Today’s market offers an ever-increasing range of cellulose pulps (derivative pulps) made fromvarious wood types through different delignification processes. Each pulp segment has its uniquecharacteristics, which makes it difficult for the producer of cellulose derivatives to choose the mostsuitable pulp for optimum processability and product quality. The objective of this study was toimprove knowledge of cellulose pulps and to describe how different pulp properties affectprocessability and quality in the production of viscose dope and cellulose ethers.Ten pulp samples were investigated, originating from both sulfite and sulfate processes, with highand low viscosities and with softwood and hardwood as raw material. The pulps were analyzed fortheir properties and then processed to viscose dope and a cellulose ether in two separate pilotfacilities. The intermediates in the viscose process as well as the quality of the viscose dope andcellulose ether were analyzed and the results correlated to pulp properties.Multivariate regression methods were applied to investigate the dominating physical and chemicalproperties of each pulp and pulp segment, and to study the use of spectroscopic analyses inpredicting pulp origin, concentration and composition of hemicelluloses as well as the content ofreducing end groups in cellulose. For the production of viscose dope, the models presented showedthe most important pulp properties for good cellulose reactivity and viscose filterability. In addition,the properties affecting gel formation, flocculation, degree of substitution and clarity in theproduction of cellulose ether were highlighted. The study also emphasized the need to supplementthe use of conventional analyses on pulps and viscose intermediates with other analytical methods,such as molecular weight distribution and carbohydrate analysis, to better predict the quality ofboth viscose dope and viscose fiber.The results of the present study could be useful to predict the origin and properties of new pulps, toreplace or supplement otherwise expensive pulp analyses, and to assess the impact of pulpproperties on the production of cellulose derivatives without extensive pilot-scale trials.

No description available.

In conventional viscose manufacturing, a large amount of carbondisulfide is consumed. This amount has to be decreased to keep the production cost down and to reduce the environmental impact. The purpose with this work was to show if an enzyme treatment of a dissolving pulp could increase the degree of substitution in the viscose so that the amount of carbon disulfide consumed in the process could be decreased. Previous investigations by Kvarnlöf (2007), Engström et.al. (2006) and Henriksson et.al. (2005) has shown that the reactivity of a dissolving pulp (the cellulose raw material) increased when it was pre-treated with endoglucanase (enzyme). Kvarnlöf (2007) also showed that the amount of carbon disulfide that is needed to produce an ordinary viscose (in this work a more viscous viscose has been investigated) could be reduced with one third because of the enzyme treatment.   In this thesis, viscose has been manufactured in a laboratory where the process has been adapted to look like the industrial as far as possible. Analyses were done on the viscose viscosity and degree of substitution. A reference curve was made with the percentage carbon disulfide load versus the viscose gamma number (degree of substitution). Then it was investigated how an enzyme treatment of the dissolving pulp affected the viscose. After the enzyme treatment, the manufacturing process for viscose was done in the exact same way as when the reference tests were done. The enzyme used in this thesis was Carezyme which contents endoglucanase. Then the results from the analyses of the viscose manufactured from enzyme treated dissolving pulp and the reference curve was compared. A positive result would have been that viscose manufactured with enzyme treatment gets a higher gamma number than viscose, with the same load of carbon disulfide, manufactured in the regular way.   The results showed that the degree of substitution had no effect at all; the viscose that has been manufactured from enzyme treated dissolving pulp resulted in gamma numbers on or very close to the reference curve. The only effect that could be shown was a decrease in viscosity, which unfortunately was an unwanted effect. The enzyme treatment has also hampered the process, where shorter fibres among other things have given poorer dewatering properties. Analyses on the viscose manufactured in the laboratory showed that it didn't have the same characteristics as viscose manufactured in a plant. / I den konventionella tillverkningsprocessen för viskos förbrukas stora mängder koldisulfid. Denna mängd behöver minskas, både för att hålla nere produktionskostnaderna men också för att minska miljöpåverkan. Syftet med arbetet var att undersöka om en enzymbehandling av en dissolvingmassa kunde öka substitutionsgraden så att koldisulfid-förbrukningen skulle kunna minskas. Det har i flera tidigare undersökningar av Kvarnlöf (2007), Engström m.fl. (2006) och Henriksson m.fl. (2005) visats att reaktiviteten hos en dissolvingmassa (råvaran i viskosprocessen) ökar när den förbehandlats med endoglukanas (enzym). Kvarnlöf (2007) visade dessutom att mängden koldisulfid som behövdes för att tillverka spinnviskos (i detta examensarbete har en viskösare viskos undersökts) kunde minskas med en tredjedel tack vare enzymbehandlingen.   I detta examensarbete har viskos tillverkats i laboratoriet där processen har anpassats så att den liknar den industriella så mycket som möjligt. Analyser gjordes på viskosens viskositet och substitutionsgrad. En referenskurva tillverkades där den procentuella koldisulfid-satsningen plottades mot viskosens gammatal (substitutionsgraden). Därefter undersöktes hur en enzymbehandling av dissolvingmassan påverkade den färdiga viskosen. Efter enzymbehandlingen av dissolvingmassan utfördes tillverkningsprocessen precis som vanligt för att man skulle kunna se effekterna av enzymet. Enzymet som användes i arbetet var enzympreparationen Carezyme som innehåller endoglukanas. Sedan jämfördes resultaten från analyserna av viskosen tillverkad från enzymbehandlad dissolvingmassa med referensvärdena. Ett positivt resultat hade varit att enzymbehandlad viskos hade ett högre gammatal än viskos tillverkad på vanligt sätt utan enzymförbehandling men med samma koldisulfidsats.   Resultaten visar att substitutionsgraden inte har påverkats alls, dvs. den viskos som tillverkats från enzymbehandlad dissolvingmassa fick gammatal som låg på eller mycket nära referenskurvan. Den enda effekt av enzymet som kunde visas var en viskositetssänkning, vilket inte var något som eftersträvades. Processen har dessutom försvårats av enzymsteget, där kortare fibrer bl.a. gav sämre avvattningsegenskaper. Viskosanalyser har visat att viskosen som tillverkats på laboratoriet inte har samma egenskaper som viskos tillverkad på fabrik.

Transdermal drug delivery system has been limited to small and lipophilic drugs because skin has the intrinsic function to protect the body preventing entry of the external species into the body. In this thesis, two physical methods were studied to overcome the skin barrier in the controlled breakage of the skin barrier and to deliver macromolecules-based drugs through the skin; (1) polysaccharide dissolving microneedles and (2) micro thermal skin ablation. Polysaccharide dissolving microneedles system was designed to break the skin barrier in a minimized size with the mechanically poor material, to release them into skin with the dissolution of microneedles, and to deliver human growth hormone into the living hairless rats. Micro thermal skin ablation was designed to fabricate the device generating the energy impact with the basis of arc discharge, to transfer the energy impact on the skin, to remove stratum corneum selectively with three-dimensionally controlled manner, and to deliver hydrophilic macromolecules through skin.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2004. / Härtill 5 uppsatser.

Orientador: Prof. Dr. Arnaldo Rodrigues dos Santos Júnior / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Biotecnociência, 2017. / Os fosfatos de calcio, tendo como principais componentes inorganicos de hidroxiapatita (HAp - Ca10(PO4)6(OH)2) e ¿À-Fosfato tricalcico (¿À-TCP-Ca3(PO4)2), vem sendo estudados como substitutos osseo, devido a constituicao mineral similar a dos ossos e dentes, apresentando elevada biocompatibilidade e baixa toxicidade. A substituicao dos ions Ca2+ por ions Mg2+ favorece o metabolismo da mineralizacao dos tecidos mineralizados e estimula a proliferacao osteoblastica. A dopagem com ion Eu3+ possibilita a obtencao de fosfatos de calcio fluorescentes, permitindo assim o bioimageamento das nanoparticulas nos testes in vitro. Neste trabalho, nanoparticulas de HAp, ¿À-TCP e bifasicas (50%HAp e 50%¿À-TCP) dopadas com europio (1,5%) e/ou magnesio (1%) foram sintetizadas pelo metodo de co-precipitacao e tratadas termicamente a 1000¿C por 10-20 minutos. O po foi caracterizado por microscopia eletronica de varredura (MEV), difracao de raios-X (DRX), FTIR e espectroscopia de fluorescencia. Todas as bioceramicas foram analisadas quanto a dissolucao, em meio simulado (pH 7,4) e meio extremo (pH 3,0) por 120 horas. Foi avaliada a citotoxidade in vitro dos extratos com celulas Vero pelo metodo do cristal violeta e por contraste de fase das celulas vivas. Essas celulas foram cultivadas em meio de cultura 199 com 10% de soro fetal bovino a 37o C com 5% de CO2, durante 24 horas. Por MEV caracterizou-se o tamanho e morfologia das particulas puras e dopadas com Mg+2 e/ou Eu+3. O DRX apresenta as fases cristalinas caracterizadas nas respectivas amostras de HAp, ¿À-TCP e HAp/¿ÀTCP com a incorporacao de seus dopantes Mg+2 e/ou Eu+3. Por FTIR identificou-se os grupos funcionais atraves da comparacao dos modos vibracionais nas amostras antes e apos os testes de dissolucao simulado e extremo. Pela tecnica de espectroscopia de fluorescencia obteve-se os espectros de emissao caracteristicos para as diferentes estruturas dos fosfatos de calcio (HAp, ¿À-TCP e bifasicas) dopados com Eu+3 e Mg+2/Eu+3 antes e apos os testes de dissolucao no meio simulado e extremo, por 120 horas. Por ICP OES determinou as concentracoes de ions dissolvidos das amostras apos os testes de dissolucao no meio simulado e extremo. Os ensaios citotoxicos mostraram que os biomateriais estudados nao apresentaram efeitos toxicos a viabilidade celular, sendo, portanto, materiais biocompativeis para aplicacoes in vitro. / Synthetic calcium phosphate bioceramics containing inorganic components hydroxyapatite (HAp-Ca10(PO4)6(OH)2) and â-phosphate tricalcium (â-TCP-Ca3(PO4)2) have been studied for bone repair applications because of their mineral constitution similar to that of bones and teeth, high biocompatibility and low toxicity. The substitution of Ca2+ by Mg2+ in the crystal structure of either the HAp or the â-TCP favors mineralization metabolism of mineralized tissues and stimulates osteoblast proliferation. The Eu3+ doping enables obtaining fluorescent calcium phosphates, thus allowing bioimaging of nanoparticles in vitro. In this work, HAp, â-TCP and biphasic (50% HAp and 50% â-TCP) nanoparticles doped with europium (1.5%) and / or magnesium (1%) were synthesized by the co-precipitation method and termically treated at 1000°C for 10-20 minutes. The powder was characterized by scanning electron microscopy (SEM), diffraction X-ray (XRD), FTIR and fluorescence spectroscopy. All bioceramics were analyzed on dissolution test in simulated (pH 7.4) and extreme (pH 3.0) during 120 hours. The bioceramic extracts were also used for cytotoxicity on vero cells in vitro by the crystal violet method and phase contrast microscopy of living cells. These cells were grown in culture medium 199 with 10% FBS at 37 °C with 5% CO2 for 24 hours. The particle size, and morphology characterized by SEM were compared with the ceramics without dopants and with incorporation of Mg+2 and / or Eu+3. The XRD shows the crystal phases characterized in their respective samples of HAp, â-TCP and HAp / âTCP with the incorporation of its dopants Mg2+ and / or Eu+3. With FTIR were identified functional groups by comparing the vibrational modes in the samples before and after the dissolution tests simulated and extreme. The fluorescence spectroscopy technique yielded the characteristic emission spectra for the different structures of calcium phosphates HAp, â-TCP and biphasic, dopants Mg+2 and / or Eu+3 before and after the dissolution test in simulated and extreme through time 120 hours. The ICP OES determined the dissolved ion concentrations of the samples after the dissolution tests in the medium simulated and extreme. Cytotoxic assays showed that the biomaterial studies showed no toxic effects on cell viability and, therefore, biocompatible materials in vitro applications.

No description available.

Yes / Polymeric hydrogels are a complex class of materials with one common feature—the ability to form three-dimensional networks capable of imbibing large amounts of water or biological fluids without being dissolved, acting as self-sustained containers for various purposes, including pharmaceutical and biomedical applications. Transdermal pharmaceutical microneedles are a pain-free drug delivery system that continues on the path to widespread adoption—regulatory guidelines are on the horizon, and investments in the field continue to grow annually. Recently, hydrogels have generated interest in the field of transdermal microneedles due to their tunable properties, allowing them to be exploited as delivery systems and extraction tools. As hydrogel microneedles are a new emerging technology, their fabrication faces various challenges that must be resolved for them to redeem themselves as a viable pharmaceutical option. This article discusses hydrogel microneedles from a material perspective, regardless of their mechanism of action. It cites the recent advances in their formulation, presents relevant fabrication and characterization methods, and discusses manufacturing and regulatory challenges facing these emerging technologies before their approval.

The textile industry is one of the largest industries in the world and it causes up to 10 % of the global greenhouse gas emissions. With large environmental issues of cotton- and oil-based textiles, other options are explored such as man-made fibers producing fibers like viscose and lyocell. Renewcell is a sustaintech company within textile recycling, producing Circulose®. Circulose® is a dissolving pulp made from 100 % recycled cotton material. It can be used to produce man-made fibers such as viscose or lyocell. The viscose process uses chemical modification to make man-made fibers for the textile industry. The process has changed during the years, but the main steps remains the same and was the outline for the method used in this thesis.  The aim of the thesis was to examine the mechanical properties dry tenacity, dry elongation and dry titer and how these change for various viscose filaments made from recycled cotton textile pulp and dissolving wood pulp from softwood. Evaluating the impact that different spinning conditions had on the mechanical properties. Quality of the viscose dope and the viscose filament was analyzed with ball-fall, filterability and microscopic imaging. The purpose was to gain an understanding for the new dissolving pulp made from recycled cotton textile pulp when used to produce viscose dope and viscose filament. By varying the spinning conditions, the impact it had on the mechanical properties for viscose filaments made of recycled cotton textile pulp could be evaluated.  In this thesis, 4 different types of viscose filaments were examined: 100 % dissolving wood pulp; 100 % recycled cotton textile pulp; a blend of 50 % recycled cotton textile pulp and 50 % dissolving wood pulp; and a blend of 70 % recycled cotton textile pulp and 30 % dissolving wood pulp. The filaments were produced by preparing a viscose dope from dissolving pulp, followed by wet spinning. The result showed that good viscose dopes and viscose filaments could be produced from all pulps and blends. Similar mechanical properties was obtained for 100 % dissolving wood pulp and 100 % recycled cotton textile pulp. The tenacity and titer changed with the different blends, and the spinning conditions affected mostly the elongation. The viscose dope’s containing recycled cotton textile pulp eventually had lumps forming and a slight increase in breakage.  The conclusion of this thesis was that viscose filament of 100 % recycled cotton textile pulp and blends with recycled cotton textile pulp was successfully spun, the mechanical properties obtained was promising and showed great possibilities for improvement by altering the spinning conditions. Using a larger amount of recycled cotton textile pulp could lower some sustainability issues regarding the viscose production. Several aspects of the laboratory viscose process can be improved by further research. A focus on optimizing the viscose dope and synthetic fiber handling, analyzing the black particles, lowering lumps and breakage for the viscose containing recycled cotton textile pulp would be optimal. / Textilindustrin är idag en av de största industrierna i världen och orsakar upp till 10 % av de globala växthusgaserna. Det finns stora miljöproblem med bomull och olje-baserade textilier, därför utforskas andra alternativ som till exempel regenererade cellulosafiber som lyocell och viskos. Renewcell är ett sustaintech företag med fokus på textilåtervinning och tillverkar produkten Circulose®. Circulose® är en dissolvingmassa tillverkad av 100 % återvunnet bomullsmaterial, det kan användas för att tillverka regenererade cellulosafiber så som viskos och lyocell. Viskosprocessen använder kemiska modifieringar för att få fram regenererade cellulosafiber som sedan till exempel kan användas i textilier. Viskosprocessen har ändrats under åren men de huvudsakliga stegen kvarstår och har använts som riktlinje för metoden i denna studie.  Målet med detta arbete var att undersöka de mekaniska egenskaperna torr brottstyrka, torr maximal töjning före brott och torr vikt per längdenhet for viskosfilament, samt hur det förändras för olika viskosfilament tillverkade av återvunnen bomullstextilmassa och dissolving vedmassa av barrved. Påverkan som olika spinnförhållanden hade på de mekaniska egenskaperna analyserades. Kvaliteten på viskosdop och viskosfilament att utvärderas med kulfall, filtrerbarhet och mikroskopi. Syftet var att få en ökad förståelse för den nya dissolvingmassan tillverkad av återvunnen bomullstextil när den används för att tillverka viskosdop och viskosfilament. Genom att variera spinnförhållandena kunna utvärdera inverkan på de mekaniska egenskaperna hos viskosfilament av återvunnen bomullstextilmassa.  I detta arbete undersöktes 4 olika typer av viskosfilament, 100 % dissolving vedmassa, 100 % återvunnen bomullstextilmassa, en blandning med 50 % återvunnen bomulls textilmassa och 50 % dissolving vedmassa och en blandning med 70 % återvunnen bomullstextilmassa och 30 % dissolving vedmassa. Filament tillverkades genom framställning av viskosdop från dissolvingmassa följt av våt-spinning. Resultatet visade att bra viskosdop och viskosfilament kunde framställas utifrån alla massor och blandningar. Liknande mekaniska egenskaper uppnåddes för 100 % dissolving vedmassa och 100 % återvunnen bomullstextilmassa. Brottstyrka och vikt per längdenhet varierade för olika blandningar, variationen i spinningförhållande påverkade mestadels maximala töjningen. Mer klumpar och brott uppstod för spinning av viskosdop bestående av återvunnen bomulls textilmassa.  Slutsatsen för detta arbete var att viskosfilament av 100 % återvunnen bomulls textilmassa och blandningar innehållande återvunnen bomullstextilmassa kunde med framgång spinnas, de erhållna mekaniska egenskaperna var lovande och visade på stora förbättringsmöjligheter genom att variera spinningsförhållanden. Att använda en större mängd återvunnen bomullstextilmassa skulle kunna förbättra vissa hållbarhetsaspekter gällande viskosproduktionen. Flera aspekter av laboratorieviskosprocessen kan förbättras genom ytterligare forskning. Ett fokus på att optimera viskosdopar och syntetfiberhantering, undersöka svarta partiklar, minska klumpar och brott för viskos innehållande återvunnen bomullstextilmassa skulle vara optimalt.

The purpose of this thesis is, in collaboration with the Swedish company Innventia, to explore the possibilities of using paper machines to create fabric-like nonwoven materials. As part of a relatively new research-area, it serves as some of the ground knowledge that is needed to drive this field forward. The research of this thesis is born from the increasing need for more environmental friendly textiles, and to find new uses for the paper production facilities and companies that are currently experiencing a decline in paper production. The materials used in the research were produced with the Finnish handsheet former and the StratEx sheet-maker made by Innventia. The research consists of the following tests: Tissue Softness Analysis, (TSA), tensile strength and bending stiffness. The tests are done with different combinations of lyocell, PLA, softwood and dissolving pulp in the tested sheets. It is also tested if the lyocell can be a meaningful substitution for PLA in combination with softwood pulp and dissolving pulp when creating the fabric-like materials. In conclusion of this research it can be said that, compared to benchmarking samples like bedding sheets, table cloths and cotton shirts, the sheets created and tested are competitive alternatives to existing materials when it comes to softness. It also became clear that the tensile strength has to be increased to make fabric-like nonwoven materials applicable on the same level as existing textiles. Even so, it is still evident that there is a potentiality in the use of paper machines in the development and creation of new fabric-like materials.