Presence Of Hydrochloric Acid Research Articles

Statistical and Artificial Neural Network Analysis for Corrosion of Mild Steel in Hydrochloric Acid in Presence of Eco-Friendly Inhibitor

In present work, the inhibition performance of the Portulaca Grandiflora Leaf Extract (PGL), as environmental-friendly corrosion inhibitor, for low-carbon steel in 0.5 M hydrochloric acid solution at variable inhibitor concentrations and temperatures is evaluated by mass loss technique. The dependent variable was corrosion rate, while the independent variables were inhibitor concentration and temperatures. Several mathematical and artificial neural network (ANN) models have been suggested. A computer aided program is used during regression and estimation processes. Several models were used. Polynomial – individual effect, polynomial – interaction effect, linear effect, exponential growth, and piecewise regression models were estimated. Results show that the Piecewise regression model was the best one with high correlation coefficient (R2) equal to 0.9994. For ANN studies, Linear Model (LM), Radial Basis Function (RBF), and Multi-Layer Perceptron (MLP) were evaluated. The data were divided into training and testing. MLP of two inputs, multi-hidden layers, and one output (2:2-8-1:1) was the highly accurate artificial neural network model ANN with a high correlation coefficient (R2=0.9826). The effect of temperature was lower than the effect of PGL concentration as shown by mathematical and ANN analysis.

OBTAINING LOW-MOLECULAR WEIGHT GALACTOMANNANES AND STUDYING THEIR PHYSICO-CHEMICAL CHARACTERISTICS

The aim of this study was studying the effect of acidic hydrolysis conditions on the molecular parameters of galactomannan, such as weight average degree of polymerization (DPw), weight average molecular weight (Mw), product yield, depolymerization reaction rate, and mannose/galactose (Man/Gal) ratio in the presence of hydrochloric acid and obtaining low molecular weight oligogalactomannans soluble in water. A preparing possibility low molecular weight galactomannans by acid hydrolysis of guar galactomannan (DPw=1160, Mw=563.8 kDa, Man/Gal=1.89) in the presence of hydrochloric acid was studied. The studies were carried out in hydrochloric acid solutions with various concentrations (0.05–1.0 mol/L) for different times (10–240 min) at a constant temperature (80 °C). In the course of the studies, effects of the reaction conditions on the molecular parameters of the product obtained were analyzed. The conducted reactions yielded low molecular weight galactomannans and oligogalactomannans with different molecular parameters (DPw=6–1021, Mw=2.6–505.1 kDa, Man/Gal=1.90–3.19) and yields (2.8–97.1%). Based on the results obtained, the optimal reaction conditions (HCl 0.1 mol/L, 240 min, 80 °C) were supposed for the preparation of galactomannan oligosaccharides. The structural studies of the products indicated that products with reduced galactose residues could be prepared by this method.

Speciation of inorganic arsenic in aqueous samples using a novel hydride generation microfluidic paper-based analytical device (µPAD)

The development of the first microfluidic paper-based analytical device (µPAD) for the speciation of inorganic arsenic in environmental aqueous samples as arsenite (As(III)) and arsenate (As(V)) which implements hydride generation on a paper platform is described. The newly developed µPAD has a 3D configuration and uses Au(III) chloride as the detection reagent. Sodium borohydride is used to generate arsine in the device’s sample zone by reducing As(III) in the presence of hydrochloric acid or both As(III) and As(V) (total inorganic As) in the presence of sulfuric acid. Arsine then diffuses across a hydrophobic porous polytetrafluoroethylene membrane into the device’s detection zone where it reduces Au(III) to Au nanoparticles. This results in a color change which can be related to the concentration of As(III) or total inorganic As (i.e., As(III) and As(V)) concentration. Under optimal conditions, the µPAD is characterized by a limit of detection of 0.43 mg L−1 for total inorganic As (As(III) + As(V)) and 0.41 mg L−1 for As(III) and a linear calibration range in both cases of 1.2–8.0 mg As L−1. The newly developed µPAD-based method was validated by applying it to groundwater and freshwater samples and comparing the results with those obtained by conventional atomic spectrometric techniques.Graphical abstract

The Effect of Corrosion on Crude Oil Distillation Plants

The analysis of the corrosion phenomenon of the installations of the largest refinery in Romania confirmed the existence of its conditions, in the atmospheric distillation plants of crude oil, in the heat exchangers, and in the petrol and diesel hydrofining plants. However, the slightest effect of this phenomenon was found in the dome, the plates, and the exhaust pipes at the top of the distillation column, as well as in the reflux vessel of the atmospheric distillation plant. The main cause of the corrosion phenomenon and the increase in the corrosion areas of the material of the crude oil refining installations is the presence of hydrochloric acid, obtained after incorrect desalination (hydrolysis of calcium and magnesium chloride). To prevent this phenomenon, in laboratory conditions, we tested an antacid inhibitor (alkyl phenol) and a residual product (undistilled polyamine), with the role of supplementing the commercial inhibitor with a cheap product. The effectiveness of these additives was evaluated by introducing specimens made from the material taken from the refining column and from the reflux vessel into a solution of hydrochloric acid of various concentrations (5–15%). This solution was treated with the two corrosion inhibitors, the analysis of their effectiveness being performed at concentrations ranging between 0.05 and 0.2%. In addition, in this article, we deduced the equations of variation of the corrosion rate, depending on the working temperature of the refinery.

Estimation of p-Aminophenol via Diazotization and Coupling Reaction with 4-Chlororesorcinol –Application on Paracetamol

A spectrophotometric method has been proposed for the direct determination of p-aminophenol (p-Amp). The method includes diazotisation of p-Amp using an excess of sodium nitrite and in the presence of hydrochloric acid, and after destroying the remaining nitrous acid by adding sulphamic acid, then the produced diazonium salt coupled with the reagent 4-chlororenocinol (4-Chlr) in an alkaline medium of sodium hydroxide to form a water-soluble azo dye that gives the highest absorption at the wavelength of 488 nm. The linear range that follows Beer's law was from 0.5 to 15 μg/ml. The value of the molar absorptivity was 1.9905x104 l/mol. cm. After investigation of the optimal conditions by studying all factors affecting the absorption of the formed azo dye. The method was applied to estimate paracetamol in its pharmaceutical preparations after hydrolysis process. The results of standard addition method proved that there is no interference by additives.

Synthesis and evaluation of grafted xanthan gum as a drug carrier in developing lornoxicam gel formulations

Background: In the medical and pharmaceutical fields, man has successfully used natural-origin things for millennia. Polymers obtained from plant sources have flashed much consideration in current eras owing to their various pharmaceutical properties, such as gelling agents in gels. Also incorporated in cosmo products, fabrics, dyes, and paper manufacture as binders, diluents, disintegrating agents, thickeners in oral fluids, protective colloids in suspensions, and bases in a suppository. Objectives: Natural polymers are chosen over semisynthetic and synthetic excipients due to their lack of toxicity, low cost, availability, soothing action, and nonirritant nature, as well as their ability to undergo a variety of chemical modifications. However, they have some drawbacks, including microbial contamination, lot to lot variation, reduced viscosity throughout storage, inappropriate mechanical properties, low storage, and an uninhibited rate of hydration. Current research work aims to chemically modify xanthan gum and study its impact on the formulation of topical gels. Materials and Methods: Chemical modification of xanthan gum is conceded by using a thiol-esterification reaction with thioglycolic acid (TGA) in the presence of hydrochloric acid. Microwave irradiated thiolated xanthan gum was also willing by further irradiation of thiolated xanthan gum by microwave using 750 W frequency. Topical drug delivery of lornoxicam release applications of thiolated and microwave irradiated xanthan gum are comparatively evaluated with pure xanthan gum polymer by formulating gel incorporated lornoxicam as a drug. Results: The physical properties of gel-like physical evaluation and viscosity results are within official limits. Formation of gel with idyllic properties. Determination of drug content, spreadability, and extrudability of modified xanthan gum was high compared with native xanthan gum. In vitro drug release study showed that prepared gel sustains the drug release for 24 h. Conclusion: Thiolation and irradiated xanthan gum sustain the release of lornoxicam over a prolonged period and might be a promising lornoxicam carrier in topical drug delivery to enhance antinociceptive and anti-inflammatory efficiency.

Synthesis of new corrosion inhibitors with high efficiency in aqueous and oil phase for low carbon steel for missan oil field equipment

The Iraqi oil field environment is filled with metal pipes and other components that are often exposed to chemicals that can cause corrosion, especially when the metal and chemicals are in a solution such as downhole fluids. Inhibitors are among the most important industrial additives that are commonly used in Iraqi petroleum industry to decrease the corrosion that cause damage to pipelines, water and waste water system. This fact evoked the urgent need to prepare corrosion inhibitor materials; one of the most important properties of these compounds is to act as surfactants working to remove or reduce the surface tension between the two immiscible phases with each other and make it easier to mix. Three types of corrosion inhibitors were prepared by using fatty acids and converted them into the fatty alkyl halides in presence of hydrochloric acid. Finally, the products reacted with various mole ratios of tertiary amine in various mole ratios, and then they were identified by classical methods melting point measurement, solubility test and [FTIR, 1H-NMR and 13C-NMR]. Morphology of the carbon steel was examined using scanning electron microscopy (SEM) in presence and absence of inhibitors. In the last step, the inhibitors of low carbon steel in acidic medium were assessed as a case study by using potentiostat device and weight loss to calculate the corrosion rate and inhibition efficiency. The result was as follows: P1 was 81.30%, P2 was 81.79% and P3 was 97.56%. In addition, inhibitors prepared in this study were evaluated in organic phase (Bazrcan iraqi oil fields) by weight loss method using different concentrations of corrosion inhibitors (50,75,100 ppm) and the inhibition efficiency as follows:P1: inhibition efficiency (91.8%) at a concentration of inhibitor (100 ppm);P2: inhibition efficiency (83.8%) at a concentration of inhibitor (100 ppm); andP3: inhibition efficiency (81.2%) at a concentration of inhibitor (100 ppm).

Analysis of Polarization Curves of a Commercial Membrane With an Extract of Metal Ions from Soils Impacted with Mining Tailings

Polarization curves are obtained in cation exchange membranes (Neosepta CMX Tokuyama Co., Japan). The analysis allowed to determine the transition zone in which the depletion of the counterion in the diffusion layer occurs. The fixed charge of the membrane confers selective properties depending on the size of the mixture of ions extracted from the soil sample. The results of the limit current analysis in the membrane reflect the presence of a mixture of ions where the diffusion layer is altered [1-2]. The soils were obtained from mining tailings disposed of in the open pit in Guanajuato, Gto. Mexico. The extracts of the ion mixture were obtained by contacting the soil samples with 0.5 M magnesium chloride. The polarization curves were obtained from extracts digested in an acid medium and without this treatment. The digestion of the extracts was carried out to total dryness on a heating plate with a solution of HNO3 and resuspended to a volume of 25 mL. The polarization curves were obtained in a two-cell device made with acrylic tubes containing 25 mL of solution each.The CMX membrane was placed between the two cells by applying progressive potential with a power source to the working electrodes placed at the ends of the device. The potential difference was measured with a multimeter on two Ag / AgCl reference electrodes (3 M NaCl) placed on each side of the membrane. At the same time the current developed in the system was recorded. The polarization curves were constructed from the current and potential recorded in the multimeters. The results suggest that the diffusion layer is thinner in the reference soil. The high values of Ilim in the mining tailings show the presence of an important mixture of ions.[1] M. Garcia-Gabaldon, V. Perez-Herranz, E. Ortega., Evaluation of two ion-exchange membranes for the transport of tin in the presence of hydrochloric acid, J. Membr. Sci., 371 (2011) 65-74.[2] F.G. Wilhelm, N.F.A. van der Vegt, M. Wessling, H. Strathmann, Chronopotentiometry for the advanced current – voltage characterization of bipolar membranes, Journal of Electroanalytical Chemistry 502 (2001) 152–166.The authors assign the rights toThe Electrochemical Society Advancing Solid State & Electrochemical Science & Technology.

Synthesis of copper nanoparticles with controllable crystallinity and their photothermal property

Synthesis of copper (Cu) nanoparticles in aqueous solution is of great challenge due to their tendency to oxidization upon exposure to air. In this work, well crystallized Cu nanoparticles with diameters of about 80 nm were successfully prepared in aqueous solution via simply reducing copper salts by sodium hypophosphite at presence of hydrochloric acid, and with polyacrylamide (PAM) as the capping agent. Experimental results showed that the presence of H+ facilitated formation of Cu nanoparticles and the crystallinity of the nanoparticles is highly dependent on Cl- concentration. Meanwhile, the size and morphology of the resulted nanoparticles could be controlled by concentration of PAM. The obtained Cu nanoparticles were further uniformly distributed in polyvinyl alcohol, forming a Cu-PVA hydrogel, which showed a significant photothermal conversion efficiency as high as 23.9% upon laser illumination. Continuous cycling test confirmed the long-term photothermal performance of the Cu-PVA hydrogel, and a bacterial killing efficiency of more than 99% could be realized after incubating it with E. coli under laser irradiation for 10 min. Besides, the prepared Cu nanoparticles may find practical applications in electronic and catalytic areas where the properties are closely related to nanoparticles crystallinity.

In English

The effect of the medium on the parameters of water bound to the surface of alginic acid powder was studied by low-temperature 1H NMR spectroscopy. The aim of this work was to study the effect of hydrophobic environment on the binding of water with alginic acid and to compare the parameters of the interfacial layers of water in air, in chloroform and chloroform with the addition of hydrochloric acid. It is shown that when adsorbed on the surface (500 mg/g H2O), most of it is strongly bound. It is shown that for most dispersed systems, when replacing the air with chloroform, the interfacial energy of water increases from 11.8 to 15.2 kJ/mol, which is due to the capability of weakly polar organic molecules to diffuse on the surface of solid particles, thereby reducing the interaction energy with the adsorbed surface water clusters. It is concluded that chloroform molecules cannot diffuse on the surface of alginic acid particles and affect only the structure of water clusters localized in the outer adsorption layer. In the presence of hydrochloric acid on the surface of alginic acid, a system of water clusters is formed, most of which does not dissolve hydrochloric acid, and the radii of these clusters is 2 nm, which are likely to form in the gaps between the polymer chains of polysaccharide.

The non-templating synthesis of macro-cyclic Schiff base ligands containing pyrrole and homopiperazine and their binuclear nickel(II), cobalt(II) and mononuclear platinum(II) complexes: X-ray single crystal and anticancer studies

A new dialdehyde N, N'-bis(5-formylpyrrol-2-ylmethyl) homopiperazine (A) was synthesized by the Mannich reaction of pyrrole 2-carbaldehyde, formaldehyde and homopiperazine in the presence of hydrochloric acid. From the direct reaction of A with 1,3-diaminopropane or 1,4- diaminobutane two new macrocyclic Schiff base ligands were obtained, L1 and L2, respectively. The reaction of these ligands with Ni(II), Co(II) and Pt(II) metal ions results in formation of the relevant macrocyclic Schiff base complexes. Compounds were characterized by FT-IR, elemental analysis, mass spectrometry, UV-Vis and, in the case of the ligands, by 1H and 13C-NMR. The crystal structure of the complex [Ni2L2(CH3O)]ClO4 (4) showed a binuclear macro-cyclic structure, with each Ni coordinated by three nitrogen atoms from the ligand and by a methoxide bridging the two metal centers. The cytotoxic activities of these compounds indicated that the ligands, and some of the complexes, have high anti-proliferative effect towards A549 and HeLa cells, but not HT29 cells. Pt complex with L1 and L2 displayed stronger anti-proliferative activity toward HeLa (IC50 = 11 µM for both of them and A549 IC50 = 7 µM and 8 µM, respectively) relative to L1 and L2. In addition, the cytotoxic effects of the compounds were assayed in rat fibroblast cells as a model of the normal cell, however none of them showed any significant cytotoxic effects. Thereby upholding the potential of these compounds for further development as chemotherapeutic agents.

New possibilities of the functionalization of 6-hydrazino-1,3-dimethyluracils: one-pot synthesis of 5,7-dimethylpyrazolopyrimidine-4,6-dione and 1,3-dimethyl-5-arylidenebarbituric acid derivatives

3-aryl-5,7-dimethylpyrazolopyrimidine-4,6-diones and 5-benzylidene-1,3-dimethylpyrimidine-2,4,6-triones were obtained by heating hydrazones of 1,3-dimethyl-6 -hydrazinouraciles in trifluoroacetic acid (TFA). The same compounds were also obtained by heating the hydrazones of 1,3-dimethyl-6-hydrazinouraciles in aqueous ethanol in the presence of hydrochloric acid.

Utility of dipyrromethane in the synthesis of some new A2B2 porphyrin and their related porphyrin like derivatives with their evaluation as antimicrobial and antioxidant agents

In this work, the dipyrromethane derivatives 2a,b were synthesized from an aldehyde and excess of pyrrole at room temperature in solvent-free conditions. The reaction of dipyrromethanes 2a,b with different aromatic aldehydes in the presence of hydrochloric acid or p-toluenesulfonic acid as a catalyst afforded some new porphyrin like and A2B2 porphyrin derivatives 4a-g and 5a-d, respectively. Biological evaluation of the newly synthesized compounds 4a-g and 5a-d showed promising activity as antimicrobial and antioxidant agents. Compounds 4c,4e,4g,5c, and 5d exhibited the highest antimicrobial activity, whereas, compounds 4a,4f,5a,5b, and 5d recorded the highest antioxidant activity.

SYNTHESIS AND STUDY OF THE PROPERTIES OF XEROGELS DERIVED FROM SULFATED PINE ETHANOL LIGNIN

Organic xerogels based on lignin and tannins isolated from pine bark and wood were first obtained by condensation with formaldehyde and furfuryl alcohol in the presence of hydrochloric acid. The use of pine sulfated ethanol lignin made it possible for the first time to obtain sulfur-containing (up to 1.3% wt.) lignin-(tannin)-formaldehyde and lignin-(tannin)-furfuryl xerogels. The density of the obtained gels increases with the addition of tannins to lignin and varies in the range 0.13–0.39 g/cm3. Xerogels synthesized by condensation with furfuryl alcohol are stronger than those obtained using formaldehyde. The presence of sulfur in xerogels was confirmed by elemental and chemical analysis and IR spectroscopy. It was shown by scanning electron microscopy, that lignin-formaldehyde xerogels are formed from large polymer chains, consisting of interconnected aggregates of micron-sized particles and have large pores. The addition of tannins to the polycondensation system is accompanied by the formation of a more compact spatially crosslinked gel structure. BET method showed that all xerogels have low porosity, and lignin-furfuryl samples have a larger average pore diameter (7.2–14.5 nm) compared to lignin-formaldehyde samples (3.03–6.80 nm).

Studies on Synthesis, Characterization and Transport Properties of Ta2O5 Doped Polyaniline Composites

Polyaniline (PANI) and PANI/Ta2O5 composite samples were prepared using chemical oxidative polymerization technique in the presence of hydrochloric acid (HCl) at room temperature. The effect of Ta2O5 on surface morphology and structural changes have been investigated and evaluated by X-ray diffraction (XRD) and scanning electron microscope (SEM) techniques. The XRD pattern of the PANI and PANI/Ta2O5 confirm the formation of PANI and its composite. The average crystallite size of the PANI is 2.86 nm which is increased to 46.80 nm when Ta2O5 was doped in the PANI matrix. SEM micrographs of the composite confirm the morphological changes in the composite materials. In the electrical conductivity studies, ac conductivity was carried as function of frequency and dc conductivity was studied as a function of temperature. Further to describe the dielectric properties of the PANI and composite, dielectric constant and dielectric loss was studied as a function of frequency.

Synthesis and investigation of the structural properties of vanadium pentaoxide nano thread at low temperature

Vanadium Oxides nanomaterial has shown a great potential in numerous application due to its high light absorption phenomena in the visible range. Among all the possible phases of vanadium oxides, herein we report a simple and facile hydrothermal route for the synthesis of vanadium pentaoxide (V2O5) synthesis at low temperatures. Thread like nanostructures of V2O5 were developed by calcination of vanadyl glycolate (VO(CH2O)2) which was synthesized by hydrothermal route using ammonium vanadate as precursor in the presence of hydrochloric acid (HCL) at low temperature 180 °C. Our develop process of synthesis is free from any templates and reduction agents. Further, the morphology, chemical and structural properties was characterized using Field Emission-Scanning Electron Microscopy, X-ray diffraction, Raman profile and FTIR spectroscopy. The FESEM studies confirms the formation of vanadium pentaoxide in thread shape with thickness in the range of 80 ± 20 nm and length in 4–5 µm. Also, X-Ray diffraction and Raman profile reveals the formation of the orthohombic phase of V2O5.The above synthesized nanostructure materials can be further used in enhancing li-ion batteries efficiency and various thermal and optoelectronic applications.

Spectrophotometric Determination of Benzocaine via Oxidation and Bleaching Colour of Rifampicin Dye

Benzocaine(BENZ) has been estimated by indirect spectrophotometric method. The suggested method based on oxidation of BENZ via N-bromosuccinamide (NBSA) in presence of hydrochloric acid, then the unreacted or the excess NBSA was immerse in bleaching the colour of rifampicin dye(REFPD),the absorbance of unreacted REFPD has been estimated at wavelength 476 nm (the highest absorption of REFPD) .The measured absorbance is directly proportional to the amount of BENZ in the solution. All parameters affected the oxidation of BENZ and bleaching the colour of REFPD and the optimum values have been fixed. Beer’s law(linearity) of the method is in the range of 2 to 15 μ.g.ml−1, the molar absorptivity value equal to 4.295 x 10 3 l.mol−1.cm−1 and the Sandall’s index for sensitivity is calculated and equal to 0.0384 μg.cm−2. The suggested method has an application part included estimation of BENZ in its pharmaceutical formulation (sterile ear drops).

Effect of the hydrochloric acid concentration on the surface-active and functional characteristics of linear alkylbenzenesulfonic acid

The surface-active (surface tension, adsorption, molecule cross-sectional area in the adsorption monomolecular layer) and colloidal (viscosity, critical micelle concentration, solubilization) properties in aqueous and hydrochloric acid solutions of anionic surfactant alkylbenzenesulfonic acid (ABSA) were studied. Surface activity of ABSA increases in the presence of hydrochloric acid. Two inflections were established on adsorption isotherms with inorganic acid content of 5 and 10 wt. %, which are indicative of stepwise micelle formation. The ABSA dissociation is suppressed in the presence of hydrochloric acid, and therefore it behaves as a nonionic surfactant, forming micelles at lower concentrations. Mixed micelles, formed by dissociated and non-dissociated surfactant particles, are organized with an increase of ABSA content in mixture. The value of the surfactant limiting adsorption increases significantly at small hydrochloric acid amounts in comparison with an aqueous solution. The formed monomolecular layer is denser in the presence of inorganic acid than in an aqueous solution. The solubilization of Sudan I dye in alkylbenzenesulfonic acid increases with increasing in solution acidity. The extremum points on isotherms of solubilizing ability with 5 and 10 wt. % HCl content are observed at surfactant concentrations corresponding to the beginning and end of the formation of micelles containing alkylbenzenesulfonate ion.

Study of oxidation of dyes by N-chlorosuccinimide in aqueous acetic acid medium: A kinetic and mechanistic

Kinetics of oxidation of Dyes by N-Chlorosuccinamide(NCS) in acetic acid medium has been done in the presence of hydrochloric acid. The reaction follows first order kinetics with respect to both [NCS], [Substrate] and [HCl]. Increases in ionic strength increases the rate and addition of the reaction product succinamide has a slight retarding effect on the reaction rate. Increase in the dielectric constant of the medium decreases the rate. Activation parameters have been evaluated from Arrhenius plot by studying the reaction at different temperature [40-55 oC] and oxidation products are identified. A most probable reaction mechanism is proposed and an appropriate rate law is deduced to account for the observed kinetic data.

From cyclohexanone to photosensitive polyesters: Synthetic pathway, basic characterization, and photo-/halochromic properties

A bifunctional photosensitive monomer, 2,6-bis-(4-hydroxybenzylidene)cyclohexanone (DHCH) was successfully synthesized by the condensation reaction of cyclohexanone with p-hydroxybenzaldehyde in the presence of hydrochloric acid, as a catalyst. Based on DHCH, a series of new photosensitive polyesters were prepared by a polycondensation reaction, in solution, using two phosphonic dichlorides, namely, phenylphosphonic dichloride and phenyl dichlorophosphate, or two aromatic dichlorides, namely, terephthaloyl chloride and terephthaloyl-bis-(4-oxybenzoylchloride). The synthesis of monomer and polymers was structurally confirmed by FT-IR and NMR spectroscopies. The thermal behavior of polyesters was investigated by DSC measurements and polarized optical microscopy observations, which evidenced thermotropic liquid crystalline properties for some of the studied polymers. The photoresponsive properties of the prepared polyesters were extensively investigated in CHCl3 and DMSO solutions, under irradiation with UV light (254 and 365 nm) at different time intervals and after successive titrations with acid/base solutions. Under UV light irradiation, these compounds undergo photocrosslinking reactions and their photoluminescence properties were strongly enhanced. Deprotonation (under the basic conditions) of the polymers led to the emergence of a new absorption band (with maximum at 508 nm), accompanied by a photochromic behavior. This color change, from colorless to orange, observed upon titration with dilute NaOH solution, was completely recovered to its original colorless after the addition of an equivalent amount of dilute HCl solution. The reversible color changes (halochromic properties) observed upon protonation/deprotonation prove that these polymers have potential applications in chemical sensors.