Coalescence est une association d'investisseurs ayant pour mission de participer de façon minoritaire au financement et au développement rapide et rentable de jeunes entreprises innovantes pendant les difficiles premières années.

Coalescence Members

Hervé Castres Saint-Martin

Hervé graduated from the Higher School of Industrial Physics and Chemistry of Paris (Ecole Supérieure de Physique et de Chimie Industrielles de Paris), the IPF School (ENSPM) and holds an MBA from INSEAD.

Hervé is currently Director of Direct Purchasing for Arkema. He has worked in the group for more than 20 years in marketing and sales functions, as well as in management.  


Christian Dailly

Christian is an engineer from the Higher School of Industrial Physics and Chemistry of Paris (Ecole Supérieure de Physique et de Chimie Industrielles de Paris). After various positions in the development of new products in several fields, he ended his career as International Director of Arkema.

He has an excellent background that contributes to the research, development strategy and execution of start-ups.

Christian is one of the founders of Coalescence.


Alain Devic

Alain is an engineer who has graduated from Ecole Centrale de Paris and who hold a DEA degree in Physical Organic Chemistry. He has spent his entire career in the chemical industry.

After holding various positions in engineering, he was General Manager of ATOFINA and then General Industry Manager of ARKEMA until his retirement in 2012.

From 2004 to 2008, he was President of the UIC (Union des Industries Chimiques) and a member of the executive board of MEDEF.

He is currently Chairman of the Board of ENSIACET within the National Polytechnic Institute of Toulouse.


Henri Dugert

After graduating from ESSEC and holding various sales positions at CDF Chimie and PCUK, he was Acquisitions Director for Chemistry of the ELF group (Elf Atochem) and headed operational sectors as Division Director of the TOTAL group and ARKEMA. When he retired in October 2008, he was Director of the Acrylic Division of Arkema and President of Oxochemistry.

Henri is now a member of the Board of Directors and Secretary General of the House of Chemistry (Maison de la Chimie Foundation).


Gerard Ellia

Gerard graduated from the Higher School of Industrial Physics and Chemistry of Paris (Ecole Supérieure de Physique et de Chimie Industrielles  de Paris) and hold a PhD in Engineering in Nuclear Physics. He participated in negotiations for the sale of nuclear reactors in several countries, notably China.

He was commercial and administrative director of NPI, the joint subsidiary created by Framatome and Siemens KWU to develop the EPR reactor, and actively participated in the merger of these two companies just before the creation of AREVA. Gerard ended his career as Vice-President of Marketing Reactors at AREVA.


Philippe Gœbel

Philippe graduated from the Superior School of Industrial Physics and Chemistry of Paris (Ecole Supérieure de Physique et de Chimie Industrielles de Paris) and Sciences-Po Paris.

He was a member of the management committee of Total from 2002 to 2006, Arkema’s Comex from 2006 to 2008, Chairman and CEO of Total Petrochemicals France from 2008 to 2011, Chairman of the Union des Industries Chimiques from 2012 to 2016, and completed his career as Advisor to the Chairman and CEO of the Total group.


Jean-Pierre Lacroux.

Holder of a DESS degree in Law and a diploma in Higher European Studies (Hautes Etudes Européennes), Jean-Pierre Lacroux initially worked as a corporate lawyer in various companies and professional organizations. He later became legal director of the chemicals branch of Elf, Total and finally of Arkema where he ended his career.

Within Coalescence, Jean-Pierre is very active in the search for new investments, negotiations with start-ups. He is one of the founders of Coalescence.


Gérard Langlais.

Gérard is an engineer from the Nancy School of Mines (Ecole des Mines), with a Masters of Science from Stanford University and ICG.

After starting his professional career in 1978 in the search for a large housing group, he held the position of Business Engineer in an oil company before joining a chemical group where he successively held positions of business, logistics, HSE and finally sustainable development management.

He has been self-employed since 2016 as a teacher, trainer and consultant in CSR.


Thierry Lemonnier

Thierry graduated from the National School of Geology (E.N.S.G.) and Stanford University.

He spent more than 25 years in the Total group where he was CFO of the refining and distribution branch from 1993 to 1999, and then CFO of the chemicals branch from 2001 to 2006. Thierry ended his career as CFO of Arkema in 2018.

Since 2019, Thierry has been a director of SNF Floerger, a French company headquartered in Saint Etienne and world leader in polyacrylamides. 

Naturally, Thierry is Coalescence’s expert in matters of finance …


Jean-Baptiste Magnen

Jean-Baptiste is currently president of ChetWode, a consulting and investment company that he co-founded in 2009, which works in the field of financing capital goods for SMEs.

A graduate of the ESCP Business School and Master of Taxation from Université Paris Dauphine, he began his career in 1987 at BNP, and then worked at Dexia before becoming managing director in financing structured by Crédit Agricole / CaCib from 1995 to 2009.

Jean-Baptiste has invested in more than twenty start-ups since 1999.


Olivier Marembaud

Olivier is a civil engineer who has graduated from Ecole des Mines. He held managerial positions at SNCF, notably as Deputy Managing Director in charge of the freight business. He was also chairman for 5 years of the management board of the Keolis group, one of the leaders in public transport in Europe. He is currently chairman of the board of a public institution, the army commissary.

Olivier is an investor and director of BioCydex, a biotechnology company.


Jacques Moirez

Jacques graduated from the Higher School of Industrial Physics and Chemistry of Paris (Ecole Supérieure de Physique et de Chimie Industrielles de Paris) and the Higher Institute of Materials and Mechanical Construction. For more than 15 years, he has been the manager of Moirez Industrie trading in technical products. Previously, he was Production Director of CILAS ALCATEL and Technical Director of SOPELEM.


Jean Netter

Jean is an economist engineer (Polytechnique, ENSAE, Faculty of Economics).

In 1986, he joined the strategy department of the Schneider group and took part in the group’s « turn round » that embarked on its creation as a leader in the sector of electrical construction. He held various positions in this group, at Jeumont Schneider, Telemecanique, and then at the head of various Business Units before founding Schneider Electric Ventures (now Aster Capital) in 2000, a corporate venture capital tool.

Since 2006, after leaving Schneider Electric, Jean Netter is still active in venture capital, in particular through Coalescence but also as chairman of the supervisory committee of a start-up fund (R2V) working in Auvergne Rhône Alpes and PACA.


Jean-François Paponnaud.

Jean-François holds an organic chemical engineer diploma obtained from the Higher School of Organic and Mineral Chemistry (ESCOM) and completed “Finance for Executives” training at INSEAD.

After having been export sales director at SFOS, “Business Manager” of a line of Additives for polymers and then Monomers for Optics products at GREAT LAKES CHEMICALS, Jean-François Paponnaud ended his career as “Global Business Director Optical Monomers at CHEMTURA (merger of Great Lakes Chem and Crompton) and ACOMON (German investment fund).

Currently retired, Jean-François obtained his magician’s degree in 2012 from the Cercle Magique de Paris (CMP) and is the author of a biography of the Master Magician René LAQUIER.


Philippe Pernot

Philippe is a Civil Engineer who graduated from School of Mines (Ecole des Mines). He also holds a DEA in Statistics.

In 2007, he took over the Systronic company, which manufactures printed circuits for the aerospace industry. Philippe spent 30 years in the chemical industry in production, marketing and general management positions. Until 2006, he was Managing Director of the chlorine and vinyls branch of Arkema.

Philippe is currently Chairman of Coalescence. In recent years, he has also invested in many innovative companies.


Henri-Dominique Petit

Henri-Dominique graduated from the Ecole Supérieure de Physique et de Chimie Industrielles de Paris and holds a DEA degree in Nuclear Physics, as well as a PhD in Corpuscular Electronics.

He was Chairman of the Board of Directors of Spérian Protection until October 2010 after having been Chief Executive Officer for 5 years.

He spent 29 years at Kodak where, after various management positions in the United States, England and China, he ended up as senior vice-president responsible for operations outside North America. Henri-Dominique has managed or participated in numerous acquisition projects both in France and abroad.

He is currently Senior Advisor of the Business Bank DC Advisory Partners.


Jean-William Souffront

Jean-William holds a DESS in Business Law and a diploma from the ICH (CNAM). He ended his career as Director of Urban Operations at Semaest, a company specializing in the renovation of local commerce and crafts.

Before joining Semaest as Director of Development and then Director of Urban Operations in 2002, Jean-William worked as Legal Manager and later Program Director in real estate development companies.

In recent years, Jean-William has participated in supporting several start-ups as part of Coalescence.


Sacha Tikhomiroff.

Sacha graduated from the National Institute of Telecommunications and has an MBA from Insead.

After beginning his career in consulting, he took up general management positions, first in commercial subsidiary (Groupe SEB in Russia), followed by Strategic Marketing World (Rowenta), and then in distribution at the head of the subsidiaries in France of Dixons, Office DEPOT “Retail”, “Sales force”, Marionnaud, and Staples (DG France then VP Southern Europe).

In 2008, he gained entrepreneurial experience, raising capital and then taking over two companies in the distribution of luxury furniture (Artelano, Forum Diffusion).


Antoine Vallantin.

Antoine holds a DESS degree in Business Law and Taxation from Université Paris II. He is currently a business lawyer in the firm he founded in 2002 in partnership with 3 other lawyers.

He previously practiced in a Parisian business law firm where he had the opportunity to develop a clientele of small and medium-sized companies, but also groups of international size, for which he worked mainly in M&A and Corporate law.


Josiane Daudon Vincent.

Former EFAP, after 20 years at L’Oréal in Marketing positions (Biotherm, Helena Rubinstein, Vichy), Josiane embarked on the entrepreneurial adventure with 2 companies:

  • Octée, a pioneering brand of personalized beauty, sold a few years later.
  • Essens, which successfully opened up the B2B market in Perfumes and Make-up in France with textile brands such as Pimkie or 1.2.3.

Business Angel from the beginning, she became vice-president of Paris Business Angels for 6 years after selling her company Essens in 2007.

Josiane has supported around thirty companies to date.


Sylvain Visconti.

Sylvain graduated from l’Ecole Supérieure de Physique et de Chimie Industrielles de Paris, and completing an MBA from INSEAD.

Sylvain held general management positions within several large international groups before creating a firm specializing in management and communication crisis. 

He has been involved on numerous occasions in creations, acquisitions or mergers of large and small businesses.