Addition Of Sodium Dodecyl Sulfate Research Articles

Effect of sodium dodecyl sulphate on the rheological and carbon sequestration properties of cemented paste backfill with CO2 injection

Cemented paste backfill (CPB) is a technology that has a positive impact on both the environment and mining safety. In recent years, it has been widely applied and developed. To improve the carbon sequestration efficiency of CPB, air-entraining agent addition to CO2-injected CPB (CO2-CPB) has been proposed. However, the influence of air-entraining agents on the rheological and carbon sequestration properties of CO2-CPB has not been investigated to date. Therefore, sodium dodecyl sulphate (SDS), an air-entraining agent, was selected in this study, and the rheological and carbon sequestration properties of CO2-CPB added with SDS were comprehensively investigated. CO2-CPB samples with 0.0‰, 0.5‰, 1.0‰, and 1.5‰ SDS were prepared, and the rheological parameters (yield stress and viscosity) were tested after curing for 0, 0.25, 1, and 2 h. Gas content testing, microscopic analysis, and zeta potential measurements were performed. The results show that SDS addition decreased the yield stress and viscosity of CO2-CPB at 0–1 h; however, the yield stress and viscosity increased at 2 h. SDS addition significantly improved the carbon sequestration performance of CO2-CPB. The findings of this study have important implications for carbon sequestration development in CPB and solid waste utilisation.

Investigation of SDS on Corrosion Behavior and Discharge Performance of AZ31B Magnesium Alloys in Aqueous Magnesium Air Batteries

Abstract To address the issue of high self-corrosion rate of Mg anodes in seawater batteries leading to low discharge efficiency, the green inhibitor, sodium dodecyl sulfate (SDS), was utilized to enhance the discharging performance of AZ31B alloy. The addition of SDS in a 3.5% NaCl solution led to a reduction in the corrosion rate of AZ31B alloy due to the formation of S-containing compounds. During the continuous-discharging period, the addition of 0.05M SDS increased the anodic utilization efficiency from 64% to 81% and the specific energy density of the entire battery elevated from 1280 to 1912 mAh g-1 (an increase of 49%). The enhancement of the discharge performance of AZ31B Mg alloy in a 3.5% NaCl solution by SDS can be attributed to three aspects: reducing the negative difference effect of the Mg alloy, decreasing the accumulation of corrosion products on the surface of the Mg alloy, and promoting a more uniform dissolution of the Mg alloy.

Effective Corrosion Inhibition of Galvanic Corrosion of Cu Coupled to Au by Sodium Dodecyl Sulfate (SDS) and Polyethylene Glycol (PEG) in Acid Solution

This study investigates the effects of sodium dodecyl sulfate (SDS) and polyethylene glycol (PEG) on the galvanic corrosion behavior of copper (Cu) coupled to gold (Au) in a printed circuit board (PCB) etching solution. Galvanic corrosion tests using ZRA (zero resistance ammeter) were performed to determine the optimal SDS concentration for corrosion inhibition. The corrosion current between Cu and Au decreased significantly with the addition of SDS, from 3.26 mA/cm2 to 0.248 mA/cm2 at 4 mM SDS, achieving an inhibitor efficiency (IE) of 92.3%. However, at 15 mM SDS, the corrosion current increased, and IE decreased to 80.5%. This phenomenon is attributed to the critical micelle concentration (CMC) of SDS, where surfactant molecules aggregate and reduce surface adsorption properties. Similarly, ZRA tests were conducted to analyze the effects of PEG on galvanic corrosion. The corrosion current significantly decreased with PEG addition, achieving 98.1% IE at 1 g/L and 99.5% IE at 2 g/L. Beyond this concentration, no significant change in IE was observed, indicating saturation. Potentiodynamic polarization tests were also conducted to study the individual effects of SDS and PEG on Cu and Au. The results showed that SDS effectively inhibited Cu corrosion but had a minimal impact on Au. In contrast, PEG significantly reduced the corrosion current density for both Cu and Au, with reductions of 99.5% and 95.1%, respectively.

Impedance Spectroscopy Unveiled the Surfactant-Induced Unfolding and Subsequent Refolding of Human Serum Albumin.

Protein-surfactant interaction is a dynamic interplay of electrostatic and hydrophobic forces that ensues from the folding of a protein. We employ impedance spectroscopy (IS), a label-free method, to investigate the unfolding and refolding of human serum albumin (HSA), a globular plasma protein, in the presence of two surfactants: polysorbate-20 (Tween-20), a nonionic surfactant, and sodium dodecyl sulfate (SDS), an anionic surfactant. The equivalent electrical analog circuit was predicted from impedance spectra of HSA in an aqueous solution at physiological pH and room temperature, focusing on varying the concentration of codissolved surfactants. A change in the dielectric constant (ε') and ionic conductivity (κ) is observed by comparing the surfactant-treated protein samples to the bare surfactant solutions to assess the conformational changes induced by surfactants in HSA. Far-UV circular dichroism analysis revealed a decrease in α-helices and an increase in β-sheets and random coils upon SDS addition, which were reversed by Tween-20. Dynamic light scattering supported the findings by measuring changes in the hydrodynamic diameter (dh) of HSA. Unfolding and refolding of HSA with surfactants were also observed through photoluminescence spectroscopy by examining the microenvironment surrounding the single tryptophan (W) within the protein, and the thermodynamic parameters were obtained using the modified Stern-Volmer equation. Our research explores the intriguing domain of protein-surfactant interactions, offering insights with promising applications across diverse biological processes and IS as a suitable alternative technique for investigating protein conformational changes by studying the electrical response of the samples.

Impact of four surfactants on the uptake of per- and polyfluoroalkyl substances (PFAS) by red fescue grass

Per- and polyfluoroalkyl substances (PFAS) pose great risks to human health and the ecosystem, necessitating effective remediation strategies such as phytoremediation. Surfactants, due to their ability to increase the bioavailability of hydrophobic contaminants, are considered as potential agents to improve phytoremediation for PFAS. In this research, we explored the impact of four surfactants (sodium dodecyl sulfate (SDS), rhamnolipid, Triton X-100, and Glucopone 600 CS UP) on plant growth and the uptake of PFAS by red fescue over 110 days. The results showed that while surfactants at lower concentrations did not negatively affect plant growth, the highest dose (2,500 mg/kg) significantly reduced the dry weight of plant shoots. Although none of the four surfactants led to an increased overall removal efficiency of ∑PFAS by red fescue over 110 days, SDS did enhance the uptake of PFAS compounds with long carbon chain lengths. With SDS addition at 2,500 mg/kg, the average fold increases of long chain PFAS removal were 1.99 for perfluorooctanoic acid (PFOA), 2.44 for perfluorononanoic acid (PFNA), 2.11 for perfluorodecanoic acid (PFDA), 1.52 for perfluoroundecanoic acid (PFUnA), 1.88 for perfluorohexanesulphonic acid (PFHxS), and 2.97 for perfluorooctanesulfonic acid (PFOS). The research indicated that using surfactants, such as SDS at appropriate doses could improve phytoremediation effectiveness in mitigating long-chain PFAS, which is a known challenge in soil remediation.

Unravelling the polymorphic characteristics of carbamazepine through additive-assisted sonocrystallisation

ABSTRACT This paper investigates the influence of additives on the antisolvent crystallisation process of carbamazepine (CBZ) using methanol as the solvent and water as the antisolvent, with ultrasonic irradiation at a specific solvent-to-antisolvent (S/A) ratio of 1:2 and a 30-watt power ultrasonic horn. Various additives, such as Hydroxypropyl Methyl Cellulose (HPMC), Bovine Serum Albumin (BSA), Tween 80, and Sodium Dodecyl Sulphate (SDS), were employed to examine their effects on the morphology, stability (including suspension and thermal stability), crystallinity, and polymorphism of CBZ crystals. Raw CBZ exhibited irregular shapes during crystallisation, while SDS addition resulted in both plate-like and needle-like crystals. Conversely, BSA, HPMC, and Tween 80 induced the formation of needle, plate, and block-like crystal structures, respectively. Suspension stability ranked as SDS > BSA > HPMC > Tween 80. Regarding polymorphism, HPMC favoured Form 1, BSA and SDS favoured Form IV, and Tween 80 favoured Form I. Additionally, Tween 80 depicted similar preference for Form I polymorph as HPMC. Notably, Form II and Form III polymorphs were present to varying degrees in all samples, except for Tween 80. This study provides crucial insights into the controlled crystallisation of CBZ and the impact of additives on crystal properties, offering valuable information for tailoring CBZ crystal production for specific pharmaceutical applications.

CO2/H2 Separation by Synergistic Enhanced Hydrate Method with SDS and R134a.

The synergistic effect of thermodynamic promoter tetrafluoroethane (R134a) and kinetic promoter sodium dodecyl sulfate (SDS) can significantly improve the phase equilibrium conditions required for CO2 hydrate formation and promote rapid generation of CO2 hydrate. Based on this, this study investigates the influence of SDS and R134a synergy on the separation of CO2/H2 mixed gas using the hydrate method. The research reveals that without SDS addition, R134a hydrate forms first at the gas-liquid interface before CO2 hydrate induction, hindering gas-liquid exchange. The addition of SDS can inhibit the formation of the hydrate film, enhance the initiator effect of R134a in the CO2 hydrate formation process, accelerate the nucleation of CO2 hydrate, and thus synergistically strengthen the separation of CO2/H2 mixed gases. Hydrate formation can be achieved at a concentration of 100 ppm of SDS solution, and the synergistic growth effect of R134a and CO2 hydrate becomes more significant with increasing SDS concentration. Optimal separation efficiency and maximum H2 concentration are achieved at 500 ppm of SDS, with 42.29 and 54.88% separation efficiency and H2 concentration, respectively. Decreasing the initial charge temperature has little impact on separation efficiency but significantly reduces the induction time, reducing it to 3 min at 12 °C. This study improved the separation efficiency of CO2 and H2 mixed gas, providing a better reference for hydrogen purification by the hydrate method.

Voltammetric determination of the antifungal drug posaconazole in the presence of an anionic surfactant on a boron-doped diamond electrode

This study describes a new, fast and simple procedure of electrochemical assay of posaconazole (PCZ), which is currently regarded as one of the most important antifungal agents, recommended in the treatment of systemic infections, effective even against rare and atypical kinds of fungi. PCZ is very effective and safe, displaying much lower toxicity than other traditional antifungal drugs. A new, attractive procedure of assaying the compound on boron-doped diamond (BDD) electrode after cathodic pretreatment in the presence of sodium dodecyl sulfate (SDS) is presented in the work. The anionic surfactant SDS was selected after the comparative analysis of various cationic surfactants. PCZ gave a single irreversible oxidation peak at the potential of 0.59 V. The addition of SDS resulted in an almost 5-fold growth in the value of recorded currents as compared to those observed in the absence of the surfactant. The highest peak was obtained in Britton-Robinson buffer at pH 3.78. The calibration curve of PCZ plotted using the SWV technique was linear in the concentration range from 1.34·10−8 mol/L to 1.44·10−6 mol/L. The limit of detection and limit of quantification were 3.78·10−9 mol/L and 1.14·10−8 mol/L, respectively. The value of relative standard deviation of the measurements did not exceed 4.42 %, which proves good precision of the proposed method. The proposed procedure was successfully used in assaying PCZ in simulated gastric juice.

Microscopic characteristics of CO2 residual trapping in saline aquifers: Experimental study based on X-ray microtomography

The occurrence form and migration characteristics of CO2 in pores have a direct impact on CO2 residual trapping and the safety of CO2 sequestration. In this work, we conduct core flooding and CT scanning experiments at different permeabilities, brine salinities, and sodium dodecyl sulfate (SDS) concentrations. We measure the CO2-brine-rock contact angles in situ and quantitatively analyze the microscopic characteristics of CO2 residual trapping in the pores. The experimental results indicate that CO2 primarily occurs in the form of network, cluster, and droplet. The efficiency of CO2 residual trapping is closely linked to the pore structure, with a higher permeability resulting in less effective trapping. Furthermore, an increase in salinity weakens the hydrophilicity of the sandstone, while the addition of SDS enhances it. The higher the SDS concentration, the greater the sandstone hydrophilicity. When the sandstone hydrophilicity is enhanced, the efficiency of CO2 residual trapping also increases. Additionally, a low permeability, low salinity, and high SDS concentration all result in 20%–35% increase in the frequency of CO2 network formed in the pores, which is advantageous for CO2 residual trapping. These findings clarify the possible occurrence forms of gaseous CO2 in the pores and their variations under different conditions and are also expected to help establish methods for improving CO2 residual trapping efficiency to enhance the long-term safety of CO2 sequestration in shallow saline aquifers.

Colloidal interactions between nanochitin and surfactants: Connecting micro- and macroscopic properties by isothermal titration calorimetry and rheology

This study elucidates the intricate interactions between chitin nanocrystals (ChNC) and surfactants of same hydrophobic tail (C12) but different head groups types (anionic, cationic, nonionic): sodium dodecyl sulfate (SDS), dodecyltrimethylammonium bromide (DTAB), and polyoxyethylene(23)lauryl ether (Brij-35). Isothermal Titration Calorimetry (ITC) and rheology are used to study the complex ChNC-surfactant interactions in aqueous media, affected by adsorption, self-assembly and micellization. The ITC results demonstrate that the surfactant head group significantly influences the dynamics and nature of the involved phenomena. Cationic DTAB's reveal minimal interaction with ChNC, non-ionic Brij-25's interact moderately at low concentrations driven by hydrophobic effects while SDS's interacts strongly and show complex interaction patterns that fall across four distinct regimes with SDS addition. We attribute such behavior to initiate through electrostatic attraction and terminate in surfactant micelle formation on ChNC surfaces. ITC also elucidates the impact of ChNC concentration on key parameters including critical aggregation concentration (CAC) and saturation concentration (C2). Dynamic rheological analysis indicates the molecular interactions translate to non-linear variations in the elastic modulus (G') upon SDS addition mirroring that observed in ITC experiments. Such a direct correlation between molecular interactions and macroscopic rheological properties provides insights to aid in the creation of nanocomposites with tailored properties.

Enhanced environmental stability and luminescence performance of CsPbI3 nanocrystals through SDS passivation and LEuH anchoring

CsPbI3 perovskite nanocrystals (NCs) have been identified as promising candidates for optoelectronic devices due to their low bandgap, wide absorption spectrum, and high color purity. However, their practical applications are limited by their vulnerability to transforming into the yellow non-perovskite phase in ambient conditions. In this study, we propose a novel approach to prepare highly stable black-phase CsPbI3 NCs by passivating them with sodium dodecyl sulfate (SDS) and anchoring them with flower-like layered europium hydroxide (LEuH). The addition of SDS to CsPbI3 NCs plays a crucial role in inhibiting defect formation by preventing the ligand from desorbing. Furthermore, LEuH, with its surface OH– groups, effectively anchors the CsPbI3 NCs onto its nanosheets, preventing their agglomeration. The resulting composite LEuH-SDS-CsPbI3 nanocomposites exhibit extraordinary environmental stability, maintaining their phase structure even after 60 days of storage under ambient conditions. Additionally, their photoluminescence quantum yield reaches an impressive 95 %. The exceptional luminescence performance of the LEuH-SDS-CsPbI3 nanocomposites opens up new possibilities for their application in optoelectronic devices. Furthermore, when used in white LEDs, these nanocomposites exhibit excellent luminescence efficiencies, further highlighting their potential for commercial utilization in the field.

Effects of substrate (track-etched filter) properties on the performance of forward osmosis membranes

Highly permeable membranes can improve the validity of water treatment using forward osmosis (FO) membranes. This study aims to identify the effects of substrate (track-etched (TE) filter) properties on the permeability of FO membranes. The polyamide active layer properties of three types of TE filters with similarly-sized pore diameters (0.2 μm) were observed to be equivalent regardless of the substrate porosity (13.7%–15.8 %) and substrate thickness (10–25 μm). Under the same fabrication protocol using 1.5 wt% m-phenylenediamine (MPD) solution with 0.25 wt% sodium dodecyl sulfate (SDS) addition, the increased porosity of the TE filter increased water flux. This suggested that further reduction in thickness and increase in porosity can enhance the water flux. The addition of SDS to an MPD solution was crucial in maximizing the water flux of TE filter-based FO membranes, and the other approaches (no surfactant addition or the addition of Tween80 or hexadecyltrimethylammonium bromide) produced lower water flux. The optimized fabrication protocol presented the highest water flux of 43 L/m2h and reverse salt flux of 10 g/m2h with the draw (1.0 M NaCl) and feed (pure water) solutions. This study determined the best approach for forming a highly permeable PA active layer on TE filters.

Surfactant Effects in Porous Electrodes for Microemulsion Redox Flow Batteries

The effect of surfactant additives on electrochemical behavior in porous electrodes was investigated using vanadium redox flow battery half-cells and the dependence of volumetric kinetics and mass transport on electrolyte, surfactant, and electrode type was explored. Without surfactant added, carbon paper electrodes demonstrated greater kinetics and transport compared to carbon felt, for a given electrolyte. Additionally, posolyte kinetics are greater than negolyte kinetics by one to three orders of magnitude, depending on the electrode type. Addition of surfactant increased electrode wettability and possibly electrochemical surface area. However, this was accompanied by a decrease in volumetric mass transport, due to stronger electrolyte-electrode interactions. The presence of sodium dodecyl sulfate (SDS) influenced posolyte and negolyte kinetics differently. Kinetics showed a dependence on electrode type and surfactant. On carbon felt, volumetric kinetics decreased for both posolyte and negolyte with SDS addition. On carbon paper, SDS decreased volumetric kinetics for the posolyte but increased (>2X) kinetics for the negolyte! This kinetic enhancement depends on surfactant chemistry: cetyltrimethylammonium bromide, a cationic surfactant, failed to increase kinetics. Furthermore, SDS did not increase areal specific resistance. These findings show the superior performance of carbon paper compared to carbon felt and suggest SDS as a possible VRFB negolyte additive.

Polyvinyl alcohol: Starch based membrane scaffolds for tissue transparency requirements: Fabrication, characterization and cytotoxicity studies

In this study, the characterization and cytocompatibility of polyvinyl alcohol:starch (PVA:ST) based membrane tissue scaffolds developed for tissue transparency requirements in tissue engineering applications were evaluated in the presence of sodium dodecyl sulphate (SDS). In this context, two different amounts of SDS were added to the polymer structure of transparent membrane scaffolds to roughen the surfaces of PVA:ST membranes and to promote cell adhesion. In the light of this aim, three different types of membranes were created: A constant PVA:ST ratio of 9:1 (wt:wt) was used as a control and varying amounts of SDS (2 and 4 wt% of the total polymer amount) were added to the polymer solutions. Membrane tissue scaffolds were formed by freeze-drying method. Scaffold properties such as morphology, transparency, water absorption, chemical structure and cytocompatibility were investigated. In terms of physicochemical properties, it was observed that with the addition of SDS, the membranes had a rougher surface while retaining water retention and transparency. In cytotoxicity studies, the membranes were found to be non-cytotoxic and promoted cell proliferation as assessed by MTT assay. Furthermore, the PVA:ST membrane scaffold with 4% SDS added was able to promote the attachment, migration and proliferation of Mouse Embryonic Fibroblasts (MEFs) more than the control group. Overall, the results indicate that SDS-added PVA:ST scaffold membranes are suitable for human corneal stromal regeneration, wound dressing material and neural tissue engineering applications.

Enhanced hydrogen sequestration through hydrogen foam generation with SDS Co-Injection in subsurface formations

Inherent obstacles of hydrogen injection encompass preferential channeling through larger pathways, hampering microscopic sweep efficiency within porous media. This work pioneers hydrogen foam generation via co-injection with aqueous sodium dodecyl sulfate (SDS) to enhance subsurface hydrogen trapping capacity. SDS addition substantially reduces hydrogen-water interfacial tension and enhances viscoelasticity. In contrast to robust hydrogen foam stability, CO2 foams display compromised integrity, stemming from surfactant aggregation and ensuing infiltration channels that permit aqueous phase CO2 dissolution. Hydrogen foams conversely sustain uniform surfactant films, forestalling hydrogen ingress into water. Synergetic microfluidic and pore-scale simulations visualise mechanisms underlying intensified hydrogen capture and mobility reduction attributed to deformation and flow resistance when traversing constricted pores. Introducing the amphiphilic SDS surfactant considerably promotes hydrogen adsorption through its hydrophobic tail. Core flooding experiments quantify over 2 times hydrogen storage ratio amplification with SDS relative to sole hydrogen injection. The framework contributes pragmatic strategies to harness high-efficiency hydrogen foam for scalable clean energy storage.

Impact of anthracite blending and SDS addition on slurryability and stability of Indian high ash coal water slurry

ABSTRACT The conventional modes of transporting coal frequently result in substantial fiscal challenges and environmental deterioration. Slurry-based hydraulic transportation of coal through pipelines has proven to be a feasible and efficient method, offering economic benefits, reliability and minimal ecological damage. Due to the limited and rapidly depleting reserves of high-rank coal, the scientific community is compelled to utilize high ash coal (HAC) to meet the growing demands of the population. The HAC slurry is characterized by poor slurryability, stability and low calorific value. This research presents a straightforward solution to enhance the slurryability and stability of Indian HAC while improving its calorific value. Anthracite and anionic additive sodium dodecyl sulfate (SDS) were added in Indian HAC to prepare a high solid loading blended slurry with improved stability. The rheological characteristics, stability and zeta potential of prepared slurry samples were assessed and analyzed to determine the optimum anthracite proportion and SDS concentration. The optimum anthracite proportion and SDS concentration for low apparent viscosity and maximum stability were 30% and 0.6%, respectively. The inclusion of anthracite and SDS at optimal proportion yielded a slurry with 66% solid concentration, indicating a surge of 14% in the maximum possible solid loading.

Ultrasound assisted electrodeposition of photocatalytic antibacterial MoS2-Zn coatings controlled by sodium dodecyl sulfate

Photocatalytic MoS2 with visible light response is considered as a promising bactericidal material owing to its non–toxicity and high antibacterial efficiency. However, photocatalysts always exist as powder, so it is difficult to settle photocatalysts on the metal surface, which limits their application in aqueous environments. To solve this problem, ultrasound and sodium dodecyl sulfate (SDS) were introduced into the co-deposition process of MoS2 and zinc matrix, so that novel MoS2–Zn coatings were obtained. In this process, ultrasound and SDS strongly promoted the dispersion and adsorption of MoS2 on the co-depositing surfaces. Then MoS2 were proved to be composited into the Zn matrix with effective structures, and the addition of SDS effectively increased the loading content of MoS2 in the MoS2–Zn coatings. Besides, the antibacterial performance of the MoS2–Zn coatings was evaluated with three typical fouling bacteria E.coli, S.aureus and B.wiedmannii. The MoS2–Zn coating showed high and broad–spectrum antibacterial properties with over 98 % inhibition rate against these three bacteria. Furthermore, it is proved that the MoS2–Zn coatings generated superoxide (·O2−) and hydroxyl radicals (·OH) under visible light, which played the dominant and subordinate roles in the antibacterial process, respectively. The MoS2–Zn coatings also showed high antibacterial stability after four “light–dark” cycles. According to the results of the attached bacteria, the MoS2–Zn coatings were considered to effectively repel the living pelagic bacteria instead of killing the attached ones, which was highly environmentally friendly. The obtained MoS2–Zn coatings were considered promising in biofilm inhibiting and marine antifouling fields.

(Invited) The Effect of Surfactants on Vanadium Electrochemistry in Porous Carbon Electrodes

We present a study of vanadium electrochemistry in porous electrodes with and without sodium dodecyl sulfate (SDS) additives present. Carbon paper and felt electrodes are compared. Carbon felt electrodes are the de facto standard in flow batteries. There are significant differences in the electronic conductivity of these media. The carbon paper has a much higher conductivity than the felt, which has an electronic conductivity similar to the ionic conductivity of the electrolytes used. The latter fact motivates an extension of available theory for polarization curve fitting to explicitly include both electronic and ionic contributions in the porous electrode. We demonstrate agreement between our model and an existing model evaluated at the limit where electrode conductivity is significantly greater than electrolyte conductivity. Our model uses the product of the electrode surface area per volume ratio and the heterogeneous electron transfer rate constant, and the Damköhler number as fitting parameters for carbon paper and felt electrodes. We discuss the effect of SDS additives on kinetics in the context of the cation hydration shell for the vanadium ions. To this point, we apply Marcus-Hush-Chidsey formalism to our porous electrode model to quantify reorganization energies obtained through polarization curve fitting. This work was supported as part of the Breakthrough Electrolytes for Energy Storage (BEES2), an Energy Frontier Research Center funded by the United States. Department of Energy, Office of Science, Basic Energy Sciences under Award # DE-SC0019409.

Study of Chemical Polymerization of Polypyrrole with SDS Soft Template: Physical, Chemical, and Electrical Properties.

Polypyrrole (PPy) is a conductive polymer known for its biocompatibility and ease of synthesis. Chemically polymerized PPy was synthesized in the presence of sodium dodecyl sulfate (SDS), showing correlations among chemical properties, physical morphology, and electrical properties. Focused synthesis parameters included the pyrrole (Py) concentration, SDS concentration, and ammonium persulfate (APS)/Py ratio. The addition of SDS during chemical polymerization influenced the physical morphology of PPy by altering the self-assembling process via micelle formation, yielding sheet-like morphologies. However, the phenomenon also relied heavily on other synthesis parameters. Varying SDS concentrations within the 0.01 to 0.30 M window produced PPy sheets with no significant difference in optical band gap or physical size. While using 0.10 M SDS, an increase in Py concentration from 0.10 to 0.30 M yielded a larger size of PPy as the morphology changed from sheet-like to irregular shape. The band gap dropped from 2.35 to 1.10 eV, and the conductivity rose from 6.80 × 10-1 to 9.40 × 10-1 S/m. With an increase in the APS/Py ratio, the PPy product changed from a random to a sheet-like form. The product provided a larger average size, a decreased band gap, and increased electrical conductivity. Py polymerization in the absence of SDS revealed no significant change in shape or size as the Py concentration increased from 0.10 to 0.30 M; only a sphere-like form was observed, with a large band gap and small conductivity. Results from Raman spectral analysis indicated a correlation between optical band gap, physical morphology, and bipolaron/polaron ratio, mainly at the wavelengths associated with C-C stretching and C-H deformation. The increase in average size was associated with a decrease in band gap and resistance as well as an increase in the bipolaron/polaron ratio. This work indicates a strong correlation between size, morphology, electrical properties, and the bipolaron/polaron ratio of PPy in the presence of SDS.

Investigation of Deposition Conditions and Basic Properties of CNF Composite Ni Plated Film by Electroless Plating Method

Ni-cellulose nanofiber (CNF) composite plated films were fabricated by electroless plating method. The deposition conditions and basic properties of the Ni-CNF composite film were investigated. A C1100 plate was used as the plated material, and a Ni-P electroless plating bath was prepared as the plating solution. 5 g/L of 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) oxidized CNF or carboxymethyl cellulose was added to the plating solution. Sodium dodecyl sulfate (SDS) was added as a surfactant. It was confirmed that CNFs were complexed on the surface of the plated film, and the addition of SDS made CNFs disperse into the plated film. The surface of the plated film obtained by adding both TEMPO oxidized CNF and SDS had the highest Vickers hardness among all conditions investigated.