Vapor Bath Research Articles

Preparation of carboxylated-silk nanofibers by the one-pot method of maleic acid hydrolysis.

In this study, a maleic acid (MA) hydrolysis one-pot method is proposed to prepare carboxylated silk nanofibers (MA-SNFs). The MA concentration, hydrolysis temperature, and processing time were optimized. Combined with high-pressure homogenization, MA-SNFs with a carboxyl content of 0.617±0.019mmol/g and length of 333±116nm were obtained with a yield of 54.90±1.98% at the optimal conditions: 50wt% of MA concentration, 110°C of hydrolysis temperature and 120min of processing time. The morphology, chemical structure, and crystal structure of raw silk fibroin (SF), acid-hydrolyzed silk fibroin and nanofibers were studied. Furthermore, MA was reused several times with a recovery rate of >94% and maintained almost the same treatment effect. Finally, due to the presence of carboxyl groups, MA-SNF hydrogels were successfully prepared by an acetic coagulation vapor bath which exhibited excellent self-supporting ability and mechanical properties as well as a more sensitive pH response compared with regenerated silk fibroin solution and other non-carboxylated silk nanofibers. The MA-SNF aerogels had the characteristics of light weight, high strength and porous with cross-linked nanostructures.

Heat Therapy: Concept, Mechanism and Application in Unani Medicine

Background: Application of heat either generalised or localised is among various means employed in Unani medicine for promoting health, preventing as well as treating diseases. The concept of hotness (Ḥarārat) and application of physical heat have been in vogue during different periods of human civilization and it exists even today with certain modifications. Heating Modalities: Unani medicine offers various methods for the application of mild to moderate heat that includes Turkish bath (Ḥammām), massage (Dalk), cupping (Ḥijāma), sitz bath (Ābzan), inducing diaphoresis (Ta‘rīq), douche (Naṭūl), vapour bath (Inkibāb) and footbath (Pāshoya). Application of Heat: Heating modalities are commonly used by Unani physicians for relieving pain and stiffness, relaxing muscles, increasing blood circulation, liquefying the sticky and adherent humours lodged in the peripheral tissues and reducing inflammation. Application of severe heat also finds a place among various modes of treatment mentioned in Unani medicine. Cauterisation (Kayy) is the mode that is employed for the stoppage of bleeding, removing putrefactive matter and destroying lesions. Conclusion: Unani medicine offers classical methods and instruments for heat therapy used for centuries for the promotion of health, prevention and management of diseases. Heat therapy has been found considerably effective in managing certain health problems and diseases.

Fabrication of µFFE Devices in COC via Hot Embossing with a 3D-Printed Master Mold.

The fabrication of high-performance microscale devices in substrates with optimal material properties while keeping costs low and maintaining the flexibility to rapidly prototype new designs remains an ongoing challenge in the microfluidics field. To this end, we have fabricated a micro free-flow electrophoresis (µFFE) device in cyclic olefin copolymer (COC) via hot embossing using a PolyJet 3D-printed master mold. A room-temperature cyclohexane vapor bath was used to clarify the device and facilitate solvent-assisted thermal bonding to fully enclose the channels. Device profiling showed 55 µm deep channels with no detectable feature degradation due to solvent exposure. Baseline separation of fluorescein, rhodamine 110, and rhodamine 123, was achieved at 150 V. Limits of detection for these fluorophores were 2 nM, 1 nM, and 10 nM, respectively, and were comparable to previously reported values for glass and 3D-printed devices. Using PolyJet 3D printing in conjunction with hot embossing, the full design cycle, from initial design to production of fully functional COC µFFE devices, could be completed in as little as 6 days without the need for specialized clean room facilities. Replicate COC µFFE devices could be produced from an existing embossing mold in as little as two hours.

Zwitterionic polyvinylidene fluoride membranes with strong underwater superoleophobicity and oil-fouling resistance for oily water purification

Polyvinylidene fluoride (PVDF) membrane offers excellent potential for efficient separation and purification of O/W emulsions. However, oil-fouling presents a major obstacle to its further application. Herein, a strong underwater superoleophobic surface was engineered to efficiently inhibit oil-fouling. PVDF-graft-poly(2-(dimethylamino) ethyl methacrylate) (PVDF-g-PDMAEMA) membranes were first fabricated via vapor-induced phase separation (VIPS), in which the nascent liquid film was left in a vapor bath for a predesigned time (te). The surface roughness increases by an order of magnitude when te increases from 0 to 240 s, and the underwater oil contact angle (UWOCA) correspondingly increases to more than 150°. However, it declines with time gone until the oil droplets on the underwater membranes were swallowed up. After surface zwitterionicalization by the reaction between PDMAEMA and 1, 3-propane sulfonate, a strong underwater superoleophobic surface was obtained, even after being soaked in water for 24 h. It endows the zwitterionic membrane with superior crude oil/water emulsion separation (with a flux of 749.7 ± 44.8 L m−2 h−1 and separation efficiency of 99.4 ± 0.1%) and excellent oil-fouling resistance (with a flux recovery rate of more than 90%), improving the potential value of porous membranes in oily water treatment.

Toward an Architecture of Air and Steam: Climate, Bathing, and Public Health in Victorian Britain

This essay highlights how nineteenth-century epidemic diseases catalyzed environmental thinking in architecture by examining air and vapor bathing technologies and their role in transmitting environmental medical principles into British building culture. Vapor baths were popular medical devices used to fortify a patient’s health by passing hot or cold air charged with steam over the skin, a vital membrane through which impurities were thought to be excreted from the body. This essay discusses vapor bathing’s role in establishing environmental mediation as an underlying principle of modern British architecture. It shows how bathing practices were adapted to deliver localized forms of atmospheric medicine inside buildings, making architectural interiors a key site for the formulation of Victorian ideas of public health. Bathing offers evidence of how the climate-controlled interior emerged out of a confluence of medical ecology, moral demography, and technical innovation.

Dosimetric Comparison of Exposure Pathways to Human Organs and Tissues in Radon Therapy.

Three therapeutic applications are presently prescribed in the radon spas in Gastein, Austria: exposure to radon in a thermal bath, exposure to radon vapor in an exposure chamber (vapor bath), and exposure to radon in the thermal gallery, a former mine. The radiological exposure pathways to human organs and tissues in these therapeutic radon applications are inhalation of radon and radon progeny via the lungs, radon transfer from water or air through the skin, and radon-progeny deposition on the skin in water or air. The objectives of the present study were to calculate radon and radon-progeny doses for selected organs and tissues for the different exposure pathways and therapeutic applications. Doses incurred in red bone marrow, liver, kidneys, and Langerhans cells in the skin may be correlated with potential therapeutic benefits, while doses to the lungs and the basal cells of the skin indicate potential carcinogenic effects. The highest organ doses among the three therapeutic applications were produced in the thermal gallery by radon progeny via inhalation, with lung doses of 5.0 mSv, and attachment to the skin, with skin doses of 4.4 mSv, while the radon contribution was less significant. For comparison, the primary exposure pathways in the thermal bath are the radon uptake through the skin, with lung doses of 334 μSv, and the radon-progeny attachment to the skin, with skin doses of 216 μSv, while the inhalation route can safely be neglected.

Investigation on the Effects of Acetone Vapor-Polishing to Fracture Behavior of ABS Printed Materials at Different Operating Temperature

Fused Deposition Modelling (FDM) technology is one of most common technique used in 3D printing as of today for several reasons such as it is low cost and high speed printing capacity. However, common characteristic of FDM 3D printed materials are poor layer adhesion strength and rough surface finish which requires post-processing to improve it. Heat treatment and vapor-polishing are post-processing techniques used to address the poor layer adhesion and rough surface finish of 3D printed materials, respectively. This study will combine these two post-processing techniques and investigate its effect on the mechanical properties of 3D printed materials. The present study describes the effect of acetone vapor-polishing to facture behavior of ABS 3D printed material at higher operating temperatures. The study will compare the fracture behavior of ABS 3D-printed material when polished using acetone vapor bath and tested at high operating temperature to unpolished material. Five replications for each test condition were conducted. All experiment was carried out using ASTM Izod Type E tests with a 2.75J pendulum. The results showed that acetone vapor polishing strongly affects the fracture behavior of ABS 3D printed materials when operating at high temperature.

Surface roughness of FDM parts after post-processing with acetone vapor bath smoothing process

Additive manufacturing (AM) has become a prominent manufacturing technology due to its capability in manufacturing complex geometries without the demand for specific tools. However, AM technologies suffer from poor surface roughness limiting its widespread industrial application. Application of AM parts in industrial services highly relies on an appropriate post-processing stage to improve the surface roughness of the products. In the case of fused deposition modeling (FDM), acetone vapor bath smoothing is an effective solution for the post-processing stage. However, a vast understanding of the smoothing process is required. This paper presents an experimental study on the effect of the smoothing parameters on the resulting surface roughness of the final FDM products. The smoothing parameters are divided into the number of smoothing cycles and the cycle duration. The surface roughness is calculated based on the deviations from the total least square plane fitted to the surface topographic data sets. The effects of the design and the smoothing parameters are studied, experimental models are developed, and the best smoothing setups are proposed. The developed experimental models enable the engineers to predict the final surface roughness based on the exposure time to the acetone vapor bath or define the required post-processing steps to achieve the desired surface quality.

3D Printed Micro Free-Flow Electrophoresis Device.

The cost, time, and restrictions on creative flexibility associated with current fabrication methods present significant challenges in the development and application of microfluidic devices. Additive manufacturing, also referred to as three-dimensional (3D) printing, provides many advantages over existing methods. With 3D printing, devices can be made in a cost-effective manner with the ability to rapidly prototype new designs. We have fabricated a micro free-flow electrophoresis (μFFE) device using a low-cost, consumer-grade 3D printer. Test prints were performed to determine the minimum feature sizes that could be reproducibly produced using 3D printing fabrication. Microfluidic ridges could be fabricated with dimensions as small as 20 μm high × 640 μm wide. Minimum valley dimensions were 30 μm wide × 130 μm wide. An acetone vapor bath was used to smooth acrylonitrile-butadiene-styrene (ABS) surfaces and facilitate bonding of fully enclosed channels. The surfaces of the 3D-printed features were profiled and compared to a similar device fabricated in a glass substrate. Stable stream profiles were obtained in a 3D-printed μFFE device. Separations of fluorescent dyes in the 3D-printed device and its glass counterpart were comparable. A μFFE separation of myoglobin and cytochrome c was also demonstrated on a 3D-printed device. Limits of detection for rhodamine 110 were determined to be 2 and 0.3 nM for the 3D-printed and glass devices, respectively.

Post processing for Fused Deposition Modeling Parts with Acetone Vapour Bath

Additive Manufacturing (AM) has the benefit being capable to create very complex geometries, which could be impossible with traditional methods or fabricated at high cost. However, the manufacturing cost of AM is not directly related to the parts complexity. From material costs perspective, the cost of AM parts is mostly related to the size of the product. However, some AM techniques, such as Fused Deposition Modelling (FDM), suffers from poor surface roughness restricting its application in some areas requiring high surface integrity. Because of this issue, a post processing stage is required to improve the surface roughness of the AM parts. In this work, an acetone vapor bath smoothing post process is employed to improve the surface roughness of parts manufactured by FDM. The smoothing parameters are the number of smoothing cycles and the cycle duration. Eventually, the total time during which the part is in acetone vapour is found to be the main factor affecting the final surface roughness. The surface of the parts are digitized using a 3D microscope and the extracted point cloud was used to analyze the surface. A total least square plane is fitted to the points and the deviation of points from this plane is used for calculation of the surface roughness. The results of this study suggests the best smoothing parameters to get the best surface roughness for each set of design parameters. The final surface roughness can be predicted by the experimental models developed based on the build orientation and layer thickness.

Investigation of Rapid-Prototyping Methods for 3D Printed Power Electronic Module Development

The recent research in wide-bandgap (WBG) power electronic semiconductors has produced a wide variety of device and combinational topologies, such as HFETS, MOSHFETS, and the Cascode Pair. Each variation needs to be tested with certain package criteria (e.g. high voltage SiC devices up to 15kV, high current GaN devices up to 300A, or unprecedented high frequencies). Having a common package is costly and cannot provide an investigation of optimized performance. Hence, use of a rapid prototyping method to print power electronic packages and modules is needed. Also, the continual move to higher frequencies will require greater integration of packaging into the end application, as is presently done with point-of-load converters. The future modules will take on more functional integration, including more mechanical features, which further supports use of printed fabrication technologies. It is not reasonable to assume that a complete module can be directly printed, though most would be; some assembly is required. This paper discusses partitioning of a module process, and identifying key elements that can be combined for optimum power package production. To select the best process, or combination, for rapid-prototype printing of power modules current, Additive Manufacturing (AM) methods are evaluated, such as Stereolithography (SLA), Selective Laser sintering (SLS), and Fused Deposition Manufacturing (FDM). Several modules were fabricated to demonstrate mechanical resolutions in the packaging. A thermoplastic printer, specifically the MakerBot, which is a high end consumer 3D printer, produces packages with 100 micron resolution. The Acrylonitrile butadiene styrene (ABS) build object can have surface texture enhancement with post chemical treatment, such as an acetone vapor bath. Today, this is finding a home and proving useful in low volume rapid prototyping in small electronics companies. The ABS plastics are typically rated for <105°C applications. Another printed module to be reported uses a high-end commercial machine with <20 microns in resolution (Stratasys Objet) using standard UV curable polymers. This provides a slightly higher temperature range with greater mechanical integrity. Materials for >250°C that use both UV and thermal sintering are available, but not evaluated in this paper. Functional integration can include electrical, mechanical, and thermal appendages and sub-systems. Electrical sub-systems, such as gate drivers and sensors, can impact process partitioning, by requiring “low power” circuit fabrication processes integrated with those for high power. This paper demonstrates a printed polymer substrate process for functional integration of a signal-circuit. Since nearly all AM processes were developed initially for mechanical systems, many processed materials have not been electrically characterized, though the basic material compositions may have suitable electrical characteristics. This paper categorizes several materials for their potential suitability for power packaging. The evaluation is based on the electrical, mechanical, and thermal parameters, along with precision, surface texture (affecting electric field contours) and process times. Cost and performance will be of main concern.

Survol ethnobotanique de quelques plantes utilisées contre la schistosomiase urogénitale à Lubumbashi et environs

For contributing to the assemblage of medicinal plants used against schistosomiasis in Lubumbashi and nearby, a survey was piloted in this area. This ethnobotanic survey involving 43 respondents permitted us to collect information about 61 plants used as anti-schistosomal. These species belong to 55 different genuses distributed among 32 families. The result allows us to know that these anti-schistosomial species are also used in 37 indications, including intestinal worms and malaria. Many parts of these species (bark of roots and stalks, leaves, fruits, seeds, rhizomes) are used in different manners (decoction, infusion, maceration, powder) to make different doses. Different manners of taking prepared medicines are employed: drinking, local application, painting, vapor bath, purgative. Drinking the product remains the most common way of administration.

Disease modification in systemic sclerosis: the search for the Holy Grail

Descriptions of a systemic sclerosis (SSc)-like illness can be found in the writings of Hippocrates (460– 370 BC), however the first welldocumented case was reported by Carlo Cursio in 1755. He described a 17-year-old female patient from Naples (Italy) who presented with “an excessive tension and hardness of her skin all over her body, by which she found herself so bound and straiten’d, that she could hardly move her limbs.” She was treated with warm milk, vapor baths, “bleeding from her foot” and quicksilver, and reportedly her skin became soft and flexible after a period of 11 months [1]. Not all patients with SSc are as fortunate. More than 250 years have since passed and there is no treatment for SSc. The etiology of SSc is unknown and the complex pathogenesis is not clearly understood. The initial stage of the disease is characterized by an early inflammatory infiltrate, microvascular dysfunction and dysregulated immunity, which is superseded by overwhelming fibrosis [2]. Treatment studies for SSc are few and difficult to conduct owing to a low disease prevalence, a complicated pathogenesis unique to individual patients (even with a similar disease phenotype) and suboptimal primary outcome measures, such as the modified Rodnan skin score (mRSS), which may not correlate well with disease activity and severity in all patients. Trials with agents such as imatinib, IFN-g, IFN-a, d-penicillamine, relaxin and minocycline, which target only the fibrotic component of the disease, have shown improvement in open-label studies for the treatment of SSc. However, when randomized studies were carried out, a similar benefit was not observed. Agents that potentially target other pathogenic

Nasal Drug Delivery in Traditional Persian Medicine

Over one hundred different pharmaceutical dosage forms have been recorded in literatures of Traditional Persian Medicine among which nasal forms are considerable. This study designed to derive the most often applied nasal dosage forms together with those brief clinical administrations. In the current study remaining pharmaceutical manuscripts of Persia during 9th to 18th century AD have been studied and different dosage forms related to nasal application of herbal medicines and their therapeutic effects were derived. By searching through pharmaceutical manuscripts of medieval Persia, different nasal dosage forms involving eleven types related to three main groups are found. These types could be derived from powder, solution or liquid and gaseous forms. Gaseous form were classified into fumigation (Bakhoor), vapor bath (Enkebab), inhalation (Lakhlakheh), aroma agents (Ghalieh) and olfaction or smell (Shomoom). Nasal solutions were as drops (Ghatoor), nasal snuffing drops (Saoot) and liquid snuff formulations (Noshoogh). Powders were as nasal insufflation or snorting agents (Nofookh) and errhine or sternutator medicine (Otoos). Nasal forms were not applied only for local purposes. Rather systemic disorders and specially CNS complications were said to be a target for these dosage forms. While this novel type of drug delivery is known as a suitable substitute for oral and parenteral administration, it was well accepted and extensively mentioned in Persian medical and pharmaceutical manuscripts and other traditional systems of medicine as well. Accordingly, medieval pharmaceutical standpoints on nasal dosage forms could still be an interesting subject of study. Therefore, the current work can briefly show the pharmaceutical knowledge on nasal formulations in medieval Persia and clarify a part of history of traditional Persian pharmacy.

Charles Whitlaw (né Whitly) (1771–1850): botanist, horticulturist, charlatan and quack

Charles Whitlaw (otherwise Whitly) was born in Yester, East Lothian, and received training in Edinburgh as a horticulturist before emigrating to North America where he spent about two decades from 1794. He collected botanical specimens, some of which are preserved in the herbarium at the National Botanic Gardens, Glasnevin, Dublin. In the United States, Whitlaw obtained a patent for processing the fibres of Urtica whitlawii which was named after him by Muhlenberg. On returning to Britain, he was proposed for election as a Fellow of The Linnean Society of London, but was black-balled. Returning again to North America Whitlaw gave lectures on botanical topics to general audiences using hand-painted “transparencies” acquired from Dr Robert Thornton. Later Whitlaw established “patent medicated vapour baths” in which he employed various North American plants with reputed medicinal properties. Claiming to be able to cure diseases such as scrofula, Whitlaw outraged the medical establishment and he was branded a charlatan and a quack.

Deposition of radon progeny on skin surfaces and resulting radiation doses in radon therapy

In the Gastein valley, Austria, radon-rich thermal water and air have been used for decades for the treatment of various diseases. To explore the exposure pathway of radon progeny adsorbed to the skin, progeny activities on the skin of patients exposed to thermal water (in a bathtub) and hot vapour (in a vapour chamber) were measured by alpha spectrometry. Average total alpha activities on the patients' skin varied from 1.2 to 4.1 Bq/cm(2) in the bathtub, and from 1.1 to 2.6 Bq/cm(2) in the vapour bath. Water pH-value and ion concentration did affect radon progeny adsorption on the skin, whereas skin greasiness and blood circulation did not. Measurements of the penetration of deposited radon progeny into the skin revealed a roughly exponential activity distribution in the upper layers of the skin. Based on the radon progeny surface activity concentrations and their depth distributions, equivalent doses to different layers of the skin, in particular to the Langerhans cells located in the epidermis, ranged from 0.12 mSv in the thermal bath to 0.33 mSv in the vapour bath, exceeding equivalent doses to the inner organs (kidneys) by inhaled radon and progeny by about a factor 3, except for the lung, which receives the highest doses via inhalation. These results suggest that radon progeny attachment on skin surfaces may play a major role in the dosimetry for both thermal water and hot vapour treatment schemes.

Morrice McCrae, Physicians and society: a history of the Royal College of Physicians of Edinburgh, Edinburgh, John Donald, 2007, pp. 282, illus., £25.00 (hardback 978-0-85976-698-2).

This book promises much. The press release which accompanied its launch described it as a “remarkable social history” and the preface claimed that the founding members resolved to “take the lead” in providing free medical care to the poor of Edinburgh and that the College remained the “chief agency in promoting measures to secure and maintain the health of the people of Scotland” for the two centuries following its foundation in 1681. The volume fails to support these initial claims, despite the author’s mastery of his sources and a deft touch in telling his story. The early chapters eloquently chart the impact upon the College of the political and religious upheavals of the late seventeenth and early eighteenth centuries before turning to more familiar territory, with sections on the emergence of the Edinburgh Faculty of Medicine and the Royal Infirmary. Many of the subsequent chapters are crafted around the contributions of individual physicians, with extended biographies. Chapter 5, for example, examines William Cullen’s contribution to the medical curriculum, and chapter 6 is headed ‘The invention of medical ethics: the legacy of John Gregory’. Chapter 8—‘Certain measures for the public good’—is a detailed account of the deliberations of the six committees set up in 1791 at the instigation of Andrew Duncan to report on inoculation, asylums, apothecary shops, sea bathing, and vapour baths; the focus of the sixth committee is not revealed. The author admits that their recommendations were not implemented because of a lack of good will on the part of a “tiny and corrupt ruling elite” (p. 127). The author pinpoints the plight of the urban poor as the great social problem of the mid-nineteenth century and asserts that the College “played the leading role in ensuring that relevant legislation conformed to the problems as they existed in Scotland” (p. 133). It is clear, however, that the College enjoyed very limited success in its attempts to influence public health measures. McCrae offers no evidence to support his claim that its attempts to improve the medical provisions of the 1845 Poor Law Amendment Act bore fruit (p. 161); one offshoot, the 1852 College report on medical aid in the Highlands and Islands, had no obvious impact, and another sixty years elapsed before the creation of a Highlands and Islands Medical Scheme. A similar outcome befell College attempts to influence the deliberations of the General Board of Health during the 1848 cholera epidemic, medical registration (chapter 12) and mid-nineteenth century legislation dealing with mental health (chapter 14). When the College was involved, it often had equal representation with the Royal College of Surgeons of Edinburgh. The one area where the College did claim priority was in the establishment in 1887 of what is stated to be Britain’s first medical research laboratory. The final sentence of the last chapter—a miscellany which includes accounts of the Scottish triple qualification, the school of medicine of the two Edinburgh colleges, and a perfunctory summary of the Edinburgh School of Medicine for Women—asserts that “at the end of the nineteenth century the Royal College of Physicians of Edinburgh was already playing a leading part in preparing for the medicine of the twentieth century” (p. 260). This is a disappointing ending to a book whose cover notes claimed it would provide a social history of the College from the foundation in 1681 until 1918.

The first cosmetic treatise of history. A female point of view

The Schola Medica Salernitana was an early medieval medical school in the south Italian city of Salerno and the most important native source of medical knowledge in Europe at the time. The school achieved its splendour between the 10th and 13th centuries, during the final decades of Longobard kingdom. In the school, women were involved as both teachers and students for medical learning. Among these women, there was Trotula de Ruggiero (11th century), a teacher whose main interest was to alleviate suffering of women. She was the author of many medical works, the most notable being De Passionibus Mulierum Curandarum (about women's diseases), also known as Trotula Major. Another important work she wrote was De Ornatu Mulierum (about women's cosmetics), also known as Trotula Minor, in which she teaches women to conserve and improve their beauty and treat skin diseases through a series of precepts, advices and natural remedies. She gives lessons about make-up, suggests the way to be unwrinkled, remove puffiness from face and eyes, remove unwanted hair from the body, lighten the skin, hide blemishes and freckles, wash teeth and take away bad breath, dying hair, wax, treat lips and gums chaps.

Des bains de vapeurs térébenthinés aux pastilles de Pin mugho

This article presents the history of turpentined vapour baths used to treat rheumatismes. In the same time appeared patent medicines made with coniferous oil, sold by chemist near those baths establishments.

Water‐absorptive blend fibers of copoly(acrylic acid–acrylamide) and poly(vinyl alcohol)

AbstractThrough the addition of N‐hydroxymethyl acrylamide as a potential crosslinker, water‐absorptive blend fibers of copoly(acrylic acid–acrylamide) and poly(vinyl alcohol) with three‐dimensional network structures were prepared with heat‐crosslinking technology after fiber formation. Fourier transform infrared, scanning electron microscopy, dynamic mechanical analysis, and thermogravimetry were used to analyze the structures and properties of the fibers. The tensile behavior and absorbent capacities of the fibers were also studied. The results showed that there were lots of chemical crosslinking points in the fibers, the compatibility of copoly(acrylic acid–acrylamide) and poly(vinyl alcohol) was perfect, and the tensile properties of the fibers could be improved effectively through stretching in a vapor bath. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3353–3357, 2006