of such sample matrices requires the application of multistage analytical procedures, which by many analysts is considered the most critical step in the whole analytical process. Sample preparation techniques dedicated to bioanalysis must ensure effective isolation and enrichment of various, often trace, amounts of analytes. Furthermore, the high selectivity of extraction of the target analytes, in relation to other interfering substances co-presented in the sample, is important in this case. Therefore, over the last two decades, the …