abstract: "Sensor Decade" has been labeled on the first decade of the 21st century. Similar to the revolution of micro-computer in 1980s, sensor R&D; developed rapidly during the past 20 years. Hard workings were mainly made to minimize the size of devices with optimal the performance. Efforts to develop the small size devices are mainly concentrated around Micro-electro-mechanical-system (MEMS) technology. MEMS accelerometers are widely published and used in consumer electronics, such as smart phones, gaming consoles, anti-shake camera and vibration detectors. This study represents liquid-state low frequency micro-accelerometer based on molecular electronic transducer (MET), in which inertial mass is not the only but also the conversion of mechanical movement to electric current signal is the main utilization of the ionic liquid. With silicon-based planar micro-fabrication, the device uses a sub-micron liter electrolyte droplet sealed in oil as the sensing body and a MET electrode arrangement which is the anode-cathode-cathode-anode (ACCA) in parallel as the read-out sensing part. In order to sensing the movement of ionic liquid, an imposed electric potential was applied between the anode and the cathode. The electrode reaction, I_3^-+2e^___3I^-, occurs around the cathode which is reverse at the anodes. Obviously, the current magnitude varies with the concentration of ionic liquid, which will be effected by the movement of liquid droplet as the inertial mass. With such structure, the promising performance of the MET device design is to achieve 10.8 V/G (G=9.81 m/s^2) sensitivity at 20 Hz with the bandwidth from 1 Hz to 50 Hz, and a low noise floor of 100 ug/sqrt(Hz) at 20 Hz. / Dissertation/Thesis / M.S. Electrical Engineering 2013

Foram realizadas pesquisas em uma série de condutores iônicos que apresentam aplicações na área dos dispositivos eletroquímicos de estado sólido, utilizando-se basicamente a técnica de Ressonância Magnética Nuclear (RMN). A primeira parte deste trabalho é dedicada aos compostos de intercalação baseados na matriz de dissulfeto de molibdênio (MoS2) onde as espécies intercalantes (íons de lítio e moléculas de aminas) são inseridas num espaço de dimensionalidade reduzida gerado pela matriz. Já a segunda parte envolve os condutores iônicos poliméricos do tipo compósitos, nos quais foram utilizadas nanopartículas de carbono (Carbon Black) e titânio (TiO2) no eletrólito formado pelo poli(óxido de etileno) (POE) e o perclorato de lítio (LiClO4). Todos estes sistemas apresentam, em geral, uma considerável complexidade estrutural, o que significa que os movimentos moleculares e de difusão iônica se produzem num meio semicristalino (caso dos compósitos) ou num meio de dimensionalidade reduzida (caso dos intercalados). A espectroscopia de RMN dos núcleos de 7Li e 1H é uma técnica conveniente para o estudo destes materiais, pois é possível avaliar, através dos resultados obtidos das medidas dos tempos de relaxação e formas de linha, os efeitos provocados pela baixa dimensionalidade dos movimentos em estruturas laminares (caso dos intercalados), bem como identificar e aferir as interações e os mecanismos de relaxação resultantes dos diferentes graus de liberdade dos movimentos (iônicos e moleculares), fornecer parâmetros estruturais (distâncias interatômicas) que auxiliam na proposta de possíveis modelos estruturais e caracterizar completamente a escala temporal dos movimentos iônicos e moleculares. / Nuclear Magnetic Resonance (RMN) techniques were used to study a series of ionic conductor materials, which present applications in the area of the solid-state electrochemical devices. The first part of this work is dedicated to the study of intercalation compounds based on the molybdenum disulfide matrix (MoS2), where the intercalated species (lithium ion and amine molecule) are inserted in the low-dimensionality space generated by the matrix. The second part involves the study of a composite polymer electrolyte, employing fillers like Carbon Black and titanium dioxide (Tio2) nano particles in the electrolyte formed by the poly(ethy1ene oxide) and a lithium salt (LiClO4). In general, these systems present a considerable structural complexity, meaning that the molecular movements and ionic diffusion are produced in a semicrystalline environment (case of the composites) or in an environment of reduced dimensionality (case of intercalates). The 7Li and 1H NMR spectroscopy is a convenient technique for the study of these materials. Relaxation time and line shape measurements may provide a tool to investigate the effects provoked by the low-dimensionality of the movements in laminate structures (case of intercalate), to identify the interactions and relaxation mechanisms of the ionic and molecular motions, to supply structural parameters (interatomic distances) that would help the proposal of possible structural models, and finally, to characterize the time scale of the ionic and molecular movements completely.

Orientadores: Vitor Baranauskas, Alfredo Carlos Peterlevitz / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-14T06:10:46Z (GMT). No. of bitstreams: 1 Tsukada_Jackson_D.pdf: 2934896 bytes, checksum: b2a5f44f609f42a0f2e1e9857584c401 (MD5) Previous issue date: 2009 / Resumo: O presente trabalho trata da síntese de materiais carboníferos pela técnica de eletrodeposição na fase líquida realizada em temperatura ambiente. Durante o processo de deposição, foi utilizada uma célula eletrolítica de arranjo simples e diferença de potencial, entre os eletrodos, não superior a 300V. A solução utilizada foi etanol puro bem como água deionizada misturada com etanol. As amostras foram caracterizadas por microscopia óptica, microscopia eletrônica de varredura e espectroscopia Raman. Dentre o conjunto de amostras produzidas, houve as que apresentaram estruturas de Carbono Tipo Diamante (DLC) e diamante. O interesse na técnica de eletrodeposição na fase líquida justifica-se pela possibilidade de sintetizar materiais de carbono em baixas temperaturas. / Abstract: This work describes the synthesis of carbon materials by the liquid phase electrodeposition technique performed at room temperature. During the process of deposition, was used an electrolytic cell with potential diference between the electrodes not exceeding 300V. The solution used was pure ethanol well as deionized water mixed with ethanol. The samples were characterized by optical microscopy, scanning electron microscopy and Raman spectroscopy. Among the set of samples produced, there were those that presented structures of Diamond-Like Carbon (DLC) and diamond. The interest in the liquid phase electrodeposition technique is justified by the possibility of synthesizing carbon materials at low temperatures. / Doutorado / Eletrônica, Microeletrônica e Optoeletrônica / Doutor em Engenharia Elétrica

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / This PhD dissertation aimed to review the concept of the nursing outcome Fluid Balance from the Nursing Outcome Classification (NOC) in postoperative patients who underwent cardiac surgery, and develop operational definitions. For so, a concept analysis was carried out according to the Walker and Avant Model (2005), using the integrative review for searching. It was developed from October to December/2010, based on the leading questions: Which indicators allow the body fluid volume assessment on the postoperative period of cardiac surgery? How these indicators are defined and how could they be evaluated? Which features or values are indicative of normal and altered body fluid volume on the postoperative period of cardiac surgery? Water electrolyte balance, thoracic surgery, and postoperative period were used as searching descriptors. The sample consisted of articles which answered at least one of the searching question(s); with full text available through Portal da CAPES, the University of Iowa electronic system, or the interlibrary loan service; in Portuguese, English, or Spanish. Editorials, letters to the editor, qualitative studies, case report studies, proceedings, duplicate articles, and animal research were excluded. The identified works were submitted to a four step evaluation, which resulted on the selection of 48 articles (CINAHL: 12; PubMed: 12; Scopus: 21; Lilacs: 3). Predominated the narrative reviews, cohort, and descriptive studies (level of evidence IV and VI). From the analysis, 14 indicators were identified, plus the 23 present on the Fluid Balance NOC outcome. The integrative review had a limited contribution for the operational definitions construction, mainly due to the nature of the concept of interest. The concept analysis highlighted the attributes: solvent and/or solute movement (active or passive) through semi-permeable membranes and between physiological compartments; effective regulation by homeostatic mechanisms (gradient between hydrostatic and coloidosmotic pressure, electroneutrality, and neurohormonal mechanisms); and maintenance of compartments concentration and volume. The case model represented a healthy individual, with hormonal and fluid compartments control functions preserved, whereas the contrary cases opposed the attributes partially. The borderline cases consisted of morbid situations in which alterations occurred in at most two attributes. The antecedents of fluid balance corresponded to organic, behavioral, and/or environmental conditions that opposed to those listed for the unbalance, or even their absence. The consequences of unbalance encompassed the estates of fluid deficit or excess, as well as the related concepts of hydration, electrolyte balance (sodium) and systemic (volemia) and local (tissue) perfusion. The consequence of balance consisted of the fluid homeostasis or the absence of consequences of unbalance while the empirical referents corresponded to the indicators. The concept analysis allowed its scope delimitation and identify which parameters assure its presence or even its alteration (unbalance). It encompasses the electrolyte balance, perfusion, and hydration phenomena and is beyond the simple measurement and control of fluid intake and output. As initial validity phase of the nursing outcome, it requires the development of experts and clinical research. / Esta tese teve o objetivo de revisar o conceito do resultado de enfermagem EquilÃbrio HÃdrico da Nursing Outcomes Classification (NOC) em pacientes no pÃs-operatÃrio de cirurgia cardÃaca e desenvolver definiÃÃes operacionais. Para isso, realizou-se anÃlise do conceito, segundo o modelo de Walker e Avant (2005), utilizando a revisÃo integrativa para busca. A mesma foi empreendida de outubro a dezembro/2010, com base nas questÃes norteadoras: que indicadores permitem a avaliaÃÃo do volume de lÃquidos corporais no perÃodo pÃs-operatÃrio de cirurgia cardÃaca? Como esses indicadores sÃo definidos e como podem ser avaliados? Quais as caracterÃsticas ou valores indicativos de normalidade e de alteraÃÃo no volume de lÃquidos corporais, no perÃodo pÃs-operatÃrio de cirurgia cardÃaca? Para busca, utilizaram-se os descritores equilÃbrio hidroeletrolÃtico, cirurgia torÃcica e perÃodo pÃs-operatÃrio. A amostra foi composta por artigos que contemplassem pelo menos uma das questÃes norteadoras; com resumo disponÃvel; texto completo acessÃvel pelo Portal da CAPES, pelo sistema eletrÃnico da University of Iowa ou pelo sistema de comutaÃÃo; em portuguÃs, inglÃs ou espanhol. Foram excluÃdos os editoriais, cartas ao editor, estudos reflexivos, relatos de experiÃncia, anais de eventos, produÃÃes duplicadas e pesquisas com animais. ApÃs o levantamento, as produÃÃes foram submetidas a quatro etapas de avaliaÃÃo, que resultaram na seleÃÃo de 48 artigos (CINAHL: 12; PubMed: 12; Scopus: 21; Lilacs: 3). Destacaram-se os estudos de revisÃo narrativa, coorte e descritivos (nÃvel de evidÃncia IV e VI). A partir da anÃlise, identificaram-se quatorze indicadores, alÃm dos vinte e trÃs presentes no resultado EquilÃbrio HÃdrico da NOC. A revisÃo integrativa teve contribuiÃÃo limitada para a construÃÃo das definiÃÃes operacionais, sobretudo devido à natureza do conceito de interesse. A anÃlise do conceito evidenciou os atributos: movimento de solvente e/ou soluto (ativo ou passivo) atravÃs de membranas semi-permeÃveis e entre compartimentos fisiolÃgicos; regulaÃÃo efetiva por mecanismos homeostÃticos (gradiente entre a pressÃo hidrostÃtica e coloidosmÃtica, eletroneutralidade e mecanismos neuro-hormonais); e manutenÃÃo da concentraÃÃo e do volume dos compartimentos. O caso modelo refletiu indivÃduo saudÃvel, com funÃÃes hormonais e de controle dos compartimentos hÃdricos preservadas, enquanto os casos contrÃrios se opuseram aos atributos apenas em parte. Os casos limÃtrofes compreenderam as situaÃÃes mÃrbidas, nas quais ocorrem alteraÃÃo de, no mÃximo, dois atributos. Os antecedentes do EquilÃbrio HÃdrico corresponderam Ãs condiÃÃes orgÃnicas, comportamentais e/ou ambientais que se opunham Ãquelas listadas para o desequilÃbrio, ou mesmo sua ausÃncia. Os consequentes do desequilÃbrio abrangeram os estados de dÃficit e excesso de lÃquidos, bem como os conceitos relacionados de hidrataÃÃo, equilÃbrio eletrolÃtico (sÃdio) e perfusÃo, tanto sistÃmica (volemia) quando localizada (tecidual). Jà o consequente do equilÃbrio consistiu na homeostase hÃdrica ou na ausÃncia dos consequentes de desequilÃbrio, enquanto os referentes empÃricos corresponderam aos indicadores. A anÃlise do conceito permitiu delimitar seu escopo e identificar quais parÃmetros asseguram sua presenÃa ou mesmo sua alteraÃÃo (desequilÃbrio). O mesmo engloba os fenÃmenos de equilÃbrio eletrolÃtico, perfusÃo e hidrataÃÃo e està alÃm da simples mensuraÃÃo e controle das perdas e ganhos de lÃquidos. Como fase inicial da validaÃÃo do resultado de enfermagem, requer o desenvolvimento de pesquisa com experts e clÃnica.

Esta dissertação apresenta a caracterização e o preparo de filmes a partir de amido de mandioca nativo e modificado industrialmente (amido acetilado e amido oxidado - acetilado), através da plastificação com glicerol , sorbitol ou etileno glicol. Estes filmes foram preparados adicionando-se um sal (perclorato de lítio) com o propósito de serem utilizados como eletrólitos sólidos poliméricos (ESP), os quais apresentam grande potencial de aplicação em dispositivos eletrocrômicos, sensores e baterias, por isso os ESPs devem ser: transparentes, apresentar boa aderência e maleabilidade além de boa condutividade iônica. As modificações conferidas ao amido foram estudadas empregando-se técnicas caracterização por espectroscopia no infravermelho, RMN e análise elementar. A distribuição de massa molecular das amostras de amido nativo e dos amidos modificados também foi estudada através da técnica de cromatografia de permeação em gel (GPC). Os filmes foram preparados utilizando-se diferentes proporções de plastificante e de sal e em seguida com intuito de efetuar as caracterizações físico-químicas estas amostras foram submetidas à análises de espectroscopia de impedância eletroquímica, difração de Raios-X, Microscopia Eletrônica de Varredura (MEV), análises espectrofotométricas de UV-visível, além das análises térmicas (TG e DSC). / This dissertation presents the preparation and characterization of films obtained from native and industrially modified (acetilate and oxidate-acetilate), cassava starches, through the plasticization with glycerol, sorbitol or ethylene glycol. These films are prepared adding a salt (lithium perchlorate) so that they can be used as solid polymeric electrolytes (ESP), which present great application potential in electrochromic devices, sensors and batteries, therefore the films obtained must be transparent, present good adherence and flexibility besides good ionic conductivity. The modifications of the starch were studied using techniques of characterization by infrared espectroscopy, RMN and elementary analysis. The distribution of the molecular mass of the samples of native and modified starches was also studied by means of gel permeation chromatography (GPC). The films were prepared using different proportions of plasticizers and salt. For the physical-chemical characterization of the samples, they were subjected to analyses of electrochemical impedance spectroscopy, X-Ray diffraction, Scanning Electronic Microscopy (SEM), Uv-visible spectroscopy, besides thermal analyses (TG and DSC).

Os líquidos iônicos (LIs) são eletrólitos promissores para uso em baterias de lítio e outros dispositivos eletroquímicos, devido às suas propriedades físico-químicas únicas como, por exemplo, ampla faixa de temperatura como liquido, boa condutividade, baixa pressão de vapor e estabilidade térmica, química e eletroquímica. Um LI é composto normalmente por um cátion orgânico e um ânion orgânico ou inorgânico. Neste trabalho, foram sintetizados novos líquidos tanto modificando o ânion como o cátion. Em ambos os casos procurou-se LIs com ótimas propriedades de transporte e que melhorassem a condutividade do lítio em relação condutividade total da mistura LI - sal de lítio. Em primeira instância, foram sintetizados e caracterizados os seguintes líquidos iônicos derivados do ânion [B(CN)4]-: [BMPYR][B(CN)4] (N-butil-N-metilpirrolidínio tetracianoborato), [BMP][B(CN)4] (N-nbutil- N-metilpiperidínio tetracianoborato) e [BMMI][B(CN)4] (1-n-butil-2,3-dimetilimidazólio tetracianoborato), sendo os dois primeiros são líquidos na temperatura ambiente. Quando comparados com os derivados de bis(trifluorometanosulfonil)imideto, [Tf2N]-, os líquidos iônicos derivados de tetracianoborato apresentam melhores valores de condutividade e viscosidade, sendo isto refletidos em um maior valor do parâmetro condutividade do lítio (σLi). Além disso, estes LI possuem maior estabilidade química e eletroquímica. Utilizou-se a técnica de espectroscopia Raman para estudar os líquidos [BMPYR][B(CN)4] e [BMP][B(CN)4] e suas misturas com sal de lítio (0,1 molL-1 de LiB(CN)4), demostrando-se que a interação entre o íon lítio e o ânion tetracianoborato é muito baixa, o que explica o altos valores do número de transporte e condutividade do lítio nestes sistemas. já através da Modificação do cátion, foram sintetizados cinco líquidos iônicos derivados de fosfônio, usando sempre o ânion [Tf2N]-. Entre eles são líquidos na temperatura unicamente os LIs [P2225][Tf2N] (Bis(trifluormetilsulfonil)imideto de trieltilpentilfosfônio) e [P222(201)][Tf2N] (Bis(trifluormetilsulfonil)imideto de trietil(2-metoxietil)fosfônio). Estes líquidos apresentaram excelentes propriedades de transporte e estabilidade eletroquímica quando comparados com seus equivalentes derivados de nitrogênio. Quando se adicionou o sal de lítio, LiTf2N, em concentrações de 1 e 2 molL-1 , os líquidos apresentaram um decréscimo das propriedades de transporte, embora demostrarem efeito menor em comparação com os líquidos iônicos derivados de nitrogênio, apresentando inclusive maiores valores nos números de transporte e de condutividade do lítio nas misturas estudadas. / Ionic liquids (ILs), are of great interest nowadays as electrolytes for lithium ion batteries due their unique characteristics, which include: liquid state over a wide temperature range; nonvolatility, which assures thermal stability and nonflammability; high ion content, which results in high ionic conductivity; and excellent chemical and electrochemical stability. ILs consists of an organic cation and an inorganic or organic anion. In order to improve the transport properties, the cation and anion of the ionic liquid were changed. Three ionic liquids derived from the anion [B(CN)4]- were synthetized and chararacterized: [BMPYR][B(CN)4] (N-n-butyl-N-methylpyrrolidinium tetracyanoborate) [BMP][B(CN)4] (N-n-butyl-Nmethylpiperidinium tetracyanoborate) and [BMMI][B(CN)4] (1-n-butyl-2,3-dimethylimidazolium tetracyanoborate). The first two are liquid at room temperature. When comparing these ionic liquid with the analogous ones containing the anion Tf2N, it was found that ILs derivates from tetracyanoborate have better transport properties which is reflected in a larger value of parameter conductivity of lithium (σLi). Moreover these ILs have higher chemical and electrochemical stability. The Raman spectroscopy was employed to study the BMPYRB(CN)4 and BMPB(CN)4 liquids and their mixtures with lithium salt (0.1 mol L-1 of LiB(CN)4); it was demonstrated that the interaction between the lithium ion and anion tetracyanoborate is very low, which explains the high values of conductivity and transport numbers of lithium in these systems. Furthermore five ionic liquids from the phosphonium cation was synthesized always using the anion [Tf2N]-; being liquid at room temperature only the ILs [P2225][Tf2N] (triethyln-pentylphosphonium bis(trifluoromethylsulfonyl)imide) and [P222(201)][Tf2N] (triethyl (2- methoxyethyl) phosphonium bis(trifluoromethylsulfonyl imide) imide). It was found that these liquids have excellent transport properties and electrochemical stability when compared with their counterparts derived from nitrogen; furthermore, when lithium salt LiTf2N, was added at concentrations of 1 and 2 mol L-1, the ILs containing the phosphonium cations have also shown a decrease in the transport properties, however, the effect is less pronounced when compared to ionic liquids derived from nitrogen, presenting higher transport number and lithium ion conductivity.

Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第15584号 / 工博第3296号 / 新制||工||1497(附属図書館) / 28105 / 京都大学大学院工学研究科材料化学専攻 / (主査)教授 瀧川 敏算, 教授 木村 俊作, 教授 長谷川 博一 / 学位規則第4条第1項該当

Philosophiae Doctor - PhD / High Temperature Polymer Electrolyte Membrane Fuel Cells (HT-PEMFC) have received renewed interest in recent years due to its inherent advantages associated with the limitations faced by Low Temperature Polymer Electrolyte Membrane Fuel Cells (LT-PEMFC). The high Pt loadings required for PEMFCs have significantly hindered its commercialisation. Electrophoretic Deposition (EPD) is a promising route to reduce the noble metal loading. EPD is a method in which charged colloidal particles are deposited onto a target substrate under the force of an externally applied electric field. To effectively study the EPD method, the methodology of this study was divided into two parts: (i) the EPD method was studied via known empirical methods to fabricate, test and characterise MEAs suitable for HT-PEMFCs. The feasibility of the EPD method was determined by comparing the performance of the fabricated EPD MEAs to MEAs fabricated via spraying methods, and (ii) due to the promising results obtained in part (i) of the methodology, a theoretical model was developed to obtain a deep understanding about nature of the interactions between the Pt/C particles in a colloidal suspension. The theoretical model will serve as a foundation for future studies. In part (i) of the methodology, the Pt/C particles were studied in organic solutions (i.e. Isopropyl Alcohol, IPA) via the Zetasizer Nano ZS instrument under various salt (NaCl) concentrations and pH conditions while introducing polymeric surfactants, i.e. Nafion® ionomer and Polytetrafluoroethylene (PTFE) to the suspension. The optimum catalyst suspensions were selected to fabricate GDEs via the EPD method. Physical characterisations revealed that the EPD GDEs exhibited cracked morphology with high porosity. Electrochemical characterisations revealed that the EPD MEA showed significantly better performance (i.e. 73% higher peak power) compared to the hand vi sprayed MEA due to lower charge transfer and mass transport resistance at high current densities. Compared to the ultrasonically sprayed MEA, the EPD MEA exhibited a peak power increase of ~12% at a slightly lower Pt loading (i.e. ~4 wt%). A comparative study between the Nafion® ionomer and PTFE in the CLs of two EPD MEAs revealed superior performance for the EPD MEA with the PTFE in the CLs. Part (ii) of the methodology deals with the electrical interfacial properties of the aqueous Pt/C suspension. The study consists of two sets of measurements (i.e. electrophoretic and coagulation dynamic studies) conducted for different electrolyte compositions. A theoretical background on determining the interfacial potential and charge from electrophoretic and coagulation dynamic measurements are provided. Detailed statements of the Standard Electrokinetic and Derjaguin, Landau, Vervey and Overbeek Models are given in the forms that are capable of addressing electrophoresis and the interaction of particles for an arbitrary ratio of the particle to Debye radius, interfacial potential and electrolyte composition. The obtained experimental data were processed by using numerical algorithms based on the formulated models for obtaining the interfacial potential and charge. While analysing the dependencies of interfacial potential and charge on the electrolyte compositions charge, conclusions were made regarding the mechanisms of charge formation. It was established that the behaviour of system stability is in qualitative agreement with the results computed from the electrophoretic data. The verification of quantitative applicability of the employed models was conducted by calculating the Hamaker constant from the experimental data. It was proposed how to explain the observed variations of the predicted Hamaker constant and its unusually high value.

No abstract available. / Thesis (DPhil)--University of Pretoria, 2011. / Biokinetics, Sport and Leisure Sciences / unrestricted

An aqueous solution of electrolytes can be modelled simplistically as charged hard spheresdispersed in a dielectric continuum. We review various classical theories for hard sphere systems including the Percus-Yevick theory, the mean spherical approximation, the Debye-Hückel theory and the hyper-netted chain theory, and we compare the predictions of the theories with simulation results. The statistical associating fluid theory (SAFT) has proved to be accurate for neutral polymers. It is modified to cope with charged polyelectrolyte systems. A chain term for the charged reference fluid is introduced into the theory. Some well-established results are reproduced in this study and we also introduce new terms and discuss their effects. The results show that the SAFT is semi-quantitatively correct in predicting the phase behaviour of polyelectrolytes. The electrostatic attraction between unlike charged particles at low temperature is very strong. The short-range attractions between unlike pairs are treated via an association theory while the remaining interactions are handled by hypernetted chain theory. This method works quite well with multiple associating sites. The phase prediction for the size and charge symmetric restricted primitive model is quantitatively correct as compared with simulation results. Furthermore, it also gives semi-quantitatively correct predictions for the phase behaviour of size- and charge-asymmetric cases. Dissipative particle dynamics (DPD) is a powerful simulation technique for mesoscopic systems. Molecules with specific shapes (rods and spheres) are simulated using this technique.By tuning the density of the system, some liquid crystal phase transitions can be observed.The properties of spider silk fibroin are also modelled by DPD, indicating a possible route offorming spider silk.