Fine characterization of plasma‐polymerized films from a methane/air mixture

The plasma polymerization of methane/air mixtures was performed to produce a hydrophilic film on a substrate, and the obtained films were characterized with ellipsometry, elemental analysis, Fourier transform infrared spectroscopy, X‐ray photoelectron spectroscopy, atomic force microscopy, and contact‐angle measurements. Fourier transform infrared revealed that the structure of the plasma‐polymerized films changed with increasing film thickness; that is, an increase in the film thickness led to an increase in the absorbance ratio of the carbonyl band at 1664 cm^?1 to the methyl band at 1385 cm^?1. Although the contents of nitrogen and oxygen measured by elemental analysis changed with the film thickness, the contact angle and X‐ray photoelectron spectroscopy atomic ratio of the films were independent of it. Nitrogen and oxygen were contained in the bulk more than on the surface of the films. Nitrogen and oxygen were copolymerized with methane, and the properties of the obtained films were similar to those of an amide compound. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3408–3414, 2006     

Characterization of air plasma‐treated polymer surfaces by ESCA and contact angle measurements for optimization of surface stability and cell growth

A radiofrequency air plasma has been used to incorporate new functionalities at the surface of cycloolefin polymers (Zeonex® and Topas®), polymethyl methacrylate (PMMA), styrene–acrylonitrile copolymer (SAN), and polystyrene (PS). The main goals with the plasma treatment of the different plastics were to hydrophilize the surfaces and to provide good cell culture properties. Surfaces treated at high RF power/gas flow ratios (50 to 100 W/sccm) became highly hydrophilic (water contact angles of about 5 degrees) and stable towards washing in 70% (v/v) ethanol. Those treated at lower power/gas flow ratios (3 to 10 W/sccm) were less hydrophilic and not wash‐stable. Cell growth properties of HeLa cervix carcinoma cells as good as on commercial tissue‐culture polystyrene could be obtained for Zeonex, SAN, and PS, treated at relatively low RF power/gas flow ratios. However, no untreated plastics were suitable for culturing these cells. XPS spectra features show that ester, ether/alcohol, and ester/carboxyl groups are formed during the plasma treatments of the different plastics. Measurable amounts of carboxylic acid carbon after plasma treatment were only observed for PS and Topas. Furthermore, at high RF power/gas flow ratios fluorine, aluminium and silicon were incorporated in all investigated plastics surfaces due to ablation–deposition processes in the reaction chamber. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2618–2625, 2002     

Dry Processes for Surface Modification of a Biopolymer: Chitosan

Standard dry surface modification reactions have been applied to partially deacetylated chitosan without affecting its bulk properties. Chitin, extracted from shells of Penaeus vannamei, yielded chitosan with a degree of acetylation of 70% and molecular weight of 250 000 D. The copolymer consists of (β‐(1‐4)‐2‐2‐acetamido‐D ‐glucose) units linked to (β‐(1‐4)‐2‐amino‐D ‐glucose) units. Since the main interest of this work was to study the surface properties of films on substrates, a method to cast this material onto Al‐coated silicon wafers had to be developed. X ray photoelectron spectroscopy (XPS) has been used to determine the surface composition of the unmodified films and to follow modification changes. The films were treated in either an oxygen plasma environment or under UV/ozone irradiation. Water advancing contact angle measurements and infrared spectroscopy (FTIR) were used to complement XPS measurements. The films appeared to orient on the silicon wafer surface in the type II chitin structure. The rates of oxidation are faster for the plasma process but they result in similar changes to those induced by UV/ozone treatment. Atomic force microscopy (AFM) clearly shows the advantage of the milder modification reaction without much change in surface morphology. The oxidation processes, as detected by XPS, proceed without much alteration of the amine nitrogen atoms but carbonyl containing moieties are formed as a function of treatment time. Specific reactions with a fluorosilane to measure the activity of hydroxyl groups indicate that at short treatment times, these groups are essentially inactive. The resulting surfaces can also serve as a potential way to induce silica‐like domains that can function as diffusion barriers. Irradiation of chitosan solutions shows that UV/ozone induces depolymerization. In both cases, i.e., plasma and UV/ozone reactions, the main active component to surface modification appears to be UV irradiation with a wavelength below 360 nm.

AFM surface profile for oxygen plasma treated film in barrel etcher for 1 min.     

Mechanism of dielectric‐barrier discharge initiated wet‐strength development

The fundamental mechanism of wet‐strength development for dielectric‐barrier discharge treated thermomechanical pulp fibers was explored. Electron spectroscopy for chemical analysis (ESCA), vapor phase fluorine surface derivatization followed by ESCA, and dynamic contact angle analysis were performed to assess the surface chemistry in terms of both chemical functionality and wettability. Effects of the intensity of dielectric‐barrier discharge treatment on the surface chemistry of lignocellulosic fibers and the corresponding impacts to fiber wet‐tensile properties are described. This study indicates that low treatment intensities result in increased wettability due to surface oxidation, which leads to a small reduction in wet‐tensile index. However, increased treatment intensity brings about diminished wettability due to covalent crosslinking, which leads to increases in wet‐tensile index. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2219–2225, 2005     

Development of antimicrobial stainless steel via surface modification with N‐halamines: Characterization of surface chemistry and N‐halamine chlorination

N‐halamine modification of materials enables the development of antimicrobial materials whose activity can be regenerated after exposure to halogenated sanitizers. Surface and bulk modification of polymers by N‐halamines has shown great success, however, modification of inorganic substrates (e.g., stainless steel) remains an area of research need. Herein, we report the covalent surface modification of stainless steel to possess rechargeably antimicrobial N‐halamine moieties. Multilayers of branched polyethyleneimine and poly(acrylic acid) were immobilized onto the surface of stainless steel and the number of N‐halamines available to complex chlorine was quantified. Samples were characterized through contact angle, Fourier transform infrared spectroscopy, ellipsometry, dye assay for amine quantification, and X‐ray photoelectron spectroscopy. Increasing the number of multilayers from one to six increased the number of N‐halamines available to complex chlorine from 0.30 ± 0.5 to 36.81 ± 5.0 nmol cm^?2. XPS and FTIR confirmed successful covalent layer‐by‐layer deposition of the N‐halamine multilayers. The reported layer‐by‐layer deposition technique resulted in a greater than seven‐fold increase of available N‐halamine compared to prior reports of N‐halamine surface modifications. The N‐halamine modified steel demonstrated antimicrobial activity (99.7% reduction) against the pathogen Listeria monocytogenes. Such surface modified stainless steel with increased N‐halamine functionality, and therefore potential for rechargeable antimicrobial activity, supports efforts to reduce cross‐contamination by pathogenic organisms in the food and biomedical industries. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Estimation of surface properties of grafted layers formed on low- and high-density polyethylene plates by photografting of methacrylic acid and acrylic acid at different monomer concentrations and temperatures

An investigation was carried out on estimation of hydrophilicity, wettability and water-absorptivity, and surface analysis by X-ray photoelectron spectroscopy of the low- and high-density polyethylene (LDPE and HDPE) plates photografted with methacrylic acid (MAA) and acrylic acid (AA) at different monomer concentrations or temperatures. Wettability of the MAA-grafted LDPE and HDPE plates increased with grafted amounts, and became constant when the substrate surfaces were fully covered with the grafted polymer chains. On the other hand, for the AA-grafted LDPE and HDPE plates, wettability had the maximum value, and then gradually decreased against the grafted amount probably due to aggregation of grafted PAA chains, although the surfaces were covered with grafted PAA chains at lower grafted amounts compared with grafted PMAA chains. Water-absorptivity sharply increased at lower grafted amounts due to formation of shorter grafted polymer chains for photografting at lower monomer concentrations or due to restriction of the location of grafting to the outer surface region for photografting at lower temperatures. Therefore, for photograftings of AA or onto the HDPE plates, the substrate surfaces were covered with grafted polymer chains and the grafted layers formed possessed higher water-absorptivity at lower grafted amounts. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Surface attachment of horseradish peroxidase to nylon modified by plasma‐immersion ion implantation

The surface of polyamide (nylon 6) was modified by plasma‐immersion ion implantation (PIII) with nitrogen ions. Structural changes associated with carbonization, oxidation, and depolymerization were observed in the modified surface layer with Fourier transform infrared/attenuated total reflection (FTIR–ATR) spectroscopy, surface energy measurements, and X‐ray photoelectron spectroscopy (XPS). The enzyme activity of surface‐attached horseradish peroxidase was studied with a tetramethylbenzidine colorimetric activity assay. Compared to untreated controls, the PIII‐treated surface showed a higher level of the attached protein with increased longevity of bioactivity. Detection of the immobilized protein layer was made difficult by the presence of amide groups in nylon. Here we demonstrate the potential of combining FTIR–ATR spectroscopy with XPS measurements for this purpose. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci 120:2891–2903, 2011     

Surface‐functionalization of plasma‐treated polystyrene by hyperbranched polymers and use in biological applications

Nitrogen plasma was used to amino‐functionalize polystyrene surfaces, which were further modified via the selective introduction of polyamines suitable for the immobilization of biological compounds. This chemical modification was carried out using a multifunctional amine compound linked to glutaraldehyde, leading to the formation of hyperbranched structures at the surface. Up to three generations of branched polymers at the polystyrene (PS) surface were created by successive addition of the functional compounds. Amine functions introduced at the surface were labeled with 2,3,4,5,6‐pentafluorobenzaldehyde and analyzed by X‐ray photoelectron spectroscopy (XPS), confirming the successful attachment of each generation of branching. Finally, bovine serum albumin and trypsin were immobilized on N₂‐plasma‐treated PS modified with different amounts of branched graft polymer and found to remain bioactive after immobilization. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Surface functionalization of polyolefin films via the ultraviolet‐induced photografting of acrylic acid: Topographical characterization and ability for binding antifungal agents

The photoinduced graft copolymerization of acrylic acid with ultraviolet radiation onto films of poly(vinyl chloride), polypropylene, and polyethylene was studied. Benzophenone was used as the initiator for most of the experiments performed. The percentage of grafting was determined by gravimetric measurements, and the characterization of the grafted films was carried out by chemical analysis (Fourier transform infrared spectroscopy, volumetric titration, and dye adsorption). In all samples, the grafted yield increased with the ultraviolet exposure time. High levels of grafting were obtained at room temperature. In addition, optical and atomic force microscopy allowed the topography of the modified films to be studied as a function of the reaction time. The pendant functional groups that were grafted were then used to bind antifungal agents, such as natamycin and crystal violet, and the antifungal properties of the films were demonstrated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:2254–2263, 2006     

Surface modification of linear low‐density polyethylene film by amphiphilic graft copolymers based on poly(higher α‐olefin)‐graft‐poly(ethylene glycol)

In this article, a series of amphiphilic graft copolymers, namely poly(higher α‐olefin‐co‐para‐methylstyrene)‐graft‐poly(ethylene glycol), and poly(higher α‐olefin‐co‐acrylic acid)‐graft‐poly(ethylene glycol) was used as modifying agent to increase the wettability of the surface of linear low‐density polyethylene (LLDPE) film. The wettability of the surface of LLDPE film could be increased effectively by spin coating of the amphiphilic graft copolymers onto the surface of LLDPE film. The higher the content of poly(ethylene glycol) (PEG) segments, the lower the water contact angle was. The water contact angle of modified LLDPE films was reduced as low as 25°. However, the adhesion between the amphiphilic graft copolymer and LLDPE film was poor. To solve this problem, the modified LLDPE films coated by the amphiphilic graft copolymers were annealed at 110° for 12 h. During the period of annealing, heating made polymer chain move and rearrange quickly. When the film was cooled down, the alkyl group of higher α‐olefin units and LLDPE began to entangle and crystallize. Driven by crystallization, the PEG segments rearranged and enriched in the interface between the amphiphilic graft copolymer and air. By this surface modification method, the amphiphilic graft copolymer was fixed on the surface of LLDPE film. And the water contact angle was further reduced as low as 14.8°. The experimental results of this article demonstrate the potential pathway to provide an effective and durable anti‐fog LLDPE film. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Film formation from pigmented latex systems: Drying kinetics and bulk morphologies of ground calcium carbonate/functionalized poly(n‐butyl methacrylate‐co‐n‐butyl acrylate) blend films

The drying kinetics and bulk morphology of pigmented latex films obtained from poly(n‐butyl methacrylate‐co‐n‐butyl acrylate) latex particles functionalized with carboxyl groups and ground calcium carbonate blends were studied. Latex/pigment blends with higher carboxyl group coverage on the latex particle surfaces dried faster than films with few or no carboxyl groups present. The latex/pigment dispersions also dried faster when there was more stabilizer present in the blend system because of the hydrophilic nature of the stabilizer. The net effect of increasing the pigment volume concentration in the blend system was to shorten the drying time. The bulk morphologies of the freeze‐fractured surfaces of the pigmented latex films were studied with scanning electron microscopy. Scanning electron microscopy analysis showed that increased surface coverage of carboxyl groups on the latex particles in the latex/pigment blends resulted in the formation of smaller pigment aggregates with a more uniform size distribution in the blend films. In addition, the use of smaller latex particles in the blends reduced the ground calcium carbonate pigment aggregate size in the resulting films. Scanning electron microscopy analysis also showed that when the initial stabilizer coverage on the latex particles was equal to 18%, smaller aggregates of ground calcium carbonate were distributed within the copolymer matrix of the blend films in comparison with the cases for which the initial stabilizer coverage on the latex particles was 8 or 36%. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2267–2277, 2006     

Preparation and performance of a transparent poly(3,4‐ethylene dioxythiophene)–poly(p‐styrene sulfonate‐co‐acrylic acid sodium) film with a high stability and water resistance

Poly(p‐styrene sulfonate‐co‐acrylic acid sodium) (PSA) from the copolymerization of acrylic acid sodium and p‐styrene sulfonate monomers were used to dope poly(3,4‐ethylene dioxythiophene) (PEDOT) to generate PEDOT–PSA antistatic dispersions. Compared to those of the PEDOT–poly(p‐styrene sulfonate sodium) (PSS), the physical and electrical properties of the PEDOT–PSA conductive liquids were much better. The PEDOT–PSA films possessed a better water resistance without a decrease in the conductivity. The sheet resistance of the PEDOT–PSA–poly(ethylene terephthalate) (PET) films was about 1.5 × 10⁴ Ω/sq with a 100 nm thickness, the same as the PEDOT–PSS–PET films. The transmittance of the PEDOT–PSA–PET films exceeded 88%. Furthermore, the environmental dispersity of the PEDOT–PSA antistatic dispersion was apparently improved by the dopant PSA so that the stability was extraordinarily promoted. Meanwhile, the water resistances of the PEDOT–PSA–PET and PEDOT–PSA films were also enhanced. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45163.     

Surface modification of polymethyl methacrylate intraocular lenses with the mixture of acrylic acid and acrylamide via plasma‐induced graft copolymerization

An approach is presented for the graft copolymerization of acrylic acid (AAc) and acrylamide (AAm) mixture onto the surfaces of polymethyl methacrylate intraocular lenses (PMMA IOLs) treated with an Argon gas plasma, followed by the exposure to the oxygen atmosphere. In this case, peroxides formed by the plasma treatment are likely to be responsible for initiating the graft copolymerization. The amount of peroxides on the surface of PMMA IOLs was determined using 1,1‐diphenyl‐2‐picrylhydrazyl, and the maximum amount was found with the plasma treatment at 30 W for 20 s under 5 mTorr pressure. The surfaces of the grafted PMMA IOLs were characterized using Fourier transform infrared spectroscopy‐attenuated total reflectance (FTIR‐ATR), electron spectroscopy for chemical analysis, and contact angle meter. The FTIR‐ATR spectrum of PMMA‐g‐AAc‐AAm showed the characteristic band of PAAc at 1580 cm^?1 together with those of PAAm at 1670 and 1630 cm^?1, confirming that the copolymer of AAc and AAm was successfully grafted onto the surfaces of PMMA IOLs. The experimental data of O1s/C1s and N1s/C1s reasonably concurred with the calculated data, a strong indication that the pH value of the reaction medium at 3.77 could produce a graft with an equal molar ratio. Surface tension of the samples increased to 52 dyn/cm due to the graft of the hydrophilic monomers. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2361–2366, 2002     

Altering associations of doxorubicin‐loaded alginate esters micelles in presence of β‐cyclodextrin

The aim of this article was to evaluate the effects of β‐cyclodextrin (β‐CD) on doxorubicin (DOX)‐loaded alginate esters (SA‐C₁₆) micelles (DOX/SA‐C₁₆) in aqueous solution. DOX was physically loaded into SA‐C₁₆ micelles by an o/w emulsion method with a substantial encapsulation efficiency (EE) level (36.12%), and DOX/SA‐C₁₆ was distributed in size diameters of approximately 254 nm. SA‐C₁₆ as carriers for the DOX can lead to the formation of associative networks in aqueous solutions between the hydrophobic tails of SA‐C₁₆ and DOX, and the dried morphology of DOX/SA‐C₁₆ aggregate was spherical shape. Addition of β‐CD to the system of DOX/SA‐C₁₆ facilitated decoupling of these associations via inclusion complex formation between β‐CD cavities and the polymer hydrophobic tails that produced the release of DOX immediately, and the EE level was dropped to 0.08%, and at the same time the size distribution of aggregate was increased to about 413 nm, moreover, the aggregate was relatively large and becoming irregular spherical shape. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40702.     

Modification of poly(octadecene‐alt‐maleic anhydride) films by reaction with functional amines

Thin films of poly(octadecene‐alt‐maleic anhydride) on top of Si wafers and glass plates were modified by reactions with different functional amines to be used in future studies on the relevance of certain molecular surface properties for the covalent immobilization of proteins. For that aim, a strategy was developed and applied to convert the anhydride moieties of the copolymer by functional amines into side chains bearing hydrophilic groups of acidic (carboxylic acid, sulfonic acid), basic (amines), or neutral (poly(ethylene oxide) (PEO), glucose) character. The modification of the copolymer films was achieved through the two‐step formation of a cyclic imide, which was very stable in aqueous solution. Depending on the reactivity of the applied amine, the adjustment of the reaction time was suitable for the preparation of partially converted surfaces of the polymer film. Degrees of modification between 5 and 30% (according to X‐ray photoelectron spectroscopy data) were obtained. Annealing the modified polymer films induced efficient back‐formation of the anhydride groups. By reaction of the layered polyanhydrides with highly crosslinked diamines, amine‐functionalized polymer films were produced that were capable of binding secondary polyanhydride layers. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1255–1266, 2003     

Impact of the starch source on the physicochemical properties and biodegradability of different starch‐based films

Concern about environmental issues has motivated research into the development of biodegradable packaging from renewable sources. Natural polymers such as starch constitute a good alternative for diminishing the use of nonbiodegradable and nonrenewable components in the packaging industry. However, depending on the botanical source, films with different properties are formed. The aim of this study was to evaluate the film‐forming capacity of different starch sources (cassava, corn, potato, and wheat) by casting with starch contents from 2 to 6%. Principal component analysis methodology was used to evaluate the correlation between the formulations and their physicochemical and mechanical properties. It was not possible to produce continuous films based on potato starch, probably because of its very low amylose content (10%). The corn‐, cassava‐, and wheat‐starch‐based films were characterized by their thicknesses (0.06–0.22 mm), moisture contents (19–26%), water solubilities (13.7–26.5%), water‐vapor permeabilities (WVPs; 0.19–0.48 g mm h^?1 m^?2 kPa^?1), wettabilities (35–106°), biodegradabilities in soil, and thermal and mechanical properties (tensile strength = 1.9–6.7 MPa, elongation = 41–166%, and Young's modulus = 8–127 MPa). The wheat starch films presented higher WVPs and lower mechanical properties. The cassava starch films presented lower wettabilities and good mechanical properties; this suggested that their use in packaging for products, such as fruits and vegetables, with higher water activities could be feasible. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46564.     

A novel mono‐methacryloyloxy terminated fluorinated macromonomer used for the modification of UV curable acrylic copolymers

A novel macromonomer containing fluorinated units (PHFBMA‐GMA) was synthesized through a two‐step procedure: firstly, hexafluoro‐butyl methacrylate (HFBMA) was polymerized in the presence of functional chain transfer agent 3‐mercaptopropionic acid (MPA) and then the carboxyl acid group terminated polymer was end‐capped with glycidyl methacrylate (GMA). Chemical structures of PHFBMA‐GMA were characterized by gel permeation chromatography, fourier transform infrared spectroscopy (FTIR), and ¹H nuclear magnetic resonance (NMR). Subsequently, PHFBMA‐GMA was employed as reactive surface additives added into UV‐cured polyacrylate to modify UV‐curable coatings. It is convenient to control the tail length of the fluorinated segments in this study by adjusting the ratio of initiator and chain transfer agent. The influence of both the concentration and the molecular weight of PHFBMA‐GMA on the surface properties of UV‐cured films was investigated. With increasing both the concentration and the molecular weight of PHFBMA‐GMA, the surface energy of the UV‐cured films decreased. X‐ray photoelectron spectroscopy was employed to characterize and quantify the surface composition and the results confirm the enrichment of fluorinate atoms on the surface. Moreover, the physical properties of UV‐cured films, such as gel content, water absorption, pencil hardness, adhesion, chemical resistance, mechanical properties, optical transmittance, and thermal properties, were also investigated in detail. The novel macromonomer was economical but effective to modify the properties of the UV‐curable coatings. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43116.     

Characterization of multiwalled carbon nanotube filled,palm‐oil‐based polyalkyds: Effects of loading and in situ reaction

In this study, the contribution of multiwalled carbon nanotubes (MWCNTs) was studied for the evaluation of the performances of polyalkyd‐based films produced from dehydrated palm oil. Initially, different percentages of MWCNTs, including 0.5, 1.0, and 1.5 wt %, were considered for loading into the resin with the help of sonication. Additionally, a 1.0 wt % loading was considered for in situ conditions during the esterification process to achieve better dispersion and obtain improved properties of the film. The loading was evaluated by different performance tests, such as those of tensile, elongation, pencil hardness, swelling ratio, gel content, wettability, chemical resistivity, adhesion, and surface morphology. The results of mechanical testing showed that the addition of 1.0 wt % MWCNTs enhanced the tensile strength by 50%, whereas in situ conditions were found to be favorable for significantly improving the tensile strength by 75%. Moreover, the wettability, surface morphology, and thermal properties were also found to be in favor of in situ conditions for the dispersion of the MWCNTs. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42934.     

Modification of silica gel,cellulose, and polyurethane with a sterically hindered N‐halamine moiety to produce antimicrobial activity

The sterically hindered amine monomer 4‐[3‐triethoxysilylpropoxyl]‐2,2,6,6‐tetramethylpiperidine has been synthesized and covalently bonded to the surfaces of silica gel particles and cellulose (cotton) and copolymerized in a polyurethane coating formulation. Upon exposure to dilute sodium hypochlorite (household bleach), a very stable N‐Cl bond is formed in situ at the hindered amine nitrogen site. This source of oxidative chlorine provides an antimicrobial function to the silica gel, cotton, and polyurethane. Stability, regenerability, and biocidal efficacy data are presented. The new N‐halamine materials were remarkably effective against Staphylococcus aureus and Escherichia coli O157 : H7 in brief periods of contact. The materials should find application in water treatment and medical applications. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Aging and annealing behavior of polycarbonate surfaces modified by direct‐current glow discharge in air

Aging and annealing a polycarbonate (PC) polymer surface treated by direct‐current (dc) glow discharge tend to revert it back to its virgin (pristine) state existing before surface modification by glow discharge. This structural recovery during aging and annealing has been studied in terms of the contact angles of test liquids and surface energy and correlated to the parameters of surface treatment such as the treatment time and power. Samples stored in hydrophobic environments such as air and treated by dc glow discharge at higher power levels show less recovery during aging than those treated at lower power levels. Similarly, a longer exposure time at a power level of 2.04 W decreases the extent of structural recovery in terms of surface energy during aging in air. At higher power levels, the higher kinetic energy of plasma species involved during dc glow discharge results in greater thickness of the damaged layer of the polymer surface, and so a PC sample exposed to dc glow discharge at a higher temperature also recovers at a slower rate during the initial phase of aging, whereas samples with surfaces modified by dc glow discharge at room temperature but annealed at a higher temperature show a relatively rapid recovery during the initial phase of aging. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009