Ethylene Vinyl Alcohol Copolymer Research Articles

Development and optimization of antifungal packaging for sliced pan loaf based on garlic as active agent and bread aroma as aroma corrector

The aim of the present work was the development of antimicrobial films containing garlic extract to be applied as active packaging for preservative-free sliced pan loaf, with the goal of extending its shelf-life. First, the antimicrobial capacity of garlic extract, a compound used as active agent, was tested against Penicillium expansum by the disc diffusion method. The extract showed high antimicrobial activity, 0.1 μL per Petri dish being the minimum inhibitory amount, and 0.25 μL the minimum fungicidal amount. Bread aroma was also used to mask the pungent odour of garlic and it was confirmed to have no antimicrobial activity. Subsequently, polyethylene (PE) aqueous emulsion and ethylene-vinyl alcohol copolymer (EVOH) and zein hydroalcoholic solutions containing 0.25 and 0.5% (w/w per dry polymer) of garlic extract and bread aroma were used to coat PE films, producing PE/PE, PE/EVOH and PE/zein active films. The antimicrobial capacity of the films was studied in vitro against Penicillium expansum, and in vivo with natural sliced bread. The results showed that all the films presented some antimicrobial activity, PE film coated with zein containing 0.5% of garlic extract and bread aroma being the film presenting the best results, maintaining bread free of mould infection for 30 days. Sensory tests showed that the addition of 1% of bread aroma improved the sensory experience of consumers and also revealed good purchase intention.

Histopathologic analysis of craniofacial arteriovenous malformations following Onyx embolization

Ethylene-vinyl alcohol copolymer (Onyx) has been proposed as a suitable alternative embolic agent in the management of craniofacial arteriovenous malformations (CFAVM). Short-term efficacy studies have demonstrated promising results with good nidus penetration on post-treatment angiography. This article reports the histopathologic findings of direct vascular recanalization with Onyx at the time of surgical resection. A retrospective review of eight patients who underwent Onyx embolization followed by surgical excision for CFAVM was performed. The surgical specimens were evaluated for the presence of recanalized blood vessels in the embolic cast material and inflammatory changes. A total of 8 patients (mean age 31 years, range 15–57 years) underwent 25 CFAVM embolization and 16 surgical specimens were taken. The time period between initial Onyx embolization and surgery ranged from 12 months to 108 months. Onyx was identified in all of the 16 specimens at the time of resection. Recanalization was identified in 12 of the 16 specimens (75%). Chronic inflammatory changes were present in 13 of the 16 specimens (81.25%) ranging from mild (8) and moderate (4) to severe (1). Giant cells were present in 15 of the 16 specimens (93.75%). Staged Onyx embolization has been reported as clinically efficacious in the management of CFAVM with permanent occlusive properties. Recanalization was commonly seen in this patient cohort as early as 12 months after initial endovascular treatment. Further studies are needed to confirm these findings to evaluate the permanence of Onyx as single agent management for CFAVM.

A highly selective and reversible turn-off fluorescent chemosensor for Cu2+ based on electrospun nanofibrous membrane modified with pyrenecarboxaldehyde.

A fluorescent nanofibrous membrane (NFM) was successfully fabricated by functionalizing electrospun ethylene-vinyl alcohol copolymer (EVOH) NFM with 4‑aminobenzoic acid (PABA) and 1‑pyrenecarboxaldehyde (Py-CHO) for fast and selective determination of Cu2+ in aqueous solution. The effective grafting of PABA and Py-CHO on the surface of EVOH NFM was confirmed by FTIR and XPS spectra. Benefiting from the integrated merits of electrospun EVOH NFM, PABA and Py-CHO, the as-appeared EVOH-PABA-Py NFM exhibited high sensitivity and selectivity towards Cu2+ detection. The quenching efficiency was 91.7% when the concentration of Cu2+ reached 5 × 10-3 M, while the detectable fluorescence response of the NFM was still observed when the concentration of Cu2+ was 1 × 10-9 M. The fluorescence quenching caused by Cu2+ was hardly affected by other commonly co-existent metal ions. More importantly, the fluorescent NFM exhibited fast response and high reversibility towards Cu2+ detection. The "off-on" fluorescence switching process via alternating addition of Cu2+ and Na2EDTA occurred in 3 min, and the quenching efficiency of the NFM kept relatively stable values within 10 cycles. This work may provide a new insight into the development of rapid, portable, stable and reusable fluorescent sensor based on electrospun nanofibers that can satisfy the requirements of practical metal ions detection.

Antimicrobial LDPE/EVOH Layered Films Containing Carvacrol Fabricated by Multiplication Extrusion.

This work describes the fabrication of antimicrobial multilayered polymeric films containing carvacrol (used as a model essential oil) by co-extrusion and multiplication technique. The microlayering process was utilized to produce films, with up to 65 alternating layers, of carvacrol-containing low-density polyethylene (LDPE) and ethylene vinyl alcohol copolymer (EVOH). Carvacrol was melt compounded with LDPE or loaded into halloysite nanotubes (HNTs) in a pre-compounding step prior film production. The detailed nanostructure and composition (in terms of carvacrol content) of the films were characterized and correlated to their barrier properties, carvacrol release rate, and antibacterial and antifungal activity. The resulting films exhibit high carvacrol content despite the harsh processing conditions (temperature of 200 °C and long processing time), regardless of the number of layers or the presence of HNTs. The multilayered films exhibit superior oxygen transmission rates and carvacrol diffusivity values that are more than two orders of magnitude lower in comparison to single-layered carvacrol-containing films (i.e., LDPE/carvacrol and LDPE/(HNTs/carvacrol)) produced by conventional cast extrusion. The (LDPE/carvacrol)/EVOH and (LDPE/[HNTs/carvacrol])/EVOH films demonstrated excellent antimicrobial efficacy against E. coli and Alternaria alternata in in vitro micro-atmosphere assays and against A. alternata and Rhizopus in cherry tomatoes, used as the food model. The results presented here suggest that sensitive essential oils, such as carvacrol, can be incorporated into plastic polymers constructed of tailored multiple layers, without losing their antimicrobial efficacy.

Facile fabrication of sodium styrene sulfonate-grafted ethylene-vinyl alcohol copolymer as adsorbent for ammonium removal from aqueous solution.

An adsorbent EVOH-g-SSS(H) was successfully synthesized for ammonium removal by one-step grafting SSS onto EVOH particles directly using radiation-induced grafting technique followed by protonation. The effects of adsorbed dose and monomer concentration on grafting yield were investigated. The adsorption behaviors of the EVOH-g-SSS(H) towards ammonium ions (NH4+) were discussed. The adsorption isotherm of NH4+ was a followed Langmuir model with the maximum adsorption capacity of 22.53mg/g at optimal pH 6.5. For comparison, adsorption kinetics towards NH4+ removal by EVOH-g-SSS(H) and commercially available DIAION PK228 were studied. Both adsorbents were better obeyed pseudo-second-order mode. EVOH-g-SSS(H) for NH4+ uptake was faster than PK228 and reached equilibrium within 5min. Column experiment showed that the column adsorption capacity of EVOH-g-SSS(H) adsorbent was 9.69mg/g-ad at SV 10h-1. The NH4+ concentration in outlet solution can maintain at a very low level even SV was as high as 800h-1. The elution curve showed the EVOH-g-SSS(H) adsorbent can be regenerated using 1M HCl. Besides, the removal percentage of NH4+ can be 97% from actual groundwater within 1min. Such high adsorption efficiency of EVOH-g-SSS(H) makes it to be employed as an adsorbent for NH4+ removal in practical application.

Safety and Feasibility of Balloon-Assisted Embolization with Onyx of Brain Arteriovenous Malformations Revisited: Personal Experience with the Scepter XC Balloon Microcatheter

Background/Objective: Compliant dual-lumen balloon microcatheters have been used to perform balloon-assisted embolization (BAE) of brain arteriovenous malformations (AVMs) with ethylene vinyl alcohol copolymer (Onyx). However, vessel rupture and microcatheter retention have been reported from BAE using these microcatheters. Using an extra-compliant balloon microcatheter (Scepter XC; Microvention, Tustin, CA, USA) could help avoid pial vessel rupture during BAE. We herein report our experience using this balloon microcatheter for BAE. Methods: This retrospective study included patients who underwent BAE of brain AVMs at our institution between June 2012 and March 2017. Results: The extra-compliant Scepter XC balloon microcatheter was used for BAE of brain AVMs in 23 patients aged 44.3 ± 16.7 years (range 0–65 years). A total of 40 intracranial vessels (39 pial arteries and 1 pial vein) were catheterized and embolized during 30 separate sessions. In all instances, the balloon microcatheter could be successfully advanced to the AVM nidus. A mean volume of 2.4 ± 1.7 mL (range 0.65–4.6 mL) of Onyx was injected per session. There were no instances of vessel rupture, microcatheter retention, or stroke. Conclusion: Utilization of the extra-compliant balloon microcatheter results in safe and effective BAE, which adds to the growing experience with BAE for AVM treatment.

Ethylene vinyl alcohol copolymer

Ethylene vinyl alcohol copolymer

Unique percutaneous direct puncture technique for occlusion of a hypoglossal canal dural arteriovenous fistula

PurposeTo report percutaneous transcranial puncture, embolization and occlusion of a very symptomatic hypoglossal canal/anterior condylar vein dural arteriovenous fistula (DAVF) using syngo iGuide navigational software in a patient in whom...

The Onyx Liquid Embolic System: Another Chance in the Management of Peripheral Bleeding

Ethylene vinyl alcohol or Onyx copolymer (Medtronic) is an embolization agent increasingly used in peripheral interventional radiology. The Onyx Liquid Embolic System (LES) offers a liquid, non-adhesive, non-absorbable, injectable and permanent embolic agent with an indication for neuro-interventional procedures. Due to its physical properties, Onyx has more embolic predictability than other currently available liquid agents and seems to have good potential in endovascular bleeding management, especially for patients with coagulopathies or anti-coagulation therapy. The aim of this brief review is to analyze the advantages of Onyx in the emergency setting on the basis of evidence in the current literature.

Ethylene vinyl alcohol copolymer for occlusion of specific portal branches during preoperative portal vein embolisation with n-butyl-cyanoacrylate.

To evaluate the safety and efficacy of ethylene vinyl alcohol copolymer (EVOH) injection for selective occlusion of portal branches considered at risk for non-target embolisation during preoperative portal vein embolisation (PVE). Twenty-nine patients (mean age, 57 ± 17 years) submitted to PVE with n-butyl-cyanoacrylate (NBCA) and additional EVOH for selected portal branches were retrospectively analysed. Indications for the use of EVOH and the selected portal branches were evaluated. Degree of hypertrophy of the future liver remnant (FLR) and kinetic growth were assessed by CT volumetry performed before and 3-6 weeks after PVE. Clinical outcome and histopathological analysis of portal veins occluded with EVOH were reviewed. EVOH was indicated intraoperatively for embolisation of selected portal branches that the operator reported at risk to provoke non-target embolisation with NBCA. Indications for the use of EVOH were embolisation of segment IV (n = 21), embolisation of segmental portal branches with early bifurcation (n = 7) and PVE in a 1-year-old girl with cystic hamartomas. All targeted portal branches were successfully embolised. There were no cases with non-target embolisation by EVOH. The degree of hypertrophy of the FLR was 14.3 ± 8.1% and the kinetic growth rate was 2.7 ± 1.8% per week. EVOH is safe and effective for embolisation of selected portal vein branches considered at risk for non-target embolisation. • EVOH is another effective liquid embolic agent for preoperative PVE. • EVOH is relatively simple to handle with a minimal risk of non-target embolisation. • During PVE, some portal branches considered complicated to occlude with NBCA may be efficiently embolised with EVOH.

Trans Arterial Embolization of Non-variceal Upper Gastrointestinal Bleeding: Is the Use of Ethylene–Vinyl Alcohol Copolymer as Safe as Coils?

The safety of liquid embolics over the conventional coils for the treatment of non-variceal upper gastrointestinal bleeding (UGIB) approach is still unclear. Purpose of this study is to assess the safety of ethylene-vinyl alcohol copolymer (EVOH 6%) over coils in the treatment of UGIB. All the upper gastrointestinal tract embolization procedures performed in a single center in a 6-year period were reviewed. Patients embolised with coils (Group A) versus those embolised with EVOH 6% (Group B) were compared. Technical/clinical success, bleeding recurrence, complication and mortality rates were analyzed. A total 71 patients were included in the study (41 Group A and 30 Group B). Coagulopathy was present in 21% of Group A and 46% of Group B patients (p < 0.05). Technical and clinical success was 97.6 and 92.7% for Group A, and 100 and 93.3% for Group B respectively, (p > 0.05). Ten patients (17% Group A; 10% Group B) re-bled within the first 36h and all of them were re-treated successfully with a second embolization. In Group A one major complication (bowel ischemia) occurred. No complication occurred in Group B. The survival rate in the first 30days was 90.3% for group A and 90% for group B (p > 0.05). This study demonstrated EVOH 6% appears to be as safe and effective as coils in the treatment of non-variceal UGIB.

Nonisothermal Crystallization Kinetics of Ethylene Vinyl Alcohol Copolymer with Poly(oxypropylene)diamine Intercalated Montmorrilonite

ABSTRACTFilms of ethylene vinyl alcohol copolymer (EVOH) and EVOH containing poly(oxypropylene)diamine intercalated montmorrilonite were prepared by solution casting. The nanostructures and viscosity were characterized by small angle x-ray scattering (SAXS), transmission electron microscopy (TEM) and rheological testing. The nonisothermal crystallization kinetics of the samples were investigated by the Ozawa's and Mo's methods and the crystallization activation energy by Kissinger's model. The SAXS and TEM analysis demonstrated that the nanoplatelets, with an intercalated structure, were dispersed in the EVOH matrix. The rheological tests showed that the incorporation of the modified clay could increase the viscosity of the composite system. The Mo's method more successfully described the nonisothermal ctystallization behavior of neat EVOH and its nanocomposites as compared with the Ozawa's method. Adding the nanoclays had a heterogeneous nucleation effect to accelerate the crystallization of EVOH despite hindering the macromolecular chains movement.

Barrier permeation properties of EVOH thin-film membranes under aqueous and non-aqueous conditions

Ethylene vinyl alcohol (EVOH) copolymers can provide a superior barrier to hydrocarbons and are increasingly being used in co-extruded geomembranes for geoenvironmental applications. These thin-films behave differently under different humidity conditions. This study investigated the permeation properties of toluene through two EVOH thin-films (32 mol% ethylene and 44 mol% ethylene) for both non-aqueous and aqueous solutions. The results of this study are used to gain a better understanding of the behaviour of the EVOH layer used in co-extruded geomembranes. The thin-film results are compared with published values for co-extruded linear low density polyethylene (LLDPE) and high density polyethylene (HDPE) geomembranes with an EVOH core. Permeation coefficients are presented over a range of contaminant concentrations from 25 ppm to 99% toluene based on almost five years of continuous testing and the effect of moisture is discussed. A number of EVOH thin-films were affected by humidity (i.e., where moisture diffused into the film) prior to diffusion testing under non-aqueous conditions. This observation led to an investigation of the effect of moisture uptake on the permeation of toluene under non-aqueous testing. In these cases, the 44 mol% thin-film had lower toluene permeation coefficient values than the 32 mol% thin-film. These values were similar to toluene permeation coefficient values from tests with aqueous solutions. When relative humidity was less than 60%, the 32 mol% had slightly lower permeability values than 44 mol% thin-film. However, even when affected by humidity, the permeability of both thin-films were considerably (two to three orders of magnitude) lower than previously observed in a water-saturated solution. Permeation of toluene from a 1/1 toluene/hexane solution was also examined for the 32 mol% EVOH thin-film at temperatures of 23–50 °C and results fit well with a conventional Arrhenius relationship of increasing Pg values with increasing temperature.

The role of ethylene-vinyl alcohol copolymer in association with other embolic agents for the percutaneous and endovascular treatment of type Ia endoleak.

To evaluate safety, technical and clinical success of embolization of type Ia endoleak (T1a EL) using ethylene-vinyl alcohol copolymer as embolic agent alone or in combination with other materials. Five patients presented T1a EL after endovascular repair of aortic aneurysms (EVAR) with radiological evidence of expanding sac size; in particular, three had contained rupture. In one patient, proximal cuff insertion was previously performed, in three patients proximal cuff was urgently inserted but T1a EL persisted; one patient, previously treated with Ovation Abdominal Stent Graft System, was directly proposed for endovascular treatment. In all cases, endovascular embolization was successfully performed and the transfemoral approach was always chosen; in one case it failed and translumbar approach by direct puncture of the sac was required. Used embolization agents were glue, ethylene-vinyl alcohol copolymer (Onyx) and coils in three cases, n-butyl cyanoacrylate and Onyx in one case, Onyx and coils in the last case. Technical success rate was 100% as well as clinical success. No major or minor complication, including non-target embolization, was registered. Clinical success was 100% until today and the sac diameter remained stable in four patients and decreased in one. Onyx may be considered a suitable embolic agent in the treatment of patients with type Ia endoleaks after EVAR, after failure of conventional treatments such as prolonged balloon inflation of the aortic neck or deployment of large bare stent.

Assessment of Compatibility in Polypropylene/Poly(lactic acid)/Ethylene Vinyl Alcohol Ternary Blends: Relating Experiments and Molecular Dynamics Simulation Results

ABSTRACTTwo systems of polypropylene (PP), poly(lactic acid) (PLA) and ethylene vinyl alcohol copolymer (EVOH) ternary blends having different compositions were extruded in a co-rotating twin screw extruder. The first system was PP/PLA (75/25) with various EVOH contents, the second one was PP/EVOH (75/25) having various PLA contents. The effects of composition on the morphology and the tensile and impact properties of the blends were investigated. There were increases in the tensile modulus and tensile strength with an increase in the EVOH and PLA contents in the first and second systems, respectively. A molecular dynamics (MD) simulation was used to investigate the compatibility between the components. Prediction of the miscibility of the blends was carried out by determining the interaction parameters (χ), mixing energies (ΔHmix), phase diagrams and Gibbs free energies. The MD simulation showed a UCST behavior for the components. Moreover, the simulation results showed a compatibilizer effect for the EVOH component. The experimental values of the dynamic mechanical thermal analysis (DMTA) and mechanical properties were correlated to the MD results. There was a good correlation between the MD and DMTA results. The modulus values using the parallel and Davis models were near to the experimental ones. A good fitting to the mixture law with addition of EVOH confirmed a good compatibilzing effect of it between the PP and PLA components.

Embolization with ethylene vinyl alcohol copolymer (Onyx®) for peripheral hemostatic and non-hemostatic applications: a feasibility and safety study.

Onyx® is a liquid embolic agent, which is approved for the treatment of cerebral vascular lesions but still rarely used in peripheral interventional radiology. The goal of this study is to report the feasibility and safety of embolization with Onyx® for peripheral hemostatic and non-hemostatic endovascular procedures. Retrospective study of all consecutive patients who underwent visceral or peripheral embolization with Onyx® for hemostatic or non-hemostatic purpose in our department between May 2014 and November 2016. Demographic data, clinical presentation, underlying etiology, culprit vessel, endovascular procedure, pain during embolization, outcomes, and follow-up data were collected. Fifty patients (males, 34; females, 16; mean age, 56±18 years; range, 15-89 years) were included. Twenty-nine (58%) of patients underwent hemostatic embolization for arterial (n=22, 44%) or venous (n=7, 14%) bleeding lesions, whereas 21 (42%) of patients underwent non-hemostatic embolization for arterial aneurysms (n=8, 16%), preoperative portal vein deprivation (n=6, 12%) or other indications (n=7, 14%). Onyx-18 was used in 37 (74%) patients, Onyx-34 in 9 (18%) patients, and a combination of both in 4 (8%) patients. Onyx was used alone in 25 (50%) patients and in combination with other agent in 25 (50%) patients. Mean number of Onyx® vials used was 3.7 (range, 1-17). Immediate technical success rate was 100%. Primary clinical success was achieved in all patients. Recurrent bleeding occurred in two patients. Significant pain (pain score ≥3) was noted during injection in 10 (20%) patients. No major complication or side effects were noted within 1 month. Transcatheter embolization with Onyx® is feasible and safe in the peripheral arterial or venous vasculature for both bleeding and non-bleeding patients whatever the anatomic site.

4:10 PM Abstract No. 388 Ethylene vinyl alcohol copolymer (Onyx) for treatment of large venous vascular malformations: long-term results

To describe the long-term results and advantages of ethylene vinyl alcohol polymer for treatment of venous vascular malformations. Since 2005, we have used Ethylene vinyl alcohol copolymer (Onyx 18 & 34) in the treatment of 62 patients with large, low-flow venous vascular malformations. There were 34 females and 28 males with ages ranging from 7–59 years (mean 25 years). Fifty-one of the malformations involved the extremities and 11 involved the chest, abdominal wall or pelvis. All patients were evaluated with MRI/MRA pretreatment. Onyx was delivered by direct injection with ultrasound and fluoroscopic guidance under tourniquet control. In a few cases Onyx was also delivered via a transarterial micro catheter positioned in large feeding vessels. Sodium tetradecyl (3%) foam was used also in conjunction with Onyx in six patients where there were associated smaller foci of malformation. Histologic examination of tissues from patients whose embolized lesions were subsequently explanted was performed. Ethylene vinyl alcohol copolymer (Onyx) was found to be useful for occlusion of large venous channels in venous malformations. Unlike sclerosing agents, its visibility allowed direct observation of filling of the venous malformation during injection. When used alone, there was minimal post procedure discomfort. There were two complications: one extrusion of Onyx from a lesion on the sole of the foot, which healed without sequelae and one instance of embolization of a small Onyx fragment to the lung, also without sequelae. On H & E stains, the Onyx was noted to be distributed in the intraluminal spaces with associated mild foreign body type giant cell reaction. Permanency of the copolymer was demonstrated on long-term imaging follow-up. Ethylene vinyl alcohol copolymer (Onyx) is a safe, durable agent for treatment of venous vascular malformations. It is of particular value in malformations with large venous channels. Unlike standard sclerosing agents, Onyx behaves as a filler, and is not dependent upon generation of an inflammatory reaction for occlusion. Its opacity allows visualization of filled channels. It can be used alone or in conjunction with sclerosing agents.

3:18 PM Abstract No. 103 Balloon-assisted Onyx embolization of high-flow peripheral arteriovenous malformations with dual-lumen coaxial balloon microcatheter: technical aspects and clinical results

The aim of this study was to demonstrate our experience in balloon-assisted Onyx (ethylene vinyl alcohol copolymer) embolization of high-flow peripheral arteriovenous malformations (AVMs) using dual-lumen coaxial balloon microcatheter technique, which does not necessitate a plug formation around the catheter that is required to allow antegrade flow of Onyx while preventing reflux and non-target embolization. This study expands the technique with its utilization on types of AVMs not described previously. Three patients with peripheral high-flow AVMs treated with balloon-assisted Onyx embolization using dual-lumen coaxial balloon microcatheter were retrospectively analyzed. AVMs were located in the kidney, pelvis, and chest wall. One patient required two sessions of Onyx embolization treatment. A total of 4 sessions were performed with Onyx 18 and/or Onyx 34 using Scepter XC occlusion balloon catheter. Imaging and clinical follow-ups were performed for all patients. Technical success was achieved in all patients. Complete devascularization was obtained in two patients with renal and pelvic AVMs with one treatment, while the patient with chest wall AVM required two sessions, which resulted in complete devascularization. There was no evidence of excessive reflux of Onyx or entrapment of the microcatheter. Non-target Onyx embolization or microcatheter fracture was not observed. After the final treatment, all patients were free of symptoms on clinical follow-up, and there was no evidence of recurrence identified on follow-up imaging. From our single-institutional experience, the technique using dual-lumen coaxial balloon microcatheter for balloon-assisted Onyx embolization appears to be safe and effective in treating high-flow peripheral AVMs, while allowing more precise injection of Onyx with the capability to reduce the risks associated with reflux of Onyx.

Non-isothermal crystallization and oxygen permeability of PP/PLA/EVOH ternary blends

Casting films of polypropylene (PP), poly(lactic acid) (PLA) and ethylene vinyl alcohol copolymer (EVOH) ternary blends having different compositions were prepared. The thermal properties in correlation to the oxygen permeability and mechanical properties of the films were investigated. The morphology of the blends, before and after the film extrusion process was investigated. The SEM images of casted films show a great laminar morphology development in the machine direction. The effects of EVOH and compatibilizer on the relative changes in the crystallization behavior, i.e., melting peak crystallization (Xm%) and degree of crystallization (Xc) are considered. While the compatibilization facilitated the crystallization of PP, it had reverse effect on EVOH crystallization. There is an increase in the Xm% as well as Xc% of EVOH in ternary blend with an increase in EVOH content. The permeability to oxygen was decreased with an increase in EVOH content and compatibilization led to improvement in barrier properties. The crystallinity degree of EVOH revealed to have a greater effect on barrier and mechanical properties as compared to that of PP. Finally, the study of the interaction parameters using Nishi and Wang theory confirmed an effective interaction between the components.

Similarly sized protein separation of charge‐selective ethylene‐vinyl alcohol copolymer membrane by grafting dimethylaminoethyl methacrylate

ABSTRACTSimilarly sized protein separation was investigated using a charge‐selective membrane, which prepared by grafting dimethylaminoethyl methacrylate (DMAEMA) onto ethylene vinyl alcohol copolymer (EVAL) membrane. Bovine serum albumin (BSA) and bovine hemoglobin (BHb) was used as model proteins. P(DMAEMA), the weak cationic polyelectrolyte with ionizable tertiary amine groups, contributed to the charge‐selective separation for BSA and BHb. At pH 6.0, the grafted EVAL membrane surface was positively charged and BSA was negatively charged, while BHb was positively charged. The BSA was adsorbed onto the membrane surface due to electrostatic interaction and the BHb passed through the membrane into the permeate. The charge‐selective behavior resulted in the separation of the similarly sized protein. The maximum separation factors of static adsorption separation for model protein and binary mixture were 32.4 and 37.2, respectively. In the dynamic separation process, the maximum separation factor value was 6.2. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46374.