Study of the Synthesis and Characterization of Poly(acrylic acid-co-acrylamide)-kaolinite Composite Reference to Adsorption of Cd and Pb from Aqueous Solutions

2021 ◽  
Vol 43 (2) ◽  
pp. 165-165
Author(s):  
Munazzah Saeed Munazzah Saeed ◽  
Manzoor Iqbal Manzoor Iqbal ◽  
Mahmood Iqbal Mahmood Iqbal ◽  
Sayed Muhammad Salman and Sadiq Afridi Sayed Muhammad Salman and Sadiq Afridi
Keyword(s):  
Acrylic Acid ◽  
Langmuir Isotherm ◽  
Structural Equation ◽  
Cost Effective ◽  
Equation Modeling ◽  
Order Kinetic ◽  
Freundlich Adsorption Isotherm ◽  
Equilibrium Amount ◽  
Cadmium And Lead ◽  
Poly Acrylic Acid

A novel poly(acrylic acid-co-acrylamide)/ kaolinite composite was produced by copolymerization of partially neutralized acrylic acid and acrylamide with sawdust for crosslinking applying Bis-acrylamide having linear formulae (C₇H₁₀N₂O₂.), (H₂C=CHCONH) 2CH₂, potassium persulfate, K2S2O8 as initiator and sodium sulphite used as accelerator to reduce the polymerization time. Physiognomy of the composite was performed by techniques viz., Fourier Transform Infrared Spectroscopy, X-Radiation Diffractometry (Crystallography), Structural-Equation-Modeling, Energy-Dispersal X-Radiation-Analysis and Brunauer-Emmett-Teller methods. Divalent cadmium and lead electrolytes (adsorbate) adsorption on the adsorbent (composite) in aqueous solution was studied in batch experiments optimizing reaction parameters like “IA” of equilibrium amount, “CT” (wet time), neutrality (alkalinity and acidity) and calefaction (thermal reading). The quasi 2nd order kinetic archetypal ensued by AK. Adsorption isotherrms were applied to the empirical statistics which fitted well with a) Irving-Langmuir-isotherm and b) Freundlich adsorption isotherm. The supreme adsorption dimensions, qm (from Irving-Langmuir isotherm) at 25oC, were 28.57 mg g-1 and 32.25 mg g-1 for divalent cadmium and lead electrolytes, respectively. Data of activation energy (12.148 kJ mol-1 and 7.165 kJ mol-1 for divalent cadmium and lead electrolytes respectively) indicated physio-absorption. Results of thermodynamic parameters like ∆Go, ∆Ho and ∆So for both divalent cadmium and lead electrolytes suggested the phenomenon of the endothermic and spontaneity nature of the process. The newly synthesized composite attributed to its cost effective and environment friendly nature of the synthesis which will be deemed as a capable substance for the exclusion of adsorbent divalent cadmium and lead electrolytes from aqueous suspensions.

scholarly journals Preparation and structure of SiOCN fibres derived from cyclic silazane/poly-acrylic acid hybrid precursor

2019 ◽  
Vol 6 (10) ◽  
pp. 190690
Author(s):  
Zhongkan Ren ◽  
Christel Gervais ◽  
Gurpreet Singh
Keyword(s):  
Acrylic Acid ◽  
Photoelectron Spectroscopy ◽  
Thermo Gravimetric Analysis ◽  
Ceramic Matrix Composite ◽  
Linear Structure ◽  
Cost Effective ◽  
Gravimetric Analysis ◽  
Low Viscosity ◽  
Hybrid Precursor ◽  
Poly Acrylic Acid

Ceramic matrix composite (CMC) materials have been considered a desired solution for lightweight and high-temperature applications. Simultaneously, among all different CMC reinforcements, polymer-derived ceramic (PDC) fibres have gained attention for the intrinsic thermal stability and mechanical strength with simple and cost-effective synthesis techniques. Here, carbon-rich SiOCN fibres were synthesized via hand-drawing and polymer pyrolysis of a hybrid precursor of 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasilazane (TTCSZ) and poly-acrylic acid (PAA). The type of silazane reported in this work is considered as a major precursor for SiCN; however, it is unspinnable, due to its unfavourable physical properties (low viscosity) and chemical structure (cyclic rather than linear structure). The introduction of PAA to TTCSZ to create a hybrid precursor remarkably improved the spinnability of the silazane and should be widely applicable to other unspinnable PDC pre-ceramic polymers. Investigations on the structural and compositional development of the fibres were mainly conducted via Raman spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, nuclear magnetic resonance and thermo-gravimetric analysis to determine spinnability, free carbon content, cross-linking and pyrolysis behaviour of the fibres, respectively.

scholarly journals Towards Sustainable Digital Innovation of SMEs from the Developing Countries in the Context of the Digital Economy and Frugal Environment

2021 ◽  
Vol 13 (10) ◽  
pp. 5715
Author(s):  
Zahid Yousaf ◽  
Magdalena Radulescu ◽  
Crenguta Ileana Sinisi ◽  
Luminita Serbanescu ◽  
Loredana Maria Păunescu
Keyword(s):  
Structural Equation ◽  
Quantitative Research ◽  
Business Models ◽  
Small And Medium Enterprises ◽  
Cost Effective ◽  
Digital Economy ◽  
Equation Modeling ◽  
Economic Activities ◽  
Digital Innovation ◽  
Digital Platforms

This study aims to explore the direct impact of the digital orientation, Internet of Things (IoT) and digital platforms on the sustainable digital innovation in the context of the digital economy and frugal environment. This study also investigated the mediating role of the digital platforms in these relations. The study was based on the quantitative research design and data were collected from the 397 CEOs and managing directors of Small and Medium Enterprises in Pakistan. Correlation and structural equation modeling approaches were applied for the analysis and testing of the hypotheses. Results revealed that the digital orientation, IoT and digital platform are major antecedents of the sustainable digital innovation. Results also show that the digital platforms mediate between both digital orientation-sustainable digital innovation link and IoT-sustainable digital innovation link. The rapid pace of change in the technology has forced the business organizations to think out of box and align their operational mechanism accordingly. The need for the sustainable digital innovation is a major need of the current decade for meeting the increasing demands of the society in a sustainable way. Organizations, especially SMEs, should be able to deal with these challenges and rapid technological transformations through cost effective frugal business models. The frugal innovation is an important element of sustainable digital innovation enables SMEs to reduce resources usage and waste and to enhance sustainable economic activities. In this way, they can develop and gain advantages in this highly competitive digital environment. This is the first study showing the bright harmony of the digital orientation, IoT and digital platforms for achieving the sustainable digital innovation in the rapid evolving digital economy.

scholarly journals Promoting full-fledged electronic money in South Asia: evidence from Bangladesh

2019 ◽  
Vol 14 (4) ◽  
pp. 166-182
Author(s):  
Mohammad Saiful Islam ◽  
Md. Foysal Hasan ◽  
Md. Mashiur Rahman ◽  
Dr. Md. Azizul Baten ◽  
Mohammad Ziaul Islam
Keyword(s):  
Structural Equation ◽  
High Speed ◽  
Economic Effect ◽  
Cost Effective ◽  
Equation Modeling ◽  
Electronic Money ◽  
Revolutionary Change ◽  
Technological Infrastructure ◽  
Gdp Growth Rate ◽  
Financial Framework

The study aims to develop several models for instigating full-fledged electronic money and to study prospects and challenges in the digitization process in the context of South Asian countries such as Bangladesh. Besides, the economic effect of full digitization of currency was analyzed considering its impact on vital economic indicators. Regression analysis, factor analysis and structural equation modeling were used to analyze data. The study suggests some models within the existing financial framework to support the process of instigating and implementing full-fledged electronic money in Bangladesh. The research defines a full-fledged e-money mechanism as a consumption-driven, production-oriented, creditworthy, cost-effective, prompt, technologically based inclusive payment system, as a prospect of full-fledged e-money. Besides, the requirement of an advanced technological infrastructure having secured and user-friendly software with high-speed internet services is identified as a major challenge to full-fledged e-money. The study also found out that a revolutionary change in GDP growth rate and inflation rate will occur through this mechanism.

scholarly journals Recombination of Poly(Acrylic Acid) Radicals in Acidic Aqueous Solutions: A Pulse Radiolysis Study

2021 ◽  
Vol 11 (21) ◽  
pp. 10142
Author(s):  
Małgorzata Matusiak ◽  
Sławomir Kadłubowski ◽  
Piotr Ulański
Keyword(s):  
Acrylic Acid ◽  
Aqueous Solutions ◽  
Ph Dependence ◽  
Polymer Concentration ◽  
Second Order ◽  
Order Kinetic ◽  
Initial Number ◽  
Linear Charge Density ◽  
Kinetics Of ◽  
Poly Acrylic Acid

Carbon-centered radicals have been randomly generated on the chains of poly(acrylic acid), PAA, the simplest synthetic anionic polyelectrolyte, by pulse-irradiating its dilute, oxygen-free aqueous solutions by 6 MeV electron beam. In some experiments, oligo(acrylic acid), OAA, and propionic acid, PA, were used as PAA models. Recombination kinetics of PAA radicals has been followed by fast spectrophotometry. A strong pH dependence of radical lifetime on pH, and thus on the linear charge density due to deprotonated carboxylate groups, has been confirmed, while a weaker amplitude of pH dependence was observed for OAA and PA. Decay kinetics of PAA radicals in the protonated state, at pH 2, have been studied in some detail. At moderate doses of ionizing radiation, resulting in a moderate average initial number of radicals per chain, ZR0, the decay can be satisfactorily described by a second-order kinetic model, but a somewhat better fit is obtained by using a dispersive kinetics approach. While for a constant polymer concentration the reciprocal half-lives are proportional to the initial radical concentrations, such a data series for different PAA concentrations do not overlap, indicating that the overall radical concentration is not the decisive factor controlling the kinetics. Arranging all data, in the form of second-order rate constants, as a function of the average initial number of radicals per chain allows one to obtain a common dependence. The latter seems to consist of two parts: a horizontal one at low ZR0 and another one of positive slope at higher ZR0. This is interpreted as two kinetic regimes where two distinct reactions dominate, intermolecular and intramolecular recombination, respectively. Comparison of the low ZR0 data with calculations based on the translational diffusion model indicate that the latter is not the rate-controlling process in intermolecular recombination of polymer radicals; segmental diffusion is the more likely candidate.

Poly(acrylic acid) modifying bentonite with in-situ polymerization for removing lead ions

2012 ◽  
Vol 65 (8) ◽  
pp. 1383-1391 ◽  
Author(s):  
Y. F. He ◽  
L. Zhang ◽  
D. Z. Yan ◽  
S. L. Liu ◽  
H. Wang ◽  
...  
Keyword(s):  
Experimental Data ◽  
Acrylic Acid ◽  
Metal Ions ◽  
In Situ Polymerization ◽  
Second Order ◽  
Order Kinetic ◽  
Freundlich Isotherms ◽  
Pseudo Second Order ◽  
Poly Acrylic Acid

In this paper, a new kind of poly(acrylic acid) modified clay adsorbent, the poly(acrylic acid)/bentonite composite (PAA/HB) was prepared by in-situ polymerization, and utilized to remove lead(II) ions from solutions. The maximum adsorption of adsorbent is at pH 5 for metal ions, whereas the adsorption starts at pH 2. The effects of contact time (5–60 min), initial concentration of metal ions (200–1,000 mg/L) and adsorbent dosage (0.04–0.12 g/100 mL) have been reported in this article. The experimental data were investigated by means of kinetic and equilibrium adsorption isotherms. The kinetic data were analyzed by the pseudo-first-order and pseudo-second-order equation. The experimental data fitted the pseudo-second-order kinetic model very well. Langmuir and Freundlich isotherms were tried for the system to better understand the adsorption isotherm process. The maximal adsorption capacity of the lead(II) ions on the PAA/HB, as calculated from the Langmuir model, was 769.2 mg/g. The results in this study indicated that PAA/HB was an attractive candidate for removing lead(II) (99%).

Selective Adsorption and Separation of Organic Dyes by Poly(acrylic acid) Hydrogels Formed with Spherical Polymer Brushes and Chitosan

2018 ◽  
Vol 71 (11) ◽  
pp. 846 ◽  
Author(s):  
Rui Zhang ◽  
Hongwei Peng ◽  
Tianxu Zhou ◽  
Min Li ◽  
Xuhong Guo ◽  
...  
Keyword(s):  
Acrylic Acid ◽  
Polymer Brushes ◽  
Electrostatic Interactions ◽  
Separation Efficiency ◽  
Organic Dyes ◽  
Selective Adsorption ◽  
Cationic Dyes ◽  
Order Kinetic ◽  
Double Network ◽  
Poly Acrylic Acid

Direct discharge of industry organic dyes has caused serious environmental pollution. In this study, a series of double network poly(acrylic acid) (PAA) hydrogels were fabricated with spherical polymer brushes (SPBs) and chitosan (CS) as crosslinker. Neutral spherical polyelectrolyte brushes of polystyrene–poly-N-isopropylacrylamide (PNIPAM@PS) in which poly(N-isopropylacrylamide) (PNIPAM) arms were grafted on polystyrene (PS) nanospheres, were employed as macro-crosslinkers. The innumerable hydrogen bonds both between the highly entangled PAA chains and between PNIPAM and the PAA chains composed the first network of the hydrogels. The electrostatic interactions between CS and the PAA chains formed the second network of the hydrogels. These double network hydrogels, named PNIPAM@PS/CS/PAA, achieve good compressive performance and a low swell ratio because of their compact structure through plentiful hydrogen bonding and electrostatic interactions. The hydrogel could absorb cationic dyes from water with high separation efficiency and selectivity due to the electrostatic interaction between the carboxy groups and dye molecules. The adsorption process fitted a pseudo-second-order kinetic model and Langmuir isotherm model very well. Moreover, the hydrogel can separate cationic dyes from mixed dye solutions through electrostatic interactions. After being loaded with silver nanoparticles, the obtained silver@hydrogel exhibited a good capacity for the photocatalytic degradation towards different dyes. The hydrogels are promising for dye-containing wastewater treatment.

Impact of Value Proposition of Digital Marketing Communication on Car Buyers’ Attitude

Paradigm ◽  
2017 ◽  
Vol 21 (2) ◽  
pp. 175-191
Author(s):  
Rekha ◽  
Aparna Mishra ◽  
Ajay Kr. Chauhan
Keyword(s):  
Structural Equation ◽  
Cost Effective ◽  
Digital Marketing ◽  
Primary Data ◽  
Equation Modeling ◽  
Rank Test ◽  
Marketing Communication ◽  
Value Proposition ◽  
Signed Rank Test ◽  
The Impact

Digital marketing communication has affected almost every business along with significantly altering the consumer behaviour. Businesses around the globe are accepting digital marketing communication as an advanced, cost-effective and more relevant alternative to its traditional counterpart, that is, conventional marketing. Consumers have also become accustomed to digital technology and exercising their control over content along with dictating the terms for time and place of purchase. Marketers are resorting to digital marketing because it is interactive, personalized, relevant, informative and cost-effective. FMCG, BFSI and automobiles have been consistently ranked at top digital spenders of the country for last 5 years. The present study deals with understanding the value proposition of digital marketing in Indian car market by applying Neil Rackham’s model. The study also aimed to assess the impact of value proposition on car buyers’ attitude. Primary data were collected from 603 actual and potential car buyers using area-wise proportionate sampling from Delhi. One sample Wilocoxon-Signed Rank Test was applied as test of significance to understand the value proposition. Structural equation modeling (SEM) was used to assess the overall fit and impact of value proposition on car buyers’ attitude. Value proposition model successfully explained 67 per cent of the variation in car buyers’ attitude.

scholarly journals Predicting Postpartum Depressive Symptoms from Pregnancy Biopsychosocial Factors: A Longitudinal Investigation Using Structural Equation Modeling

2020 ◽  
Vol 17 (22) ◽  
pp. 8445
Author(s):  
Verónica Martínez-Borba ◽  
Carlos Suso-Ribera ◽  
Jorge Osma ◽  
Laura Andreu-Pejó
Keyword(s):  
Structural Equation Modeling ◽  
Negative Affect ◽  
Structural Equation ◽  
Cost Effective ◽  
Equation Modeling ◽  
Use Of Technology ◽  
Effective Option ◽  
Biopsychosocial Perspective ◽  
The Stability ◽  
Affective Ambivalence

The prediction of postpartum depression (PPD) should be conceptualized from a biopsychosocial perspective. This study aims at exploring the longitudinal contribution of a set of biopsychosocial factors for PPD in perinatal women. A longitudinal study was conducted, assessment was made with a website and included biopsychosocial factors that were measured during pregnancy (n = 266, weeks 16–36), including age, affective ambivalence, personality characteristics, social support and depression. Depression was measured again at postpartum (n = 101, weeks 2–4). The analyses included bivariate associations and structural equation modeling (SEM). Age, affective ambivalence, neuroticism, positive, and negative affect at pregnancy were associated with concurrent depression during pregnancy (all p < 0.01). Age, affective ambivalence, positive affect, and depression at pregnancy correlated with PPD (all p < 0.05). Affective ambivalence (β = 1.97; p = 0.003) and positive (β = −0.29; p < 0.001) and negative affect (β = 0.22; p = 0.024) at pregnancy remained significant predictors of concurrent depression in the SEM, whereas only age (β = 0.27; p = 0.010) and depression (β = 0.37; p = 0.002) at pregnancy predicted PPD. Biopsychosocial factors are clearly associated with concurrent depression at pregnancy, but the stability of depression across time limits the prospective contribution of biopsychosocial factors. Depression should be screened early during pregnancy, as this is likely to persist after birth. The use of technology, as in the present investigation, might be a cost-effective option for this purpose.

Antecedents of social media usage and performance benefits in small- and medium-sized enterprises (SMEs)

2017 ◽  
Vol 30 (3) ◽  
pp. 383-399 ◽  
Author(s):  
Raphael Odoom ◽  
Thomas Anning-Dorson ◽  
George Acheampong
Keyword(s):  
Social Media ◽  
Structural Equation ◽  
Group Analysis ◽  
Cost Effective ◽  
Past Research ◽  
Study Data ◽  
Equation Modeling ◽  
Content Type ◽  
Media Usage ◽  
And Performance

Purpose Despite the blossoming nature of social media marketing, the nuances and implications among small- and medium-sized enterprises (SMEs) appear to be under-researched in literature. The purpose of this paper is to progress knowledge and offer extended understanding of the motivations and performance benefits of social media accrued by SMEs with an empirical study from an emerging economy. Design/methodology/approach Based on past research, the study hypothesizes that interactivity, compatibility and cost effectiveness are motivations germane to social media usage, which consequently offer performance benefits. Data from 210 SMEs (having Facebook and/or Twitter accounts) are employed to investigate the proposed conceptual model using structural equation modeling with sub-group analysis. Findings Finding from this study demonstrate that the interdependencies of social media motivations, as well as effects of social media usage are positive but erratic across product-based and service-based SMEs. Moreover, SMEs who offer physical products are more likely to employ social media based on cost-effective motives while service SMEs are more likely to consider interactivity as a key motivation. Additionally, findings from the study data suggest that in a tale of two sites, Facebook proved to edge Twitter in terms of engendering performance benefits among SME users. Originality/value The findings provide evidence to issues of potential research and managerial interest, offering insightful implications to the academic and practitioner communities. Evidently, irrespective of some usage bottlenecks, SMEs in emerging markets appears to be reaping enhanced social media benefits by deploying their marketing campaigns via multiple platforms.

Soft ionic liquid based resistive memory characteristics in a two terminal discrete polydimethylsiloxane cylindrical microchannel

2020 ◽  
Vol 8 (38) ◽  
pp. 13368-13374
Author(s):  
Muhammad Umair Khan ◽  
Gul Hassan ◽  
Jinho Bae
Keyword(s):  
Ionic Liquid ◽  
Acrylic Acid ◽  
Sodium Hydroxide ◽  
Sodium Salt ◽  
Resistive Memory ◽  
Cylindrical Microchannel ◽  
Memory Characteristics ◽  
Poly Acrylic Acid

This paper proposes a novel soft ionic liquid (IL) electrically functional device that displays resistive memory characteristics using poly(acrylic acid) partial sodium salt (PAA-Na+:H2O) solution gel and sodium hydroxide (NaOH) in a thin polydimethylsiloxane (PDMS) cylindrical microchannel.

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