Diester Research Articles

Invited Perspective: PFAS Bioconcentration and Biotransformation in Early Life Stage Zebrafish and Its Implications for Human Health Protection.

Invited Perspective: PFAS Bioconcentration and Biotransformation in Early Life Stage Zebrafish and Its Implications for Human Health Protection.

Alkaline Phosphatase Serum Level at Time of Diagnosis Is a Prognostic Marker in Patients with Hodgkin Lymphoma

BackgroundHodgkin lymphoma (HL) is a potentially curable lymphoma with distinct histology, biologic behavior, and clinical characteristics. It is among the neoplastic diseases that has the best long-term outcome after treatment. Cure rates approach 80-90%; however, 15-20% of patients will be resistant to therapy or relapse after treatment. International Prognostic Score (IPS) is The most widely utilized clinical index to assign risk in HL patients. Alkaline Phosphatase (ALP) comprises a group of enzymes that catalyze the hydrolysis of phosphate esters in an alkaline environment, generating an organic radical and inorganic phosphate .ALP presents in all human tissues, but it's highest concentrations are found in the liver, bones, kidneys and placenta. Elevated ALP serum levels was shown to be a bad prognostic factor in patient with metastatic colorectal and breast cancers.AimTo study the prognostic role of ALP serum level at time of diagnosis in HL patients.Methods109 patients diagnosed with HL between January 2004 to December 2016 were retrospectively reviewed at King Abdullah University Hospital (KAUH) . Clinical and laboratory data at time of diagnosis including gender, age, presenting symptoms, ALP level, Complete Blood Count (CBC), Lactate Dehydrogenase (LDH) level, pathological subtypes, CT and PET/CT scans were studied. All IPS 7 variables including: male sex, age >45 years, stage IV disease, hemoglobin (Hb) <10.5g/dl, white blood count (WBC) ≥ 15 × 109/L, lymphocyte count < 0.6 × 109/L or <8% of total WBC, and albumin < 40g/dL were recorded at time of diagnosis. Extranodal involvement was confirmed by tissue diagnosis. All our patients received the same ABVD treatment regimen. The optimal cut-off value for ALP level was obtained using the Receiver Operating Curve (ROC) with a determination of the sensitivity and specificity . We analyzed for associations between ALP serum level and patient characteristics. Data were assessed using the Kaplan-Meier method, and the log-rank test was utilized to compare survival time between the groups.ResultsThe median age at diagnosis was 31 years (Range = 18-89 years). 55% were males and 45% were females. Patient characteristics are summarized in the table. Median ALP serum level was 250 U/L (range , 88-1234) and the optimal cutoff value of ALP serum level for predicting overall survival (OS) was 219 U/L (Sensitivity 86.4% , Specificity 46.50%; area under the curve [AUC] value: 0.668, 95% confidence interval [CI] 0.548-0.778, P= 0.019). In univariate analysis, elevated ALP level was significantly associated with poorer OS (HR=4.21, 95% CI: 1.24-14.26 , P-value=0.012). Mean survival time for patients with high ALP level was 11.68 years , compared to patients with low ALP level 10.96 years. In multivariate analysis ,there was significant association between high serum ALP level and IPS (P-value<.001), low Hb level (P-value=.002) , low Albumin level (P-value=.001) and high LDH level (.019). Involvement of more than one extra-nodal site was associated with poorer OS (HR=4.35 ,95% CI: 1.23-15.34 , P-value=0.022). There was no significant association between high ALP level and bone involvement (P-value=.072) ,liver involvement (P-value=.12) and HL subtype (P-value=.45).SummaryALP serum level may be a useful and un-expensive prognostic marker in patient with HL. The OS rate in patient with high ALP serum level at time of diagnosis is significantly lower than OS rate in patients with low serum levels. High ALP level is significantly associated with high IPS score , more than one EN site involvement , low Hb level , low albumin level and high LDH level. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Nose-to-brain delivery of phenytoin and its hydrophilic prodrug fosphenytoin combined in a microemulsion - formulation development and in vivo pharmacokinetics.

Phenytoin is a low aqueous solubility antiepileptic drug, but its phosphate ester prodrug fosphenytoin is soluble, although less permeable. In a previous study, the intranasal administration of aqueous-based formulations of fosphenytoin led to high but delayed phenytoin bioavailability compared to the intravenous route. In this work, we hypothesized that formulating an association of the prodrug fosphenytoin and the drug phenytoin (the active and diffusible form), could result in a faster and/or more effective brain targeting. Hence, nano or microemulsions containing both active drug and prodrug were developed and characterized regarding viscosity, osmolality, pH, mean size and in vitro drug release. Then, in vivo pharmacokinetics of a selected microemulsion containing fosphenytoin and phenytoin was evaluated in mice following intranasal administration and compared with a similar microemulsion containing fosphenytoin only. Both microemulsions led to higher brain drug levels at short time points than previously developed simpler aqueous based fosphenytoin formulations, likely due to the microemulsion's permeation enhancing effect. In addition, having a small amount of phenytoin in the formulation led to an equivalent maximum brain drug concentration and an overall higher absolute bioavailability, with a prolonged drug exposure. Hence, it can be concluded that if there is a need for a fast and prolonged therapeutic effect, a drug/phosphate ester prodrug combination in a microemulsion is ideal, but if a fast effect is all that is needed, having the prodrug alone could be enough, while considering a formulation with permeation enhancing components.

Sorption mechanisms of pesticides removal from effluent matrix using biochar: Conclusions from molecular modelling studies validated by single-, binary and ternary solute experiments

Sorption of atrazine (ATZ), imidacloprid (IMIDA) and azoxystrobin (AZOXY) in single-, bi- and ternary-solutes system was modelled using phosphoric acid-treated rice straw biochar (T-RSBC). The T-RSBC showed stronger sorption capacity for IMIDA in single- and bi-solute systems. The Freundlich constant (KFads) in ternary system followed the order: ATZ (222.7) < IMIDA (1314) < AZOXY (1459). Adsorption modeling and molecular dynamics suggested that non-bonding interactions between aromatic groups and electrostatic interactions with the phosphate ester group in T-RSBC played an important role. Enhanced sorption by pore-filling may be attributed to the stacking of pesticide molecules in the form of multilayer. IMIDA was predominantly sorbed by pore-filling mechanism, whereas, ATZ adsorbed by partitioning mechanism. The percent removal of three pesticides in waste water effluent followed the order: AZOXY > IMIDA > ATZ. The Freundlich isotherm based multicomponent Sheindorf-Rebuhn-Sheintuch equation's suggested that the extent of ATZ adsorption, in the presence of co-habiting pesticides, decreased with increase in number of solutes (KiATZ, Singlev> KiATZ, Binary> KiATZ, Ternary). The competitive coefficient values (αATZ/IMIDA, Ternary > αATZ/AZOXY,Ternary) revealed that ATZ adsorption in ternary system was inhibited more by the presence of IMIDA than AZOXY. Findings suggested that biochar with a large fraction of non-carbonized phase promoted non-competitive sorption.

Self-assembly of an anion receptor with metal-dependent kinase inhibition and potent in vitro anti-cancer properties

One topical area of supramolecular chemistry is the binding of anionic species but despite the importance of anions in diverse cellular processes and for cancer development, anion receptors or ‘binders’ have received little attention as potential anti-cancer therapeutics. Here we report self-assembling trimetallic cryptands (e.g. [L2(Metal)3]6+ where Metal = Cu2+, Zn2+ or Mn2+) which can encapsulate a range of anions and which show metal-dependent differences in chemical and biological reactivities. In cell studies, both [L2Cu3]6+ and [L2Zn3]6+ complexes are highly toxic to a range of human cancer cell lines and they show significant metal-dependent selective activity towards cancer cells compared to healthy, non-cancerous cells (by up to 2000-fold). The addition of different anions to the complexes (e.g. PO43ˉ, SO42ˉ or PhOPO32ˉ) further alters activity and selectivity allowing the activity to be modulated via a self-assembly process. The activity is attributed to the ability to either bind or hydrolyse phosphate esters and mechanistic studies show differential and selective inhibition of multiple kinases by both [L2Cu3]6+ and [L2Zn3]6+ complexes but via different mechanisms.

Complex profiles of azaspiracid analogues in two culture strains of Azadinium poporum (Amphidomataceae, Dinophyceae) isolated from Japanese coastal waters determined by LC-MS/MS

Lipophilic marine biotoxins azaspiracids (AZAs) are produced by dinoflagellates Azadinium and Amphidoma. Recently, several strains of Azadinium poporum were isolated from Japanese coastal waters. In our present study, AZA analogues in two strains (mdd421 and HM536) of A. poporum were analyzed by several detection techniques on the liquid chromatography-tandem mass spectrometry (LC-MS/MS) and liquid chromatography-quadrupole time of flight mass spectrometry (LC-QTOFMS). The dominant AZA analogue in the Japanese A. poporum strains was AZA2. Other known AZA analogues were AZA11, AZA35, AZA2 methyl ester and AZA2 phosphate ester. Besides these AZAs, thirteen new AZA analogues were discovered in the two strains. A putative AZA analogue (Compound 1) with the smallest molecular weight ever found in nature was also discovered in the two strains. This is the first report describing detailed AZA profiles in Japanese isolates of A. poporum.

Effect of AtPAP17 and AtPAP26 genes overexpression on yield and yield components under salt stress in Arabidopsis thaliana plant

Effect of AtPAP17 and AtPAP26 genes overexpression on yield and yield components under salt stress in Arabidopsis thaliana plant

Fluorinated Compounds in North American Cosmetics

Per- and polyfluoroalkyl substances (PFAS), a highly persistent and potentially toxic class of chemicals, are added to cosmetics to increase their durability and water resistance. To assess this potential health and environmental risk, 231 cosmetic products purchased in the U.S. and Canada were screened for total fluorine using particle-induced gamma-ray emission spectroscopy. Of the eight categories tested, foundations, mascaras, and lip products had the highest proportion of products with high total fluorine ≥0.384 μg F/cm2. Twenty-nine products including 20 with high total fluorine concentrations were analyzed using targeted LC-MS/MS and GC-MS. PFAS concentrations ranged from 22–10,500 ng/g product weight, with an average and a median of 264 and 1050 ng/g product weights, respectively. Here, 6:2 and 8:2 fluorotelomer compounds, including alcohols, methacrylates, and phosphate esters, were most commonly detected. These compounds are precursors to PFCAs that are known to be harmful. The ingredient lists of most products tested did not disclose the presence of fluorinated compounds exposing a gap in U.S. and Canadian labeling laws. The manufacture, use, and disposal of cosmetics containing PFAS are all potential opportunities for health and ecosystem harm. Given their direct exposure routes into people, better regulation is needed to limit the widespread use of PFAS in cosmetics.

Interactions of primaquine and chloroquine with PEGylated\ufeff phosphatidylcholine liposomes

This study aimed to analyze the interaction of primaquine (PQ), chloroquine (CQ), and liposomes to support the design of optimal liposomal delivery for hepatic stage malaria infectious disease. The liposomes were composed of hydrogenated soybean phosphatidylcholine, cholesterol, and distearoyl-sn-glycero-3-phosphoethanolamine-N-(methoxy[polyethyleneglycol]-2000), prepared by thin film method, then evaluated for physicochemical and spectrospic characteristics. The calcein release was further evaluated to determine the effect of drug co-loading on liposomal membrane integrity. The results showed that loading PQ and CQ into liposomes produced changes in the infrared spectra of the diester phosphate and carbonyl ester located in the polar part of the phospholipid, in addition to the alkyl group (CH2) in the nonpolar portion. Moreover, the thermogram revealed the loss of the endothermic peak of liposomes dually loaded with PQ and CQ at 186.6 °C, which is identical to that of the phospholipid. However, no crystallinity changes were detected through powder X-ray diffraction analysis. Moreover, PQ, with either single or dual loading, produced the higher calcein release profiles from the liposomes than that of CQ. The dual loading of PQ and CQ tends to interact with the polar head group of the phosphatidylcholine bilayer membrane resulted in an increase in water permeability of the liposomes.

A feasible and universal one-step method for functionalizing carbon dots efficiently via in-situ free radical polymerization

The passivation of carbon dots (CDs) are usually implemented through coupling reactions, which requires either specific functional groups on the surface of CDs or multiple steps. In this paper, we propose a feasible method to passivate CDs via in-situ free radical polymerization, which has no dependence on functional groups and thus is suitable for CDs prepared via either bottom-up or top-down route. Taking bare CDs that cut from active carbon by top-down method as an example. When putting acrylic acid, sodium methallyl sulfonate and acrylic phosphate ester as monomers into the bare CDs solution along with ammonium persulfate, stirring at room temperature for 2h, the monomers were polymerized and formed terpolymer-passivated CDs (T-CDs) of which quantum yields (QY) increased obviously. The QY of the bare CDs and the T-CDs were 0.2% and 29.1%, respectively. More interestingly, the bare CDs were found capable of constructing a redox-initiated couple with ammonium persulfate to initiate polymerization. Another example token to further approve the feasibility and universality of “in-situ free radical polymerization” passivation method is our reported poly (N-vinylcarbazole)-passivated CDs (PVK-CDs) that prepared by bottom-up method. The PVK-CDs were synthesized via thermal treatment of a mixture composed of citric acid and N-vinylcarbazole molecules at 300 °C for 2 h. During the process the citric acid was carbonized to provide pristine CDs and N-vinylcarbazole was in-situ polymerized on the surface of the pristine CDs through thermal initiation, which enhances the fluorescence QY up to 40%.

Prodrug Approach toward the Development of a PET Radioligand for Imaging the GluN2A Subunits of the NMDA Receptor.

A straightforward synthesis of a fluorine-18-labeled prodrug of AFA233 is reported. The key step in the preparation of [18F]AFA233-prodrug is the selective deprotection of the tert-butyl protection groups of the quinoxalinedione moiety without cleavage of the tert-butyl-S-acyl-2-thioethyl protection groups on the phosphate esters. In addition, the preparation of the nonradioactive prodrug reference compound of AFA233 is reported.

Evaluating Spatiotemporal Dynamics of Phosphorylation of RNA Polymerase II Carboxy-Terminal Domain by Ultraviolet Photodissociation Mass Spectrometry.

The critical role of site-specific phosphorylation in eukaryotic transcription has motivated efforts to decipher the complex phosphorylation patterns exhibited by the carboxyl-terminal domain (CTD) of RNA polymerase II. Phosphorylation remains a challenging post-translational modification to characterize by mass spectrometry owing to the labile phosphate ester linkage and low stoichiometric prevalence, two features that complicate analysis by high-throughput MS/MS methods. Identifying phosphorylation sites represents one significant hurdle in decrypting the CTD phosphorylation, a problem exaggerated by a large number of potential phosphorylation sites. An even greater obstacle is decoding the dynamic phosphorylation pattern along the length of the periodic CTD sequence. Ultraviolet photodissociation (UVPD) is a high-energy ion activation method that provides ample backbone cleavages of peptides while preserving labile post-translational modifications that facilitate their confident localization. Herein, we report a quantitative parallel reaction monitoring (PRM) method developed to monitor spatiotemporal changes in site-specific Ser5 phosphorylation of the CTD by cyclin-dependent kinase 7 (CDK7) using UVPD for sequence identification, phosphosite localization, and differentiation of phosphopeptide isomers. We capitalize on the series of phospho-retaining fragment ions produced by UVPD to create unique transition lists that are pivotal for distinguishing the array of phosphopeptides generated from the CTD.

Ultrafast and efficient removal of Pb(II) from acidic aqueous solution using a novel polyvinyl alcohol superabsorbent

The direct removal of heavy metal ions from acidic wastewater is a hard problem. In this study, a novel superabsorbent, polyvinyl alcohol phosphate ester (PVAP), was designed and prepared to remove Pb(II) from acidic wastewater (pH = 3). The PVAP can absorb water and swell to reach equilibrium within 30 s, which provides the conditions for ultrafast kinetic adsorption. For 100 mg/L Pb(II) solution, the adsorption reaches equilibrium within 5 min, and the removal ratio is more than 99.9% over a wide pH range of 3–6. Adsorption kinetics and isotherm data are consistent with pseudo-second-order and Langmuir model, respectively. The calculated maximum adsorption capacity for Pb(II) is 558.66 mg/g. Thermodynamic results show that the adsorption is spontaneous and exothermic process. The removal ratio for Pb(II) of PVAP still maintains above 99% after ten recycles. The PVAP can also simultaneously remove more than 97% of other heavy metal ions (Cu(II), Cd(II), Zn(II), Co(II), and Ni(II)) from an acidic solution. Moreover, the PVAP can efficiently purify simulated acid mine heavy metal wastewater, and the results meet EPA drinking water standards. The studies of X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FT-IR) spectroscopy prove that the adsorption mechanism involves surface complexation. This new superabsorbent is a promising candidate for acidic heavy metal sewage disposal.

Thickening CO2 with Direct Thickeners, CO2-in-Oil Emulsions, or Nanoparticle Dispersions: Literature Review and Experimental Validation

High molecular weight associating random copolymers, such as poly(fluoroacrylate-styrene) (polyFAST), are direct CO₂ thickeners that can dissolve readily in CO₂ and significantly increase viscosity. Although polyfluoroacrylate (PFA) is more CO₂-soluble than polyFAST, PFA induces less thickening because it is non-associating. High molecular weight poly(dimethylsiloxane) (PDMS) and poly(vinyl acetate) (PVAc) can increase CO₂ viscosity if toluene cosolvent is introduced. Bis(2-ethylhexyl) sulfosuccinate sodium salt (AOT) can thicken CO₂ modestly if ethanol cosolvent is added. Little CO₂ thickening has been reported for low molecular weight polymers, including poly(vinyl ethyl ether) (PVEE) and poly-1-decene (P1D). Associating oligomers of poly(propylene oxide) (PPO) with pendant aromatic groups showed modest CO₂ viscosity enhancement. Cross-linked phosphate esters can increase the viscosity of CO₂ if a very substantial concentration of a light alkane cosolvent is added. Indirect thickening of CO₂ involves the generation of high apparent viscosity, completely waterless CO₂-in-oil (C/O) emulsions that can be attained when CO₂ is mixed with mineral oil containing a silicone-alkyl copolymeric surfactant; similar behavior was observed with a proprietary blend of oil and surfactants. Only one nanoparticle-based thickening of CO₂ involving the dispersal of dilute concentrations of nanoparticles that are surface-functionalized with highly CO₂-philic groups was reported (however, no explanation was provided to explain how the high molecular weight polymer used in this study could be CO₂-soluble). New experimental results were obtained for some readily available or easily synthesized CO₂-thickening candidates. PolyFAST yielded very substantial viscosity increases. PFA, PDMS-toluene, and PVAC-toluene could appreciably thicken CO₂. Very little detectable viscosity enhancement was achieved with low molecular weight PVEE or P1D. CO₂ was thickened slightly with AOT-ethanol. Regarding future studies, novel, nonfluorous associating CO₂-philic oligomers, and highly CO₂-philic phosphate esters that remain dissolved in CO₂ after cross-linking are the most obvious candidates for CO₂ direct thickeners.

Highly Proton Conductive Phosphoric Acid Porous Organic Polymers via Knitting Method

Phosphoric acid group, which possesses a low energy barrier for proton conduction and high water bonding energy, favors proton conduction and water retention. In this study, a phosphoric acid porous organic polymer (PAPOP) with high proton conductivity was synthesized. The diethyl benzylphosphonate (DBP) monomer and the benzyl monomer were directly knitted via the Friedel–Crafts alkylation reaction to form a porous scaffold. The phosphate ester group on DBP not only enhanced the monomer reactivity but also realized the in situ introduction of the phosphoric acid group precursor during the formation of the porous scaffold. It is found that p-dichloroxylene (DCX) monomer, due to its higher electrophilic activity, is easier to react with DBP and thus easier to introduce phosphoric acid groups. The higher ratio of DCX leads to a more continuous hydrogen-bond network within the scaffold, which facilitates the proton-conducting process. The resultant porous organic polymers exhibited high hydrophilicity and excellent stability in strong acid as well as antiswelling ability in water. The highest ion-exchange capacity reached 2.68 mmol g–¹, much higher than that of most reported polymers. The proton conductivity of powders reached the highest value of 7.09 × 10–² S cm–¹ at 348 K and 98% relative humidity.

Fabrication of organophosphate-grafted kaolinite and its effect on the fire-resistant and anti-ageing properties of amino transparent fire-retardant coatings

In this work, a series of organophosphate-grafted kaolinite flame retardants (KPPBs) were fabricated via grafting flexible phosphate ester (PPB) on the surface of kaolinite (Kaol), and the chemical structure of KPPBs was characterized in detail. Afterward, the obtained KPPBs were blended with amino resin to prepare transparent fire-retardant coatings. The results indicate that the KPPBs endow the resulting coatings with a high light transmittance due to the uniform distribution of Kaol in the amino matrix. The results of combustion behavior indicate that the addition of Kaol greatly enhances the fire protection and smoke suppression properties of the transparent coatings, exhibiting superior synergistic flame retardant and smoke suppression effect. Especially, when the weight ratio of PPB and Kaol is 95:5, the fabricating MKPPB3 coating acquires the best synergistic effect, and the flame spread rating and smoke density rate values are decreased by 64.9% and 45.0%, respectively, compared to those of MKPPB0 coating without Kaol. The superior synergistic effect of Kaol in the coatings is ascribed to the formation of more thermally stable cross-linking structures and aromatic structures that generate a high-quality intumescent char against the fire, as supported by FTIR and SEM analyses. TG analysis shows that the addition of Kaol can strengthen the thermal stability and char-forming of the coatings, and the residual weight of MKPPB3 at 800°C increases to 31.9%. The results of accelerated ageing test indicate that the incorporation of Kaol can weaken the blistering and powdering phenomenon, thus endowing superior durability of structural integrity and fire protection to transparent coatings.

Synthesis of alkyl phosphates and investigation of their surface-active properties in an alkaline surfactant polymer system for enhanced oil recovery

Chemical flooding is a technique of enhanced oil recovery (CEOR) using formulations containing alkaline components, surfactants and polymers (ASP technology). The development and synthesis of novel highly efficient industrial surfactants take this technology to a new level, allowing the chemical composition of reagents to be tailored to the reservoir conditions of fields in Western Siberia. Alkyl phosphates with various structures are one type of the surfactants that can be used in ASP technology. This work aimed to synthesize and examine the properties of commercial (semi-industrial) alkyl phosphates and alkoxylated alkyl phosphates of mixed composition that meet the requirements of an efficient surfactant component of an ASP-flooding formulation. The synthesis was carried out using industrial fatty alcohols by the phosphating reaction with phosphorus pentoxide. A mixture of monoand disubstituted phosphoric acid esters of a defined ratio can be obtained by target tailoring of the feedstock properties (structural changes, molecular weight distribution in alcohols) and the synthesis conditions. This mixture, requiring no addition of cosurfactants, is an effective multi-component surfactant for an ASP-system. In this work, three effective alkyl phosphates and alkoxylated alkyl phosphates blends were synthesized. The composition of the synthesized phosphoric esters was evaluated by high-resolution mass spectrometry (HRMS), infrared (IR) spectroscopy and potentiometric titration. At reservoir temperature, the obtained samples provided sufficient solubility in an oil-displacing aqueous solution in the technologically required salinity interval, compatibility with other components, low interfacial tension (IFT) values at the interface between ASP solution and oil from Western Siberia fields, and the formation of the sufficient volume of the emulsion phase in a phase experiment. The primary laboratory research data proved the efficiency of the synthesized surfactants in ASP technology in the fields of Western Siberia.

Size shifting of solid lipid nanoparticle system triggered by alkaline phosphatase for site specific mucosal drug delivery

We aim to prepare a size-shifting nanocarrier for site-targeting mucosal drug delivery that can penetrate through mucus gel layer and remain close to the absorption membrane. As nanocarriers can be engineered to penetrate mucus but they can also back diffuse into outer mucus regions, a size shifting to micron range once they have reached the absorption membrane would prevent back-diffusion effect and extend drug release over a long period of time. For this purpose, we loaded solid lipid nanoparticles (SLN) with a phosphate ester surfactant and octadecylamine. Alkaline phosphatase (AP), a membrane bound enzyme was for the first time utilized as an in situ partner for triggering the size conversion at epithelial cell surface. Having the size of ~120 nm, SLN with hydrophilic and phosphate-decorated shells were shown to penetrate through mucus gel and form aggregates above cell layer surface. Aggregates of 5–8 µm were formed due to interparticle interactions induced by enzymatic phosphate removal after ~30 min in contact with isolated AP. The developed SLN system could be a potential tool for mucosal drug delivery to AP-expressing tissues like colon, lung, cervix, vagina and some mucus-secreting tumors.

Multifunctional Cotton Fabrics Obtained by Modification with Silanes Containing Esters of Phosphoric Acid as Substituents.

The development of novel flame retardants for cotton textiles that form a stable layer on textile fiber is of high economical and practical relevance. A novel flame retardant fluorinated phosphoric acid esters modified silicone resins for cotton modification were synthesized. The investigated phosphoric acid esters based compounds were substituted by a fluorinated chain or ring, and alkoxysilyl groups. The presence of alkoxysilyl groups allowed the formation of bonds with cellulose, while derivatives of phosphoric esters reduced the flammability of fabrics. Additionally, the presence of fluoride in their structures affected the hydrophobic properties. Cotton fabrics were modified in a simple one-step process by dip-coating method. The flame retardant properties of modified textiles were examined by performing microcalorimetric analysis, thermogravimetry analysis, and measuring oxygen index. The hydrophobicity was evaluated by measuring the water contact angle. The modified fabrics were characterized by SEM-EDS (Scanning Electron Microscopy with Energy Dispersive Spectroscopy) analysis and surface morphology. As a result of the tests, multifunctional fabrics were obtained.

A theoretical and experimental study of phosphate ester inhibitors for AISI 1018 in carbon dioxide‐saturated 3.5 wt% NaCl solution

AbstractPhosphate ester was investigated as a corrosion inhibitor for AISI 1018 carbon steel in carbon dioxide‐saturated chloride solutions at different temperatures and pressures. The corrosion tests were realized by electrochemical techniques, weight loss measurements, bubble tests, and a high‐pressure/high‐temperature autoclave system. The corrosion tests demonstrated that the investigated molecule is an excellent corrosion inhibitor. The inhibiting effect is even bigger at high pressure and temperature than at atmospheric pressure and room temperature. The thermodynamic parameters were calculated and determined to obey the Langmuir isotherm. Polarization studies revealed that the evaluated inhibitor is a mixed type.