Hamed KarkhanechiFerdowsi University Of Mashhad | FUM · Department of Chemical Engineering
Hamed Karkhanechi
PhD
About
43
Publications
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Introduction
Fabrication and Characterization of polymeric membranes (flat sheet and hollow fiber geometry)
Additional affiliations
October 2010 - present
Publications
Publications (43)
Polyvinylidene fluoride (PVDF) films were prepared for evaluating the effect of electromagnetic field and Eucalyptus oil Citriodora as an additive on the polymorphism. The values of PVDF crystalline phases were determined by attenuated total reflection‐Fourier transform infrared spectroscopy. Differential scanning calorimetry was performed to achie...
Membrane fouling is a significant drawback in the implementation of membrane processes. To tackle this problem, the polyvinyl chloride (PVC) membrane was made by non-solvent induced phase separation (NIPS) and then placed on the 3D printed wavy support using a vacuum to prepare the patterned membrane. Characteristic tests were applied to study the...
This cover image by Salma Ghorab (supervised by Hamed Karkhanechi) illustrates the calculation of enthalpy of mixing (ΔHM) within a polymeric system using Schneier's equation. While this equation is widely applied in the context of polymer compatibility systems and is an adaptation of Gee's foundational relation, it does exhibit some errors. Notabl...
This concise note highlights certain errors, encompassing dimensional inconsistency and flaws in the expression of fundamental relationships, associated with Schneier's equation. This equation was initially published in the Journal of Applied Polymer Science [17.10 (1973): 3175] and has subsequently found application in consequent studies.
The flash point (FP) modeling of ternary mixtures containing partially miscible regions, even by known models, is still challenging. This work proposes a practical and easy-to-use hybrid machine learning method, which combines artificial neural networks (ANNs) with the genetic algorithm (GA), to calculate the FPs of complex alcohol-based mixtures,...
The prediction of organic solvent reverse osmosis (OSRO) performance is challenging because of the numerous variables influencing the process. Therefore, applying a machine learning model, such as an artificial neural network (ANN), instead of physics-based modeling is helpful because it can consider many variables and learn patterns to generate a...
Salinity gradient energy (SGE), as clean and renewable energy, can be harvested from the mixing of solutions with different salinity (such as river water and seawater). Reverse electrodialysis (RED) based on membrane technology is an effective method for harvesting SGE. A RED stack consists of alternating patterns of ion exchange membranes: cation...
Polymeric membranes are widely used for gas separation but most polymers are non-biodegradable and consequently contaminate the environment when discarded. Therefore biodegradable polymers, such as Zein protein, are suggested to solve this problem.
Zein is a biopolymer extracted from maize as a byproduct of corn-based ethanol production. As a biode...
The pervaporation separation process (PV) has received much attention in the chemical and pharmaceutical industries as a cleaner and more cost-effective method compared to other traditional methods, including distillation and adsorption. Moreover, PV and hybrid processes do not require frequent module replacements and allow continuous operation wit...
A novel and effective fluorinated graphene hydroxide has been synthesis based on graphene hydroxide. Afterward, X-ray diffraction analysis (XRD) and particle-induced X-ray emission (PIXE) techniques were employed in order to evaluate the degree of fluorination process. Synthesis was successfully accomplished using the hydrothermal method, resulting...
In recent years, a well-known membrane-based process called pervaporation (PV), has attracted remarkable attention due to its advantages for selective separation of a wide variety of liquid mixtures. However, some restrictions of polymeric membranes have led to research studies on developing membranes for efficient separation in the PV process. Rec...
Association theories by statistical associating fluid theory (SAFT) and cubic plus association (CPA) equation of states (EoS) have effectively handled various thermodynamic purposes thus far; they consider hydrogen bonding effects in associating compounds (those with hydrogen bonds such as water and alcohols) in a proper way. The objective of this...
Reverse electrodialysis (RED) generates electricity from the potential energy created by mixed water solutions producing a salinity gradient. This study presents a review of the most important parameters related to the RED process. Membranes are an essential component of an RED system. Hence, this review investigates different types of membranes, s...
Recent years, the separation of organic liquid mixtures achieved by organic solvent nanofiltration (OSN), organic solvent reverse osmosis (OSRO), and organic solvent forward osmosis (OSFO) has gained a great momentum. In the methods, it is of particular importance to know the osmotic pressure of liquid mixtures for the correct process design. Altho...
Hollow fiber membranes (HFMs) possess desired properties such as high surface area, desirable filtration efficiency, high packing density relative to other configurations. Nevertheless, they are often possible to break or damage during the high-pressure cleaning and aeration process. Recently, using the braid reinforcing as support is recommended t...
A review was done about the membrane preparation based on the thermally induced phase separation (TIPS) method. TIPS is an alternative to conventional nonsolvent-induced phase separation (NIPS) method that has been widely applied in commercial scale. After the evaluation of the thermodynamic of the TIPS process, the effect of the different paramete...
In the present work, polyvinylidenedifluoride-co-chlorotrifluoroethylene (PVDF-co-CTFE) hollow fiber membranes were prepared via non-induced phase separation (NIPS) using 1-methyl-2-pyrrolidone (NMP) or triethyl phosphate (TEP) as the solvent. The thermodynamic characterization of both systems PVDF-co-CTFE/NMP/water and PVDF-co-CTFE/TEP/water) and...
Polyamide 6 hollow fiber membranes were successfully fabricated via a thermally induced phase separation (TIPS) method for the first time to the best of our knowledge. Dimethyl sulfone (DMSO2) and sulfolane were used as diluents for the TIPS method. Also, poly(ethylene glycol) 200, 300, and 400 and 1,3-butanediol were used as bore solutions to cont...
With the fast growth of population during last century, serious global issues raised that global warming and potable water shortage are the major ones that challenge humankind life. During last decades, membrane technology has developed very quickly and attracted much attention as a great potential for solving humankind problems. Poly(vinylidene fl...
Reverse electrodialysis (RED) is an electrochemical process for converting salinity gradient energy into electric energy. Biofouling of anion exchange membranes (AEMs) is a severe problem affecting RED performance. In this study, we examined the biofouling of AEMs during RED and attempted to improve the anti-biofouling properties of AEMs through su...
Global warming is occurring because of emission of greenhouse gases due to human activities. Capture of CO2 from fossil-fuel industries and absorption of CO2 for natural gas sweetening are crucial industrial tasks to address the threat from greenhouse gases. Amino acid ionic liquids (AAILs) are used for reversible CO2 capture. In this study, the ef...
The fouling of anion exchange membranes (AEMs) during an electrodialysis (ED) is a serious problem. Membrane fouling is often classified into organic fouling, inorganic fouling (scaling) and biofouling. In our previous studies, we reduced organic fouling by modifying the membrane surface with dopamine solution, which formed a negatively charged, hy...
A porous poly (ethylene-chlorotrifluoroethylene) (ECTFE) membrane was prepared and evaluated in this study. Initially, solvent screening revealed diethyl phthalate (DEP) and glycerol triacetate (GTA) as proper solvents for the preparation of homogenous ECTFE solutions with the required properties for fabricating a hollow fiber membrane. The thermod...
We systematically evaluated the effects of operating conditions on biofouling behaviors in reverse osmosis (RO) membrane processes. The biofouling experiment was performed by filtrating nutrient-containing feed water with a cross-flow cylindrical membrane cell through a circular polyamide RO membrane with pre-adhered Pseudomonas putida. The trans-m...
Electrodialysis (ED) is a useful method to make drinking water from brackish water. In ED, high selectivity for monovalent anions is required to effectively remove harmful ions like NO3− and F−, and to prevent the precipitation of CaSO4 scale. In our previous paper, we theoretically discussed the effect of several parameters of the system (includin...
Biofouling is the undesired attachment of microorganism communities to a membrane surface. Bacteria adhered to the surface release extracellular polymeric substances (EPS) and consequently, a biofilm EPS matrix with embedded bacteria is formed. Because biofilms reduce salt rejection and flux, biofouling is a serious obstacle in reverse osmosis (RO)...
There is an increasing demand for potable water production from brine water and seawater. Electrodialysis (ED) is one of useful processes to produce drinking water from underground water and surface water. Especially, ED is useful to remove harmful ions, like NO 3 -and F -from feed water. In ED processes, ions are selectively transported from dilut...
It has been reported that polyzwitterions (PZs) can significantly improve the antibiofouling properties of membrane surfaces. In addition, it is known that polydopamine (PDA) can deposit non-selectively from solution onto virtually any solid surface and creates a versatile surface for further modification through its reactive groups. In this paper,...
It has been reported that surface modification with polydopamine (PDA) increases the hydrophilicity and the negative charge density of membrane surfaces, which improves their antifouling potential against organic foulants. Thus, in this paper, we attempted to modify a reverse osmosis (RO) membrane with PDA to improve antibiofouling potential. The d...
The fouling, in particular the organic fouling of anion exchange membranes (AEMs), is a serious problem in electrodialysis (ED). In this paper, we attempted to improve the antifouling potential of AEM by surface modification with polydopamine (PDA). The antifouling potential was evaluated by the transition time, i.e. the time elapsed before fouling...
Biofouling of reverse osmosis (RO) membranes used in water treatment processes is major obstacle to more widespread uptake of this technology. In this paper, a commercial RO membrane was modified by adsorption of copper hydroxide (Cu(OH)2) particles to improve antibiofouling properties of the membrane. The adsorption of Cu(OH)2 particles was confir...
Polydopamine coating as a relatively new approach was investigated to improve a membrane fouling resistance [1]. In this study, we tried to improve an antibiofouling performance of commercial RO membrane (Nitto Denko ES20) by polydopamine coating. Dopamine solution of 0.5 g/l was prepared by dissolving dopamine in the Tris-HCl (pH 8.8) buffer solut...
To improve antibiofouling properties, a commercial reverse osmosis (RO) membrane was modified by surface deposition of a polyelectrolyte multilayers (PEMs) embedded with silver nanoparticles. The modified membrane was further coated with an amphiphilic polyzwitterion, a 2-methacryloyloxyethyl phosphorylcholine (MPC) copolymer with 2-aminoethyl meth...
Biofouling by undesired attachment of microorganism communities to the membrane surface is a serious problem in wastewater treatment, water desalination as well as other membrane process. Membrane biofouling negatively affects membranes performance by decreasing salt rejection and flux. In this work, commercial RO membrane surface was treated with...
Interfacial void-free mixed-matrix membranes (MMMs) of polyimide (PI)/zeolite were developed using 13X and Linde type A nano-zeolites and tested for gas separation purposes. Fabrication of a void-free polymer-zeolite interface was verified by the decreasing permeability developed by the MMMs for the examined gases, in comparison to the pure PI memb...
Questions
Questions (5)
I need to calculate the HANSEN SOLUBILITY PARAMETERS of a commercial copolymer. I know the ratio and solubility parameters of two polymers those included in this copolymer.
Can I calculate the solubility parameters of the copolymer using the solubility parameters of polymers based on the rule of mixtures?
I carried out MD simulation for polymeric material composed of 1000 repeating unit. Also, after equilibration temperature was increased from 300K to 500K gradually. Later I determined the enthalpy of the system by MD simulation using the Gromacs g_energy tool. However, the enthalpy increasing completely linear and no peak or kink were obtained.
If we have two membranes with the same crystallinity degree, the elongation of a membrane with larger spherulites would be higher? Does the crystallinity degree influence either on the elongation or both of the elongation and the tensile strength? Is the crystallinity degree a dominant factor for elongation?or size and morphology of spherulites are dominant paramters?
To determine if the parameters of two molecules (usually a solvent and a polymer) are within range a value called interaction radius (R0) is given to the substance being dissolved. This value determines the radius of the sphere in Hansen space and its center is the three Hansen parameters.
It would be appreciated if you could introduce some references to me about pH resistance of E. coli.
